remove "clean"

# Conflicts:
#	build-all.sh

aws/springcloudwatch/.mvn/wrapper/MavenWrapperDownloader.java

@@ -0,0 +1,117 @@
+/*
+ * Copyright 2007-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import java.net.*;
+import java.io.*;
+import java.nio.channels.*;
+import java.util.Properties;
+
+public class MavenWrapperDownloader {
+
+    private static final String WRAPPER_VERSION = "0.5.6";
+    /**
+     * Default URL to download the maven-wrapper.jar from, if no 'downloadUrl' is provided.
+     */
+    private static final String DEFAULT_DOWNLOAD_URL = "https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/"
+        + WRAPPER_VERSION + "/maven-wrapper-" + WRAPPER_VERSION + ".jar";
+
+    /**
+     * Path to the maven-wrapper.properties file, which might contain a downloadUrl property to
+     * use instead of the default one.
+     */
+    private static final String MAVEN_WRAPPER_PROPERTIES_PATH =
+            ".mvn/wrapper/maven-wrapper.properties";
+
+    /**
+     * Path where the maven-wrapper.jar will be saved to.
+     */
+    private static final String MAVEN_WRAPPER_JAR_PATH =
+            ".mvn/wrapper/maven-wrapper.jar";
+
+    /**
+     * Name of the property which should be used to override the default download url for the wrapper.
+     */
+    private static final String PROPERTY_NAME_WRAPPER_URL = "wrapperUrl";
+
+    public static void main(String args[]) {
+        System.out.println("- Downloader started");
+        File baseDirectory = new File(args[0]);
+        System.out.println("- Using base directory: " + baseDirectory.getAbsolutePath());
+
+        // If the maven-wrapper.properties exists, read it and check if it contains a custom
+        // wrapperUrl parameter.
+        File mavenWrapperPropertyFile = new File(baseDirectory, MAVEN_WRAPPER_PROPERTIES_PATH);
+        String url = DEFAULT_DOWNLOAD_URL;
+        if(mavenWrapperPropertyFile.exists()) {
+            FileInputStream mavenWrapperPropertyFileInputStream = null;
+            try {
+                mavenWrapperPropertyFileInputStream = new FileInputStream(mavenWrapperPropertyFile);
+                Properties mavenWrapperProperties = new Properties();
+                mavenWrapperProperties.load(mavenWrapperPropertyFileInputStream);
+                url = mavenWrapperProperties.getProperty(PROPERTY_NAME_WRAPPER_URL, url);
+            } catch (IOException e) {
+                System.out.println("- ERROR loading '" + MAVEN_WRAPPER_PROPERTIES_PATH + "'");
+            } finally {
+                try {
+                    if(mavenWrapperPropertyFileInputStream != null) {
+                        mavenWrapperPropertyFileInputStream.close();
+                    }
+                } catch (IOException e) {
+                    // Ignore ...
+                }
+            }
+        }
+        System.out.println("- Downloading from: " + url);
+
+        File outputFile = new File(baseDirectory.getAbsolutePath(), MAVEN_WRAPPER_JAR_PATH);
+        if(!outputFile.getParentFile().exists()) {
+            if(!outputFile.getParentFile().mkdirs()) {
+                System.out.println(
+                        "- ERROR creating output directory '" + outputFile.getParentFile().getAbsolutePath() + "'");
+            }
+        }
+        System.out.println("- Downloading to: " + outputFile.getAbsolutePath());
+        try {
+            downloadFileFromURL(url, outputFile);
+            System.out.println("Done");
+            System.exit(0);
+        } catch (Throwable e) {
+            System.out.println("- Error downloading");
+            e.printStackTrace();
+            System.exit(1);
+        }
+    }
+
+    private static void downloadFileFromURL(String urlString, File destination) throws Exception {
+        if (System.getenv("MVNW_USERNAME") != null && System.getenv("MVNW_PASSWORD") != null) {
+            String username = System.getenv("MVNW_USERNAME");
+            char[] password = System.getenv("MVNW_PASSWORD").toCharArray();
+            Authenticator.setDefault(new Authenticator() {
+                @Override
+                protected PasswordAuthentication getPasswordAuthentication() {
+                    return new PasswordAuthentication(username, password);
+                }
+            });
+        }
+        URL website = new URL(urlString);
+        ReadableByteChannel rbc;
+        rbc = Channels.newChannel(website.openStream());
+        FileOutputStream fos = new FileOutputStream(destination);
+        fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
+        fos.close();
+        rbc.close();
+    }
+
+}

aws/springcloudwatch/.mvn/wrapper/maven-wrapper.properties

@@ -0,0 +1,2 @@
+distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.6.3/apache-maven-3.6.3-bin.zip
+wrapperUrl=https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar

aws/springcloudwatch/README.md

@@ -0,0 +1,9 @@
+# Publishing Metrics from Spring Boot Application to Amazon CloudWatch
+
+Example code for using Spring Boot Application with Amazon CloudWatch
+
+## Blog posts
+
+Blog posts about this topic:
+
+* [Publishing Metrics from Spring Boot Application to Amazon CloudWatch](https://reflectoring.io/spring-aws-cloudwatch/)

aws/springcloudwatch/mvnw

@@ -0,0 +1,310 @@
+#!/bin/sh
+# ----------------------------------------------------------------------------
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+# ----------------------------------------------------------------------------
+
+# ----------------------------------------------------------------------------
+# Maven Start Up Batch script
+#
+# Required ENV vars:
+# ------------------
+#   JAVA_HOME - location of a JDK home dir
+#
+# Optional ENV vars
+# -----------------
+#   M2_HOME - location of maven2's installed home dir
+#   MAVEN_OPTS - parameters passed to the Java VM when running Maven
+#     e.g. to debug Maven itself, use
+#       set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+#   MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+# ----------------------------------------------------------------------------
+
+if [ -z "$MAVEN_SKIP_RC" ] ; then
+
+  if [ -f /etc/mavenrc ] ; then
+    . /etc/mavenrc
+  fi
+
+  if [ -f "$HOME/.mavenrc" ] ; then
+    . "$HOME/.mavenrc"
+  fi
+
+fi
+
+# OS specific support.  $var _must_ be set to either true or false.
+cygwin=false;
+darwin=false;
+mingw=false
+case "`uname`" in
+  CYGWIN*) cygwin=true ;;
+  MINGW*) mingw=true;;
+  Darwin*) darwin=true
+    # Use /usr/libexec/java_home if available, otherwise fall back to /Library/Java/Home
+    # See https://developer.apple.com/library/mac/qa/qa1170/_index.html
+    if [ -z "$JAVA_HOME" ]; then
+      if [ -x "/usr/libexec/java_home" ]; then
+        export JAVA_HOME="`/usr/libexec/java_home`"
+      else
+        export JAVA_HOME="/Library/Java/Home"
+      fi
+    fi
+    ;;
+esac
+
+if [ -z "$JAVA_HOME" ] ; then
+  if [ -r /etc/gentoo-release ] ; then
+    JAVA_HOME=`java-config --jre-home`
+  fi
+fi
+
+if [ -z "$M2_HOME" ] ; then
+  ## resolve links - $0 may be a link to maven's home
+  PRG="$0"
+
+  # need this for relative symlinks
+  while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+      PRG="$link"
+    else
+      PRG="`dirname "$PRG"`/$link"
+    fi
+  done
+
+  saveddir=`pwd`
+
+  M2_HOME=`dirname "$PRG"`/..
+
+  # make it fully qualified
+  M2_HOME=`cd "$M2_HOME" && pwd`
+
+  cd "$saveddir"
+  # echo Using m2 at $M2_HOME
+fi
+
+# For Cygwin, ensure paths are in UNIX format before anything is touched
+if $cygwin ; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME=`cygpath --unix "$M2_HOME"`
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME=`cygpath --unix "$JAVA_HOME"`
+  [ -n "$CLASSPATH" ] &&
+    CLASSPATH=`cygpath --path --unix "$CLASSPATH"`
+fi
+
+# For Mingw, ensure paths are in UNIX format before anything is touched
+if $mingw ; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME="`(cd "$M2_HOME"; pwd)`"
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME="`(cd "$JAVA_HOME"; pwd)`"
+fi
+
+if [ -z "$JAVA_HOME" ]; then
+  javaExecutable="`which javac`"
+  if [ -n "$javaExecutable" ] && ! [ "`expr \"$javaExecutable\" : '\([^ ]*\)'`" = "no" ]; then
+    # readlink(1) is not available as standard on Solaris 10.
+    readLink=`which readlink`
+    if [ ! `expr "$readLink" : '\([^ ]*\)'` = "no" ]; then
+      if $darwin ; then
+        javaHome="`dirname \"$javaExecutable\"`"
+        javaExecutable="`cd \"$javaHome\" && pwd -P`/javac"
+      else
+        javaExecutable="`readlink -f \"$javaExecutable\"`"
+      fi
+      javaHome="`dirname \"$javaExecutable\"`"
+      javaHome=`expr "$javaHome" : '\(.*\)/bin'`
+      JAVA_HOME="$javaHome"
+      export JAVA_HOME
+    fi
+  fi
+fi
+
+if [ -z "$JAVACMD" ] ; then
+  if [ -n "$JAVA_HOME"  ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+      # IBM's JDK on AIX uses strange locations for the executables
+      JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+      JAVACMD="$JAVA_HOME/bin/java"
+    fi
+  else
+    JAVACMD="`which java`"
+  fi
+fi
+
+if [ ! -x "$JAVACMD" ] ; then
+  echo "Error: JAVA_HOME is not defined correctly." >&2
+  echo "  We cannot execute $JAVACMD" >&2
+  exit 1
+fi
+
+if [ -z "$JAVA_HOME" ] ; then
+  echo "Warning: JAVA_HOME environment variable is not set."
+fi
+
+CLASSWORLDS_LAUNCHER=org.codehaus.plexus.classworlds.launcher.Launcher
+
+# traverses directory structure from process work directory to filesystem root
+# first directory with .mvn subdirectory is considered project base directory
+find_maven_basedir() {
+
+  if [ -z "$1" ]
+  then
+    echo "Path not specified to find_maven_basedir"
+    return 1
+  fi
+
+  basedir="$1"
+  wdir="$1"
+  while [ "$wdir" != '/' ] ; do
+    if [ -d "$wdir"/.mvn ] ; then
+      basedir=$wdir
+      break
+    fi
+    # workaround for JBEAP-8937 (on Solaris 10/Sparc)
+    if [ -d "${wdir}" ]; then
+      wdir=`cd "$wdir/.."; pwd`
+    fi
+    # end of workaround
+  done
+  echo "${basedir}"
+}
+
+# concatenates all lines of a file
+concat_lines() {
+  if [ -f "$1" ]; then
+    echo "$(tr -s '\n' ' ' < "$1")"
+  fi
+}
+
+BASE_DIR=`find_maven_basedir "$(pwd)"`
+if [ -z "$BASE_DIR" ]; then
+  exit 1;
+fi
+
+##########################################################################################
+# Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+# This allows using the maven wrapper in projects that prohibit checking in binary data.
+##########################################################################################
+if [ -r "$BASE_DIR/.mvn/wrapper/maven-wrapper.jar" ]; then
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Found .mvn/wrapper/maven-wrapper.jar"
+    fi
+else
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Couldn't find .mvn/wrapper/maven-wrapper.jar, downloading it ..."
+    fi
+    if [ -n "$MVNW_REPOURL" ]; then
+      jarUrl="$MVNW_REPOURL/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+    else
+      jarUrl="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+    fi
+    while IFS="=" read key value; do
+      case "$key" in (wrapperUrl) jarUrl="$value"; break ;;
+      esac
+    done < "$BASE_DIR/.mvn/wrapper/maven-wrapper.properties"
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Downloading from: $jarUrl"
+    fi
+    wrapperJarPath="$BASE_DIR/.mvn/wrapper/maven-wrapper.jar"
+    if $cygwin; then
+      wrapperJarPath=`cygpath --path --windows "$wrapperJarPath"`
+    fi
+
+    if command -v wget > /dev/null; then
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo "Found wget ... using wget"
+        fi
+        if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+            wget "$jarUrl" -O "$wrapperJarPath"
+        else
+            wget --http-user=$MVNW_USERNAME --http-password=$MVNW_PASSWORD "$jarUrl" -O "$wrapperJarPath"
+        fi
+    elif command -v curl > /dev/null; then
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo "Found curl ... using curl"
+        fi
+        if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+            curl -o "$wrapperJarPath" "$jarUrl" -f
+        else
+            curl --user $MVNW_USERNAME:$MVNW_PASSWORD -o "$wrapperJarPath" "$jarUrl" -f
+        fi
+
+    else
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo "Falling back to using Java to download"
+        fi
+        javaClass="$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.java"
+        # For Cygwin, switch paths to Windows format before running javac
+        if $cygwin; then
+          javaClass=`cygpath --path --windows "$javaClass"`
+        fi
+        if [ -e "$javaClass" ]; then
+            if [ ! -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+                if [ "$MVNW_VERBOSE" = true ]; then
+                  echo " - Compiling MavenWrapperDownloader.java ..."
+                fi
+                # Compiling the Java class
+                ("$JAVA_HOME/bin/javac" "$javaClass")
+            fi
+            if [ -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+                # Running the downloader
+                if [ "$MVNW_VERBOSE" = true ]; then
+                  echo " - Running MavenWrapperDownloader.java ..."
+                fi
+                ("$JAVA_HOME/bin/java" -cp .mvn/wrapper MavenWrapperDownloader "$MAVEN_PROJECTBASEDIR")
+            fi
+        fi
+    fi
+fi
+##########################################################################################
+# End of extension
+##########################################################################################
+
+export MAVEN_PROJECTBASEDIR=${MAVEN_BASEDIR:-"$BASE_DIR"}
+if [ "$MVNW_VERBOSE" = true ]; then
+  echo $MAVEN_PROJECTBASEDIR
+fi
+MAVEN_OPTS="$(concat_lines "$MAVEN_PROJECTBASEDIR/.mvn/jvm.config") $MAVEN_OPTS"
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME=`cygpath --path --windows "$M2_HOME"`
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME=`cygpath --path --windows "$JAVA_HOME"`
+  [ -n "$CLASSPATH" ] &&
+    CLASSPATH=`cygpath --path --windows "$CLASSPATH"`
+  [ -n "$MAVEN_PROJECTBASEDIR" ] &&
+    MAVEN_PROJECTBASEDIR=`cygpath --path --windows "$MAVEN_PROJECTBASEDIR"`
+fi
+
+# Provide a "standardized" way to retrieve the CLI args that will
+# work with both Windows and non-Windows executions.
+MAVEN_CMD_LINE_ARGS="$MAVEN_CONFIG $@"
+export MAVEN_CMD_LINE_ARGS
+
+WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+exec "$JAVACMD" \
+  $MAVEN_OPTS \
+  -classpath "$MAVEN_PROJECTBASEDIR/.mvn/wrapper/maven-wrapper.jar" \
+  "-Dmaven.home=${M2_HOME}" "-Dmaven.multiModuleProjectDirectory=${MAVEN_PROJECTBASEDIR}" \
+  ${WRAPPER_LAUNCHER} $MAVEN_CONFIG "$@"

aws/springcloudwatch/mvnw.cmd

@@ -0,0 +1,182 @@
+@REM ----------------------------------------------------------------------------
+@REM Licensed to the Apache Software Foundation (ASF) under one
+@REM or more contributor license agreements.  See the NOTICE file
+@REM distributed with this work for additional information
+@REM regarding copyright ownership.  The ASF licenses this file
+@REM to you under the Apache License, Version 2.0 (the
+@REM "License"); you may not use this file except in compliance
+@REM with the License.  You may obtain a copy of the License at
+@REM
+@REM    http://www.apache.org/licenses/LICENSE-2.0
+@REM
+@REM Unless required by applicable law or agreed to in writing,
+@REM software distributed under the License is distributed on an
+@REM "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+@REM KIND, either express or implied.  See the License for the
+@REM specific language governing permissions and limitations
+@REM under the License.
+@REM ----------------------------------------------------------------------------
+
+@REM ----------------------------------------------------------------------------
+@REM Maven Start Up Batch script
+@REM
+@REM Required ENV vars:
+@REM JAVA_HOME - location of a JDK home dir
+@REM
+@REM Optional ENV vars
+@REM M2_HOME - location of maven2's installed home dir
+@REM MAVEN_BATCH_ECHO - set to 'on' to enable the echoing of the batch commands
+@REM MAVEN_BATCH_PAUSE - set to 'on' to wait for a keystroke before ending
+@REM MAVEN_OPTS - parameters passed to the Java VM when running Maven
+@REM     e.g. to debug Maven itself, use
+@REM set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+@REM MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+@REM ----------------------------------------------------------------------------
+
+@REM Begin all REM lines with '@' in case MAVEN_BATCH_ECHO is 'on'
+@echo off
+@REM set title of command window
+title %0
+@REM enable echoing by setting MAVEN_BATCH_ECHO to 'on'
+@if "%MAVEN_BATCH_ECHO%" == "on"  echo %MAVEN_BATCH_ECHO%
+
+@REM set %HOME% to equivalent of $HOME
+if "%HOME%" == "" (set "HOME=%HOMEDRIVE%%HOMEPATH%")
+
+@REM Execute a user defined script before this one
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPre
+@REM check for pre script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_pre.bat" call "%HOME%\mavenrc_pre.bat"
+if exist "%HOME%\mavenrc_pre.cmd" call "%HOME%\mavenrc_pre.cmd"
+:skipRcPre
+
+@setlocal
+
+set ERROR_CODE=0
+
+@REM To isolate internal variables from possible post scripts, we use another setlocal
+@setlocal
+
+@REM ==== START VALIDATION ====
+if not "%JAVA_HOME%" == "" goto OkJHome
+
+echo.
+echo Error: JAVA_HOME not found in your environment. >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+:OkJHome
+if exist "%JAVA_HOME%\bin\java.exe" goto init
+
+echo.
+echo Error: JAVA_HOME is set to an invalid directory. >&2
+echo JAVA_HOME = "%JAVA_HOME%" >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+@REM ==== END VALIDATION ====
+
+:init
+
+@REM Find the project base dir, i.e. the directory that contains the folder ".mvn".
+@REM Fallback to current working directory if not found.
+
+set MAVEN_PROJECTBASEDIR=%MAVEN_BASEDIR%
+IF NOT "%MAVEN_PROJECTBASEDIR%"=="" goto endDetectBaseDir
+
+set EXEC_DIR=%CD%
+set WDIR=%EXEC_DIR%
+:findBaseDir
+IF EXIST "%WDIR%"\.mvn goto baseDirFound
+cd ..
+IF "%WDIR%"=="%CD%" goto baseDirNotFound
+set WDIR=%CD%
+goto findBaseDir
+
+:baseDirFound
+set MAVEN_PROJECTBASEDIR=%WDIR%
+cd "%EXEC_DIR%"
+goto endDetectBaseDir
+
+:baseDirNotFound
+set MAVEN_PROJECTBASEDIR=%EXEC_DIR%
+cd "%EXEC_DIR%"
+
+:endDetectBaseDir
+
+IF NOT EXIST "%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config" goto endReadAdditionalConfig
+
+@setlocal EnableExtensions EnableDelayedExpansion
+for /F "usebackq delims=" %%a in ("%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config") do set JVM_CONFIG_MAVEN_PROPS=!JVM_CONFIG_MAVEN_PROPS! %%a
+@endlocal & set JVM_CONFIG_MAVEN_PROPS=%JVM_CONFIG_MAVEN_PROPS%
+
+:endReadAdditionalConfig
+
+SET MAVEN_JAVA_EXE="%JAVA_HOME%\bin\java.exe"
+set WRAPPER_JAR="%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.jar"
+set WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+set DOWNLOAD_URL="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+
+FOR /F "tokens=1,2 delims==" %%A IN ("%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.properties") DO (
+    IF "%%A"=="wrapperUrl" SET DOWNLOAD_URL=%%B
+)
+
+@REM Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+@REM This allows using the maven wrapper in projects that prohibit checking in binary data.
+if exist %WRAPPER_JAR% (
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Found %WRAPPER_JAR%
+    )
+) else (
+    if not "%MVNW_REPOURL%" == "" (
+        SET DOWNLOAD_URL="%MVNW_REPOURL%/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+    )
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Couldn't find %WRAPPER_JAR%, downloading it ...
+        echo Downloading from: %DOWNLOAD_URL%
+    )
+
+    powershell -Command "&{"^
+		"$webclient = new-object System.Net.WebClient;"^
+		"if (-not ([string]::IsNullOrEmpty('%MVNW_USERNAME%') -and [string]::IsNullOrEmpty('%MVNW_PASSWORD%'))) {"^
+		"$webclient.Credentials = new-object System.Net.NetworkCredential('%MVNW_USERNAME%', '%MVNW_PASSWORD%');"^
+		"}"^
+		"[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; $webclient.DownloadFile('%DOWNLOAD_URL%', '%WRAPPER_JAR%')"^
+		"}"
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Finished downloading %WRAPPER_JAR%
+    )
+)
+@REM End of extension
+
+@REM Provide a "standardized" way to retrieve the CLI args that will
+@REM work with both Windows and non-Windows executions.
+set MAVEN_CMD_LINE_ARGS=%*
+
+%MAVEN_JAVA_EXE% %JVM_CONFIG_MAVEN_PROPS% %MAVEN_OPTS% %MAVEN_DEBUG_OPTS% -classpath %WRAPPER_JAR% "-Dmaven.multiModuleProjectDirectory=%MAVEN_PROJECTBASEDIR%" %WRAPPER_LAUNCHER% %MAVEN_CONFIG% %*
+if ERRORLEVEL 1 goto error
+goto end
+
+:error
+set ERROR_CODE=1
+
+:end
+@endlocal & set ERROR_CODE=%ERROR_CODE%
+
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPost
+@REM check for post script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_post.bat" call "%HOME%\mavenrc_post.bat"
+if exist "%HOME%\mavenrc_post.cmd" call "%HOME%\mavenrc_post.cmd"
+:skipRcPost
+
+@REM pause the script if MAVEN_BATCH_PAUSE is set to 'on'
+if "%MAVEN_BATCH_PAUSE%" == "on" pause
+
+if "%MAVEN_TERMINATE_CMD%" == "on" exit %ERROR_CODE%
+
+exit /B %ERROR_CODE%

aws/springcloudwatch/pom.xml

@@ -0,0 +1,90 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<groupId>org.springframework.boot</groupId>
+		<artifactId>spring-boot-starter-parent</artifactId>
+		<version>2.5.3</version>
+		<relativePath /> <!-- lookup parent from repository -->
+	</parent>
+	<groupId>io.pratik</groupId>
+	<artifactId>metricscapture</artifactId>
+	<version>0.0.1-SNAPSHOT</version>
+	<name>metricscapture</name>
+	<description>Demo project for capturing cloudwatch metrics in Spring Boot</description>
+	<properties>
+		<java.version>11</java.version>
+	</properties>
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-web</artifactId>
+		</dependency>
+
+		<dependency>
+			<groupId>org.projectlombok</groupId>
+			<artifactId>lombok</artifactId>
+			<optional>true</optional>
+		</dependency>
+		<dependency>
+			<groupId>io.micrometer</groupId>
+			<artifactId>micrometer-core</artifactId>
+		</dependency>
+
+		<!--  <dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-actuator</artifactId>
+		</dependency>-->
+		<dependency> 
+		    <groupId>io.micrometer</groupId> 
+		    <artifactId>micrometer-registry-cloudwatch2</artifactId> 
+		</dependency> 
+	<!--  	<dependency>
+			<groupId>software.amazon.awssdk</groupId>
+			<artifactId>cloudwatch</artifactId>
+		</dependency>-->
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-test</artifactId>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+	<dependencyManagement>
+		<dependencies>
+			<dependency>
+				<groupId>io.awspring.cloud</groupId>
+				<artifactId>spring-cloud-aws-dependencies</artifactId>
+				<version>2.3.0</version>
+				<type>pom</type>
+				<scope>import</scope>
+			</dependency>
+			<dependency>
+				<groupId>software.amazon.awssdk</groupId>
+				<artifactId>bom</artifactId>
+				<version>2.17.14</version>
+				<type>pom</type>
+				<scope>import</scope>
+			</dependency>
+		</dependencies>
+	</dependencyManagement>
+
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.springframework.boot</groupId>
+				<artifactId>spring-boot-maven-plugin</artifactId>
+				<configuration>
+					<excludes>
+						<exclude>
+							<groupId>org.projectlombok</groupId>
+							<artifactId>lombok</artifactId>
+						</exclude>
+					</excludes>
+				</configuration>
+			</plugin>
+		</plugins>
+	</build>
+
+</project>

aws/springcloudwatch/src/main/java/io/pratik/metricscapture/AppConfig.java

@@ -0,0 +1,62 @@
+/**
+ * 
+ */
+package io.pratik.metricscapture;
+
+import java.time.Duration;
+import java.util.Map;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.scheduling.annotation.EnableScheduling;
+
+import io.micrometer.cloudwatch2.CloudWatchConfig;
+import io.micrometer.cloudwatch2.CloudWatchMeterRegistry;
+import io.micrometer.core.instrument.Clock;
+import io.micrometer.core.instrument.MeterRegistry;
+import io.micrometer.core.instrument.Metrics;
+import software.amazon.awssdk.auth.credentials.ProfileCredentialsProvider;
+import software.amazon.awssdk.regions.Region;
+import software.amazon.awssdk.services.cloudwatch.CloudWatchAsyncClient;
+
+/**
+ * @author pratikdas
+ *
+ */
+@Configuration
+public class AppConfig {
+	
+
+
+	@Bean
+	public CloudWatchAsyncClient cloudWatchAsyncClient() {
+		return CloudWatchAsyncClient.builder().region(Region.US_EAST_1)
+				.credentialsProvider(ProfileCredentialsProvider.create("pratikpoc")).build();
+	}
+	
+	@Bean
+	public MeterRegistry getMeterRegistry() {
+		CloudWatchConfig cloudWatchConfig = setupCloudWatchConfig();
+		
+		MeterRegistry meterRegistry = new CloudWatchMeterRegistry(cloudWatchConfig, Clock.SYSTEM,
+				cloudWatchAsyncClient());
+				
+		return meterRegistry;
+	}
+
+	private CloudWatchConfig setupCloudWatchConfig() {
+		CloudWatchConfig cloudWatchConfig = new CloudWatchConfig() {
+			
+			private Map<String, String> configuration
+	          = Map.of("cloudwatch.namespace", "productsApp",
+	                   "cloudwatch.step", Duration.ofMinutes(1).toString());
+			
+			@Override
+			public String get(String key) {
+				return configuration.get(key);
+			}
+		};
+		return cloudWatchConfig;
+	}
+
+}

aws/springcloudwatch/src/main/java/io/pratik/metricscapture/MetricPublisher.java

@@ -0,0 +1,87 @@
+/**
+ * 
+ */
+package io.pratik.metricscapture;
+
+import java.time.Instant;
+import java.time.ZoneOffset;
+import java.time.ZonedDateTime;
+import java.time.format.DateTimeFormatter;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+
+import io.pratik.metricscapture.models.MetricTag;
+import software.amazon.awssdk.services.cloudwatch.CloudWatchAsyncClient;
+import software.amazon.awssdk.services.cloudwatch.model.CloudWatchException;
+import software.amazon.awssdk.services.cloudwatch.model.Dimension;
+import software.amazon.awssdk.services.cloudwatch.model.MetricDatum;
+import software.amazon.awssdk.services.cloudwatch.model.PutMetricDataRequest;
+import software.amazon.awssdk.services.cloudwatch.model.StandardUnit;
+
+/**
+ * @author pratikdas
+ *
+ */
+@Service
+public class MetricPublisher {
+	
+	private CloudWatchAsyncClient cloudWatchAsyncClient;
+	
+	
+    @Autowired
+	public MetricPublisher(CloudWatchAsyncClient cloudWatchAsyncClient) {
+		super();
+		this.cloudWatchAsyncClient = cloudWatchAsyncClient;
+	}
+
+
+
+    public void putMetricData(final String nameSpace, 
+            final String metricName, 
+            final Double dataPoint,
+            final List<MetricTag> metricTags) {
+
+		try {
+			
+			List<Dimension> dimensions = metricTags
+					.stream()
+					.map((metricTag)->{
+				         return Dimension
+					         .builder()
+					         .name(metricTag.getName())
+					         .value(metricTag.getValue())
+					         .build();
+			}).collect(Collectors.toList());			
+			
+			// Set an Instant object
+			String time = ZonedDateTime
+			           .now(ZoneOffset.UTC)
+			           .format(DateTimeFormatter.ISO_INSTANT);
+			Instant instant = Instant.parse(time);
+			
+			MetricDatum datum = MetricDatum
+			         .builder()
+			         .metricName(metricName)
+			         .unit(StandardUnit.NONE)
+			         .value(dataPoint)
+			         .timestamp(instant)
+			         .dimensions(dimensions)
+			         .build();
+			
+			PutMetricDataRequest request = 
+			           PutMetricDataRequest
+			           .builder()
+			           .namespace(nameSpace)
+			           .metricData(datum)
+			           .build();
+			
+			cloudWatchAsyncClient.putMetricData(request);
+		
+		} catch (CloudWatchException e) {
+		   System.err.println(e.awsErrorDetails().errorMessage());
+		}
+	}
+}

aws/springcloudwatch/src/main/java/io/pratik/metricscapture/MetricscaptureApplication.java

@@ -0,0 +1,27 @@
+package io.pratik.metricscapture;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.web.client.RestTemplateBuilder;
+import org.springframework.context.annotation.Bean;
+import org.springframework.http.converter.StringHttpMessageConverter;
+import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
+import org.springframework.scheduling.annotation.EnableScheduling;
+import org.springframework.web.client.RestTemplate;
+
+@SpringBootApplication
+@EnableScheduling
+public class MetricscaptureApplication {
+	
+	@Bean
+    RestTemplate restTemplate(RestTemplateBuilder builder) {
+		return builder
+				.messageConverters(new StringHttpMessageConverter(), new MappingJackson2HttpMessageConverter())
+				.build();
+	}
+
+	public static void main(String[] args) {
+		SpringApplication.run(MetricscaptureApplication.class, args);
+	}
+
+}

aws/springcloudwatch/src/main/java/io/pratik/metricscapture/PricingEngine.java

@@ -0,0 +1,34 @@
+/**
+ * 
+ */
+package io.pratik.metricscapture;
+
+import java.util.Random;
+
+import org.springframework.scheduling.annotation.Scheduled;
+import org.springframework.stereotype.Service;
+
+/**
+ * @author pratikdas
+ *
+ */
+@Service
+public class PricingEngine {
+	
+	private Double price;
+	
+	public Double getProductPrice() {
+		return price;
+		
+	}
+	
+	@Scheduled(fixedRate = 70000)
+	public void computePrice() {
+		
+		Random random = new Random();
+		price = random.nextDouble() * 100;
+		System.out.println("computing price "+price);
+		
+	}
+
+}

aws/springcloudwatch/src/main/java/io/pratik/metricscapture/ProductController.java

@@ -0,0 +1,89 @@
+/**
+ * 
+ */
+package io.pratik.metricscapture;
+
+import java.time.Duration;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.scheduling.annotation.Scheduled;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.ResponseBody;
+import org.springframework.web.bind.annotation.RestController;
+
+import io.micrometer.core.instrument.Counter;
+import io.micrometer.core.instrument.Gauge;
+import io.micrometer.core.instrument.MeterRegistry;
+import io.micrometer.core.instrument.Timer;
+import io.pratik.metricscapture.models.Order;
+import io.pratik.metricscapture.models.Product;
+import lombok.extern.slf4j.Slf4j;
+
+/**
+ * @author pratikdas
+ *
+ */
+@RestController
+@Slf4j
+public class ProductController {
+	private Counter pageViewsCounter;
+	private Timer productTimer;
+	private Gauge priceGauge;
+	
+	private MeterRegistry meterRegistry;
+	
+	private PricingEngine pricingEngine;
+
+	@Autowired
+	ProductController(MeterRegistry meterRegistry, PricingEngine pricingEngine){
+		
+		 this.meterRegistry = meterRegistry;
+		 this.pricingEngine = pricingEngine;
+				 
+		 priceGauge = Gauge
+				    .builder("product.price", pricingEngine , 
+							 (pe)->{return pe != null? pe.getProductPrice() : null;})
+				    .description("Product price")
+				    .baseUnit("ms")
+				    .register(meterRegistry);
+			
+		 pageViewsCounter = meterRegistry
+				 .counter("PAGE_VIEWS.ProductList");
+		 
+		 productTimer = meterRegistry
+				 .timer("execution.time.fetchProducts");
+	
+	}
+	
+	
+	
+	
+	@GetMapping("/products")
+	@ResponseBody
+	public List<Product> fetchProducts() {
+		long startTime = System.currentTimeMillis();
+		
+		List<Product> products = fetchProductsFromStore();
+		
+		// increment page views counter
+		pageViewsCounter.increment();
+
+		// record time to execute the method
+		System.out.println("productTimer "+productTimer + " " + pageViewsCounter + " " + priceGauge);
+	    productTimer.record(Duration.ofMillis(System.currentTimeMillis() - startTime));
+	    	
+		return products;
+	}
+	
+	private List<Product> fetchProductsFromStore(){
+		List<Product> products = new ArrayList<Product>();
+		products.add(Product.builder().name("Television").build());
+		products.add(Product.builder().name("Book").build());
+		return products;
+	}
+	
+
+
+}

aws/springcloudwatch/src/main/java/io/pratik/metricscapture/models/MetricTag.java

@@ -0,0 +1,25 @@
+/**
+ * 
+ */
+package io.pratik.metricscapture.models;
+
+/**
+ * @author pratikdas
+ *
+ */
+public class MetricTag {
+	private String name;
+	private String value;
+	public MetricTag(String name, String value) {
+		super();
+		this.name = name;
+		this.value = value;
+	}
+	public String getName() {
+		return name;
+	}
+	public String getValue() {
+		return value;
+	}
+	
+}

aws/springcloudwatch/src/main/java/io/pratik/metricscapture/models/Order.java

@@ -0,0 +1,21 @@
+/**
+ * 
+ */
+package io.pratik.metricscapture.models;
+
+import java.util.List;
+
+import lombok.Builder;
+
+/**
+ * @author pratikdas
+ *
+ */
+@Builder
+public class Order {
+	private List<Product> products;
+	
+	private String orderDate;
+	
+
+}

aws/springcloudwatch/src/main/java/io/pratik/metricscapture/models/Product.java

@@ -0,0 +1,19 @@
+/**
+ * 
+ */
+package io.pratik.metricscapture.models;
+
+import lombok.Builder;
+import lombok.Data;
+
+/**
+ * @author pratikdas
+ *
+ */
+@Builder
+@Data
+public class Product {
+	private String name;
+	private Double price;
+
+}

aws/springcloudwatch/src/main/resources/application.properties

@@ -0,0 +1,8 @@
+cloud.aws.credentials.profile-name=pratikpoc
+cloud.aws.region.auto=false
+cloud.aws.region.static=us-east-1
+
+logging.level.io.micrometer=DEBUG
+
+
+

aws/springcloudwatch/src/test/java/io/pratik/metricscapture/MetricscaptureApplicationTests.java

@@ -0,0 +1,13 @@
+package io.pratik.metricscapture;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.boot.test.context.SpringBootTest;
+
+@SpringBootTest
+class MetricscaptureApplicationTests {
+
+	@Test
+	void contextLoads() {
+	}
+
+}

build-all.sh

@@ -11,7 +11,7 @@ build_gradle_module() {
   echo "+++"
   cd $MODULE_PATH && {
     chmod +x gradlew
-    ./gradlew clean build
+    ./gradlew build
     if [ $? -ne 0 ]
     then
       echo ""
@@ -64,7 +64,7 @@ build_maven_module() {
   echo "+++"
   cd $MODULE_PATH && {
     chmod +x mvnw
-    ./mvnw clean package
+    ./mvnw package
     if [ $? -ne 0 ]
     then
       echo ""
@@ -86,13 +86,21 @@ if [[ "$MODULE" == "module6" ]]
 then
   # ADD NEW MODULES HERE
   # (add new modules above the rest so you get quicker feedback if it fails)
+  build_maven_module "spring-cloud/tracing"
+  build_maven_module "core-java/versions"
+  build maven_module "java-hashes"
+  build maven_module "http-clients"
+  build maven_module "spring-boot/spring-boot-i18n"
+  build_maven_module "testing/assertJ"
+  build maven_module "spring-boot/spring-boot-scheduler"
+  build maven_module "aws/springcloudwatch"
+  build maven_module "aws/springcloudses"
+  build maven_module "spring-boot/spring-boot-camel"
   build_maven_module "logging/structured-logging"
   build_maven_module "spring-boot/zero-downtime"
   build_maven_module "resilience4j/springboot-resilience4j"
   build_maven_module "spring-boot/feature-flags"
-  build_maven_module  "aws/springcloudses"
   build_gradle_module "aws/spring-cloud-caching-redis"
-  build_maven_module "spring-boot/spring-boot-camel"
   build_maven_module "logging/spring-boot"
   build_maven_module "logging/logback"
   build_maven_module "logging/log4j"

core-java/versions/.mvn/wrapper/MavenWrapperDownloader.java

@@ -0,0 +1,117 @@
+/*
+ * Copyright 2007-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import java.net.*;
+import java.io.*;
+import java.nio.channels.*;
+import java.util.Properties;
+
+public class MavenWrapperDownloader {
+
+    private static final String WRAPPER_VERSION = "0.5.6";
+    /**
+     * Default URL to download the maven-wrapper.jar from, if no 'downloadUrl' is provided.
+     */
+    private static final String DEFAULT_DOWNLOAD_URL = "https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/"
+        + WRAPPER_VERSION + "/maven-wrapper-" + WRAPPER_VERSION + ".jar";
+
+    /**
+     * Path to the maven-wrapper.properties file, which might contain a downloadUrl property to
+     * use instead of the default one.
+     */
+    private static final String MAVEN_WRAPPER_PROPERTIES_PATH =
+            ".mvn/wrapper/maven-wrapper.properties";
+
+    /**
+     * Path where the maven-wrapper.jar will be saved to.
+     */
+    private static final String MAVEN_WRAPPER_JAR_PATH =
+            ".mvn/wrapper/maven-wrapper.jar";
+
+    /**
+     * Name of the property which should be used to override the default download url for the wrapper.
+     */
+    private static final String PROPERTY_NAME_WRAPPER_URL = "wrapperUrl";
+
+    public static void main(String args[]) {
+        System.out.println("- Downloader started");
+        File baseDirectory = new File(args[0]);
+        System.out.println("- Using base directory: " + baseDirectory.getAbsolutePath());
+
+        // If the maven-wrapper.properties exists, read it and check if it contains a custom
+        // wrapperUrl parameter.
+        File mavenWrapperPropertyFile = new File(baseDirectory, MAVEN_WRAPPER_PROPERTIES_PATH);
+        String url = DEFAULT_DOWNLOAD_URL;
+        if(mavenWrapperPropertyFile.exists()) {
+            FileInputStream mavenWrapperPropertyFileInputStream = null;
+            try {
+                mavenWrapperPropertyFileInputStream = new FileInputStream(mavenWrapperPropertyFile);
+                Properties mavenWrapperProperties = new Properties();
+                mavenWrapperProperties.load(mavenWrapperPropertyFileInputStream);
+                url = mavenWrapperProperties.getProperty(PROPERTY_NAME_WRAPPER_URL, url);
+            } catch (IOException e) {
+                System.out.println("- ERROR loading '" + MAVEN_WRAPPER_PROPERTIES_PATH + "'");
+            } finally {
+                try {
+                    if(mavenWrapperPropertyFileInputStream != null) {
+                        mavenWrapperPropertyFileInputStream.close();
+                    }
+                } catch (IOException e) {
+                    // Ignore ...
+                }
+            }
+        }
+        System.out.println("- Downloading from: " + url);
+
+        File outputFile = new File(baseDirectory.getAbsolutePath(), MAVEN_WRAPPER_JAR_PATH);
+        if(!outputFile.getParentFile().exists()) {
+            if(!outputFile.getParentFile().mkdirs()) {
+                System.out.println(
+                        "- ERROR creating output directory '" + outputFile.getParentFile().getAbsolutePath() + "'");
+            }
+        }
+        System.out.println("- Downloading to: " + outputFile.getAbsolutePath());
+        try {
+            downloadFileFromURL(url, outputFile);
+            System.out.println("Done");
+            System.exit(0);
+        } catch (Throwable e) {
+            System.out.println("- Error downloading");
+            e.printStackTrace();
+            System.exit(1);
+        }
+    }
+
+    private static void downloadFileFromURL(String urlString, File destination) throws Exception {
+        if (System.getenv("MVNW_USERNAME") != null && System.getenv("MVNW_PASSWORD") != null) {
+            String username = System.getenv("MVNW_USERNAME");
+            char[] password = System.getenv("MVNW_PASSWORD").toCharArray();
+            Authenticator.setDefault(new Authenticator() {
+                @Override
+                protected PasswordAuthentication getPasswordAuthentication() {
+                    return new PasswordAuthentication(username, password);
+                }
+            });
+        }
+        URL website = new URL(urlString);
+        ReadableByteChannel rbc;
+        rbc = Channels.newChannel(website.openStream());
+        FileOutputStream fos = new FileOutputStream(destination);
+        fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
+        fos.close();
+        rbc.close();
+    }
+
+}

core-java/versions/.mvn/wrapper/maven-wrapper.properties

@@ -0,0 +1,2 @@
+distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.6.3/apache-maven-3.6.3-bin.zip
+wrapperUrl=https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar

core-java/versions/README.md

@@ -0,0 +1,3 @@
+# Examples for [Java 8 to 17 - what has changed? on reflectoring.io](https://reflectoring.io/java-8-to-17-what-has-changed)
+
+This repository contains the source code of the article's examples.

core-java/versions/mvnw

@@ -0,0 +1,310 @@
+#!/bin/sh
+# ----------------------------------------------------------------------------
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#    https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+# ----------------------------------------------------------------------------
+
+# ----------------------------------------------------------------------------
+# Maven Start Up Batch script
+#
+# Required ENV vars:
+# ------------------
+#   JAVA_HOME - location of a JDK home dir
+#
+# Optional ENV vars
+# -----------------
+#   M2_HOME - location of maven2's installed home dir
+#   MAVEN_OPTS - parameters passed to the Java VM when running Maven
+#     e.g. to debug Maven itself, use
+#       set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+#   MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+# ----------------------------------------------------------------------------
+
+if [ -z "$MAVEN_SKIP_RC" ] ; then
+
+  if [ -f /etc/mavenrc ] ; then
+    . /etc/mavenrc
+  fi
+
+  if [ -f "$HOME/.mavenrc" ] ; then
+    . "$HOME/.mavenrc"
+  fi
+
+fi
+
+# OS specific support.  $var _must_ be set to either true or false.
+cygwin=false;
+darwin=false;
+mingw=false
+case "`uname`" in
+  CYGWIN*) cygwin=true ;;
+  MINGW*) mingw=true;;
+  Darwin*) darwin=true
+    # Use /usr/libexec/java_home if available, otherwise fall back to /Library/Java/Home
+    # See https://developer.apple.com/library/mac/qa/qa1170/_index.html
+    if [ -z "$JAVA_HOME" ]; then
+      if [ -x "/usr/libexec/java_home" ]; then
+        export JAVA_HOME="`/usr/libexec/java_home`"
+      else
+        export JAVA_HOME="/Library/Java/Home"
+      fi
+    fi
+    ;;
+esac
+
+if [ -z "$JAVA_HOME" ] ; then
+  if [ -r /etc/gentoo-release ] ; then
+    JAVA_HOME=`java-config --jre-home`
+  fi
+fi
+
+if [ -z "$M2_HOME" ] ; then
+  ## resolve links - $0 may be a link to maven's home
+  PRG="$0"
+
+  # need this for relative symlinks
+  while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+      PRG="$link"
+    else
+      PRG="`dirname "$PRG"`/$link"
+    fi
+  done
+
+  saveddir=`pwd`
+
+  M2_HOME=`dirname "$PRG"`/..
+
+  # make it fully qualified
+  M2_HOME=`cd "$M2_HOME" && pwd`
+
+  cd "$saveddir"
+  # echo Using m2 at $M2_HOME
+fi
+
+# For Cygwin, ensure paths are in UNIX format before anything is touched
+if $cygwin ; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME=`cygpath --unix "$M2_HOME"`
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME=`cygpath --unix "$JAVA_HOME"`
+  [ -n "$CLASSPATH" ] &&
+    CLASSPATH=`cygpath --path --unix "$CLASSPATH"`
+fi
+
+# For Mingw, ensure paths are in UNIX format before anything is touched
+if $mingw ; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME="`(cd "$M2_HOME"; pwd)`"
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME="`(cd "$JAVA_HOME"; pwd)`"
+fi
+
+if [ -z "$JAVA_HOME" ]; then
+  javaExecutable="`which javac`"
+  if [ -n "$javaExecutable" ] && ! [ "`expr \"$javaExecutable\" : '\([^ ]*\)'`" = "no" ]; then
+    # readlink(1) is not available as standard on Solaris 10.
+    readLink=`which readlink`
+    if [ ! `expr "$readLink" : '\([^ ]*\)'` = "no" ]; then
+      if $darwin ; then
+        javaHome="`dirname \"$javaExecutable\"`"
+        javaExecutable="`cd \"$javaHome\" && pwd -P`/javac"
+      else
+        javaExecutable="`readlink -f \"$javaExecutable\"`"
+      fi
+      javaHome="`dirname \"$javaExecutable\"`"
+      javaHome=`expr "$javaHome" : '\(.*\)/bin'`
+      JAVA_HOME="$javaHome"
+      export JAVA_HOME
+    fi
+  fi
+fi
+
+if [ -z "$JAVACMD" ] ; then
+  if [ -n "$JAVA_HOME"  ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+      # IBM's JDK on AIX uses strange locations for the executables
+      JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+      JAVACMD="$JAVA_HOME/bin/java"
+    fi
+  else
+    JAVACMD="`which java`"
+  fi
+fi
+
+if [ ! -x "$JAVACMD" ] ; then
+  echo "Error: JAVA_HOME is not defined correctly." >&2
+  echo "  We cannot execute $JAVACMD" >&2
+  exit 1
+fi
+
+if [ -z "$JAVA_HOME" ] ; then
+  echo "Warning: JAVA_HOME environment variable is not set."
+fi
+
+CLASSWORLDS_LAUNCHER=org.codehaus.plexus.classworlds.launcher.Launcher
+
+# traverses directory structure from process work directory to filesystem root
+# first directory with .mvn subdirectory is considered project base directory
+find_maven_basedir() {
+
+  if [ -z "$1" ]
+  then
+    echo "Path not specified to find_maven_basedir"
+    return 1
+  fi
+
+  basedir="$1"
+  wdir="$1"
+  while [ "$wdir" != '/' ] ; do
+    if [ -d "$wdir"/.mvn ] ; then
+      basedir=$wdir
+      break
+    fi
+    # workaround for JBEAP-8937 (on Solaris 10/Sparc)
+    if [ -d "${wdir}" ]; then
+      wdir=`cd "$wdir/.."; pwd`
+    fi
+    # end of workaround
+  done
+  echo "${basedir}"
+}
+
+# concatenates all lines of a file
+concat_lines() {
+  if [ -f "$1" ]; then
+    echo "$(tr -s '\n' ' ' < "$1")"
+  fi
+}
+
+BASE_DIR=`find_maven_basedir "$(pwd)"`
+if [ -z "$BASE_DIR" ]; then
+  exit 1;
+fi
+
+##########################################################################################
+# Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+# This allows using the maven wrapper in projects that prohibit checking in binary data.
+##########################################################################################
+if [ -r "$BASE_DIR/.mvn/wrapper/maven-wrapper.jar" ]; then
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Found .mvn/wrapper/maven-wrapper.jar"
+    fi
+else
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Couldn't find .mvn/wrapper/maven-wrapper.jar, downloading it ..."
+    fi
+    if [ -n "$MVNW_REPOURL" ]; then
+      jarUrl="$MVNW_REPOURL/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+    else
+      jarUrl="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+    fi
+    while IFS="=" read key value; do
+      case "$key" in (wrapperUrl) jarUrl="$value"; break ;;
+      esac
+    done < "$BASE_DIR/.mvn/wrapper/maven-wrapper.properties"
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Downloading from: $jarUrl"
+    fi
+    wrapperJarPath="$BASE_DIR/.mvn/wrapper/maven-wrapper.jar"
+    if $cygwin; then
+      wrapperJarPath=`cygpath --path --windows "$wrapperJarPath"`
+    fi
+
+    if command -v wget > /dev/null; then
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo "Found wget ... using wget"
+        fi
+        if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+            wget "$jarUrl" -O "$wrapperJarPath"
+        else
+            wget --http-user=$MVNW_USERNAME --http-password=$MVNW_PASSWORD "$jarUrl" -O "$wrapperJarPath"
+        fi
+    elif command -v curl > /dev/null; then
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo "Found curl ... using curl"
+        fi
+        if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+            curl -o "$wrapperJarPath" "$jarUrl" -f
+        else
+            curl --user $MVNW_USERNAME:$MVNW_PASSWORD -o "$wrapperJarPath" "$jarUrl" -f
+        fi
+
+    else
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo "Falling back to using Java to download"
+        fi
+        javaClass="$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.java"
+        # For Cygwin, switch paths to Windows format before running javac
+        if $cygwin; then
+          javaClass=`cygpath --path --windows "$javaClass"`
+        fi
+        if [ -e "$javaClass" ]; then
+            if [ ! -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+                if [ "$MVNW_VERBOSE" = true ]; then
+                  echo " - Compiling MavenWrapperDownloader.java ..."
+                fi
+                # Compiling the Java class
+                ("$JAVA_HOME/bin/javac" "$javaClass")
+            fi
+            if [ -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+                # Running the downloader
+                if [ "$MVNW_VERBOSE" = true ]; then
+                  echo " - Running MavenWrapperDownloader.java ..."
+                fi
+                ("$JAVA_HOME/bin/java" -cp .mvn/wrapper MavenWrapperDownloader "$MAVEN_PROJECTBASEDIR")
+            fi
+        fi
+    fi
+fi
+##########################################################################################
+# End of extension
+##########################################################################################
+
+export MAVEN_PROJECTBASEDIR=${MAVEN_BASEDIR:-"$BASE_DIR"}
+if [ "$MVNW_VERBOSE" = true ]; then
+  echo $MAVEN_PROJECTBASEDIR
+fi
+MAVEN_OPTS="$(concat_lines "$MAVEN_PROJECTBASEDIR/.mvn/jvm.config") $MAVEN_OPTS"
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME=`cygpath --path --windows "$M2_HOME"`
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME=`cygpath --path --windows "$JAVA_HOME"`
+  [ -n "$CLASSPATH" ] &&
+    CLASSPATH=`cygpath --path --windows "$CLASSPATH"`
+  [ -n "$MAVEN_PROJECTBASEDIR" ] &&
+    MAVEN_PROJECTBASEDIR=`cygpath --path --windows "$MAVEN_PROJECTBASEDIR"`
+fi
+
+# Provide a "standardized" way to retrieve the CLI args that will
+# work with both Windows and non-Windows executions.
+MAVEN_CMD_LINE_ARGS="$MAVEN_CONFIG $@"
+export MAVEN_CMD_LINE_ARGS
+
+WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+exec "$JAVACMD" \
+  $MAVEN_OPTS \
+  -classpath "$MAVEN_PROJECTBASEDIR/.mvn/wrapper/maven-wrapper.jar" \
+  "-Dmaven.home=${M2_HOME}" "-Dmaven.multiModuleProjectDirectory=${MAVEN_PROJECTBASEDIR}" \
+  ${WRAPPER_LAUNCHER} $MAVEN_CONFIG "$@"

core-java/versions/mvnw.cmd

@@ -0,0 +1,182 @@
+@REM ----------------------------------------------------------------------------
+@REM Licensed to the Apache Software Foundation (ASF) under one
+@REM or more contributor license agreements.  See the NOTICE file
+@REM distributed with this work for additional information
+@REM regarding copyright ownership.  The ASF licenses this file
+@REM to you under the Apache License, Version 2.0 (the
+@REM "License"); you may not use this file except in compliance
+@REM with the License.  You may obtain a copy of the License at
+@REM
+@REM    https://www.apache.org/licenses/LICENSE-2.0
+@REM
+@REM Unless required by applicable law or agreed to in writing,
+@REM software distributed under the License is distributed on an
+@REM "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+@REM KIND, either express or implied.  See the License for the
+@REM specific language governing permissions and limitations
+@REM under the License.
+@REM ----------------------------------------------------------------------------
+
+@REM ----------------------------------------------------------------------------
+@REM Maven Start Up Batch script
+@REM
+@REM Required ENV vars:
+@REM JAVA_HOME - location of a JDK home dir
+@REM
+@REM Optional ENV vars
+@REM M2_HOME - location of maven2's installed home dir
+@REM MAVEN_BATCH_ECHO - set to 'on' to enable the echoing of the batch commands
+@REM MAVEN_BATCH_PAUSE - set to 'on' to wait for a keystroke before ending
+@REM MAVEN_OPTS - parameters passed to the Java VM when running Maven
+@REM     e.g. to debug Maven itself, use
+@REM set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+@REM MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+@REM ----------------------------------------------------------------------------
+
+@REM Begin all REM lines with '@' in case MAVEN_BATCH_ECHO is 'on'
+@echo off
+@REM set title of command window
+title %0
+@REM enable echoing by setting MAVEN_BATCH_ECHO to 'on'
+@if "%MAVEN_BATCH_ECHO%" == "on"  echo %MAVEN_BATCH_ECHO%
+
+@REM set %HOME% to equivalent of $HOME
+if "%HOME%" == "" (set "HOME=%HOMEDRIVE%%HOMEPATH%")
+
+@REM Execute a user defined script before this one
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPre
+@REM check for pre script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_pre.bat" call "%HOME%\mavenrc_pre.bat"
+if exist "%HOME%\mavenrc_pre.cmd" call "%HOME%\mavenrc_pre.cmd"
+:skipRcPre
+
+@setlocal
+
+set ERROR_CODE=0
+
+@REM To isolate internal variables from possible post scripts, we use another setlocal
+@setlocal
+
+@REM ==== START VALIDATION ====
+if not "%JAVA_HOME%" == "" goto OkJHome
+
+echo.
+echo Error: JAVA_HOME not found in your environment. >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+:OkJHome
+if exist "%JAVA_HOME%\bin\java.exe" goto init
+
+echo.
+echo Error: JAVA_HOME is set to an invalid directory. >&2
+echo JAVA_HOME = "%JAVA_HOME%" >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+@REM ==== END VALIDATION ====
+
+:init
+
+@REM Find the project base dir, i.e. the directory that contains the folder ".mvn".
+@REM Fallback to current working directory if not found.
+
+set MAVEN_PROJECTBASEDIR=%MAVEN_BASEDIR%
+IF NOT "%MAVEN_PROJECTBASEDIR%"=="" goto endDetectBaseDir
+
+set EXEC_DIR=%CD%
+set WDIR=%EXEC_DIR%
+:findBaseDir
+IF EXIST "%WDIR%"\.mvn goto baseDirFound
+cd ..
+IF "%WDIR%"=="%CD%" goto baseDirNotFound
+set WDIR=%CD%
+goto findBaseDir
+
+:baseDirFound
+set MAVEN_PROJECTBASEDIR=%WDIR%
+cd "%EXEC_DIR%"
+goto endDetectBaseDir
+
+:baseDirNotFound
+set MAVEN_PROJECTBASEDIR=%EXEC_DIR%
+cd "%EXEC_DIR%"
+
+:endDetectBaseDir
+
+IF NOT EXIST "%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config" goto endReadAdditionalConfig
+
+@setlocal EnableExtensions EnableDelayedExpansion
+for /F "usebackq delims=" %%a in ("%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config") do set JVM_CONFIG_MAVEN_PROPS=!JVM_CONFIG_MAVEN_PROPS! %%a
+@endlocal & set JVM_CONFIG_MAVEN_PROPS=%JVM_CONFIG_MAVEN_PROPS%
+
+:endReadAdditionalConfig
+
+SET MAVEN_JAVA_EXE="%JAVA_HOME%\bin\java.exe"
+set WRAPPER_JAR="%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.jar"
+set WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+set DOWNLOAD_URL="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+
+FOR /F "tokens=1,2 delims==" %%A IN ("%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.properties") DO (
+    IF "%%A"=="wrapperUrl" SET DOWNLOAD_URL=%%B
+)
+
+@REM Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+@REM This allows using the maven wrapper in projects that prohibit checking in binary data.
+if exist %WRAPPER_JAR% (
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Found %WRAPPER_JAR%
+    )
+) else (
+    if not "%MVNW_REPOURL%" == "" (
+        SET DOWNLOAD_URL="%MVNW_REPOURL%/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+    )
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Couldn't find %WRAPPER_JAR%, downloading it ...
+        echo Downloading from: %DOWNLOAD_URL%
+    )
+
+    powershell -Command "&{"^
+		"$webclient = new-object System.Net.WebClient;"^
+		"if (-not ([string]::IsNullOrEmpty('%MVNW_USERNAME%') -and [string]::IsNullOrEmpty('%MVNW_PASSWORD%'))) {"^
+		"$webclient.Credentials = new-object System.Net.NetworkCredential('%MVNW_USERNAME%', '%MVNW_PASSWORD%');"^
+		"}"^
+		"[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; $webclient.DownloadFile('%DOWNLOAD_URL%', '%WRAPPER_JAR%')"^
+		"}"
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Finished downloading %WRAPPER_JAR%
+    )
+)
+@REM End of extension
+
+@REM Provide a "standardized" way to retrieve the CLI args that will
+@REM work with both Windows and non-Windows executions.
+set MAVEN_CMD_LINE_ARGS=%*
+
+%MAVEN_JAVA_EXE% %JVM_CONFIG_MAVEN_PROPS% %MAVEN_OPTS% %MAVEN_DEBUG_OPTS% -classpath %WRAPPER_JAR% "-Dmaven.multiModuleProjectDirectory=%MAVEN_PROJECTBASEDIR%" %WRAPPER_LAUNCHER% %MAVEN_CONFIG% %*
+if ERRORLEVEL 1 goto error
+goto end
+
+:error
+set ERROR_CODE=1
+
+:end
+@endlocal & set ERROR_CODE=%ERROR_CODE%
+
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPost
+@REM check for post script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_post.bat" call "%HOME%\mavenrc_post.bat"
+if exist "%HOME%\mavenrc_post.cmd" call "%HOME%\mavenrc_post.cmd"
+:skipRcPost
+
+@REM pause the script if MAVEN_BATCH_PAUSE is set to 'on'
+if "%MAVEN_BATCH_PAUSE%" == "on" pause
+
+if "%MAVEN_TERMINATE_CMD%" == "on" exit %ERROR_CODE%
+
+exit /B %ERROR_CODE%

core-java/versions/pom.xml

@@ -0,0 +1,37 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>com.reflectoring.io</groupId>
+    <artifactId>versions</artifactId>
+    <packaging>pom</packaging>
+    <version>1.0-SNAPSHOT</version>
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <source>17</source>
+                    <target>17</target>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <source>17</source>
+                    <target>17</target>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+    <properties>
+        <java.version>17</java.version>
+        <maven.compiler.source>17</maven.compiler.source>
+        <maven.compiler.target>17</maven.compiler.target>
+    </properties>
+
+</project>

core-java/versions/src/main/java/com/reflectoring/io/java10/LocalTypeVar.java

@@ -0,0 +1,45 @@
+package com.reflectoring.io.java10;
+
+import java.util.List;
+
+public class LocalTypeVar {
+
+    public void explicitTypes() {
+        Person Roland = new Person("Roland", "Deschain");
+        Person Susan = new Person("Susan", "Delgado");
+        Person Eddie = new Person("Eddie", "Dean");
+        Person Detta = new Person("Detta", "Walker");
+        Person Jake = new Person("Jake", "Chambers");
+
+        List<Person> persons =
+                List.of(Roland, Susan, Eddie, Detta, Jake);
+
+        for (Person person : persons) {
+            System.out.println(person.name + " - " + person.lastname);
+        }
+    }
+
+    public void varTypes() {
+        var Roland = new Person("Roland", "Deschain");
+        var Susan = new Person("Susan", "Delgado");
+        var Eddie = new Person("Eddie", "Dean");
+        var Detta = new Person("Detta", "Walker");
+        var Jake = new Person("Jake", "Chambers");
+
+        var persons = List.of(Roland, Susan, Eddie, Detta, Jake);
+
+        for (var person : persons) {
+            System.out.println(person.name + " - " + person.lastname);
+        }
+    }
+
+    public class Person {
+        String name;
+        String lastname;
+
+        public Person(String name, String lastname) {
+            this.name = name;
+            this.lastname = lastname;
+        }
+    }
+}

core-java/versions/src/main/java/com/reflectoring/io/java11/LocalTypeVarLambda.java

@@ -0,0 +1,35 @@
+package com.reflectoring.io.java11;
+
+import com.reflectoring.io.java10.LocalTypeVar;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class LocalTypeVarLambda {
+
+    public void explicitTypes() {
+        var Roland = new Person("Roland", "Deschain");
+        var Susan = new Person("Susan", "Delgado");
+        var Eddie = new Person("Eddie", "Dean");
+        var Detta = new Person("Detta", "Walker");
+        var Jake = new Person("Jake", "Chambers");
+
+        var filteredPersons =
+                List.of(Roland, Susan, Eddie, Detta, Jake)
+                        .stream()
+                        .filter((var x) -> x.name.contains("a"))
+                        .collect(Collectors.toList());
+        System.out.println(filteredPersons);
+    }
+
+
+    public class Person {
+        String name;
+        String lastname;
+
+        public Person(String name, String lastname) {
+            this.name = name;
+            this.lastname = lastname;
+        }
+    }
+}

core-java/versions/src/main/java/com/reflectoring/io/java14/SwitchExpression.java

@@ -0,0 +1,65 @@
+package com.reflectoring.io.java14;
+
+public class SwitchExpression {
+
+    public static void main(String[] args) {
+        int days = 0;
+        Month month = Month.APRIL;
+
+        switch (month) {
+            case JANUARY, MARCH, MAY, JULY, AUGUST, OCTOBER,
+                    DECEMBER:
+                days = 31;
+                break;
+            case FEBRUARY:
+                days = 28;
+                break;
+            case APRIL, JUNE, SEPTEMBER, NOVEMBER:
+                days = 30;
+                break;
+            default:
+                throw new IllegalStateException();
+        }
+
+        days = switch (month) {
+            case JANUARY, MARCH, MAY, JULY, AUGUST, OCTOBER, DECEMBER -> 31;
+            case FEBRUARY -> 28;
+            case APRIL, JUNE, SEPTEMBER, NOVEMBER -> 30;
+            default -> throw new IllegalStateException();
+        };
+
+        days = switch (month) {
+            case JANUARY, MARCH, MAY, JULY, AUGUST, OCTOBER, DECEMBER -> {
+                System.out.println(month);
+                yield 31;
+            }
+            case FEBRUARY -> {
+                System.out.println(month);
+                yield 28;
+            }
+            case APRIL, JUNE, SEPTEMBER, NOVEMBER -> {
+                System.out.println(month);
+                yield 30;
+            }
+            default -> throw new IllegalStateException();
+        };
+
+    }
+
+    public enum Month {
+        JANUARY,
+        FEBRUARY,
+        MARCH,
+        APRIL,
+        MAY,
+        JUNE,
+        JULY,
+        AUGUST,
+        SEPTEMBER,
+        OCTOBER,
+        NOVEMBER,
+        DECEMBER
+    }
+}
+
+

core-java/versions/src/main/java/com/reflectoring/io/java15/TextBlocks.java

@@ -0,0 +1,32 @@
+package com.reflectoring.io.java15;
+
+public class TextBlocks {
+    public static void main(String[] args) {
+        System.out.println(
+        "<!DOCTYPE html>\n" +
+                "<html>\n" +
+                "     <head>\n" +
+                "        <title>Example</title>\n" +
+                "    </head>\n" +
+                "    <body>\n" +
+                "        <p>This is an example of a simple HTML " +
+                "page with one paragraph.</p>\n" +
+                "    </body>\n" +
+                "</html>\n");
+
+        System.out.println(
+        """
+                <!DOCTYPE html>
+                <html>
+                    <head>
+                        <title>Example</title>
+                    </head>
+                    <body>
+                        <p>This is an example of a simple HTML 
+                        page with one paragraph.</p>
+                    </body>
+                </html>      
+                """
+        );
+    }
+}

core-java/versions/src/main/java/com/reflectoring/io/java16/Bicycle.java

@@ -0,0 +1,12 @@
+package com.reflectoring.io.java16;
+
+public class Bicycle extends Vehicle{
+    String type;
+    Long wheelSize;
+
+    public Bicycle(String code, String engineType, String type, Long wheelSize) {
+        super(code, engineType);
+        this.type = type;
+        this.wheelSize = wheelSize;
+    }
+}

core-java/versions/src/main/java/com/reflectoring/io/java16/Car.java

@@ -0,0 +1,12 @@
+package com.reflectoring.io.java16;
+
+public class Car extends Vehicle{
+    Long kilomenters;
+    Long year;
+
+    public Car(String code, String engineType, Long kilomenters, Long year) {
+        super(code, engineType);
+        this.kilomenters = kilomenters;
+        this.year = year;
+    }
+}

core-java/versions/src/main/java/com/reflectoring/io/java16/PatternMatching.java

@@ -0,0 +1,37 @@
+package com.reflectoring.io.java16;
+
+import java.util.Calendar;
+
+public class PatternMatching {
+    public static void main(String[] args) {
+        Car car = new Car("Kia", "Gas", 10000l, 2021l);
+        Bicycle bicycle =
+                new Bicycle("Greyp", "Electricity", "Mountain", 21l);
+
+        System.out.println("Car:" + price(car));
+        System.out.println("Bycicle: " + price(bicycle));
+    }
+
+    public static double price(Vehicle v) {
+        if (v instanceof Car c) {
+            return 10000 - c.kilomenters * 0.01 -
+                    (Calendar.getInstance().get(Calendar.YEAR) -
+                            c.year) * 100;
+        } else if (v instanceof Bicycle b) {
+            return 1000 + b.wheelSize * 10;
+        } else throw new IllegalArgumentException();
+    }
+
+    public static double priceOld(Vehicle v) {
+        if (v instanceof Car) {
+            Car c = (Car) v;
+            return 10000 - c.kilomenters * 0.01 -
+                    (Calendar.getInstance().get(Calendar.YEAR) -
+                            c.year) * 100;
+        } else if (v instanceof Bicycle) {
+            Bicycle b = (Bicycle) v;
+            return 1000 + b.wheelSize * 10;
+        } else throw new IllegalArgumentException();
+
+    }
+}

core-java/versions/src/main/java/com/reflectoring/io/java16/Vehicle.java

@@ -0,0 +1,51 @@
+package com.reflectoring.io.java16;
+
+import java.util.Objects;
+
+public class Vehicle {
+    String code;
+    String engineType;
+
+    public String getCode() {
+        return code;
+    }
+
+    public void setCode(String code) {
+        this.code = code;
+    }
+
+    public String getEngineType() {
+        return engineType;
+    }
+
+    public void setEngineType(String engineType) {
+        this.engineType = engineType;
+    }
+
+    public Vehicle(String code, String engineType) {
+        this.code = code;
+        this.engineType = engineType;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        Vehicle vehicle = (Vehicle) o;
+        return code.equals(vehicle.code) &&
+                engineType.equals(vehicle.engineType);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(code, engineType);
+    }
+
+    @Override
+    public String toString() {
+        return "Vehicle{" +
+                "code='" + code + '\'' +
+                ", engineType='" + engineType + '\'' +
+                '}';
+    }
+}

core-java/versions/src/main/java/com/reflectoring/io/java16/VehicleRecord.java

@@ -0,0 +1,3 @@
+package com.reflectoring.io.java16;
+
+public record VehicleRecord(String code, String engineType) {}

core-java/versions/src/main/java/com/reflectoring/io/java17/Bicycle.java

@@ -0,0 +1,12 @@
+package com.reflectoring.io.java17;
+
+public final class Bicycle extends Vehicle {
+    String type;
+    Long wheelSize;
+
+    public Bicycle(String code, String engineType, String type, Long wheelSize) {
+        super(code, engineType);
+        this.type = type;
+        this.wheelSize = wheelSize;
+    }
+}

core-java/versions/src/main/java/com/reflectoring/io/java17/Car.java

@@ -0,0 +1,12 @@
+package com.reflectoring.io.java17;
+
+public final class Car extends Vehicle {
+    Long kilomenters;
+    Long year;
+
+    public Car(String code, String engineType, Long kilomenters, Long year) {
+        super(code, engineType);
+        this.kilomenters = kilomenters;
+        this.year = year;
+    }
+}

core-java/versions/src/main/java/com/reflectoring/io/java17/SealedClasses.java

@@ -0,0 +1,4 @@
+package com.reflectoring.io.java17;
+
+public class SealedClasses {
+}

core-java/versions/src/main/java/com/reflectoring/io/java17/Vehicle.java

@@ -0,0 +1,51 @@
+package com.reflectoring.io.java17;
+
+import java.util.Objects;
+
+public sealed class Vehicle permits Bicycle, Car {
+    String code;
+    String engineType;
+
+    public String getCode() {
+        return code;
+    }
+
+    public void setCode(String code) {
+        this.code = code;
+    }
+
+    public String getEngineType() {
+        return engineType;
+    }
+
+    public void setEngineType(String engineType) {
+        this.engineType = engineType;
+    }
+
+    public Vehicle(String code, String engineType) {
+        this.code = code;
+        this.engineType = engineType;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        Vehicle vehicle = (Vehicle) o;
+        return code.equals(vehicle.code) &&
+                engineType.equals(vehicle.engineType);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(code, engineType);
+    }
+
+    @Override
+    public String toString() {
+        return "Vehicle{" +
+                "code='" + code + '\'' +
+                ", engineType='" + engineType + '\'' +
+                '}';
+    }
+}

core-java/versions/src/main/java/com/reflectoring/io/java8/DefaultMethods.java

@@ -0,0 +1,22 @@
+package com.reflectoring.io.java8;
+
+import java.util.Date;
+
+public class DefaultMethods {
+
+    public interface Logging {
+        void log(String message);
+
+        default void log(String message, Date date) {
+            System.out.println(date.toString() + ": " + message);
+        }
+    }
+
+    public class LoggingImplementation implements Logging {
+
+        @Override
+        public void log(String message) {
+            System.out.println(message);
+        }
+    }
+}

core-java/versions/src/main/java/com/reflectoring/io/java8/LambdaExpressions.java

@@ -0,0 +1,40 @@
+package com.reflectoring.io.java8;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class LambdaExpressions {
+
+    public static List<Car> findCarsUsingLambda(List<Car> cars) {
+        return cars.stream().filter(car -> car.kilometers < 50000)
+                .collect(Collectors.toList());
+    }
+
+    public static List<Car> findCarsOldWay(List<Car> cars) {
+        List<Car> selectedCars = new ArrayList<>();
+        for (Car car : cars) {
+            if (car.kilometers < 50000) {
+                selectedCars.add(car);
+            }
+        }
+        return selectedCars;
+    }
+
+    public static List<Car> findCarsWithModelOldWay(List<Car> cars) {
+        List<Car> selectedCars = new ArrayList<>();
+        for (Car car : cars) {
+            if (car.kilometers < 50000 &&
+                    car.model.equals("Mercedes")) {
+                selectedCars.add(car);
+            }
+        }
+        return selectedCars;
+    }
+
+    public class Car {
+        public String model;
+        public double kilometers;
+    }
+
+}

core-java/versions/src/main/java/com/reflectoring/io/java8/MethodReference.java

@@ -0,0 +1,35 @@
+package com.reflectoring.io.java8;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class MethodReference {
+
+    List<Car> cars = new ArrayList<>();
+
+    List<String> withoutMethodReference =
+            cars.stream().map(car -> car.toString())
+                    .collect(Collectors.toList());
+
+    List<String> methodReference = cars.stream().map(Car::toString)
+            .collect(Collectors.toList());
+
+    public class Car {
+        public String model;
+        public double kilometers;
+
+        public Car(String model, double kilometers) {
+            this.model = model;
+            this.kilometers = kilometers;
+        }
+
+        @Override
+        public String toString() {
+            return "Car{" +
+                    "model='" + model + '\'' +
+                    ", kilometers=" + kilometers +
+                    '}';
+        }
+    }
+}

core-java/versions/src/main/java/com/reflectoring/io/java8/RepeatingAnnotations.java

@@ -0,0 +1,27 @@
+package com.reflectoring.io.java8;
+
+import java.lang.annotation.Repeatable;
+
+public class RepeatingAnnotations {
+
+    @Repeatable(Notifications.class)
+    public @interface Notify {
+        String email();
+    }
+
+    public @interface Notifications {
+        Notify[] value();
+    }
+
+    @Notify(email = "admin@company.com")
+    @Notify(email = "owner@company.com")
+    public class UserNotAllowedForThisActionException
+            extends RuntimeException {
+        final String user;
+
+        public UserNotAllowedForThisActionException(String user) {
+            this.user = user;
+
+        }
+    }
+}

core-java/versions/src/main/java/com/reflectoring/io/java8/TypeAnnotations.java

@@ -0,0 +1,42 @@
+package com.reflectoring.io.java8;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import static java.lang.annotation.ElementType.TYPE_USE;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+
+public class TypeAnnotations {
+
+    public static void main(String[] args) {
+
+        @NotNull String userName = args[0];
+
+        List<String> request =
+                new @NotEmpty ArrayList<>(Arrays.stream(args).collect(
+                        Collectors.toList()));
+
+        List<@Email String> emails;
+
+
+    }
+
+    @Target(value = {TYPE_USE})
+    @Retention(value = RUNTIME)
+    public @interface NotNull {
+    }
+
+    @Target(value = {TYPE_USE})
+    @Retention(value = RUNTIME)
+    public @interface NotEmpty {
+    }
+
+    @Target(value = {TYPE_USE})
+    @Retention(value = RUNTIME)
+    public @interface Email {
+    }
+}

core-java/versions/src/main/java/com/reflectoring/io/java9/DiamondOperator.java

@@ -0,0 +1,16 @@
+package com.reflectoring.io.java9;
+
+public class DiamondOperator {
+
+    StringAppender<String> appending = new StringAppender<>() {
+        @Override
+        public String append(String a, String b) {
+            return new StringBuilder(a).append("-").append(b)
+                    .toString();
+        }
+    };
+
+    public abstract static class StringAppender<T> {
+        public abstract T append(String a, String b);
+    }
+}

core-java/versions/src/main/java/com/reflectoring/io/java9/PrivateInterfaceMethods.java

@@ -0,0 +1,43 @@
+package com.reflectoring.io.java9;
+
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.ArrayList;
+import java.util.List;
+
+public class PrivateInterfaceMethods {
+    public static void main(String[] args) {
+        TestingNames names = new TestingNames();
+        System.out.println(names.fetchInitialData());
+    }
+
+    public static class TestingNames implements NamesInterface {
+        public TestingNames() {
+        }
+    }
+
+    public interface NamesInterface {
+        default List<String> fetchInitialData() {
+            try (BufferedReader br = new BufferedReader(
+                    new InputStreamReader(this.getClass()
+                            .getResourceAsStream("/names.txt")))) {
+                return readNames(br);
+            } catch (IOException e) {
+                e.printStackTrace();
+                return null;
+            }
+        }
+
+        private List<String> readNames(BufferedReader br)
+                throws IOException {
+            ArrayList<String> names = new ArrayList<>();
+            String name;
+            while ((name = br.readLine()) != null) {
+                names.add(name);
+            }
+            return names;
+        }
+    }
+}

core-java/versions/src/main/java/com/reflectoring/io/java9/TryWithResources.java

@@ -0,0 +1,39 @@
+package com.reflectoring.io.java9;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.StringReader;
+
+public class TryWithResources {
+    public static void main(String[] args) {
+        BufferedReader br = new BufferedReader(
+                new StringReader("Hello world example!"));
+        try {
+            System.out.println(br.readLine());
+        } catch (IOException e) {
+            e.printStackTrace();
+        } finally {
+            try {
+                br.close();
+            } catch (IOException e) {
+                e.printStackTrace();
+            }
+        }
+
+        final BufferedReader br2 = new BufferedReader(
+                new StringReader("Hello world example2!"));
+        try (br2) {
+            System.out.println(br2.readLine());
+        } catch (IOException e) {
+            System.out.println("Error happened!");
+        }
+
+        final BufferedReader br3 = new BufferedReader(
+                new StringReader("Hello world example3!"));
+        try (BufferedReader reader = br3) {
+            System.out.println(reader.readLine());
+        } catch (IOException e) {
+            System.out.println("Error happened!");
+        }
+    }
+}

core-java/versions/src/main/java/com/reflectoring/io/java9/modules/hellos/.mvn/wrapper/MavenWrapperDownloader.java

@@ -0,0 +1,117 @@
+/*
+ * Copyright 2007-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import java.net.*;
+import java.io.*;
+import java.nio.channels.*;
+import java.util.Properties;
+
+public class MavenWrapperDownloader {
+
+    private static final String WRAPPER_VERSION = "0.5.6";
+    /**
+     * Default URL to download the maven-wrapper.jar from, if no 'downloadUrl' is provided.
+     */
+    private static final String DEFAULT_DOWNLOAD_URL = "https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/"
+        + WRAPPER_VERSION + "/maven-wrapper-" + WRAPPER_VERSION + ".jar";
+
+    /**
+     * Path to the maven-wrapper.properties file, which might contain a downloadUrl property to
+     * use instead of the default one.
+     */
+    private static final String MAVEN_WRAPPER_PROPERTIES_PATH =
+            ".mvn/wrapper/maven-wrapper.properties";
+
+    /**
+     * Path where the maven-wrapper.jar will be saved to.
+     */
+    private static final String MAVEN_WRAPPER_JAR_PATH =
+            ".mvn/wrapper/maven-wrapper.jar";
+
+    /**
+     * Name of the property which should be used to override the default download url for the wrapper.
+     */
+    private static final String PROPERTY_NAME_WRAPPER_URL = "wrapperUrl";
+
+    public static void main(String args[]) {
+        System.out.println("- Downloader started");
+        File baseDirectory = new File(args[0]);
+        System.out.println("- Using base directory: " + baseDirectory.getAbsolutePath());
+
+        // If the maven-wrapper.properties exists, read it and check if it contains a custom
+        // wrapperUrl parameter.
+        File mavenWrapperPropertyFile = new File(baseDirectory, MAVEN_WRAPPER_PROPERTIES_PATH);
+        String url = DEFAULT_DOWNLOAD_URL;
+        if(mavenWrapperPropertyFile.exists()) {
+            FileInputStream mavenWrapperPropertyFileInputStream = null;
+            try {
+                mavenWrapperPropertyFileInputStream = new FileInputStream(mavenWrapperPropertyFile);
+                Properties mavenWrapperProperties = new Properties();
+                mavenWrapperProperties.load(mavenWrapperPropertyFileInputStream);
+                url = mavenWrapperProperties.getProperty(PROPERTY_NAME_WRAPPER_URL, url);
+            } catch (IOException e) {
+                System.out.println("- ERROR loading '" + MAVEN_WRAPPER_PROPERTIES_PATH + "'");
+            } finally {
+                try {
+                    if(mavenWrapperPropertyFileInputStream != null) {
+                        mavenWrapperPropertyFileInputStream.close();
+                    }
+                } catch (IOException e) {
+                    // Ignore ...
+                }
+            }
+        }
+        System.out.println("- Downloading from: " + url);
+
+        File outputFile = new File(baseDirectory.getAbsolutePath(), MAVEN_WRAPPER_JAR_PATH);
+        if(!outputFile.getParentFile().exists()) {
+            if(!outputFile.getParentFile().mkdirs()) {
+                System.out.println(
+                        "- ERROR creating output directory '" + outputFile.getParentFile().getAbsolutePath() + "'");
+            }
+        }
+        System.out.println("- Downloading to: " + outputFile.getAbsolutePath());
+        try {
+            downloadFileFromURL(url, outputFile);
+            System.out.println("Done");
+            System.exit(0);
+        } catch (Throwable e) {
+            System.out.println("- Error downloading");
+            e.printStackTrace();
+            System.exit(1);
+        }
+    }
+
+    private static void downloadFileFromURL(String urlString, File destination) throws Exception {
+        if (System.getenv("MVNW_USERNAME") != null && System.getenv("MVNW_PASSWORD") != null) {
+            String username = System.getenv("MVNW_USERNAME");
+            char[] password = System.getenv("MVNW_PASSWORD").toCharArray();
+            Authenticator.setDefault(new Authenticator() {
+                @Override
+                protected PasswordAuthentication getPasswordAuthentication() {
+                    return new PasswordAuthentication(username, password);
+                }
+            });
+        }
+        URL website = new URL(urlString);
+        ReadableByteChannel rbc;
+        rbc = Channels.newChannel(website.openStream());
+        FileOutputStream fos = new FileOutputStream(destination);
+        fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
+        fos.close();
+        rbc.close();
+    }
+
+}

core-java/versions/src/main/java/com/reflectoring/io/java9/modules/hellos/.mvn/wrapper/maven-wrapper.properties

@@ -0,0 +1,2 @@
+distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.6.3/apache-maven-3.6.3-bin.zip
+wrapperUrl=https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar

core-java/versions/src/main/java/com/reflectoring/io/java9/modules/hellos/mvnw

@@ -0,0 +1,310 @@
+#!/bin/sh
+# ----------------------------------------------------------------------------
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#    https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+# ----------------------------------------------------------------------------
+
+# ----------------------------------------------------------------------------
+# Maven Start Up Batch script
+#
+# Required ENV vars:
+# ------------------
+#   JAVA_HOME - location of a JDK home dir
+#
+# Optional ENV vars
+# -----------------
+#   M2_HOME - location of maven2's installed home dir
+#   MAVEN_OPTS - parameters passed to the Java VM when running Maven
+#     e.g. to debug Maven itself, use
+#       set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+#   MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+# ----------------------------------------------------------------------------
+
+if [ -z "$MAVEN_SKIP_RC" ] ; then
+
+  if [ -f /etc/mavenrc ] ; then
+    . /etc/mavenrc
+  fi
+
+  if [ -f "$HOME/.mavenrc" ] ; then
+    . "$HOME/.mavenrc"
+  fi
+
+fi
+
+# OS specific support.  $var _must_ be set to either true or false.
+cygwin=false;
+darwin=false;
+mingw=false
+case "`uname`" in
+  CYGWIN*) cygwin=true ;;
+  MINGW*) mingw=true;;
+  Darwin*) darwin=true
+    # Use /usr/libexec/java_home if available, otherwise fall back to /Library/Java/Home
+    # See https://developer.apple.com/library/mac/qa/qa1170/_index.html
+    if [ -z "$JAVA_HOME" ]; then
+      if [ -x "/usr/libexec/java_home" ]; then
+        export JAVA_HOME="`/usr/libexec/java_home`"
+      else
+        export JAVA_HOME="/Library/Java/Home"
+      fi
+    fi
+    ;;
+esac
+
+if [ -z "$JAVA_HOME" ] ; then
+  if [ -r /etc/gentoo-release ] ; then
+    JAVA_HOME=`java-config --jre-home`
+  fi
+fi
+
+if [ -z "$M2_HOME" ] ; then
+  ## resolve links - $0 may be a link to maven's home
+  PRG="$0"
+
+  # need this for relative symlinks
+  while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+      PRG="$link"
+    else
+      PRG="`dirname "$PRG"`/$link"
+    fi
+  done
+
+  saveddir=`pwd`
+
+  M2_HOME=`dirname "$PRG"`/..
+
+  # make it fully qualified
+  M2_HOME=`cd "$M2_HOME" && pwd`
+
+  cd "$saveddir"
+  # echo Using m2 at $M2_HOME
+fi
+
+# For Cygwin, ensure paths are in UNIX format before anything is touched
+if $cygwin ; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME=`cygpath --unix "$M2_HOME"`
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME=`cygpath --unix "$JAVA_HOME"`
+  [ -n "$CLASSPATH" ] &&
+    CLASSPATH=`cygpath --path --unix "$CLASSPATH"`
+fi
+
+# For Mingw, ensure paths are in UNIX format before anything is touched
+if $mingw ; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME="`(cd "$M2_HOME"; pwd)`"
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME="`(cd "$JAVA_HOME"; pwd)`"
+fi
+
+if [ -z "$JAVA_HOME" ]; then
+  javaExecutable="`which javac`"
+  if [ -n "$javaExecutable" ] && ! [ "`expr \"$javaExecutable\" : '\([^ ]*\)'`" = "no" ]; then
+    # readlink(1) is not available as standard on Solaris 10.
+    readLink=`which readlink`
+    if [ ! `expr "$readLink" : '\([^ ]*\)'` = "no" ]; then
+      if $darwin ; then
+        javaHome="`dirname \"$javaExecutable\"`"
+        javaExecutable="`cd \"$javaHome\" && pwd -P`/javac"
+      else
+        javaExecutable="`readlink -f \"$javaExecutable\"`"
+      fi
+      javaHome="`dirname \"$javaExecutable\"`"
+      javaHome=`expr "$javaHome" : '\(.*\)/bin'`
+      JAVA_HOME="$javaHome"
+      export JAVA_HOME
+    fi
+  fi
+fi
+
+if [ -z "$JAVACMD" ] ; then
+  if [ -n "$JAVA_HOME"  ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+      # IBM's JDK on AIX uses strange locations for the executables
+      JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+      JAVACMD="$JAVA_HOME/bin/java"
+    fi
+  else
+    JAVACMD="`which java`"
+  fi
+fi
+
+if [ ! -x "$JAVACMD" ] ; then
+  echo "Error: JAVA_HOME is not defined correctly." >&2
+  echo "  We cannot execute $JAVACMD" >&2
+  exit 1
+fi
+
+if [ -z "$JAVA_HOME" ] ; then
+  echo "Warning: JAVA_HOME environment variable is not set."
+fi
+
+CLASSWORLDS_LAUNCHER=org.codehaus.plexus.classworlds.launcher.Launcher
+
+# traverses directory structure from process work directory to filesystem root
+# first directory with .mvn subdirectory is considered project base directory
+find_maven_basedir() {
+
+  if [ -z "$1" ]
+  then
+    echo "Path not specified to find_maven_basedir"
+    return 1
+  fi
+
+  basedir="$1"
+  wdir="$1"
+  while [ "$wdir" != '/' ] ; do
+    if [ -d "$wdir"/.mvn ] ; then
+      basedir=$wdir
+      break
+    fi
+    # workaround for JBEAP-8937 (on Solaris 10/Sparc)
+    if [ -d "${wdir}" ]; then
+      wdir=`cd "$wdir/.."; pwd`
+    fi
+    # end of workaround
+  done
+  echo "${basedir}"
+}
+
+# concatenates all lines of a file
+concat_lines() {
+  if [ -f "$1" ]; then
+    echo "$(tr -s '\n' ' ' < "$1")"
+  fi
+}
+
+BASE_DIR=`find_maven_basedir "$(pwd)"`
+if [ -z "$BASE_DIR" ]; then
+  exit 1;
+fi
+
+##########################################################################################
+# Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+# This allows using the maven wrapper in projects that prohibit checking in binary data.
+##########################################################################################
+if [ -r "$BASE_DIR/.mvn/wrapper/maven-wrapper.jar" ]; then
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Found .mvn/wrapper/maven-wrapper.jar"
+    fi
+else
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Couldn't find .mvn/wrapper/maven-wrapper.jar, downloading it ..."
+    fi
+    if [ -n "$MVNW_REPOURL" ]; then
+      jarUrl="$MVNW_REPOURL/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+    else
+      jarUrl="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+    fi
+    while IFS="=" read key value; do
+      case "$key" in (wrapperUrl) jarUrl="$value"; break ;;
+      esac
+    done < "$BASE_DIR/.mvn/wrapper/maven-wrapper.properties"
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Downloading from: $jarUrl"
+    fi
+    wrapperJarPath="$BASE_DIR/.mvn/wrapper/maven-wrapper.jar"
+    if $cygwin; then
+      wrapperJarPath=`cygpath --path --windows "$wrapperJarPath"`
+    fi
+
+    if command -v wget > /dev/null; then
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo "Found wget ... using wget"
+        fi
+        if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+            wget "$jarUrl" -O "$wrapperJarPath"
+        else
+            wget --http-user=$MVNW_USERNAME --http-password=$MVNW_PASSWORD "$jarUrl" -O "$wrapperJarPath"
+        fi
+    elif command -v curl > /dev/null; then
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo "Found curl ... using curl"
+        fi
+        if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+            curl -o "$wrapperJarPath" "$jarUrl" -f
+        else
+            curl --user $MVNW_USERNAME:$MVNW_PASSWORD -o "$wrapperJarPath" "$jarUrl" -f
+        fi
+
+    else
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo "Falling back to using Java to download"
+        fi
+        javaClass="$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.java"
+        # For Cygwin, switch paths to Windows format before running javac
+        if $cygwin; then
+          javaClass=`cygpath --path --windows "$javaClass"`
+        fi
+        if [ -e "$javaClass" ]; then
+            if [ ! -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+                if [ "$MVNW_VERBOSE" = true ]; then
+                  echo " - Compiling MavenWrapperDownloader.java ..."
+                fi
+                # Compiling the Java class
+                ("$JAVA_HOME/bin/javac" "$javaClass")
+            fi
+            if [ -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+                # Running the downloader
+                if [ "$MVNW_VERBOSE" = true ]; then
+                  echo " - Running MavenWrapperDownloader.java ..."
+                fi
+                ("$JAVA_HOME/bin/java" -cp .mvn/wrapper MavenWrapperDownloader "$MAVEN_PROJECTBASEDIR")
+            fi
+        fi
+    fi
+fi
+##########################################################################################
+# End of extension
+##########################################################################################
+
+export MAVEN_PROJECTBASEDIR=${MAVEN_BASEDIR:-"$BASE_DIR"}
+if [ "$MVNW_VERBOSE" = true ]; then
+  echo $MAVEN_PROJECTBASEDIR
+fi
+MAVEN_OPTS="$(concat_lines "$MAVEN_PROJECTBASEDIR/.mvn/jvm.config") $MAVEN_OPTS"
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME=`cygpath --path --windows "$M2_HOME"`
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME=`cygpath --path --windows "$JAVA_HOME"`
+  [ -n "$CLASSPATH" ] &&
+    CLASSPATH=`cygpath --path --windows "$CLASSPATH"`
+  [ -n "$MAVEN_PROJECTBASEDIR" ] &&
+    MAVEN_PROJECTBASEDIR=`cygpath --path --windows "$MAVEN_PROJECTBASEDIR"`
+fi
+
+# Provide a "standardized" way to retrieve the CLI args that will
+# work with both Windows and non-Windows executions.
+MAVEN_CMD_LINE_ARGS="$MAVEN_CONFIG $@"
+export MAVEN_CMD_LINE_ARGS
+
+WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+exec "$JAVACMD" \
+  $MAVEN_OPTS \
+  -classpath "$MAVEN_PROJECTBASEDIR/.mvn/wrapper/maven-wrapper.jar" \
+  "-Dmaven.home=${M2_HOME}" "-Dmaven.multiModuleProjectDirectory=${MAVEN_PROJECTBASEDIR}" \
+  ${WRAPPER_LAUNCHER} $MAVEN_CONFIG "$@"

core-java/versions/src/main/java/com/reflectoring/io/java9/modules/hellos/mvnw.cmd

@@ -0,0 +1,182 @@
+@REM ----------------------------------------------------------------------------
+@REM Licensed to the Apache Software Foundation (ASF) under one
+@REM or more contributor license agreements.  See the NOTICE file
+@REM distributed with this work for additional information
+@REM regarding copyright ownership.  The ASF licenses this file
+@REM to you under the Apache License, Version 2.0 (the
+@REM "License"); you may not use this file except in compliance
+@REM with the License.  You may obtain a copy of the License at
+@REM
+@REM    https://www.apache.org/licenses/LICENSE-2.0
+@REM
+@REM Unless required by applicable law or agreed to in writing,
+@REM software distributed under the License is distributed on an
+@REM "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+@REM KIND, either express or implied.  See the License for the
+@REM specific language governing permissions and limitations
+@REM under the License.
+@REM ----------------------------------------------------------------------------
+
+@REM ----------------------------------------------------------------------------
+@REM Maven Start Up Batch script
+@REM
+@REM Required ENV vars:
+@REM JAVA_HOME - location of a JDK home dir
+@REM
+@REM Optional ENV vars
+@REM M2_HOME - location of maven2's installed home dir
+@REM MAVEN_BATCH_ECHO - set to 'on' to enable the echoing of the batch commands
+@REM MAVEN_BATCH_PAUSE - set to 'on' to wait for a keystroke before ending
+@REM MAVEN_OPTS - parameters passed to the Java VM when running Maven
+@REM     e.g. to debug Maven itself, use
+@REM set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+@REM MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+@REM ----------------------------------------------------------------------------
+
+@REM Begin all REM lines with '@' in case MAVEN_BATCH_ECHO is 'on'
+@echo off
+@REM set title of command window
+title %0
+@REM enable echoing by setting MAVEN_BATCH_ECHO to 'on'
+@if "%MAVEN_BATCH_ECHO%" == "on"  echo %MAVEN_BATCH_ECHO%
+
+@REM set %HOME% to equivalent of $HOME
+if "%HOME%" == "" (set "HOME=%HOMEDRIVE%%HOMEPATH%")
+
+@REM Execute a user defined script before this one
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPre
+@REM check for pre script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_pre.bat" call "%HOME%\mavenrc_pre.bat"
+if exist "%HOME%\mavenrc_pre.cmd" call "%HOME%\mavenrc_pre.cmd"
+:skipRcPre
+
+@setlocal
+
+set ERROR_CODE=0
+
+@REM To isolate internal variables from possible post scripts, we use another setlocal
+@setlocal
+
+@REM ==== START VALIDATION ====
+if not "%JAVA_HOME%" == "" goto OkJHome
+
+echo.
+echo Error: JAVA_HOME not found in your environment. >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+:OkJHome
+if exist "%JAVA_HOME%\bin\java.exe" goto init
+
+echo.
+echo Error: JAVA_HOME is set to an invalid directory. >&2
+echo JAVA_HOME = "%JAVA_HOME%" >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+@REM ==== END VALIDATION ====
+
+:init
+
+@REM Find the project base dir, i.e. the directory that contains the folder ".mvn".
+@REM Fallback to current working directory if not found.
+
+set MAVEN_PROJECTBASEDIR=%MAVEN_BASEDIR%
+IF NOT "%MAVEN_PROJECTBASEDIR%"=="" goto endDetectBaseDir
+
+set EXEC_DIR=%CD%
+set WDIR=%EXEC_DIR%
+:findBaseDir
+IF EXIST "%WDIR%"\.mvn goto baseDirFound
+cd ..
+IF "%WDIR%"=="%CD%" goto baseDirNotFound
+set WDIR=%CD%
+goto findBaseDir
+
+:baseDirFound
+set MAVEN_PROJECTBASEDIR=%WDIR%
+cd "%EXEC_DIR%"
+goto endDetectBaseDir
+
+:baseDirNotFound
+set MAVEN_PROJECTBASEDIR=%EXEC_DIR%
+cd "%EXEC_DIR%"
+
+:endDetectBaseDir
+
+IF NOT EXIST "%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config" goto endReadAdditionalConfig
+
+@setlocal EnableExtensions EnableDelayedExpansion
+for /F "usebackq delims=" %%a in ("%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config") do set JVM_CONFIG_MAVEN_PROPS=!JVM_CONFIG_MAVEN_PROPS! %%a
+@endlocal & set JVM_CONFIG_MAVEN_PROPS=%JVM_CONFIG_MAVEN_PROPS%
+
+:endReadAdditionalConfig
+
+SET MAVEN_JAVA_EXE="%JAVA_HOME%\bin\java.exe"
+set WRAPPER_JAR="%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.jar"
+set WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+set DOWNLOAD_URL="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+
+FOR /F "tokens=1,2 delims==" %%A IN ("%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.properties") DO (
+    IF "%%A"=="wrapperUrl" SET DOWNLOAD_URL=%%B
+)
+
+@REM Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+@REM This allows using the maven wrapper in projects that prohibit checking in binary data.
+if exist %WRAPPER_JAR% (
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Found %WRAPPER_JAR%
+    )
+) else (
+    if not "%MVNW_REPOURL%" == "" (
+        SET DOWNLOAD_URL="%MVNW_REPOURL%/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+    )
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Couldn't find %WRAPPER_JAR%, downloading it ...
+        echo Downloading from: %DOWNLOAD_URL%
+    )
+
+    powershell -Command "&{"^
+		"$webclient = new-object System.Net.WebClient;"^
+		"if (-not ([string]::IsNullOrEmpty('%MVNW_USERNAME%') -and [string]::IsNullOrEmpty('%MVNW_PASSWORD%'))) {"^
+		"$webclient.Credentials = new-object System.Net.NetworkCredential('%MVNW_USERNAME%', '%MVNW_PASSWORD%');"^
+		"}"^
+		"[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; $webclient.DownloadFile('%DOWNLOAD_URL%', '%WRAPPER_JAR%')"^
+		"}"
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Finished downloading %WRAPPER_JAR%
+    )
+)
+@REM End of extension
+
+@REM Provide a "standardized" way to retrieve the CLI args that will
+@REM work with both Windows and non-Windows executions.
+set MAVEN_CMD_LINE_ARGS=%*
+
+%MAVEN_JAVA_EXE% %JVM_CONFIG_MAVEN_PROPS% %MAVEN_OPTS% %MAVEN_DEBUG_OPTS% -classpath %WRAPPER_JAR% "-Dmaven.multiModuleProjectDirectory=%MAVEN_PROJECTBASEDIR%" %WRAPPER_LAUNCHER% %MAVEN_CONFIG% %*
+if ERRORLEVEL 1 goto error
+goto end
+
+:error
+set ERROR_CODE=1
+
+:end
+@endlocal & set ERROR_CODE=%ERROR_CODE%
+
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPost
+@REM check for post script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_post.bat" call "%HOME%\mavenrc_post.bat"
+if exist "%HOME%\mavenrc_post.cmd" call "%HOME%\mavenrc_post.cmd"
+:skipRcPost
+
+@REM pause the script if MAVEN_BATCH_PAUSE is set to 'on'
+if "%MAVEN_BATCH_PAUSE%" == "on" pause
+
+if "%MAVEN_TERMINATE_CMD%" == "on" exit %ERROR_CODE%
+
+exit /B %ERROR_CODE%

core-java/versions/src/main/java/com/reflectoring/io/java9/modules/hellos/pom.xml

@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <artifactId>versions</artifactId>
+        <groupId>com.reflectoring.io</groupId>
+        <version>1.0-SNAPSHOT</version>
+        <relativePath>../../../../../../../../../pom.xml</relativePath>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>hello</artifactId>
+
+    <properties>
+        <java.version>17</java.version>
+        <maven.compiler.source>17</maven.compiler.source>
+        <maven.compiler.target>17</maven.compiler.target>
+    </properties>
+
+</project>

core-java/versions/src/main/java/com/reflectoring/io/java9/modules/hellos/src/main/java/com/reflectoring/io/hello/Hello.java

@@ -0,0 +1,10 @@
+package com.reflectoring.io.hello;
+
+//import com.reflectoring.io.world.World;
+
+public class Hello {
+    public static void main(String[] args) {
+        System.out.println("Hello ");
+        //World.print();
+    }
+}

core-java/versions/src/main/java/com/reflectoring/io/java9/modules/hellos/src/main/java/module-info.java

@@ -0,0 +1,3 @@
+module hello.module {
+    //requires world.module;
+}

core-java/versions/src/main/java/com/reflectoring/io/java9/modules/worlds/.mvn/wrapper/MavenWrapperDownloader.java

@@ -0,0 +1,117 @@
+/*
+ * Copyright 2007-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import java.net.*;
+import java.io.*;
+import java.nio.channels.*;
+import java.util.Properties;
+
+public class MavenWrapperDownloader {
+
+    private static final String WRAPPER_VERSION = "0.5.6";
+    /**
+     * Default URL to download the maven-wrapper.jar from, if no 'downloadUrl' is provided.
+     */
+    private static final String DEFAULT_DOWNLOAD_URL = "https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/"
+        + WRAPPER_VERSION + "/maven-wrapper-" + WRAPPER_VERSION + ".jar";
+
+    /**
+     * Path to the maven-wrapper.properties file, which might contain a downloadUrl property to
+     * use instead of the default one.
+     */
+    private static final String MAVEN_WRAPPER_PROPERTIES_PATH =
+            ".mvn/wrapper/maven-wrapper.properties";
+
+    /**
+     * Path where the maven-wrapper.jar will be saved to.
+     */
+    private static final String MAVEN_WRAPPER_JAR_PATH =
+            ".mvn/wrapper/maven-wrapper.jar";
+
+    /**
+     * Name of the property which should be used to override the default download url for the wrapper.
+     */
+    private static final String PROPERTY_NAME_WRAPPER_URL = "wrapperUrl";
+
+    public static void main(String args[]) {
+        System.out.println("- Downloader started");
+        File baseDirectory = new File(args[0]);
+        System.out.println("- Using base directory: " + baseDirectory.getAbsolutePath());
+
+        // If the maven-wrapper.properties exists, read it and check if it contains a custom
+        // wrapperUrl parameter.
+        File mavenWrapperPropertyFile = new File(baseDirectory, MAVEN_WRAPPER_PROPERTIES_PATH);
+        String url = DEFAULT_DOWNLOAD_URL;
+        if(mavenWrapperPropertyFile.exists()) {
+            FileInputStream mavenWrapperPropertyFileInputStream = null;
+            try {
+                mavenWrapperPropertyFileInputStream = new FileInputStream(mavenWrapperPropertyFile);
+                Properties mavenWrapperProperties = new Properties();
+                mavenWrapperProperties.load(mavenWrapperPropertyFileInputStream);
+                url = mavenWrapperProperties.getProperty(PROPERTY_NAME_WRAPPER_URL, url);
+            } catch (IOException e) {
+                System.out.println("- ERROR loading '" + MAVEN_WRAPPER_PROPERTIES_PATH + "'");
+            } finally {
+                try {
+                    if(mavenWrapperPropertyFileInputStream != null) {
+                        mavenWrapperPropertyFileInputStream.close();
+                    }
+                } catch (IOException e) {
+                    // Ignore ...
+                }
+            }
+        }
+        System.out.println("- Downloading from: " + url);
+
+        File outputFile = new File(baseDirectory.getAbsolutePath(), MAVEN_WRAPPER_JAR_PATH);
+        if(!outputFile.getParentFile().exists()) {
+            if(!outputFile.getParentFile().mkdirs()) {
+                System.out.println(
+                        "- ERROR creating output directory '" + outputFile.getParentFile().getAbsolutePath() + "'");
+            }
+        }
+        System.out.println("- Downloading to: " + outputFile.getAbsolutePath());
+        try {
+            downloadFileFromURL(url, outputFile);
+            System.out.println("Done");
+            System.exit(0);
+        } catch (Throwable e) {
+            System.out.println("- Error downloading");
+            e.printStackTrace();
+            System.exit(1);
+        }
+    }
+
+    private static void downloadFileFromURL(String urlString, File destination) throws Exception {
+        if (System.getenv("MVNW_USERNAME") != null && System.getenv("MVNW_PASSWORD") != null) {
+            String username = System.getenv("MVNW_USERNAME");
+            char[] password = System.getenv("MVNW_PASSWORD").toCharArray();
+            Authenticator.setDefault(new Authenticator() {
+                @Override
+                protected PasswordAuthentication getPasswordAuthentication() {
+                    return new PasswordAuthentication(username, password);
+                }
+            });
+        }
+        URL website = new URL(urlString);
+        ReadableByteChannel rbc;
+        rbc = Channels.newChannel(website.openStream());
+        FileOutputStream fos = new FileOutputStream(destination);
+        fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
+        fos.close();
+        rbc.close();
+    }
+
+}

core-java/versions/src/main/java/com/reflectoring/io/java9/modules/worlds/.mvn/wrapper/maven-wrapper.properties

@@ -0,0 +1,2 @@
+distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.6.3/apache-maven-3.6.3-bin.zip
+wrapperUrl=https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar

core-java/versions/src/main/java/com/reflectoring/io/java9/modules/worlds/mvnw

@@ -0,0 +1,310 @@
+#!/bin/sh
+# ----------------------------------------------------------------------------
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#    https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+# ----------------------------------------------------------------------------
+
+# ----------------------------------------------------------------------------
+# Maven Start Up Batch script
+#
+# Required ENV vars:
+# ------------------
+#   JAVA_HOME - location of a JDK home dir
+#
+# Optional ENV vars
+# -----------------
+#   M2_HOME - location of maven2's installed home dir
+#   MAVEN_OPTS - parameters passed to the Java VM when running Maven
+#     e.g. to debug Maven itself, use
+#       set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+#   MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+# ----------------------------------------------------------------------------
+
+if [ -z "$MAVEN_SKIP_RC" ] ; then
+
+  if [ -f /etc/mavenrc ] ; then
+    . /etc/mavenrc
+  fi
+
+  if [ -f "$HOME/.mavenrc" ] ; then
+    . "$HOME/.mavenrc"
+  fi
+
+fi
+
+# OS specific support.  $var _must_ be set to either true or false.
+cygwin=false;
+darwin=false;
+mingw=false
+case "`uname`" in
+  CYGWIN*) cygwin=true ;;
+  MINGW*) mingw=true;;
+  Darwin*) darwin=true
+    # Use /usr/libexec/java_home if available, otherwise fall back to /Library/Java/Home
+    # See https://developer.apple.com/library/mac/qa/qa1170/_index.html
+    if [ -z "$JAVA_HOME" ]; then
+      if [ -x "/usr/libexec/java_home" ]; then
+        export JAVA_HOME="`/usr/libexec/java_home`"
+      else
+        export JAVA_HOME="/Library/Java/Home"
+      fi
+    fi
+    ;;
+esac
+
+if [ -z "$JAVA_HOME" ] ; then
+  if [ -r /etc/gentoo-release ] ; then
+    JAVA_HOME=`java-config --jre-home`
+  fi
+fi
+
+if [ -z "$M2_HOME" ] ; then
+  ## resolve links - $0 may be a link to maven's home
+  PRG="$0"
+
+  # need this for relative symlinks
+  while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+      PRG="$link"
+    else
+      PRG="`dirname "$PRG"`/$link"
+    fi
+  done
+
+  saveddir=`pwd`
+
+  M2_HOME=`dirname "$PRG"`/..
+
+  # make it fully qualified
+  M2_HOME=`cd "$M2_HOME" && pwd`
+
+  cd "$saveddir"
+  # echo Using m2 at $M2_HOME
+fi
+
+# For Cygwin, ensure paths are in UNIX format before anything is touched
+if $cygwin ; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME=`cygpath --unix "$M2_HOME"`
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME=`cygpath --unix "$JAVA_HOME"`
+  [ -n "$CLASSPATH" ] &&
+    CLASSPATH=`cygpath --path --unix "$CLASSPATH"`
+fi
+
+# For Mingw, ensure paths are in UNIX format before anything is touched
+if $mingw ; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME="`(cd "$M2_HOME"; pwd)`"
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME="`(cd "$JAVA_HOME"; pwd)`"
+fi
+
+if [ -z "$JAVA_HOME" ]; then
+  javaExecutable="`which javac`"
+  if [ -n "$javaExecutable" ] && ! [ "`expr \"$javaExecutable\" : '\([^ ]*\)'`" = "no" ]; then
+    # readlink(1) is not available as standard on Solaris 10.
+    readLink=`which readlink`
+    if [ ! `expr "$readLink" : '\([^ ]*\)'` = "no" ]; then
+      if $darwin ; then
+        javaHome="`dirname \"$javaExecutable\"`"
+        javaExecutable="`cd \"$javaHome\" && pwd -P`/javac"
+      else
+        javaExecutable="`readlink -f \"$javaExecutable\"`"
+      fi
+      javaHome="`dirname \"$javaExecutable\"`"
+      javaHome=`expr "$javaHome" : '\(.*\)/bin'`
+      JAVA_HOME="$javaHome"
+      export JAVA_HOME
+    fi
+  fi
+fi
+
+if [ -z "$JAVACMD" ] ; then
+  if [ -n "$JAVA_HOME"  ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+      # IBM's JDK on AIX uses strange locations for the executables
+      JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+      JAVACMD="$JAVA_HOME/bin/java"
+    fi
+  else
+    JAVACMD="`which java`"
+  fi
+fi
+
+if [ ! -x "$JAVACMD" ] ; then
+  echo "Error: JAVA_HOME is not defined correctly." >&2
+  echo "  We cannot execute $JAVACMD" >&2
+  exit 1
+fi
+
+if [ -z "$JAVA_HOME" ] ; then
+  echo "Warning: JAVA_HOME environment variable is not set."
+fi
+
+CLASSWORLDS_LAUNCHER=org.codehaus.plexus.classworlds.launcher.Launcher
+
+# traverses directory structure from process work directory to filesystem root
+# first directory with .mvn subdirectory is considered project base directory
+find_maven_basedir() {
+
+  if [ -z "$1" ]
+  then
+    echo "Path not specified to find_maven_basedir"
+    return 1
+  fi
+
+  basedir="$1"
+  wdir="$1"
+  while [ "$wdir" != '/' ] ; do
+    if [ -d "$wdir"/.mvn ] ; then
+      basedir=$wdir
+      break
+    fi
+    # workaround for JBEAP-8937 (on Solaris 10/Sparc)
+    if [ -d "${wdir}" ]; then
+      wdir=`cd "$wdir/.."; pwd`
+    fi
+    # end of workaround
+  done
+  echo "${basedir}"
+}
+
+# concatenates all lines of a file
+concat_lines() {
+  if [ -f "$1" ]; then
+    echo "$(tr -s '\n' ' ' < "$1")"
+  fi
+}
+
+BASE_DIR=`find_maven_basedir "$(pwd)"`
+if [ -z "$BASE_DIR" ]; then
+  exit 1;
+fi
+
+##########################################################################################
+# Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+# This allows using the maven wrapper in projects that prohibit checking in binary data.
+##########################################################################################
+if [ -r "$BASE_DIR/.mvn/wrapper/maven-wrapper.jar" ]; then
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Found .mvn/wrapper/maven-wrapper.jar"
+    fi
+else
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Couldn't find .mvn/wrapper/maven-wrapper.jar, downloading it ..."
+    fi
+    if [ -n "$MVNW_REPOURL" ]; then
+      jarUrl="$MVNW_REPOURL/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+    else
+      jarUrl="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+    fi
+    while IFS="=" read key value; do
+      case "$key" in (wrapperUrl) jarUrl="$value"; break ;;
+      esac
+    done < "$BASE_DIR/.mvn/wrapper/maven-wrapper.properties"
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Downloading from: $jarUrl"
+    fi
+    wrapperJarPath="$BASE_DIR/.mvn/wrapper/maven-wrapper.jar"
+    if $cygwin; then
+      wrapperJarPath=`cygpath --path --windows "$wrapperJarPath"`
+    fi
+
+    if command -v wget > /dev/null; then
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo "Found wget ... using wget"
+        fi
+        if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+            wget "$jarUrl" -O "$wrapperJarPath"
+        else
+            wget --http-user=$MVNW_USERNAME --http-password=$MVNW_PASSWORD "$jarUrl" -O "$wrapperJarPath"
+        fi
+    elif command -v curl > /dev/null; then
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo "Found curl ... using curl"
+        fi
+        if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+            curl -o "$wrapperJarPath" "$jarUrl" -f
+        else
+            curl --user $MVNW_USERNAME:$MVNW_PASSWORD -o "$wrapperJarPath" "$jarUrl" -f
+        fi
+
+    else
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo "Falling back to using Java to download"
+        fi
+        javaClass="$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.java"
+        # For Cygwin, switch paths to Windows format before running javac
+        if $cygwin; then
+          javaClass=`cygpath --path --windows "$javaClass"`
+        fi
+        if [ -e "$javaClass" ]; then
+            if [ ! -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+                if [ "$MVNW_VERBOSE" = true ]; then
+                  echo " - Compiling MavenWrapperDownloader.java ..."
+                fi
+                # Compiling the Java class
+                ("$JAVA_HOME/bin/javac" "$javaClass")
+            fi
+            if [ -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+                # Running the downloader
+                if [ "$MVNW_VERBOSE" = true ]; then
+                  echo " - Running MavenWrapperDownloader.java ..."
+                fi
+                ("$JAVA_HOME/bin/java" -cp .mvn/wrapper MavenWrapperDownloader "$MAVEN_PROJECTBASEDIR")
+            fi
+        fi
+    fi
+fi
+##########################################################################################
+# End of extension
+##########################################################################################
+
+export MAVEN_PROJECTBASEDIR=${MAVEN_BASEDIR:-"$BASE_DIR"}
+if [ "$MVNW_VERBOSE" = true ]; then
+  echo $MAVEN_PROJECTBASEDIR
+fi
+MAVEN_OPTS="$(concat_lines "$MAVEN_PROJECTBASEDIR/.mvn/jvm.config") $MAVEN_OPTS"
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME=`cygpath --path --windows "$M2_HOME"`
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME=`cygpath --path --windows "$JAVA_HOME"`
+  [ -n "$CLASSPATH" ] &&
+    CLASSPATH=`cygpath --path --windows "$CLASSPATH"`
+  [ -n "$MAVEN_PROJECTBASEDIR" ] &&
+    MAVEN_PROJECTBASEDIR=`cygpath --path --windows "$MAVEN_PROJECTBASEDIR"`
+fi
+
+# Provide a "standardized" way to retrieve the CLI args that will
+# work with both Windows and non-Windows executions.
+MAVEN_CMD_LINE_ARGS="$MAVEN_CONFIG $@"
+export MAVEN_CMD_LINE_ARGS
+
+WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+exec "$JAVACMD" \
+  $MAVEN_OPTS \
+  -classpath "$MAVEN_PROJECTBASEDIR/.mvn/wrapper/maven-wrapper.jar" \
+  "-Dmaven.home=${M2_HOME}" "-Dmaven.multiModuleProjectDirectory=${MAVEN_PROJECTBASEDIR}" \
+  ${WRAPPER_LAUNCHER} $MAVEN_CONFIG "$@"

core-java/versions/src/main/java/com/reflectoring/io/java9/modules/worlds/mvnw.cmd

@@ -0,0 +1,182 @@
+@REM ----------------------------------------------------------------------------
+@REM Licensed to the Apache Software Foundation (ASF) under one
+@REM or more contributor license agreements.  See the NOTICE file
+@REM distributed with this work for additional information
+@REM regarding copyright ownership.  The ASF licenses this file
+@REM to you under the Apache License, Version 2.0 (the
+@REM "License"); you may not use this file except in compliance
+@REM with the License.  You may obtain a copy of the License at
+@REM
+@REM    https://www.apache.org/licenses/LICENSE-2.0
+@REM
+@REM Unless required by applicable law or agreed to in writing,
+@REM software distributed under the License is distributed on an
+@REM "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+@REM KIND, either express or implied.  See the License for the
+@REM specific language governing permissions and limitations
+@REM under the License.
+@REM ----------------------------------------------------------------------------
+
+@REM ----------------------------------------------------------------------------
+@REM Maven Start Up Batch script
+@REM
+@REM Required ENV vars:
+@REM JAVA_HOME - location of a JDK home dir
+@REM
+@REM Optional ENV vars
+@REM M2_HOME - location of maven2's installed home dir
+@REM MAVEN_BATCH_ECHO - set to 'on' to enable the echoing of the batch commands
+@REM MAVEN_BATCH_PAUSE - set to 'on' to wait for a keystroke before ending
+@REM MAVEN_OPTS - parameters passed to the Java VM when running Maven
+@REM     e.g. to debug Maven itself, use
+@REM set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+@REM MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+@REM ----------------------------------------------------------------------------
+
+@REM Begin all REM lines with '@' in case MAVEN_BATCH_ECHO is 'on'
+@echo off
+@REM set title of command window
+title %0
+@REM enable echoing by setting MAVEN_BATCH_ECHO to 'on'
+@if "%MAVEN_BATCH_ECHO%" == "on"  echo %MAVEN_BATCH_ECHO%
+
+@REM set %HOME% to equivalent of $HOME
+if "%HOME%" == "" (set "HOME=%HOMEDRIVE%%HOMEPATH%")
+
+@REM Execute a user defined script before this one
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPre
+@REM check for pre script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_pre.bat" call "%HOME%\mavenrc_pre.bat"
+if exist "%HOME%\mavenrc_pre.cmd" call "%HOME%\mavenrc_pre.cmd"
+:skipRcPre
+
+@setlocal
+
+set ERROR_CODE=0
+
+@REM To isolate internal variables from possible post scripts, we use another setlocal
+@setlocal
+
+@REM ==== START VALIDATION ====
+if not "%JAVA_HOME%" == "" goto OkJHome
+
+echo.
+echo Error: JAVA_HOME not found in your environment. >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+:OkJHome
+if exist "%JAVA_HOME%\bin\java.exe" goto init
+
+echo.
+echo Error: JAVA_HOME is set to an invalid directory. >&2
+echo JAVA_HOME = "%JAVA_HOME%" >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+@REM ==== END VALIDATION ====
+
+:init
+
+@REM Find the project base dir, i.e. the directory that contains the folder ".mvn".
+@REM Fallback to current working directory if not found.
+
+set MAVEN_PROJECTBASEDIR=%MAVEN_BASEDIR%
+IF NOT "%MAVEN_PROJECTBASEDIR%"=="" goto endDetectBaseDir
+
+set EXEC_DIR=%CD%
+set WDIR=%EXEC_DIR%
+:findBaseDir
+IF EXIST "%WDIR%"\.mvn goto baseDirFound
+cd ..
+IF "%WDIR%"=="%CD%" goto baseDirNotFound
+set WDIR=%CD%
+goto findBaseDir
+
+:baseDirFound
+set MAVEN_PROJECTBASEDIR=%WDIR%
+cd "%EXEC_DIR%"
+goto endDetectBaseDir
+
+:baseDirNotFound
+set MAVEN_PROJECTBASEDIR=%EXEC_DIR%
+cd "%EXEC_DIR%"
+
+:endDetectBaseDir
+
+IF NOT EXIST "%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config" goto endReadAdditionalConfig
+
+@setlocal EnableExtensions EnableDelayedExpansion
+for /F "usebackq delims=" %%a in ("%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config") do set JVM_CONFIG_MAVEN_PROPS=!JVM_CONFIG_MAVEN_PROPS! %%a
+@endlocal & set JVM_CONFIG_MAVEN_PROPS=%JVM_CONFIG_MAVEN_PROPS%
+
+:endReadAdditionalConfig
+
+SET MAVEN_JAVA_EXE="%JAVA_HOME%\bin\java.exe"
+set WRAPPER_JAR="%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.jar"
+set WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+set DOWNLOAD_URL="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+
+FOR /F "tokens=1,2 delims==" %%A IN ("%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.properties") DO (
+    IF "%%A"=="wrapperUrl" SET DOWNLOAD_URL=%%B
+)
+
+@REM Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+@REM This allows using the maven wrapper in projects that prohibit checking in binary data.
+if exist %WRAPPER_JAR% (
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Found %WRAPPER_JAR%
+    )
+) else (
+    if not "%MVNW_REPOURL%" == "" (
+        SET DOWNLOAD_URL="%MVNW_REPOURL%/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+    )
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Couldn't find %WRAPPER_JAR%, downloading it ...
+        echo Downloading from: %DOWNLOAD_URL%
+    )
+
+    powershell -Command "&{"^
+		"$webclient = new-object System.Net.WebClient;"^
+		"if (-not ([string]::IsNullOrEmpty('%MVNW_USERNAME%') -and [string]::IsNullOrEmpty('%MVNW_PASSWORD%'))) {"^
+		"$webclient.Credentials = new-object System.Net.NetworkCredential('%MVNW_USERNAME%', '%MVNW_PASSWORD%');"^
+		"}"^
+		"[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; $webclient.DownloadFile('%DOWNLOAD_URL%', '%WRAPPER_JAR%')"^
+		"}"
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Finished downloading %WRAPPER_JAR%
+    )
+)
+@REM End of extension
+
+@REM Provide a "standardized" way to retrieve the CLI args that will
+@REM work with both Windows and non-Windows executions.
+set MAVEN_CMD_LINE_ARGS=%*
+
+%MAVEN_JAVA_EXE% %JVM_CONFIG_MAVEN_PROPS% %MAVEN_OPTS% %MAVEN_DEBUG_OPTS% -classpath %WRAPPER_JAR% "-Dmaven.multiModuleProjectDirectory=%MAVEN_PROJECTBASEDIR%" %WRAPPER_LAUNCHER% %MAVEN_CONFIG% %*
+if ERRORLEVEL 1 goto error
+goto end
+
+:error
+set ERROR_CODE=1
+
+:end
+@endlocal & set ERROR_CODE=%ERROR_CODE%
+
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPost
+@REM check for post script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_post.bat" call "%HOME%\mavenrc_post.bat"
+if exist "%HOME%\mavenrc_post.cmd" call "%HOME%\mavenrc_post.cmd"
+:skipRcPost
+
+@REM pause the script if MAVEN_BATCH_PAUSE is set to 'on'
+if "%MAVEN_BATCH_PAUSE%" == "on" pause
+
+if "%MAVEN_TERMINATE_CMD%" == "on" exit %ERROR_CODE%
+
+exit /B %ERROR_CODE%

core-java/versions/src/main/java/com/reflectoring/io/java9/modules/worlds/pom.xml

@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <artifactId>versions</artifactId>
+        <groupId>com.reflectoring.io</groupId>
+        <version>1.0-SNAPSHOT</version>
+        <relativePath>../../../../../../../../../pom.xml</relativePath>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>world</artifactId>
+
+    <properties>
+        <java.version>17</java.version>
+        <maven.compiler.source>17</maven.compiler.source>
+        <maven.compiler.target>17</maven.compiler.target>
+    </properties>
+
+</project>

core-java/versions/src/main/java/com/reflectoring/io/java9/modules/worlds/src/main/java/com/reflectoring/io/world/World.java

@@ -0,0 +1,7 @@
+package com.reflectoring.io.world;
+
+public class World {
+    public static void print() {
+        System.out.println(" com.reflectoring.io.world.World!");
+    }
+}

core-java/versions/src/main/java/com/reflectoring/io/java9/modules/worlds/src/main/java/module-info.java

@@ -0,0 +1,3 @@
+module world.module {
+    exports com.reflectoring.io.world;
+}

core-java/versions/src/main/resources/names.txt

@@ -0,0 +1,8 @@
+John
+Martin
+Roland
+Cuthbert
+Alain
+Susan
+Rhea
+Sheemy

core-java/versions/src/main/resources/try-with-resources.txt

@@ -0,0 +1,3 @@
+First line
+Second line
+Third line

http-clients/.mvn/wrapper/MavenWrapperDownloader.java

@@ -0,0 +1,117 @@
+/*
+ * Copyright 2007-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import java.net.*;
+import java.io.*;
+import java.nio.channels.*;
+import java.util.Properties;
+
+public class MavenWrapperDownloader {
+
+    private static final String WRAPPER_VERSION = "0.5.6";
+    /**
+     * Default URL to download the maven-wrapper.jar from, if no 'downloadUrl' is provided.
+     */
+    private static final String DEFAULT_DOWNLOAD_URL = "https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/"
+        + WRAPPER_VERSION + "/maven-wrapper-" + WRAPPER_VERSION + ".jar";
+
+    /**
+     * Path to the maven-wrapper.properties file, which might contain a downloadUrl property to
+     * use instead of the default one.
+     */
+    private static final String MAVEN_WRAPPER_PROPERTIES_PATH =
+            ".mvn/wrapper/maven-wrapper.properties";
+
+    /**
+     * Path where the maven-wrapper.jar will be saved to.
+     */
+    private static final String MAVEN_WRAPPER_JAR_PATH =
+            ".mvn/wrapper/maven-wrapper.jar";
+
+    /**
+     * Name of the property which should be used to override the default download url for the wrapper.
+     */
+    private static final String PROPERTY_NAME_WRAPPER_URL = "wrapperUrl";
+
+    public static void main(String args[]) {
+        System.out.println("- Downloader started");
+        File baseDirectory = new File(args[0]);
+        System.out.println("- Using base directory: " + baseDirectory.getAbsolutePath());
+
+        // If the maven-wrapper.properties exists, read it and check if it contains a custom
+        // wrapperUrl parameter.
+        File mavenWrapperPropertyFile = new File(baseDirectory, MAVEN_WRAPPER_PROPERTIES_PATH);
+        String url = DEFAULT_DOWNLOAD_URL;
+        if(mavenWrapperPropertyFile.exists()) {
+            FileInputStream mavenWrapperPropertyFileInputStream = null;
+            try {
+                mavenWrapperPropertyFileInputStream = new FileInputStream(mavenWrapperPropertyFile);
+                Properties mavenWrapperProperties = new Properties();
+                mavenWrapperProperties.load(mavenWrapperPropertyFileInputStream);
+                url = mavenWrapperProperties.getProperty(PROPERTY_NAME_WRAPPER_URL, url);
+            } catch (IOException e) {
+                System.out.println("- ERROR loading '" + MAVEN_WRAPPER_PROPERTIES_PATH + "'");
+            } finally {
+                try {
+                    if(mavenWrapperPropertyFileInputStream != null) {
+                        mavenWrapperPropertyFileInputStream.close();
+                    }
+                } catch (IOException e) {
+                    // Ignore ...
+                }
+            }
+        }
+        System.out.println("- Downloading from: " + url);
+
+        File outputFile = new File(baseDirectory.getAbsolutePath(), MAVEN_WRAPPER_JAR_PATH);
+        if(!outputFile.getParentFile().exists()) {
+            if(!outputFile.getParentFile().mkdirs()) {
+                System.out.println(
+                        "- ERROR creating output directory '" + outputFile.getParentFile().getAbsolutePath() + "'");
+            }
+        }
+        System.out.println("- Downloading to: " + outputFile.getAbsolutePath());
+        try {
+            downloadFileFromURL(url, outputFile);
+            System.out.println("Done");
+            System.exit(0);
+        } catch (Throwable e) {
+            System.out.println("- Error downloading");
+            e.printStackTrace();
+            System.exit(1);
+        }
+    }
+
+    private static void downloadFileFromURL(String urlString, File destination) throws Exception {
+        if (System.getenv("MVNW_USERNAME") != null && System.getenv("MVNW_PASSWORD") != null) {
+            String username = System.getenv("MVNW_USERNAME");
+            char[] password = System.getenv("MVNW_PASSWORD").toCharArray();
+            Authenticator.setDefault(new Authenticator() {
+                @Override
+                protected PasswordAuthentication getPasswordAuthentication() {
+                    return new PasswordAuthentication(username, password);
+                }
+            });
+        }
+        URL website = new URL(urlString);
+        ReadableByteChannel rbc;
+        rbc = Channels.newChannel(website.openStream());
+        FileOutputStream fos = new FileOutputStream(destination);
+        fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
+        fos.close();
+        rbc.close();
+    }
+
+}

http-clients/.mvn/wrapper/maven-wrapper.properties

@@ -0,0 +1,2 @@
+distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.6.3/apache-maven-3.6.3-bin.zip
+wrapperUrl=https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar

http-clients/README.md

@@ -0,0 +1,3 @@
+# Related Blog Posts
+
+* [Comparison of Java HTTP Clients](https://reflectoring.io/comparison-of-java-http-clients/)

http-clients/mvnw

@@ -0,0 +1,310 @@
+#!/bin/sh
+# ----------------------------------------------------------------------------
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+# ----------------------------------------------------------------------------
+
+# ----------------------------------------------------------------------------
+# Maven Start Up Batch script
+#
+# Required ENV vars:
+# ------------------
+#   JAVA_HOME - location of a JDK home dir
+#
+# Optional ENV vars
+# -----------------
+#   M2_HOME - location of maven2's installed home dir
+#   MAVEN_OPTS - parameters passed to the Java VM when running Maven
+#     e.g. to debug Maven itself, use
+#       set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+#   MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+# ----------------------------------------------------------------------------
+
+if [ -z "$MAVEN_SKIP_RC" ] ; then
+
+  if [ -f /etc/mavenrc ] ; then
+    . /etc/mavenrc
+  fi
+
+  if [ -f "$HOME/.mavenrc" ] ; then
+    . "$HOME/.mavenrc"
+  fi
+
+fi
+
+# OS specific support.  $var _must_ be set to either true or false.
+cygwin=false;
+darwin=false;
+mingw=false
+case "`uname`" in
+  CYGWIN*) cygwin=true ;;
+  MINGW*) mingw=true;;
+  Darwin*) darwin=true
+    # Use /usr/libexec/java_home if available, otherwise fall back to /Library/Java/Home
+    # See https://developer.apple.com/library/mac/qa/qa1170/_index.html
+    if [ -z "$JAVA_HOME" ]; then
+      if [ -x "/usr/libexec/java_home" ]; then
+        export JAVA_HOME="`/usr/libexec/java_home`"
+      else
+        export JAVA_HOME="/Library/Java/Home"
+      fi
+    fi
+    ;;
+esac
+
+if [ -z "$JAVA_HOME" ] ; then
+  if [ -r /etc/gentoo-release ] ; then
+    JAVA_HOME=`java-config --jre-home`
+  fi
+fi
+
+if [ -z "$M2_HOME" ] ; then
+  ## resolve links - $0 may be a link to maven's home
+  PRG="$0"
+
+  # need this for relative symlinks
+  while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+      PRG="$link"
+    else
+      PRG="`dirname "$PRG"`/$link"
+    fi
+  done
+
+  saveddir=`pwd`
+
+  M2_HOME=`dirname "$PRG"`/..
+
+  # make it fully qualified
+  M2_HOME=`cd "$M2_HOME" && pwd`
+
+  cd "$saveddir"
+  # echo Using m2 at $M2_HOME
+fi
+
+# For Cygwin, ensure paths are in UNIX format before anything is touched
+if $cygwin ; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME=`cygpath --unix "$M2_HOME"`
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME=`cygpath --unix "$JAVA_HOME"`
+  [ -n "$CLASSPATH" ] &&
+    CLASSPATH=`cygpath --path --unix "$CLASSPATH"`
+fi
+
+# For Mingw, ensure paths are in UNIX format before anything is touched
+if $mingw ; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME="`(cd "$M2_HOME"; pwd)`"
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME="`(cd "$JAVA_HOME"; pwd)`"
+fi
+
+if [ -z "$JAVA_HOME" ]; then
+  javaExecutable="`which javac`"
+  if [ -n "$javaExecutable" ] && ! [ "`expr \"$javaExecutable\" : '\([^ ]*\)'`" = "no" ]; then
+    # readlink(1) is not available as standard on Solaris 10.
+    readLink=`which readlink`
+    if [ ! `expr "$readLink" : '\([^ ]*\)'` = "no" ]; then
+      if $darwin ; then
+        javaHome="`dirname \"$javaExecutable\"`"
+        javaExecutable="`cd \"$javaHome\" && pwd -P`/javac"
+      else
+        javaExecutable="`readlink -f \"$javaExecutable\"`"
+      fi
+      javaHome="`dirname \"$javaExecutable\"`"
+      javaHome=`expr "$javaHome" : '\(.*\)/bin'`
+      JAVA_HOME="$javaHome"
+      export JAVA_HOME
+    fi
+  fi
+fi
+
+if [ -z "$JAVACMD" ] ; then
+  if [ -n "$JAVA_HOME"  ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+      # IBM's JDK on AIX uses strange locations for the executables
+      JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+      JAVACMD="$JAVA_HOME/bin/java"
+    fi
+  else
+    JAVACMD="`which java`"
+  fi
+fi
+
+if [ ! -x "$JAVACMD" ] ; then
+  echo "Error: JAVA_HOME is not defined correctly." >&2
+  echo "  We cannot execute $JAVACMD" >&2
+  exit 1
+fi
+
+if [ -z "$JAVA_HOME" ] ; then
+  echo "Warning: JAVA_HOME environment variable is not set."
+fi
+
+CLASSWORLDS_LAUNCHER=org.codehaus.plexus.classworlds.launcher.Launcher
+
+# traverses directory structure from process work directory to filesystem root
+# first directory with .mvn subdirectory is considered project base directory
+find_maven_basedir() {
+
+  if [ -z "$1" ]
+  then
+    echo "Path not specified to find_maven_basedir"
+    return 1
+  fi
+
+  basedir="$1"
+  wdir="$1"
+  while [ "$wdir" != '/' ] ; do
+    if [ -d "$wdir"/.mvn ] ; then
+      basedir=$wdir
+      break
+    fi
+    # workaround for JBEAP-8937 (on Solaris 10/Sparc)
+    if [ -d "${wdir}" ]; then
+      wdir=`cd "$wdir/.."; pwd`
+    fi
+    # end of workaround
+  done
+  echo "${basedir}"
+}
+
+# concatenates all lines of a file
+concat_lines() {
+  if [ -f "$1" ]; then
+    echo "$(tr -s '\n' ' ' < "$1")"
+  fi
+}
+
+BASE_DIR=`find_maven_basedir "$(pwd)"`
+if [ -z "$BASE_DIR" ]; then
+  exit 1;
+fi
+
+##########################################################################################
+# Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+# This allows using the maven wrapper in projects that prohibit checking in binary data.
+##########################################################################################
+if [ -r "$BASE_DIR/.mvn/wrapper/maven-wrapper.jar" ]; then
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Found .mvn/wrapper/maven-wrapper.jar"
+    fi
+else
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Couldn't find .mvn/wrapper/maven-wrapper.jar, downloading it ..."
+    fi
+    if [ -n "$MVNW_REPOURL" ]; then
+      jarUrl="$MVNW_REPOURL/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+    else
+      jarUrl="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+    fi
+    while IFS="=" read key value; do
+      case "$key" in (wrapperUrl) jarUrl="$value"; break ;;
+      esac
+    done < "$BASE_DIR/.mvn/wrapper/maven-wrapper.properties"
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Downloading from: $jarUrl"
+    fi
+    wrapperJarPath="$BASE_DIR/.mvn/wrapper/maven-wrapper.jar"
+    if $cygwin; then
+      wrapperJarPath=`cygpath --path --windows "$wrapperJarPath"`
+    fi
+
+    if command -v wget > /dev/null; then
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo "Found wget ... using wget"
+        fi
+        if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+            wget "$jarUrl" -O "$wrapperJarPath"
+        else
+            wget --http-user=$MVNW_USERNAME --http-password=$MVNW_PASSWORD "$jarUrl" -O "$wrapperJarPath"
+        fi
+    elif command -v curl > /dev/null; then
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo "Found curl ... using curl"
+        fi
+        if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+            curl -o "$wrapperJarPath" "$jarUrl" -f
+        else
+            curl --user $MVNW_USERNAME:$MVNW_PASSWORD -o "$wrapperJarPath" "$jarUrl" -f
+        fi
+
+    else
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo "Falling back to using Java to download"
+        fi
+        javaClass="$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.java"
+        # For Cygwin, switch paths to Windows format before running javac
+        if $cygwin; then
+          javaClass=`cygpath --path --windows "$javaClass"`
+        fi
+        if [ -e "$javaClass" ]; then
+            if [ ! -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+                if [ "$MVNW_VERBOSE" = true ]; then
+                  echo " - Compiling MavenWrapperDownloader.java ..."
+                fi
+                # Compiling the Java class
+                ("$JAVA_HOME/bin/javac" "$javaClass")
+            fi
+            if [ -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+                # Running the downloader
+                if [ "$MVNW_VERBOSE" = true ]; then
+                  echo " - Running MavenWrapperDownloader.java ..."
+                fi
+                ("$JAVA_HOME/bin/java" -cp .mvn/wrapper MavenWrapperDownloader "$MAVEN_PROJECTBASEDIR")
+            fi
+        fi
+    fi
+fi
+##########################################################################################
+# End of extension
+##########################################################################################
+
+export MAVEN_PROJECTBASEDIR=${MAVEN_BASEDIR:-"$BASE_DIR"}
+if [ "$MVNW_VERBOSE" = true ]; then
+  echo $MAVEN_PROJECTBASEDIR
+fi
+MAVEN_OPTS="$(concat_lines "$MAVEN_PROJECTBASEDIR/.mvn/jvm.config") $MAVEN_OPTS"
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME=`cygpath --path --windows "$M2_HOME"`
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME=`cygpath --path --windows "$JAVA_HOME"`
+  [ -n "$CLASSPATH" ] &&
+    CLASSPATH=`cygpath --path --windows "$CLASSPATH"`
+  [ -n "$MAVEN_PROJECTBASEDIR" ] &&
+    MAVEN_PROJECTBASEDIR=`cygpath --path --windows "$MAVEN_PROJECTBASEDIR"`
+fi
+
+# Provide a "standardized" way to retrieve the CLI args that will
+# work with both Windows and non-Windows executions.
+MAVEN_CMD_LINE_ARGS="$MAVEN_CONFIG $@"
+export MAVEN_CMD_LINE_ARGS
+
+WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+exec "$JAVACMD" \
+  $MAVEN_OPTS \
+  -classpath "$MAVEN_PROJECTBASEDIR/.mvn/wrapper/maven-wrapper.jar" \
+  "-Dmaven.home=${M2_HOME}" "-Dmaven.multiModuleProjectDirectory=${MAVEN_PROJECTBASEDIR}" \
+  ${WRAPPER_LAUNCHER} $MAVEN_CONFIG "$@"

http-clients/mvnw.cmd

@@ -0,0 +1,182 @@
+@REM ----------------------------------------------------------------------------
+@REM Licensed to the Apache Software Foundation (ASF) under one
+@REM or more contributor license agreements.  See the NOTICE file
+@REM distributed with this work for additional information
+@REM regarding copyright ownership.  The ASF licenses this file
+@REM to you under the Apache License, Version 2.0 (the
+@REM "License"); you may not use this file except in compliance
+@REM with the License.  You may obtain a copy of the License at
+@REM
+@REM    http://www.apache.org/licenses/LICENSE-2.0
+@REM
+@REM Unless required by applicable law or agreed to in writing,
+@REM software distributed under the License is distributed on an
+@REM "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+@REM KIND, either express or implied.  See the License for the
+@REM specific language governing permissions and limitations
+@REM under the License.
+@REM ----------------------------------------------------------------------------
+
+@REM ----------------------------------------------------------------------------
+@REM Maven Start Up Batch script
+@REM
+@REM Required ENV vars:
+@REM JAVA_HOME - location of a JDK home dir
+@REM
+@REM Optional ENV vars
+@REM M2_HOME - location of maven2's installed home dir
+@REM MAVEN_BATCH_ECHO - set to 'on' to enable the echoing of the batch commands
+@REM MAVEN_BATCH_PAUSE - set to 'on' to wait for a keystroke before ending
+@REM MAVEN_OPTS - parameters passed to the Java VM when running Maven
+@REM     e.g. to debug Maven itself, use
+@REM set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+@REM MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+@REM ----------------------------------------------------------------------------
+
+@REM Begin all REM lines with '@' in case MAVEN_BATCH_ECHO is 'on'
+@echo off
+@REM set title of command window
+title %0
+@REM enable echoing by setting MAVEN_BATCH_ECHO to 'on'
+@if "%MAVEN_BATCH_ECHO%" == "on"  echo %MAVEN_BATCH_ECHO%
+
+@REM set %HOME% to equivalent of $HOME
+if "%HOME%" == "" (set "HOME=%HOMEDRIVE%%HOMEPATH%")
+
+@REM Execute a user defined script before this one
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPre
+@REM check for pre script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_pre.bat" call "%HOME%\mavenrc_pre.bat"
+if exist "%HOME%\mavenrc_pre.cmd" call "%HOME%\mavenrc_pre.cmd"
+:skipRcPre
+
+@setlocal
+
+set ERROR_CODE=0
+
+@REM To isolate internal variables from possible post scripts, we use another setlocal
+@setlocal
+
+@REM ==== START VALIDATION ====
+if not "%JAVA_HOME%" == "" goto OkJHome
+
+echo.
+echo Error: JAVA_HOME not found in your environment. >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+:OkJHome
+if exist "%JAVA_HOME%\bin\java.exe" goto init
+
+echo.
+echo Error: JAVA_HOME is set to an invalid directory. >&2
+echo JAVA_HOME = "%JAVA_HOME%" >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+@REM ==== END VALIDATION ====
+
+:init
+
+@REM Find the project base dir, i.e. the directory that contains the folder ".mvn".
+@REM Fallback to current working directory if not found.
+
+set MAVEN_PROJECTBASEDIR=%MAVEN_BASEDIR%
+IF NOT "%MAVEN_PROJECTBASEDIR%"=="" goto endDetectBaseDir
+
+set EXEC_DIR=%CD%
+set WDIR=%EXEC_DIR%
+:findBaseDir
+IF EXIST "%WDIR%"\.mvn goto baseDirFound
+cd ..
+IF "%WDIR%"=="%CD%" goto baseDirNotFound
+set WDIR=%CD%
+goto findBaseDir
+
+:baseDirFound
+set MAVEN_PROJECTBASEDIR=%WDIR%
+cd "%EXEC_DIR%"
+goto endDetectBaseDir
+
+:baseDirNotFound
+set MAVEN_PROJECTBASEDIR=%EXEC_DIR%
+cd "%EXEC_DIR%"
+
+:endDetectBaseDir
+
+IF NOT EXIST "%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config" goto endReadAdditionalConfig
+
+@setlocal EnableExtensions EnableDelayedExpansion
+for /F "usebackq delims=" %%a in ("%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config") do set JVM_CONFIG_MAVEN_PROPS=!JVM_CONFIG_MAVEN_PROPS! %%a
+@endlocal & set JVM_CONFIG_MAVEN_PROPS=%JVM_CONFIG_MAVEN_PROPS%
+
+:endReadAdditionalConfig
+
+SET MAVEN_JAVA_EXE="%JAVA_HOME%\bin\java.exe"
+set WRAPPER_JAR="%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.jar"
+set WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+set DOWNLOAD_URL="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+
+FOR /F "tokens=1,2 delims==" %%A IN ("%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.properties") DO (
+    IF "%%A"=="wrapperUrl" SET DOWNLOAD_URL=%%B
+)
+
+@REM Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+@REM This allows using the maven wrapper in projects that prohibit checking in binary data.
+if exist %WRAPPER_JAR% (
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Found %WRAPPER_JAR%
+    )
+) else (
+    if not "%MVNW_REPOURL%" == "" (
+        SET DOWNLOAD_URL="%MVNW_REPOURL%/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+    )
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Couldn't find %WRAPPER_JAR%, downloading it ...
+        echo Downloading from: %DOWNLOAD_URL%
+    )
+
+    powershell -Command "&{"^
+		"$webclient = new-object System.Net.WebClient;"^
+		"if (-not ([string]::IsNullOrEmpty('%MVNW_USERNAME%') -and [string]::IsNullOrEmpty('%MVNW_PASSWORD%'))) {"^
+		"$webclient.Credentials = new-object System.Net.NetworkCredential('%MVNW_USERNAME%', '%MVNW_PASSWORD%');"^
+		"}"^
+		"[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; $webclient.DownloadFile('%DOWNLOAD_URL%', '%WRAPPER_JAR%')"^
+		"}"
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Finished downloading %WRAPPER_JAR%
+    )
+)
+@REM End of extension
+
+@REM Provide a "standardized" way to retrieve the CLI args that will
+@REM work with both Windows and non-Windows executions.
+set MAVEN_CMD_LINE_ARGS=%*
+
+%MAVEN_JAVA_EXE% %JVM_CONFIG_MAVEN_PROPS% %MAVEN_OPTS% %MAVEN_DEBUG_OPTS% -classpath %WRAPPER_JAR% "-Dmaven.multiModuleProjectDirectory=%MAVEN_PROJECTBASEDIR%" %WRAPPER_LAUNCHER% %MAVEN_CONFIG% %*
+if ERRORLEVEL 1 goto error
+goto end
+
+:error
+set ERROR_CODE=1
+
+:end
+@endlocal & set ERROR_CODE=%ERROR_CODE%
+
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPost
+@REM check for post script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_post.bat" call "%HOME%\mavenrc_post.bat"
+if exist "%HOME%\mavenrc_post.cmd" call "%HOME%\mavenrc_post.cmd"
+:skipRcPost
+
+@REM pause the script if MAVEN_BATCH_PAUSE is set to 'on'
+if "%MAVEN_BATCH_PAUSE%" == "on" pause
+
+if "%MAVEN_TERMINATE_CMD%" == "on" exit %ERROR_CODE%
+
+exit /B %ERROR_CODE%

http-clients/pom.xml

@@ -0,0 +1,26 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<groupId>io.pratik</groupId>
+	<artifactId>JavaHttpClient</artifactId>
+	<version>0.0.1-SNAPSHOT</version>
+	<name>JavaHttpClient</name>
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-webflux</artifactId>
+			<version>2.3.5.RELEASE</version>
+		</dependency>
+		<dependency>
+			<groupId>com.squareup.okhttp3</groupId>
+			<artifactId>okhttp</artifactId>
+			<version>4.9.2</version>
+		</dependency>
+		<dependency>
+			<groupId>org.apache.httpcomponents.client5</groupId>
+			<artifactId>httpclient5</artifactId>
+			<version>5.1.1</version>
+		</dependency>
+	</dependencies>
+</project>

http-clients/src/main/java/io/pratik/ApacheHttpClientApp.java

@@ -0,0 +1,146 @@
+/**
+ * 
+ */
+package io.pratik;
+
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Future;
+
+import org.apache.hc.client5.http.ClientProtocolException;
+import org.apache.hc.client5.http.async.methods.SimpleHttpRequest;
+import org.apache.hc.client5.http.async.methods.SimpleHttpResponse;
+import org.apache.hc.client5.http.async.methods.SimpleRequestBuilder;
+import org.apache.hc.client5.http.classic.methods.HttpPost;
+import org.apache.hc.client5.http.impl.async.CloseableHttpAsyncClient;
+import org.apache.hc.client5.http.impl.async.HttpAsyncClients;
+import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
+import org.apache.hc.client5.http.impl.classic.CloseableHttpResponse;
+import org.apache.hc.client5.http.impl.classic.HttpClients;
+import org.apache.hc.core5.concurrent.FutureCallback;
+import org.apache.hc.core5.http.HttpEntity;
+import org.apache.hc.core5.http.HttpResponse;
+import org.apache.hc.core5.http.ParseException;
+import org.apache.hc.core5.http.io.entity.EntityUtils;
+import org.apache.hc.core5.http.io.entity.StringEntity;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+/**
+ * @author pratikdas
+ *
+ */
+public class ApacheHttpClientApp {
+
+	
+    public void invoke() {
+        
+            try(
+            		CloseableHttpAsyncClient client = HttpAsyncClients.createDefault();) {
+            		client.start();
+                    
+                    final SimpleHttpRequest request = SimpleRequestBuilder.get()
+                    		.setUri(URLConstants.URL)
+                    		.addHeader(URLConstants.API_KEY_NAME, URLConstants.API_KEY_VALUE)
+                            .build();
+                    
+                    Future<SimpleHttpResponse> future = 
+                    		client.execute(request, 
+                    				new FutureCallback<SimpleHttpResponse>() {
+
+						@Override
+						public void completed(SimpleHttpResponse result) {
+							String response = result.getBodyText();
+							System.out.println("response::"+response);
+						}
+
+						@Override
+						public void failed(Exception ex) {
+							System.out.println("response::"+ex);
+						}
+
+						@Override
+						public void cancelled() {
+							// TODO Auto-generated method stub
+							
+						}
+                    	
+                    });
+                    HttpResponse response = future.get();
+                    
+	                // Get HttpResponse Status
+	                System.out.println("version "+ response.getVersion());              // HTTP/1.1
+	                System.out.println(response.getCode());   // 200
+	                System.out.println(response.getReasonPhrase()); // OK
+	
+            } catch (InterruptedException | ExecutionException | IOException e) {
+				e.printStackTrace();
+			} 
+    }
+    
+    public void invokePost() {
+    	
+    	StringEntity stringEntity = new StringEntity(prepareRequest());
+    	HttpPost httpPost = new HttpPost("https://reqbin.com/echo/post/json");
+
+        httpPost.setEntity(stringEntity);
+        httpPost.setHeader("Accept", "application/json");
+        httpPost.setHeader("Content-type", "application/json");
+
+        try(
+        		CloseableHttpClient httpClient = HttpClients.createDefault();
+        		
+                CloseableHttpResponse response = httpClient.execute(httpPost);) {
+
+                // Get HttpResponse Status
+                System.out.println("version "+ response.getVersion()); // HTTP/1.1
+                System.out.println(response.getCode());   // 200
+                System.out.println(response.getReasonPhrase()); // OK
+
+                HttpEntity entity = response.getEntity();
+                if (entity != null) {
+                    // return it as a String
+                    String result = EntityUtils.toString(entity);
+                    System.out.println(result);
+                }
+
+        } catch (ParseException | IOException e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+		} 
+        
+    }
+    
+	/**
+	 * @return
+	 * @throws JsonProcessingException
+	 */
+	private String prepareRequest() {
+		var values = new HashMap<String, String>() {
+			{
+				put("Id", "12345");
+				put("Customer", "Roger Moose");
+				put("Quantity", "3");
+				put("Price","167.35");
+			}
+		};
+
+		var objectMapper = new ObjectMapper();
+		String requestBody;
+		try {
+			requestBody = objectMapper.writeValueAsString(values);
+		} catch (JsonProcessingException e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+			return null;
+		}
+		return requestBody;
+	}
+	public static void main(String[] args) throws ClientProtocolException, IOException, ParseException {
+		new ApacheHttpClientApp().invoke();
+
+	}
+
+}

http-clients/src/main/java/io/pratik/HttpClientApp.java

@@ -0,0 +1,82 @@
+/**
+ * 
+ */
+package io.pratik;
+
+import java.io.IOException;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.net.http.HttpClient;
+import java.net.http.HttpClient.Redirect;
+import java.net.http.HttpClient.Version;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import java.net.http.HttpResponse.BodyHandlers;
+import java.time.Duration;
+import java.util.HashMap;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+/**
+ * @author pratikdas
+ *
+ */
+public class HttpClientApp {
+
+	public void invoke() throws URISyntaxException {
+
+		HttpClient client = HttpClient.newBuilder().version(Version.HTTP_2).followRedirects(Redirect.NORMAL).build();
+
+		HttpRequest request = HttpRequest.newBuilder().uri(new URI(URLConstants.URL)).GET()
+				.header(URLConstants.API_KEY_NAME, URLConstants.API_KEY_VALUE).timeout(Duration.ofSeconds(10)).build();
+
+		client.sendAsync(request, BodyHandlers.ofString())
+		      .thenApply(HttpResponse::body)
+		      .thenAccept(System.out::println)
+			  .join();
+	}
+
+	public void invokePost() {
+		
+		try {
+			String requestBody = prepareRequest();
+			HttpClient client = HttpClient.newHttpClient();
+			HttpRequest request = HttpRequest.newBuilder().uri(URI.create("https://reqbin.com/echo/post/json"))
+					.POST(HttpRequest.BodyPublishers.ofString(requestBody))
+					.header("Accept", "application/json")
+					.build();
+
+			HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());
+
+			System.out.println(response.body());
+		} catch (IOException | InterruptedException e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+		}
+	}
+
+	/**
+	 * @return
+	 * @throws JsonProcessingException
+	 */
+	private String prepareRequest() throws JsonProcessingException {
+		var values = new HashMap<String, String>() {
+			{
+				put("Id", "12345");
+				put("Customer", "Roger Moose");
+				put("Quantity", "3");
+				put("Price","167.35");
+			}
+		};
+
+		var objectMapper = new ObjectMapper();
+		String requestBody = objectMapper.writeValueAsString(values);
+		return requestBody;
+	}
+
+	public static void main(String[] args) throws URISyntaxException {
+		new HttpClientApp().invoke();
+	}
+
+}

http-clients/src/main/java/io/pratik/OkHttpClientApp.java

@@ -0,0 +1,95 @@
+/**
+ * 
+ */
+package io.pratik;
+
+import java.io.IOException;
+import java.net.URISyntaxException;
+import java.util.HashMap;
+import java.util.concurrent.TimeUnit;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import okhttp3.Call;
+import okhttp3.Callback;
+import okhttp3.MediaType;
+import okhttp3.OkHttpClient;
+import okhttp3.Request;
+import okhttp3.RequestBody;
+import okhttp3.Response;
+
+/**
+ * @author pratikdas
+ *
+ */
+public class OkHttpClientApp {
+	
+	public void invoke() throws URISyntaxException, IOException {
+	    OkHttpClient client = new OkHttpClient.Builder()
+			    .readTimeout(1000, TimeUnit.MILLISECONDS)
+			    .writeTimeout(1000, TimeUnit.MILLISECONDS)
+			    .build();
+
+		Request request = new Request.Builder()
+			.url(URLConstants.URL)
+			.get()
+			.addHeader(URLConstants.API_KEY_NAME, URLConstants.API_KEY_VALUE)
+			.build();
+
+		Call call = client.newCall(request);
+		call.enqueue(new Callback() {
+	        public void onResponse(Call call, Response response) 
+	          throws IOException {
+	        	System.out.println(response.body().string());
+	        }
+	        
+	        public void onFailure(Call call, IOException e) {
+	            // error
+	        }
+	    });
+		
+	}
+	
+	public void invokePost() throws URISyntaxException, IOException {
+	    OkHttpClient client = new OkHttpClient.Builder()
+			    .readTimeout(1000, TimeUnit.MILLISECONDS)
+			    .writeTimeout(1000, TimeUnit.MILLISECONDS)
+			    .build();
+	    
+		String requestBody = prepareRequest();
+
+	    RequestBody body = RequestBody.create(
+	      requestBody,
+	      MediaType.parse("application/json"));
+	    
+		Request request = new Request.Builder()
+			.url("https://reqbin.com/echo/post/json")
+			.post(body)
+			.addHeader(URLConstants.API_KEY_NAME, URLConstants.API_KEY_VALUE)
+			.build();
+
+		Response response = client.newCall(request).execute();
+		System.out.println(response.body().string());
+	}
+
+	private String prepareRequest() throws JsonProcessingException {
+		var values = new HashMap<String, String>() {
+			{
+				put("Id", "12345");
+				put("Customer", "Roger Moose");
+				put("Quantity", "3");
+				put("Price","167.35");
+			}
+		};
+
+		var objectMapper = new ObjectMapper();
+		String requestBody = objectMapper.writeValueAsString(values);
+		return requestBody;
+	}
+	
+	public static void main(String[] args) throws URISyntaxException, IOException {
+		new OkHttpClientApp().invokePost();
+	}
+
+}

http-clients/src/main/java/io/pratik/URLConstants.java

@@ -0,0 +1,16 @@
+/**
+ * 
+ */
+package io.pratik;
+
+/**
+ * @author pratikdas
+ *
+ */
+public interface URLConstants {
+
+	String URL = "https://weatherbit-v1-mashape.p.rapidapi.com/forecast/3hourly?lat=35.5&lon=-78.5";
+	String API_KEY_NAME = "x-rapidapi-key";
+	String API_KEY_VALUE = "4b49c6b973mshf6e97423e8978fbp1d33aejsn287ed2a6d10d";
+	
+}

http-clients/src/main/java/io/pratik/WebClientApp.java

@@ -0,0 +1,74 @@
+/**
+ * 
+ */
+package io.pratik;
+
+import java.io.IOException;
+import java.util.HashMap;
+
+import org.apache.hc.client5.http.ClientProtocolException;
+import org.apache.hc.core5.http.ParseException;
+import org.springframework.web.reactive.function.BodyInserters;
+import org.springframework.web.reactive.function.client.WebClient;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+/**
+ * @author pratikdas
+ *
+ */
+public class WebClientApp {
+	
+	public void invoke() {
+		WebClient client = WebClient.create();
+		client
+		.get()
+		.uri(URLConstants.URL)
+        .header(URLConstants.API_KEY_NAME, URLConstants.API_KEY_VALUE)
+        .retrieve()
+        .bodyToMono(String.class)
+        .subscribe(result->System.out.println(result));
+	}
+	
+	public void invokePost() {
+		WebClient client = WebClient.create();
+		
+		String result = client
+		.post()
+        .uri("https://reqbin.com/echo/post/json")
+        .body(BodyInserters.fromValue(prepareRequest()))
+        .exchange()
+        .flatMap(response -> response.bodyToMono(String.class))
+        .block();
+		
+		System.out.println("result::"+result);
+	}
+	
+	private String prepareRequest()  {
+		var values = new HashMap<String, String>() {
+			{
+				put("Id", "12345");
+				put("Customer", "Roger Moose");
+				put("Quantity", "3");
+				put("Price","167.35");
+			}
+		};
+
+		var objectMapper = new ObjectMapper();
+		String requestBody;
+		try {
+			requestBody = objectMapper.writeValueAsString(values);
+		} catch (JsonProcessingException e) {
+			e.printStackTrace();
+			return null;
+		}
+		return requestBody;
+	}
+	
+	public static void main(String[] args) throws ClientProtocolException, IOException, ParseException {
+		new WebClientApp().invoke();
+
+	}
+
+}

java-hashes/.mvn/wrapper/MavenWrapperDownloader.java

@@ -0,0 +1,117 @@
+/*
+ * Copyright 2007-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import java.net.*;
+import java.io.*;
+import java.nio.channels.*;
+import java.util.Properties;
+
+public class MavenWrapperDownloader {
+
+    private static final String WRAPPER_VERSION = "0.5.6";
+    /**
+     * Default URL to download the maven-wrapper.jar from, if no 'downloadUrl' is provided.
+     */
+    private static final String DEFAULT_DOWNLOAD_URL = "https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/"
+        + WRAPPER_VERSION + "/maven-wrapper-" + WRAPPER_VERSION + ".jar";
+
+    /**
+     * Path to the maven-wrapper.properties file, which might contain a downloadUrl property to
+     * use instead of the default one.
+     */
+    private static final String MAVEN_WRAPPER_PROPERTIES_PATH =
+            ".mvn/wrapper/maven-wrapper.properties";
+
+    /**
+     * Path where the maven-wrapper.jar will be saved to.
+     */
+    private static final String MAVEN_WRAPPER_JAR_PATH =
+            ".mvn/wrapper/maven-wrapper.jar";
+
+    /**
+     * Name of the property which should be used to override the default download url for the wrapper.
+     */
+    private static final String PROPERTY_NAME_WRAPPER_URL = "wrapperUrl";
+
+    public static void main(String args[]) {
+        System.out.println("- Downloader started");
+        File baseDirectory = new File(args[0]);
+        System.out.println("- Using base directory: " + baseDirectory.getAbsolutePath());
+
+        // If the maven-wrapper.properties exists, read it and check if it contains a custom
+        // wrapperUrl parameter.
+        File mavenWrapperPropertyFile = new File(baseDirectory, MAVEN_WRAPPER_PROPERTIES_PATH);
+        String url = DEFAULT_DOWNLOAD_URL;
+        if(mavenWrapperPropertyFile.exists()) {
+            FileInputStream mavenWrapperPropertyFileInputStream = null;
+            try {
+                mavenWrapperPropertyFileInputStream = new FileInputStream(mavenWrapperPropertyFile);
+                Properties mavenWrapperProperties = new Properties();
+                mavenWrapperProperties.load(mavenWrapperPropertyFileInputStream);
+                url = mavenWrapperProperties.getProperty(PROPERTY_NAME_WRAPPER_URL, url);
+            } catch (IOException e) {
+                System.out.println("- ERROR loading '" + MAVEN_WRAPPER_PROPERTIES_PATH + "'");
+            } finally {
+                try {
+                    if(mavenWrapperPropertyFileInputStream != null) {
+                        mavenWrapperPropertyFileInputStream.close();
+                    }
+                } catch (IOException e) {
+                    // Ignore ...
+                }
+            }
+        }
+        System.out.println("- Downloading from: " + url);
+
+        File outputFile = new File(baseDirectory.getAbsolutePath(), MAVEN_WRAPPER_JAR_PATH);
+        if(!outputFile.getParentFile().exists()) {
+            if(!outputFile.getParentFile().mkdirs()) {
+                System.out.println(
+                        "- ERROR creating output directory '" + outputFile.getParentFile().getAbsolutePath() + "'");
+            }
+        }
+        System.out.println("- Downloading to: " + outputFile.getAbsolutePath());
+        try {
+            downloadFileFromURL(url, outputFile);
+            System.out.println("Done");
+            System.exit(0);
+        } catch (Throwable e) {
+            System.out.println("- Error downloading");
+            e.printStackTrace();
+            System.exit(1);
+        }
+    }
+
+    private static void downloadFileFromURL(String urlString, File destination) throws Exception {
+        if (System.getenv("MVNW_USERNAME") != null && System.getenv("MVNW_PASSWORD") != null) {
+            String username = System.getenv("MVNW_USERNAME");
+            char[] password = System.getenv("MVNW_PASSWORD").toCharArray();
+            Authenticator.setDefault(new Authenticator() {
+                @Override
+                protected PasswordAuthentication getPasswordAuthentication() {
+                    return new PasswordAuthentication(username, password);
+                }
+            });
+        }
+        URL website = new URL(urlString);
+        ReadableByteChannel rbc;
+        rbc = Channels.newChannel(website.openStream());
+        FileOutputStream fos = new FileOutputStream(destination);
+        fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
+        fos.close();
+        rbc.close();
+    }
+
+}

java-hashes/.mvn/wrapper/maven-wrapper.properties

@@ -0,0 +1,2 @@
+distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.6.3/apache-maven-3.6.3-bin.zip
+wrapperUrl=https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar

java-hashes/README.md

@@ -0,0 +1,3 @@
+# Related Blog Posts
+
+* [Creating Hashes in Java](https://reflectoring.io/creating-hashes-in-java/)

java-hashes/mvnw

@@ -0,0 +1,310 @@
+#!/bin/sh
+# ----------------------------------------------------------------------------
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+# ----------------------------------------------------------------------------
+
+# ----------------------------------------------------------------------------
+# Maven Start Up Batch script
+#
+# Required ENV vars:
+# ------------------
+#   JAVA_HOME - location of a JDK home dir
+#
+# Optional ENV vars
+# -----------------
+#   M2_HOME - location of maven2's installed home dir
+#   MAVEN_OPTS - parameters passed to the Java VM when running Maven
+#     e.g. to debug Maven itself, use
+#       set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+#   MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+# ----------------------------------------------------------------------------
+
+if [ -z "$MAVEN_SKIP_RC" ] ; then
+
+  if [ -f /etc/mavenrc ] ; then
+    . /etc/mavenrc
+  fi
+
+  if [ -f "$HOME/.mavenrc" ] ; then
+    . "$HOME/.mavenrc"
+  fi
+
+fi
+
+# OS specific support.  $var _must_ be set to either true or false.
+cygwin=false;
+darwin=false;
+mingw=false
+case "`uname`" in
+  CYGWIN*) cygwin=true ;;
+  MINGW*) mingw=true;;
+  Darwin*) darwin=true
+    # Use /usr/libexec/java_home if available, otherwise fall back to /Library/Java/Home
+    # See https://developer.apple.com/library/mac/qa/qa1170/_index.html
+    if [ -z "$JAVA_HOME" ]; then
+      if [ -x "/usr/libexec/java_home" ]; then
+        export JAVA_HOME="`/usr/libexec/java_home`"
+      else
+        export JAVA_HOME="/Library/Java/Home"
+      fi
+    fi
+    ;;
+esac
+
+if [ -z "$JAVA_HOME" ] ; then
+  if [ -r /etc/gentoo-release ] ; then
+    JAVA_HOME=`java-config --jre-home`
+  fi
+fi
+
+if [ -z "$M2_HOME" ] ; then
+  ## resolve links - $0 may be a link to maven's home
+  PRG="$0"
+
+  # need this for relative symlinks
+  while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+      PRG="$link"
+    else
+      PRG="`dirname "$PRG"`/$link"
+    fi
+  done
+
+  saveddir=`pwd`
+
+  M2_HOME=`dirname "$PRG"`/..
+
+  # make it fully qualified
+  M2_HOME=`cd "$M2_HOME" && pwd`
+
+  cd "$saveddir"
+  # echo Using m2 at $M2_HOME
+fi
+
+# For Cygwin, ensure paths are in UNIX format before anything is touched
+if $cygwin ; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME=`cygpath --unix "$M2_HOME"`
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME=`cygpath --unix "$JAVA_HOME"`
+  [ -n "$CLASSPATH" ] &&
+    CLASSPATH=`cygpath --path --unix "$CLASSPATH"`
+fi
+
+# For Mingw, ensure paths are in UNIX format before anything is touched
+if $mingw ; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME="`(cd "$M2_HOME"; pwd)`"
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME="`(cd "$JAVA_HOME"; pwd)`"
+fi
+
+if [ -z "$JAVA_HOME" ]; then
+  javaExecutable="`which javac`"
+  if [ -n "$javaExecutable" ] && ! [ "`expr \"$javaExecutable\" : '\([^ ]*\)'`" = "no" ]; then
+    # readlink(1) is not available as standard on Solaris 10.
+    readLink=`which readlink`
+    if [ ! `expr "$readLink" : '\([^ ]*\)'` = "no" ]; then
+      if $darwin ; then
+        javaHome="`dirname \"$javaExecutable\"`"
+        javaExecutable="`cd \"$javaHome\" && pwd -P`/javac"
+      else
+        javaExecutable="`readlink -f \"$javaExecutable\"`"
+      fi
+      javaHome="`dirname \"$javaExecutable\"`"
+      javaHome=`expr "$javaHome" : '\(.*\)/bin'`
+      JAVA_HOME="$javaHome"
+      export JAVA_HOME
+    fi
+  fi
+fi
+
+if [ -z "$JAVACMD" ] ; then
+  if [ -n "$JAVA_HOME"  ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+      # IBM's JDK on AIX uses strange locations for the executables
+      JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+      JAVACMD="$JAVA_HOME/bin/java"
+    fi
+  else
+    JAVACMD="`which java`"
+  fi
+fi
+
+if [ ! -x "$JAVACMD" ] ; then
+  echo "Error: JAVA_HOME is not defined correctly." >&2
+  echo "  We cannot execute $JAVACMD" >&2
+  exit 1
+fi
+
+if [ -z "$JAVA_HOME" ] ; then
+  echo "Warning: JAVA_HOME environment variable is not set."
+fi
+
+CLASSWORLDS_LAUNCHER=org.codehaus.plexus.classworlds.launcher.Launcher
+
+# traverses directory structure from process work directory to filesystem root
+# first directory with .mvn subdirectory is considered project base directory
+find_maven_basedir() {
+
+  if [ -z "$1" ]
+  then
+    echo "Path not specified to find_maven_basedir"
+    return 1
+  fi
+
+  basedir="$1"
+  wdir="$1"
+  while [ "$wdir" != '/' ] ; do
+    if [ -d "$wdir"/.mvn ] ; then
+      basedir=$wdir
+      break
+    fi
+    # workaround for JBEAP-8937 (on Solaris 10/Sparc)
+    if [ -d "${wdir}" ]; then
+      wdir=`cd "$wdir/.."; pwd`
+    fi
+    # end of workaround
+  done
+  echo "${basedir}"
+}
+
+# concatenates all lines of a file
+concat_lines() {
+  if [ -f "$1" ]; then
+    echo "$(tr -s '\n' ' ' < "$1")"
+  fi
+}
+
+BASE_DIR=`find_maven_basedir "$(pwd)"`
+if [ -z "$BASE_DIR" ]; then
+  exit 1;
+fi
+
+##########################################################################################
+# Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+# This allows using the maven wrapper in projects that prohibit checking in binary data.
+##########################################################################################
+if [ -r "$BASE_DIR/.mvn/wrapper/maven-wrapper.jar" ]; then
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Found .mvn/wrapper/maven-wrapper.jar"
+    fi
+else
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Couldn't find .mvn/wrapper/maven-wrapper.jar, downloading it ..."
+    fi
+    if [ -n "$MVNW_REPOURL" ]; then
+      jarUrl="$MVNW_REPOURL/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+    else
+      jarUrl="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+    fi
+    while IFS="=" read key value; do
+      case "$key" in (wrapperUrl) jarUrl="$value"; break ;;
+      esac
+    done < "$BASE_DIR/.mvn/wrapper/maven-wrapper.properties"
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Downloading from: $jarUrl"
+    fi
+    wrapperJarPath="$BASE_DIR/.mvn/wrapper/maven-wrapper.jar"
+    if $cygwin; then
+      wrapperJarPath=`cygpath --path --windows "$wrapperJarPath"`
+    fi
+
+    if command -v wget > /dev/null; then
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo "Found wget ... using wget"
+        fi
+        if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+            wget "$jarUrl" -O "$wrapperJarPath"
+        else
+            wget --http-user=$MVNW_USERNAME --http-password=$MVNW_PASSWORD "$jarUrl" -O "$wrapperJarPath"
+        fi
+    elif command -v curl > /dev/null; then
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo "Found curl ... using curl"
+        fi
+        if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+            curl -o "$wrapperJarPath" "$jarUrl" -f
+        else
+            curl --user $MVNW_USERNAME:$MVNW_PASSWORD -o "$wrapperJarPath" "$jarUrl" -f
+        fi
+
+    else
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo "Falling back to using Java to download"
+        fi
+        javaClass="$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.java"
+        # For Cygwin, switch paths to Windows format before running javac
+        if $cygwin; then
+          javaClass=`cygpath --path --windows "$javaClass"`
+        fi
+        if [ -e "$javaClass" ]; then
+            if [ ! -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+                if [ "$MVNW_VERBOSE" = true ]; then
+                  echo " - Compiling MavenWrapperDownloader.java ..."
+                fi
+                # Compiling the Java class
+                ("$JAVA_HOME/bin/javac" "$javaClass")
+            fi
+            if [ -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+                # Running the downloader
+                if [ "$MVNW_VERBOSE" = true ]; then
+                  echo " - Running MavenWrapperDownloader.java ..."
+                fi
+                ("$JAVA_HOME/bin/java" -cp .mvn/wrapper MavenWrapperDownloader "$MAVEN_PROJECTBASEDIR")
+            fi
+        fi
+    fi
+fi
+##########################################################################################
+# End of extension
+##########################################################################################
+
+export MAVEN_PROJECTBASEDIR=${MAVEN_BASEDIR:-"$BASE_DIR"}
+if [ "$MVNW_VERBOSE" = true ]; then
+  echo $MAVEN_PROJECTBASEDIR
+fi
+MAVEN_OPTS="$(concat_lines "$MAVEN_PROJECTBASEDIR/.mvn/jvm.config") $MAVEN_OPTS"
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME=`cygpath --path --windows "$M2_HOME"`
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME=`cygpath --path --windows "$JAVA_HOME"`
+  [ -n "$CLASSPATH" ] &&
+    CLASSPATH=`cygpath --path --windows "$CLASSPATH"`
+  [ -n "$MAVEN_PROJECTBASEDIR" ] &&
+    MAVEN_PROJECTBASEDIR=`cygpath --path --windows "$MAVEN_PROJECTBASEDIR"`
+fi
+
+# Provide a "standardized" way to retrieve the CLI args that will
+# work with both Windows and non-Windows executions.
+MAVEN_CMD_LINE_ARGS="$MAVEN_CONFIG $@"
+export MAVEN_CMD_LINE_ARGS
+
+WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+exec "$JAVACMD" \
+  $MAVEN_OPTS \
+  -classpath "$MAVEN_PROJECTBASEDIR/.mvn/wrapper/maven-wrapper.jar" \
+  "-Dmaven.home=${M2_HOME}" "-Dmaven.multiModuleProjectDirectory=${MAVEN_PROJECTBASEDIR}" \
+  ${WRAPPER_LAUNCHER} $MAVEN_CONFIG "$@"

java-hashes/mvnw.cmd

@@ -0,0 +1,182 @@
+@REM ----------------------------------------------------------------------------
+@REM Licensed to the Apache Software Foundation (ASF) under one
+@REM or more contributor license agreements.  See the NOTICE file
+@REM distributed with this work for additional information
+@REM regarding copyright ownership.  The ASF licenses this file
+@REM to you under the Apache License, Version 2.0 (the
+@REM "License"); you may not use this file except in compliance
+@REM with the License.  You may obtain a copy of the License at
+@REM
+@REM    http://www.apache.org/licenses/LICENSE-2.0
+@REM
+@REM Unless required by applicable law or agreed to in writing,
+@REM software distributed under the License is distributed on an
+@REM "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+@REM KIND, either express or implied.  See the License for the
+@REM specific language governing permissions and limitations
+@REM under the License.
+@REM ----------------------------------------------------------------------------
+
+@REM ----------------------------------------------------------------------------
+@REM Maven Start Up Batch script
+@REM
+@REM Required ENV vars:
+@REM JAVA_HOME - location of a JDK home dir
+@REM
+@REM Optional ENV vars
+@REM M2_HOME - location of maven2's installed home dir
+@REM MAVEN_BATCH_ECHO - set to 'on' to enable the echoing of the batch commands
+@REM MAVEN_BATCH_PAUSE - set to 'on' to wait for a keystroke before ending
+@REM MAVEN_OPTS - parameters passed to the Java VM when running Maven
+@REM     e.g. to debug Maven itself, use
+@REM set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+@REM MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+@REM ----------------------------------------------------------------------------
+
+@REM Begin all REM lines with '@' in case MAVEN_BATCH_ECHO is 'on'
+@echo off
+@REM set title of command window
+title %0
+@REM enable echoing by setting MAVEN_BATCH_ECHO to 'on'
+@if "%MAVEN_BATCH_ECHO%" == "on"  echo %MAVEN_BATCH_ECHO%
+
+@REM set %HOME% to equivalent of $HOME
+if "%HOME%" == "" (set "HOME=%HOMEDRIVE%%HOMEPATH%")
+
+@REM Execute a user defined script before this one
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPre
+@REM check for pre script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_pre.bat" call "%HOME%\mavenrc_pre.bat"
+if exist "%HOME%\mavenrc_pre.cmd" call "%HOME%\mavenrc_pre.cmd"
+:skipRcPre
+
+@setlocal
+
+set ERROR_CODE=0
+
+@REM To isolate internal variables from possible post scripts, we use another setlocal
+@setlocal
+
+@REM ==== START VALIDATION ====
+if not "%JAVA_HOME%" == "" goto OkJHome
+
+echo.
+echo Error: JAVA_HOME not found in your environment. >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+:OkJHome
+if exist "%JAVA_HOME%\bin\java.exe" goto init
+
+echo.
+echo Error: JAVA_HOME is set to an invalid directory. >&2
+echo JAVA_HOME = "%JAVA_HOME%" >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+@REM ==== END VALIDATION ====
+
+:init
+
+@REM Find the project base dir, i.e. the directory that contains the folder ".mvn".
+@REM Fallback to current working directory if not found.
+
+set MAVEN_PROJECTBASEDIR=%MAVEN_BASEDIR%
+IF NOT "%MAVEN_PROJECTBASEDIR%"=="" goto endDetectBaseDir
+
+set EXEC_DIR=%CD%
+set WDIR=%EXEC_DIR%
+:findBaseDir
+IF EXIST "%WDIR%"\.mvn goto baseDirFound
+cd ..
+IF "%WDIR%"=="%CD%" goto baseDirNotFound
+set WDIR=%CD%
+goto findBaseDir
+
+:baseDirFound
+set MAVEN_PROJECTBASEDIR=%WDIR%
+cd "%EXEC_DIR%"
+goto endDetectBaseDir
+
+:baseDirNotFound
+set MAVEN_PROJECTBASEDIR=%EXEC_DIR%
+cd "%EXEC_DIR%"
+
+:endDetectBaseDir
+
+IF NOT EXIST "%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config" goto endReadAdditionalConfig
+
+@setlocal EnableExtensions EnableDelayedExpansion
+for /F "usebackq delims=" %%a in ("%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config") do set JVM_CONFIG_MAVEN_PROPS=!JVM_CONFIG_MAVEN_PROPS! %%a
+@endlocal & set JVM_CONFIG_MAVEN_PROPS=%JVM_CONFIG_MAVEN_PROPS%
+
+:endReadAdditionalConfig
+
+SET MAVEN_JAVA_EXE="%JAVA_HOME%\bin\java.exe"
+set WRAPPER_JAR="%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.jar"
+set WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+set DOWNLOAD_URL="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+
+FOR /F "tokens=1,2 delims==" %%A IN ("%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.properties") DO (
+    IF "%%A"=="wrapperUrl" SET DOWNLOAD_URL=%%B
+)
+
+@REM Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+@REM This allows using the maven wrapper in projects that prohibit checking in binary data.
+if exist %WRAPPER_JAR% (
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Found %WRAPPER_JAR%
+    )
+) else (
+    if not "%MVNW_REPOURL%" == "" (
+        SET DOWNLOAD_URL="%MVNW_REPOURL%/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+    )
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Couldn't find %WRAPPER_JAR%, downloading it ...
+        echo Downloading from: %DOWNLOAD_URL%
+    )
+
+    powershell -Command "&{"^
+		"$webclient = new-object System.Net.WebClient;"^
+		"if (-not ([string]::IsNullOrEmpty('%MVNW_USERNAME%') -and [string]::IsNullOrEmpty('%MVNW_PASSWORD%'))) {"^
+		"$webclient.Credentials = new-object System.Net.NetworkCredential('%MVNW_USERNAME%', '%MVNW_PASSWORD%');"^
+		"}"^
+		"[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; $webclient.DownloadFile('%DOWNLOAD_URL%', '%WRAPPER_JAR%')"^
+		"}"
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Finished downloading %WRAPPER_JAR%
+    )
+)
+@REM End of extension
+
+@REM Provide a "standardized" way to retrieve the CLI args that will
+@REM work with both Windows and non-Windows executions.
+set MAVEN_CMD_LINE_ARGS=%*
+
+%MAVEN_JAVA_EXE% %JVM_CONFIG_MAVEN_PROPS% %MAVEN_OPTS% %MAVEN_DEBUG_OPTS% -classpath %WRAPPER_JAR% "-Dmaven.multiModuleProjectDirectory=%MAVEN_PROJECTBASEDIR%" %WRAPPER_LAUNCHER% %MAVEN_CONFIG% %*
+if ERRORLEVEL 1 goto error
+goto end
+
+:error
+set ERROR_CODE=1
+
+:end
+@endlocal & set ERROR_CODE=%ERROR_CODE%
+
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPost
+@REM check for post script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_post.bat" call "%HOME%\mavenrc_post.bat"
+if exist "%HOME%\mavenrc_post.cmd" call "%HOME%\mavenrc_post.cmd"
+:skipRcPost
+
+@REM pause the script if MAVEN_BATCH_PAUSE is set to 'on'
+if "%MAVEN_BATCH_PAUSE%" == "on" pause
+
+if "%MAVEN_TERMINATE_CMD%" == "on" exit %ERROR_CODE%
+
+exit /B %ERROR_CODE%

java-hashes/pom.xml

@@ -0,0 +1,6 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <groupId>io.pratik</groupId>
+  <artifactId>hashing</artifactId>
+  <version>0.0.1-SNAPSHOT</version>
+</project>

java-hashes/src/main/java/hashing/HashCreator.java

@@ -0,0 +1,179 @@
+/**
+ * 
+ */
+package hashing;
+
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.math.BigInteger;
+import java.nio.charset.StandardCharsets;
+import java.security.DigestInputStream;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.security.NoSuchProviderException;
+import java.security.SecureRandom;
+import java.security.spec.InvalidKeySpecException;
+
+import javax.crypto.SecretKeyFactory;
+import javax.crypto.spec.PBEKeySpec;
+
+/**
+ * @author pratikdas
+ *
+ */
+public class HashCreator {
+
+	public String createMD5Hash(final String input) throws NoSuchAlgorithmException{
+        String hashtext = null;
+		MessageDigest md = MessageDigest.getInstance("MD5");
+        // Compute message digest of the input
+        byte[] messageDigest = md.digest(input.getBytes());
+
+        hashtext = convertToHex(messageDigest);
+		
+ 		return hashtext;
+	}
+	
+    public String createSHAHash(final String input) throws NoSuchAlgorithmException { 
+       String hashtext = null;
+       MessageDigest md = MessageDigest.getInstance("SHA-256");
+	   byte[] messageDigest =  md.digest(input.getBytes(StandardCharsets.UTF_8)); 
+	   System.out.println(messageDigest.length);
+	   
+	   hashtext = convertToHex(messageDigest);
+       return hashtext;
+    }
+
+	private String convertToHex(final byte[] messageDigest) {
+		BigInteger bigint = new BigInteger(1, messageDigest);
+        String hexText = bigint.toString(16);
+        while (hexText.length() < 32) {
+        	hexText = "0".concat(hexText);
+        }
+		return hexText;
+	}
+	
+	public String createPasswordHashWithSalt(final String textToHash) {
+		try {
+			byte[] salt = createSalt();
+			return createSaltedHash(textToHash, salt);
+		}catch(Exception e) {
+			e.printStackTrace();
+		}
+		return null;
+	}
+	
+    private String createSaltedHash(final String textToHash, final byte[] salt) throws NoSuchAlgorithmException{
+            String saltedHash = null;
+            // Create MessageDigest instance for MD5
+            MessageDigest md = MessageDigest.getInstance("MD5");
+            //Add salted bytes to digest
+            md.update(salt);
+            //Get the hash's bytes 
+            byte[] bytes = md.digest(textToHash.getBytes());
+            //Convert it to hexadecimal format to
+            //get complete salted hash in hex format
+            saltedHash = convertToHex(bytes);
+            return saltedHash;
+    }
+    
+    
+    public String generateStrongPasswordHash(final String password) 
+    	    throws NoSuchAlgorithmException, InvalidKeySpecException, NoSuchProviderException
+    	{
+    	    int iterations = 1000;
+    	    byte[] salt = createSalt();
+
+    	    byte[] hash = createPBEHash(password,iterations, salt, 64); // skf.generateSecret(spec).getEncoded();
+    	    
+    	    return iterations + ":" + convertToHex(salt) + ":" + convertToHex(hash);
+    }
+    //Create salt
+    private byte[] createSalt() throws NoSuchAlgorithmException, NoSuchProviderException{
+        //Always use a SecureRandom generator for random salt
+        SecureRandom sr = SecureRandom.getInstance("SHA1PRNG", "SUN");
+        //Create array for salt
+        byte[] salt = new byte[16];
+        //Get a random salt
+        sr.nextBytes(salt);
+        //return salt
+        return salt;
+    }
+ 
+    private boolean validatePassword(final String originalPassword, final String storedPasswordHash) 
+    	    throws NoSuchAlgorithmException, InvalidKeySpecException
+    	{
+    	    // Split the string by :
+    	    String[] parts = storedPasswordHash.split(":");
+
+    	    // Extract iterations, salt, and hash 
+    	    // from the stored password hash
+    	    int iterations = Integer.valueOf(parts[0]); 
+    	    byte[] salt = convertToBytes(parts[1]);
+    	    byte[] hash = convertToBytes(parts[2]);
+
+    	    byte[] originalPasswordHash = createPBEHash(originalPassword, iterations, salt, hash.length);
+
+    	    int diff = hash.length ^ originalPasswordHash.length;
+    	    for(int i = 0; i < hash.length && i < originalPasswordHash.length; i++){
+    	        diff |= hash[i] ^ originalPasswordHash[i];
+    	    }
+    	    return diff == 0;
+    }
+
+	private byte[] createPBEHash(final String password, final int iterations, final byte[] salt, final int keyLength)
+			throws NoSuchAlgorithmException, InvalidKeySpecException {
+		PBEKeySpec spec = new PBEKeySpec(password.toCharArray(), 
+		    salt, iterations, keyLength * 8);
+		SecretKeyFactory skf = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
+		return skf.generateSecret(spec).getEncoded();
+	}
+    
+    private byte[] convertToBytes(final String hex) throws NoSuchAlgorithmException
+    {
+        byte[] bytes = new byte[hex.length() / 2];
+        
+        for(int i = 0; i < bytes.length ;i++){
+            bytes[i] = Integer.valueOf(hex.substring(2 * i, 2 * i + 2), 16).byteValue();
+        }
+        return bytes;
+    }
+    
+    public String createChecksum(final String filePath) throws FileNotFoundException, IOException, NoSuchAlgorithmException {
+    	MessageDigest md = MessageDigest.getInstance("SHA-256");
+        try (
+        		
+        	DigestInputStream dis = new DigestInputStream(
+        			new FileInputStream(filePath), md)) {
+            while (dis.read() != -1) ; 
+            md = dis.getMessageDigest();
+        }
+        
+        String checksum = convertToHex(md.digest());
+        return checksum;
+    }
+	
+	public static void main(String[] args) throws NoSuchAlgorithmException, InvalidKeySpecException, NoSuchProviderException, FileNotFoundException, IOException {
+		    HashCreator hashCreator = new HashCreator();
+		
+		    String hash = hashCreator.createMD5Hash("password123");
+			System.out.println(hash + " "+hash.length());
+			
+			hash = hashCreator.createSHAHash("password123");
+			System.out.println(hash+ " "+hash.length());
+					
+			String saltedHash = hashCreator.createPasswordHashWithSalt("password123");
+			System.out.println(saltedHash);
+			
+			String strongPwdHash = hashCreator.generateStrongPasswordHash("password123");
+			System.out.println(strongPwdHash);
+			
+			boolean matchResult = hashCreator.validatePassword("password123", strongPwdHash);
+			System.out.println("matchResult "+matchResult);
+			
+			String checksum = hashCreator.createChecksum("/Users/pratikdas/Downloads/heart.csv");
+			System.out.println("checksum "+checksum);
+	}
+
+}

resilience4j/springboot-resilience4j/README.md

@@ -5,3 +5,5 @@ Run the SpringbootResilience4jApplication program
 ## Blog posts
 
 * [Implementing Retry with Spring_Boot_Resilience4j](https://reflectoring.io/retry-with-springboot-resilience4j/)
+* [Implementing Rate Limiting with Spring_Boot_Resilience4j](https://reflectoring.io/rate-limiting-with-springboot-resilience4j/)
+* [Implementing Time Limiting with Spring_Boot_Resilience4j](https://reflectoring.io/time-limiting-with-springboot-resilience4j/)

resilience4j/springboot-resilience4j/src/main/java/io/reflectoring/resilience4j/springboot/RateLimiterExamplesRunner.java

@@ -0,0 +1,131 @@
+package io.reflectoring.resilience4j.springboot;
+
+import io.reflectoring.resilience4j.springboot.model.SearchRequest;
+import java.time.Duration;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+@Component
+public class RateLimiterExamplesRunner {
+
+  @Autowired
+  private RateLimitingService service;
+
+  public static void main(String[] args) {
+    RateLimiterExamplesRunner runner = new RateLimiterExamplesRunner();
+    runner.run();
+  }
+
+  public void run() {
+    System.out.println("Running ratelimiter examples");
+
+    System.out.println("----------------------------- basicExample ------------------------------------------");
+    basicExample();
+    System.out.println("-----------------------------------------------------------------------");
+
+    System.out.println("----------------------------- timeoutExample ------------------------------------------");
+    timeoutExample();
+    System.out.println("-----------------------------------------------------------------------");
+
+    System.out.println("------------------------------ multipleLimits_2rps_40rpm_sequential -----------------------------------------");
+    multipleLimits_2rps_40rpm_sequential();
+    System.out.println("-----------------------------------------------------------------------");
+
+    System.out.println("------------------------------- changeLimitsExample ----------------------------------------");
+    changeLimitsExample();
+    System.out.println("-----------------------------------------------------------------------");
+
+    System.out.println("------------------------------- retryAndRateLimit ----------------------------------------");
+    retryAndRateLimit();
+    System.out.println("-----------------------------------------------------------------------");
+
+   System.out.println("------------------------------ rateLimiterEvents -----------------------------------------");
+   rateLimiterEvents();
+   System.out.println("-----------------------------------------------------------------------");
+
+    System.out.println("----------------------------- fallbackExample ------------------------------------------");
+    fallbackExample();
+    System.out.println("-----------------------------------------------------------------------");
+  }
+
+  private void rateLimiterEvents() {
+    SearchRequest request = new SearchRequest("NYC", "LAX", "08/15/2021");
+
+    try {
+      System.out.println(service.rateLimiterEventsExample(request));
+      System.out.println(service.rateLimiterEventsExample(request));
+    }
+    catch (Exception e) {
+      System.out.println(e.getMessage());
+    }
+  }
+
+  private void retryAndRateLimit() {
+    SearchRequest request = new SearchRequest("NYC", "LAX", "08/15/2021");
+
+    System.out.println(service.retryAndRateLimit(request));
+    System.out.println(service.retryAndRateLimit(request));
+  }
+
+  private void changeLimitsExample() {
+    SearchRequest request = new SearchRequest("NYC", "LAX", "08/15/2021");
+
+    for (int i=0; i<6; i++) {
+      System.out.println(service.changeLimitsExample(request));
+    }
+
+    try {
+      Thread.sleep(2000);
+    } catch (InterruptedException e) {
+      e.printStackTrace();
+    }
+
+    service.updateRateLimits("changeLimitsExample", 2, Duration.ofSeconds(2));
+    System.out.println("Rate limits changed");
+
+    for (int i=0; i<6; i++) {
+      System.out.println(service.changeLimitsExample(request));
+    }
+  }
+
+  private void multipleLimits_2rps_40rpm_sequential() {
+    SearchRequest request = new SearchRequest("NYC", "LAX", "08/15/2021");
+    for (int i=0; i<45; i++) {
+      try {
+        System.out.println(service.multipleRateLimitsExample(request));
+      }
+      catch (Exception e) {
+        e.printStackTrace();
+      }
+    }
+  }
+
+  private void timeoutExample() {
+    SearchRequest request = new SearchRequest("NYC", "LAX", "08/15/2021");
+    try {
+      for (int i=0; i<3; i++) {
+        System.out.println(service.timeoutExample(request));
+      }
+    }
+    catch (Exception e) {
+      e.printStackTrace();
+    }
+  }
+
+  private void basicExample() {
+    SearchRequest request = new SearchRequest("NYC", "LAX", "08/15/2021");
+    for (int i=0; i<4; i++) {
+      try {
+        System.out.println(service.basicExample(request));
+      } catch (Exception e) {
+        e.printStackTrace();
+      }
+    }
+  }
+
+  private void fallbackExample() {
+    SearchRequest request = new SearchRequest("NYC", "LAX", "08/15/2021");
+    System.out.println(service.fallbackExample(request));
+    System.out.println(service.fallbackExample(request));
+  }
+}

resilience4j/springboot-resilience4j/src/main/java/io/reflectoring/resilience4j/springboot/RateLimitingService.java

@@ -0,0 +1,128 @@
+package io.reflectoring.resilience4j.springboot;
+
+import io.github.resilience4j.ratelimiter.RateLimiterRegistry;
+import io.github.resilience4j.ratelimiter.RequestNotPermitted;
+import io.github.resilience4j.ratelimiter.annotation.RateLimiter;
+import io.github.resilience4j.retry.RetryRegistry;
+import io.github.resilience4j.retry.annotation.Retry;
+import io.reflectoring.resilience4j.springboot.model.Flight;
+import io.reflectoring.resilience4j.springboot.model.SearchRequest;
+import io.reflectoring.resilience4j.springboot.services.FlightSearchService;
+import java.time.Duration;
+import java.time.format.DateTimeFormatter;
+import java.util.Arrays;
+import java.util.List;
+import javax.annotation.PostConstruct;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+import org.springframework.stereotype.Service;
+
+@Service
+public class RateLimitingService {
+  @Autowired
+  private FlightSearchService remoteSearchService;
+
+  @Autowired
+  private RPMRateLimitedFlightSearchSearch rpmRateLimitedFlightSearchSearch;
+
+  @Autowired
+  private RateLimiterRegistry registry;
+
+  @Autowired
+  private RetryRegistry retryRegistry;
+
+  DateTimeFormatter formatter = DateTimeFormatter.ofPattern("HH:mm:ss SSS");
+
+  @RateLimiter(name = "basicExample")
+  List<Flight> basicExample(SearchRequest request) {
+    return remoteSearchService.searchFlights(request);
+  }
+
+  @RateLimiter(name = "timeoutExample")
+  List<Flight> timeoutExample(SearchRequest request) {
+    return remoteSearchService.searchFlights(request);
+  }
+
+  @RateLimiter(name = "multipleRateLimiters_rps_limiter")
+  List<Flight> multipleRateLimitsExample(SearchRequest request) {
+    return rpmRateLimitedFlightSearchSearch.searchFlights(request, remoteSearchService);
+  }
+
+// doesn't work - @RateLimiter is not a repeatable annotation
+//  @RateLimiter(name = "multipleRateLimiters_rps_limiter")
+//  @RateLimiter(name = "multipleRateLimiters_rpm_limiter")
+//  List<Flight> multipleRateLimitsExample(SearchRequest request) {
+//    return remoteSearchService.searchFlights(request, remoteSearchService);
+//  }
+
+// doesn't work - calls within a Spring bean don't go thru the Spring proxy
+//  @RateLimiter(name = "multipleRateLimiters_rps_limiter")
+//  List<Flight> rpsLimitedSearch(SearchRequest request) {
+//    return rpmLimitedSearch(request, remoteSearchService);
+//  }
+
+//  @RateLimiter(name = "multipleRateLimiters_rpm_limiter")
+//  List<Flight> rpmLimitedSearch(SearchRequest request) {
+//    return remoteSearchService.searchFlights(request, remoteSearchService);
+//  }
+
+
+  @RateLimiter(name = "changeLimitsExample")
+  public List<Flight> changeLimitsExample(SearchRequest request) {
+    return remoteSearchService.searchFlights(request);
+  }
+
+  @Retry(name = "retryAndRateLimitExample")
+  @RateLimiter(name = "retryAndRateLimitExample")
+  public List<Flight> retryAndRateLimit(SearchRequest request) {
+    return remoteSearchService.searchFlights(request);
+  }
+
+  @RateLimiter(name = "rateLimiterEventsExample")
+  public List<Flight> rateLimiterEventsExample(SearchRequest request) {
+    return remoteSearchService.searchFlights(request);
+  }
+
+  public void updateRateLimits(String rateLimiterName, int newLimitForPeriod, Duration newTimeoutDuration) {
+    io.github.resilience4j.ratelimiter.RateLimiter limiter = registry.rateLimiter(rateLimiterName);
+    limiter.changeLimitForPeriod(newLimitForPeriod);
+    limiter.changeTimeoutDuration(newTimeoutDuration);
+  }
+
+  @RateLimiter(name = "fallbackExample", fallbackMethod = "localCacheFlightSearch")
+  public List<Flight> fallbackExample(SearchRequest request) {
+    return remoteSearchService.searchFlights(request);
+  }
+
+  private List<Flight> localCacheFlightSearch(SearchRequest request, RequestNotPermitted rnp) {
+    System.out.println("Returning search results from cache");
+    return Arrays.asList(
+        new Flight("XY 765", request.getFlightDate(), request.getFrom(), request.getTo()),
+        new Flight("XY 781", request.getFlightDate(), request.getFrom(), request.getTo()));
+  }
+
+  @PostConstruct
+  public void postConstruct() {
+    io.github.resilience4j.retry.Retry.EventPublisher retryEventPublisher = retryRegistry
+        .retry("retryAndRateLimitExample")
+        .getEventPublisher();
+
+    retryEventPublisher.onRetry(System.out::println);
+    retryEventPublisher.onSuccess(System.out::println);
+
+    io.github.resilience4j.ratelimiter.RateLimiter.EventPublisher eventPublisher = registry
+        .rateLimiter("rateLimiterEventsExample")
+        .getEventPublisher();
+
+    eventPublisher.onSuccess(System.out::println);
+    eventPublisher.onFailure(System.out::println);
+  }
+}
+
+@Component
+class RPMRateLimitedFlightSearchSearch {
+  @RateLimiter(name = "multipleRateLimiters_rpm_limiter")
+  List<Flight> searchFlights(SearchRequest request, FlightSearchService remoteSearchService) {
+    return remoteSearchService.searchFlights(request);
+  }
+}

resilience4j/springboot-resilience4j/src/main/java/io/reflectoring/resilience4j/springboot/SpringbootResilience4jApplication.java

@@ -11,6 +11,12 @@ public class SpringbootResilience4jApplication {
 	@Autowired
 	private RetryExamplesRunner retryExamplesRunner;
 
+	@Autowired
+	private RateLimiterExamplesRunner rateLimiterExamplesRunner;
+
+	@Autowired
+	private TimeLimiterExamplesRunner timeLimiterExamplesRunner;
+
 	public static void main(String[] args) {
 		SpringApplication.run(SpringbootResilience4jApplication.class, args);
 	}
@@ -18,5 +24,7 @@ public class SpringbootResilience4jApplication {
 	@EventListener(ApplicationReadyEvent.class)
 	public void runExamples() {
 		retryExamplesRunner.run();
+		rateLimiterExamplesRunner.run();
+		timeLimiterExamplesRunner.run();
 	}
 }

resilience4j/springboot-resilience4j/src/main/java/io/reflectoring/resilience4j/springboot/TimeLimiterExamplesRunner.java

@@ -0,0 +1,142 @@
+package io.reflectoring.resilience4j.springboot;
+
+import io.reflectoring.resilience4j.springboot.model.Flight;
+import io.reflectoring.resilience4j.springboot.model.SearchRequest;
+import java.time.LocalDateTime;
+import java.time.format.DateTimeFormatter;
+import java.util.List;
+import java.util.concurrent.CompletableFuture;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+@Component
+public class TimeLimiterExamplesRunner {
+
+  @Autowired
+  private TimeLimitingService service;
+
+  private DateTimeFormatter formatter = DateTimeFormatter.ofPattern("HH:mm:ss SSS");
+
+  public static void main(String[] args) {
+    TimeLimiterExamplesRunner runner = new TimeLimiterExamplesRunner();
+    runner.run();
+  }
+
+  static void delay(int seconds) {
+    // sleep to simulate delay
+    try {
+      Thread.sleep(seconds * 1000);
+    } catch (InterruptedException e) {
+      e.printStackTrace();
+    }
+  }
+
+  public void run() {
+    System.out.println("Running timelimiter examples");
+
+    System.out.println(
+        "----------------------- basicExample ----------------------------------------------------");
+    basicExample();
+
+    delay(2); // delay just to let the above async operation to complete
+
+    System.out.println(
+        "----------------------------------------------------------------------------------------------------");
+
+    System.out.println("----------------------- timeoutExample ----------------------------------------------");
+    timeoutExample();
+
+    delay(2); // delay just to let the above async operation to complete
+
+    System.out.println("----------------------------------------------------------------------------------------------------");
+
+    System.out.println("----------------------- fallbackExample ----------------------------------------------");
+    fallbackExample();
+
+    delay(2); // delay just to let the above async operation to complete
+
+    System.out.println("----------------------------------------------------------------------------------------------------");
+
+    System.out.println(
+        "----------------------- eventsExample ----------------------------------------------------");
+    eventsExample();
+    delay(10); // delay just to let the above async operation to complete
+    System.out.println(
+        "----------------------------------------------------------------------------------------------------");
+  }
+
+  private void eventsExample() {
+    SearchRequest request = new SearchRequest("NYC", "LAX", "10/30/2021");
+    for (int i = 0; i < 10; i++) {
+      int attempt = i;
+      service.eventsExample(request)
+          .whenComplete((r, t) -> {
+            if (t != null) {
+              System.out.println("Error occurred on search " + attempt + ": " + t.getMessage());
+            }
+            if (r != null) {
+              System.out
+                  .println("Search " + attempt + " successful, found " + r.size() + " flights");
+            }
+          });
+    }
+  }
+
+  private void timeoutExample() {
+    SearchRequest request = new SearchRequest("NYC", "LAX", "10/30/2021");
+    System.out.println("Calling search; current thread = " + Thread.currentThread().getName());
+    CompletableFuture<List<Flight>> results = service.timeoutExample(request);
+    results.whenComplete((result, ex) -> {
+      if (ex != null) {
+        System.out.println("Exception " +
+            ex.getMessage() +
+            " on thread " +
+            Thread.currentThread().getName() +
+            " at " +
+            LocalDateTime.now().format(formatter));
+        ex.printStackTrace();
+      }
+      if (result != null) {
+        System.out.println(result + " on thread " + Thread.currentThread().getName());
+      }
+    });
+  }
+
+  private void basicExample() {
+    SearchRequest request = new SearchRequest("NYC", "LAX", "10/30/2021");
+    System.out.println("Calling search; current thread = " + Thread.currentThread().getName());
+    CompletableFuture<List<Flight>> results = service.basicExample(request);
+    results.whenComplete((result, ex) -> {
+      if (ex != null) {
+        System.out.println("Exception " +
+            ex.getMessage() +
+            " on thread " +
+            Thread.currentThread().getName() +
+            " at " +
+            LocalDateTime.now().format(formatter));
+      }
+      if (result != null) {
+        System.out.println(result + " on thread " + Thread.currentThread().getName());
+      }
+    });
+  }
+
+  private void fallbackExample() {
+    SearchRequest request = new SearchRequest("NYC", "LAX", "10/30/2021");
+    System.out.println("Calling search; current thread = " + Thread.currentThread().getName());
+    CompletableFuture<List<Flight>> results = service.fallbackExample(request);
+    results.whenComplete((result, ex) -> {
+      if (ex != null) {
+        System.out.println("Exception " +
+            ex.getMessage() +
+            " on thread " +
+            Thread.currentThread().getName() +
+            " at " +
+            LocalDateTime.now().format(formatter));
+      }
+      if (result != null) {
+        System.out.println(result + " on thread " + Thread.currentThread().getName());
+      }
+    });
+  }
+}

resilience4j/springboot-resilience4j/src/main/java/io/reflectoring/resilience4j/springboot/TimeLimitingService.java

@@ -0,0 +1,167 @@
+package io.reflectoring.resilience4j.springboot;
+
+import io.github.resilience4j.micrometer.tagged.TaggedTimeLimiterMetrics;
+import io.github.resilience4j.ratelimiter.RequestNotPermitted;
+import io.github.resilience4j.ratelimiter.annotation.RateLimiter;
+import io.github.resilience4j.timelimiter.TimeLimiter.EventPublisher;
+import io.github.resilience4j.timelimiter.TimeLimiterConfig;
+import io.github.resilience4j.timelimiter.TimeLimiterRegistry;
+import io.github.resilience4j.timelimiter.annotation.TimeLimiter;
+import io.micrometer.core.instrument.Measurement;
+import io.micrometer.core.instrument.Meter;
+import io.micrometer.core.instrument.MeterRegistry;
+import io.micrometer.core.instrument.simple.SimpleMeterRegistry;
+import io.reflectoring.resilience4j.springboot.model.Flight;
+import io.reflectoring.resilience4j.springboot.model.SearchRequest;
+import io.reflectoring.resilience4j.springboot.services.FlightSearchService;
+import java.sql.Time;
+import java.time.Duration;
+import java.time.LocalDateTime;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.CompletionStage;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+import java.util.function.Consumer;
+import java.util.function.Supplier;
+import java.util.stream.StreamSupport;
+import javax.annotation.PostConstruct;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+
+@Service
+public class TimeLimitingService {
+  @Autowired
+  private FlightSearchService remoteSearchService;
+
+  @Autowired
+  private TimeLimiterRegistry timeLimiterRegistry;
+
+/*
+  void printDefaultValues() {
+    TimeLimiterConfig config = TimeLimiterConfig.ofDefaults();
+
+    System.out.println(
+        "getTimeoutDuration in ms = " + Duration.from(config.getTimeoutDuration()).toMillis());
+    System.out.println("shouldCancelRunningFuture = " + config.shouldCancelRunningFuture());
+  } */
+
+
+  @TimeLimiter(name = "basicExample")
+  CompletableFuture<List<Flight>> basicExample(SearchRequest request) {
+    return CompletableFuture.supplyAsync(() -> remoteSearchService.searchFlightsTakingOneSecond(request));
+  }
+
+  @TimeLimiter(name = "timeoutExample")
+  CompletableFuture<List<Flight>> timeoutExample(SearchRequest request) {
+    return CompletableFuture.supplyAsync(() -> remoteSearchService.searchFlightsTakingOneSecond(request));
+  }
+
+  @TimeLimiter(name = "timeAndRateLimiter")
+  @RateLimiter(name = "timeAndRateLimiter")
+  CompletableFuture<List<Flight>> aspectOrderExample(SearchRequest request) {
+    return CompletableFuture.supplyAsync(() -> remoteSearchService.searchFlightsTakingOneSecond(request));
+  }
+
+  /*
+  void basicExample_ExcecuteCompletionStage() {
+    TimeLimiterConfig config = TimeLimiterConfig.custom()
+        .timeoutDuration(Duration.ofMillis(500))
+        .build();
+
+    TimeLimiterRegistry registry = TimeLimiterRegistry.of(config);
+    TimeLimiter limiter = registry.timeLimiter("flightSearch");
+
+    FlightSearchService service = new FlightSearchService();
+    SearchRequest request = new SearchRequest("NYC", "LAX", "08/30/2020");
+
+    Supplier<List<Flight>> flightSupplier = () -> service.searchFlightsTakingOneSecond(request);
+    Supplier<CompletionStage<List<Flight>>> origCompletionStageSupplier = () -> CompletableFuture
+        .supplyAsync(flightSupplier);
+    ScheduledExecutorService scheduler = Executors.newSingleThreadScheduledExecutor();
+    CompletionStage<List<Flight>> decoratedCompletionStage = limiter
+        .executeCompletionStage(scheduler, origCompletionStageSupplier);
+
+    decoratedCompletionStage.whenComplete((result, ex) -> {
+      if (ex != null) {
+        System.out.println("Exception " +
+            ex.getMessage() +
+            " on thread " +
+            Thread.currentThread().getName() +
+            " at " +
+            LocalDateTime.now().format(formatter));
+      }
+      if (result != null) {
+        System.out.println(result + " on thread " + Thread.currentThread().getName());
+      }
+    });
+
+    scheduler.shutdown();
+  }
+
+
+  void whenToUseExample() {
+    CompletableFuture.supplyAsync(this::slowMethod).thenAccept(System.out::println);
+  }
+
+  void whenToUseExample_Blocking()
+      throws InterruptedException, ExecutionException, TimeoutException {
+    CompletableFuture<Integer> completableFuture = CompletableFuture
+        .supplyAsync(this::slowMethod);
+    Integer result = completableFuture.get(3000, TimeUnit.MILLISECONDS);
+    System.out.println(result);
+  }
+
+  int slowMethod() {
+    System.out.println(Thread.currentThread().getName());
+    // sleep to simulate delay
+    try {
+      Thread.sleep(2000);
+    } catch (InterruptedException e) {
+      e.printStackTrace();
+    }
+    return 0;
+  }
+
+  static void delay(int seconds) {
+    // sleep to simulate delay
+    try {
+      Thread.sleep(seconds * 1000);
+    } catch (InterruptedException e) {
+      e.printStackTrace();
+    }
+  } */
+
+  @TimeLimiter(name = "eventsExample")
+  CompletableFuture<List<Flight>>  eventsExample(SearchRequest request) {
+    return CompletableFuture.supplyAsync(() -> remoteSearchService.searchFlightsTakingRandomTime(request));
+  }
+
+  @TimeLimiter(name = "fallbackExample", fallbackMethod = "localCacheFlightSearch")
+  CompletableFuture<List<Flight>> fallbackExample(SearchRequest request) {
+    return CompletableFuture.supplyAsync(() -> remoteSearchService.searchFlightsTakingOneSecond(request));
+  }
+
+  private CompletableFuture<List<Flight>> localCacheFlightSearch(SearchRequest request, TimeoutException rnp) {
+    System.out.println("Returning search results from cache");
+    System.out.println(rnp.getMessage());
+    CompletableFuture<List<Flight>> result = new CompletableFuture<>();
+    result.complete(Arrays.asList(
+        new Flight("XY 765", request.getFlightDate(), request.getFrom(), request.getTo()),
+        new Flight("XY 781", request.getFlightDate(), request.getFrom(), request.getTo())));
+    return result;
+  }
+
+  @PostConstruct
+  void postConstruct() {
+    EventPublisher eventPublisher = timeLimiterRegistry.timeLimiter("eventsExample").getEventPublisher();
+    eventPublisher.onSuccess(System.out::println);
+    eventPublisher.onError(System.out::println);
+    eventPublisher.onTimeout(System.out::println);
+  }
+}

resilience4j/springboot-resilience4j/src/main/java/io/reflectoring/resilience4j/springboot/services/FlightSearchService.java

@@ -13,6 +13,7 @@ import java.time.format.DateTimeFormatter;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
+import java.util.Random;
 import org.springframework.stereotype.Service;
 
 @Service
@@ -20,6 +21,7 @@ public class FlightSearchService {
 
   PotentialFailure potentialFailure = new NoFailure();
   DateTimeFormatter formatter = DateTimeFormatter.ofPattern("HH:mm:ss SSS");
+  Random random = new Random();
 
   PotentialFailureCheckedException potentialFailureCheckedException = new NoCheckedExceptionFailure();
 
@@ -108,4 +110,42 @@ public class FlightSearchService {
     response.setFlights(flights);
     return response;
   }
+
+  public List<Flight> searchFlightsTakingOneSecond(SearchRequest request) {
+    System.out.println("Searching for flights; "
+        + "current time = " + LocalDateTime.now().format(formatter) +
+        "; current thread = " + Thread.currentThread().getName());
+
+    try {
+      Thread.sleep(1000);
+    } catch (InterruptedException e) {
+      e.printStackTrace();
+    }
+
+    List<Flight> flights = Arrays.asList(
+        new Flight("XY 765", request.getFlightDate(), request.getFrom(), request.getTo()),
+        new Flight("XY 746", request.getFlightDate(), request.getFrom(), request.getTo())
+    );
+    System.out.println("Flight search successful at " + LocalDateTime.now().format(formatter));
+    return flights;
+  }
+
+  public List<Flight> searchFlightsTakingRandomTime(SearchRequest request) {
+    long delay = random.nextInt(3000);
+    try {
+      Thread.sleep(delay);
+    } catch (InterruptedException e) {
+      e.printStackTrace();
+    }
+    System.out.println("Searching for flights; "
+        + "current time = " + LocalDateTime.now().format(formatter) +
+        "; current thread = " + Thread.currentThread().getName());
+
+    List<Flight> flights = Arrays.asList(
+        new Flight("XY 765", request.getFlightDate(), request.getFrom(), request.getTo()),
+        new Flight("XY 746", request.getFlightDate(), request.getFrom(), request.getTo())
+    );
+    System.out.println("Flight search successful");
+    return flights;
+  }
 }

resilience4j/springboot-resilience4j/src/main/resources/application.yml

@@ -44,6 +44,80 @@ resilience4j:
           - java.lang.Exception
         waitDuration: 2s
 
+      # Retry object used in RateLimitingService.retryAndRateLimitExample()
+      retryAndRateLimitExample:
+        maxRetryAttempts: 2
+        waitDuration: 1s
+
+  ratelimiter:
+    instances:
+
+      # RateLimiter object used in RateLimitingService.basicExample()
+      basicExample:
+        limitForPeriod: 1
+        limitRefreshPeriod: 1s
+        timeoutDuration: 1s
+
+      # RateLimiter object used in RateLimitingService.timeoutExample()
+      timeoutExample:
+        limitForPeriod: 1
+        limitRefreshPeriod: 1s
+        timeoutDuration: 250ms
+
+      # RateLimiter object used in RateLimitingService.multipleRateLimitsExample()
+      multipleRateLimiters_rps_limiter:
+        limitForPeriod: 2
+        limitRefreshPeriod: 1s
+        timeoutDuration: 2s
+
+      multipleRateLimiters_rpm_limiter:
+        limitForPeriod: 40
+        limitRefreshPeriod: 1m
+        timeoutDuration: 2s
+
+      # RateLimiter object used in RateLimitingService.changeLimitsExample()
+      changeLimitsExample:
+        limitForPeriod: 1
+        limitRefreshPeriod: 1s
+        timeoutDuration: 1s
+
+      # RateLimiter object used in RateLimitingService.retryAndRateLimitExample()
+      retryAndRateLimitExample:
+        limitForPeriod: 1
+        limitRefreshPeriod: 1s
+        timeoutDuration: 250ms
+
+      # RateLimiter object used in RateLimitingService.rateLimiterEventsExample()
+      rateLimiterEventsExample:
+        limitForPeriod: 1
+        limitRefreshPeriod: 1s
+        timeoutDuration: 50ms
+
+      # RateLimiter object used in RateLimitingService.fallbackExample()
+      fallbackExample:
+        limitForPeriod: 1
+        limitRefreshPeriod: 1s
+        timeoutDuration: 500ms
+
+  timelimiter:
+    instances:
+
+      # TimeLimiter object used in TimeLimitingService.basicExample()
+      basicExample:
+        timeoutDuration: 2s
+
+      # TimeLimiter object used in TimeLimitingService.timeoutExample()
+      timeoutExample:
+        timeoutDuration: 500ms
+
+      # TimeLimiter object used in TimeLimitingService.eventsExample()
+      eventsExample:
+        timeoutDuration: 2s
+
+      # TimeLimiter object used in TimeLimitingService.fallbackExample()
+      fallbackExample:
+        timeoutDuration: 500ms
+
 management:
   endpoints:
     web:

spring-boot/feature-flags/pom.xml

@@ -21,10 +21,18 @@
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-starter-web</artifactId>
 		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-jdbc</artifactId>
+		</dependency>
 		<dependency>
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-starter-thymeleaf</artifactId>
 		</dependency>
+		<dependency>
+			<groupId>com.h2database</groupId>
+			<artifactId>h2</artifactId>
+		</dependency>
 
 		<!-- TOGGLZ -->
 		<dependency>

spring-boot/feature-flags/src/main/java/io/reflectoring/featureflags/FeatureFlagService.java

@@ -22,4 +22,6 @@ public interface FeatureFlagService {
      */
     Boolean isUserActionTargetedFeatureActive();
 
+    Boolean isNewServiceEnabled();
+
 }

spring-boot/feature-flags/src/main/java/io/reflectoring/featureflags/ff4j/FF4JFeatureFlagService.java

@@ -33,4 +33,9 @@ public class FF4JFeatureFlagService implements FeatureFlagService {
         return null;
     }
 
+    @Override
+    public Boolean isNewServiceEnabled() {
+        return null;
+    }
+
 }

spring-boot/feature-flags/src/main/java/io/reflectoring/featureflags/implementations/FeatureFlagService.java

@@ -0,0 +1,9 @@
+package io.reflectoring.featureflags.implementations;
+
+public interface FeatureFlagService {
+
+    Boolean featureOne();
+
+    Integer featureTwo();
+
+}

spring-boot/feature-flags/src/main/java/io/reflectoring/featureflags/implementations/code/CodeBackedFeatureFlagService.java

@@ -0,0 +1,15 @@
+package io.reflectoring.featureflags.implementations.code;
+
+import io.reflectoring.featureflags.implementations.FeatureFlagService;
+
+public class CodeBackedFeatureFlagService implements FeatureFlagService {
+    @Override
+    public Boolean featureOne() {
+        return true;
+    }
+
+    @Override
+    public Integer featureTwo() {
+        return 42;
+    }
+}