feature flags

build-all.sh

@@ -86,6 +86,7 @@ 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-boot/feature-flags"
   build_maven_module "logging/spring-boot"
   build_maven_module "logging/logback"
   build_maven_module "logging/log4j"

spring-boot/feature-flags/.gitignore

@@ -0,0 +1,33 @@
+HELP.md
+target/
+!.mvn/wrapper/maven-wrapper.jar
+!**/src/main/**/target/
+!**/src/test/**/target/
+
+### STS ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+
+### IntelliJ IDEA ###
+.idea
+*.iws
+*.iml
+*.ipr
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+build/
+!**/src/main/**/build/
+!**/src/test/**/build/
+
+### VS Code ###
+.vscode/

spring-boot/feature-flags/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} $MAVEN_CONFIG "$@"

spring-boot/feature-flags/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%

spring-boot/feature-flags/pom.xml

@@ -0,0 +1,89 @@
+<?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>2.5.1</version>
+		<relativePath/> <!-- lookup parent from repository -->
+	</parent>
+	<groupId>io.reflectoring</groupId>
+	<artifactId>feature-flags</artifactId>
+	<version>0.0.1-SNAPSHOT</version>
+	<name>feature-flags</name>
+	<description>Demo project for 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.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-thymeleaf</artifactId>
+		</dependency>
+
+		<!-- TOGGLZ -->
+		<dependency>
+			<groupId>org.togglz</groupId>
+			<artifactId>togglz-spring-boot-starter</artifactId>
+			<version>2.6.1.Final</version>
+		</dependency>
+		<dependency>
+			<groupId>org.togglz</groupId>
+			<artifactId>togglz-console</artifactId>
+			<version>2.6.1.Final</version>
+		</dependency>
+
+		<!-- LAUNCHDARKLY -->
+		<dependency>
+			<groupId>com.launchdarkly</groupId>
+			<artifactId>launchdarkly-java-server-sdk</artifactId>
+			<version>5.3.0</version>
+		</dependency>
+
+		<!-- FF4J -->
+		<dependency>
+			<groupId>org.ff4j</groupId>
+			<artifactId>ff4j-spring-boot-starter</artifactId>
+			<version>1.8.11</version>
+		</dependency>
+		<dependency>
+			<groupId>org.ff4j</groupId>
+			<artifactId>ff4j-web</artifactId>
+			<version>1.8.11</version>
+		</dependency>
+		<dependency>
+			<groupId>org.ff4j</groupId>
+			<artifactId>ff4j-config-yaml</artifactId>
+			<version>1.8.11</version>
+		</dependency>
+
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-test</artifactId>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.springframework.boot</groupId>
+				<artifactId>spring-boot-maven-plugin</artifactId>
+				<configuration>
+					<environmentVariables>
+						<TOGGLZ_FEATURES_GLOBAL_BOOLEAN_FLAG_ENABLED>true</TOGGLZ_FEATURES_GLOBAL_BOOLEAN_FLAG_ENABLED>
+					</environmentVariables>
+					<jvmArguments>
+						-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=5005
+					</jvmArguments>
+				</configuration>
+			</plugin>
+		</plugins>
+	</build>
+
+</project>

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

@@ -0,0 +1,25 @@
+package io.reflectoring.featureflags;
+
+public interface FeatureFlagService {
+
+    /**
+     * A simple Boolean feature flag that returns either true or false for all users.
+     */
+    Boolean isGlobalBooleanFeatureActive();
+
+    /**
+     * A Boolean feature flag that is targeted at a cohort of users.
+     */
+    Boolean isPercentageRolloutActive();
+
+    /**
+     * A number-based feature flag that returns a number controlled by the Feature Flag service.
+     */
+    Integer getNumberFlag();
+
+    /**
+     * A feature flag based on a previous user action.
+     */
+    Boolean isUserActionTargetedFeatureActive();
+
+}

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

@@ -0,0 +1,13 @@
+package io.reflectoring.featureflags;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class FeatureFlagsApplication {
+
+	public static void main(String[] args) {
+		SpringApplication.run(FeatureFlagsApplication.class, args);
+	}
+
+}

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

@@ -0,0 +1,4 @@
+package io.reflectoring.featureflags;
+
+public class UserContext {
+}

spring-boot/feature-flags/src/main/java/io/reflectoring/featureflags/ff4j/FF4JConfiguration.java

@@ -0,0 +1,15 @@
+package io.reflectoring.featureflags.ff4j;
+
+import org.ff4j.FF4j;
+import org.ff4j.conf.XmlParser;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+public class FF4JConfiguration {
+
+    @Bean("ff4jConfig")
+    public FF4j ff4J(){
+        return new FF4j(new XmlParser(), "ff4j.xml");
+    }
+}

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

@@ -0,0 +1,36 @@
+package io.reflectoring.featureflags.ff4j;
+
+import io.reflectoring.featureflags.FeatureFlagService;
+import org.ff4j.FF4j;
+import org.springframework.stereotype.Component;
+
+@Component("ff4j")
+public class FF4JFeatureFlagService implements FeatureFlagService {
+
+    private final FF4j ff4j;
+
+    public FF4JFeatureFlagService(FF4j ff4j) {
+        this.ff4j = ff4j;
+    }
+
+    @Override
+    public Boolean isGlobalBooleanFeatureActive() {
+        return ff4j.check("global-boolean-flag");
+    }
+
+    @Override
+    public Boolean isPercentageRolloutActive() {
+        return ff4j.check("global-percentage-rollout");
+    }
+
+    @Override
+    public Integer getNumberFlag() {
+        return null;
+    }
+
+    @Override
+    public Boolean isUserActionTargetedFeatureActive() {
+        return null;
+    }
+
+}

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

@@ -0,0 +1,25 @@
+package io.reflectoring.featureflags.ff4j;
+
+import org.ff4j.core.FeatureStore;
+import org.ff4j.core.FlippingExecutionContext;
+import org.ff4j.core.FlippingStrategy;
+
+import java.util.Map;
+
+public class UserClickedFlippingStrategy implements FlippingStrategy {
+
+    @Override
+    public void init(String featureName, Map<String, String> initParam) {
+
+    }
+
+    @Override
+    public Map<String, String> getInitParams() {
+        return null;
+    }
+
+    @Override
+    public boolean evaluate(String featureName, FeatureStore store, FlippingExecutionContext executionContext) {
+        return false;
+    }
+}

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

@@ -0,0 +1,27 @@
+package io.reflectoring.featureflags.launchdarkly;
+
+import com.launchdarkly.sdk.server.LDClient;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import javax.annotation.PreDestroy;
+import java.io.IOException;
+
+@Configuration
+public class LaunchDarklyConfiguration {
+
+    private LDClient launchdarklyClient;
+
+    @Bean
+    public LDClient launchdarklyClient(@Value("${launchdarkly.sdkKey}") String sdkKey) {
+        this.launchdarklyClient = new LDClient(sdkKey);
+        return this.launchdarklyClient;
+    }
+
+    @PreDestroy
+    public void destroy() throws IOException {
+        this.launchdarklyClient.close();
+    }
+
+}

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

@@ -0,0 +1,64 @@
+package io.reflectoring.featureflags.launchdarkly;
+
+import com.launchdarkly.sdk.LDUser;
+import com.launchdarkly.sdk.server.LDClient;
+import io.reflectoring.featureflags.FeatureFlagService;
+import io.reflectoring.featureflags.web.UserSession;
+import org.springframework.stereotype.Component;
+
+import javax.annotation.PostConstruct;
+
+@Component("launchdarkly")
+public class LaunchDarklyFeatureFlagService implements FeatureFlagService {
+
+    private final LDClient launchdarklyClient;
+    private final UserSession userSession;
+
+    public LaunchDarklyFeatureFlagService(LDClient launchdarklyClient, UserSession userSession) {
+        this.launchdarklyClient = launchdarklyClient;
+        this.userSession = userSession;
+    }
+
+    /**
+     * Initializing LaunchDarkly users so that they are in the expected state at the start of the app.
+     * This is for testing purposes only.
+     */
+    @PostConstruct
+    public void initUsers() {
+        launchdarklyClient.identify(new LDUser.Builder("alice")
+                .custom("clicked", true)
+                .build());
+        launchdarklyClient.identify(new LDUser.Builder("bob")
+                .custom("clicked", true)
+                .build());
+        launchdarklyClient.identify(new LDUser.Builder("charlie")
+                .custom("clicked", true)
+                .build());
+    }
+
+    @Override
+    public Boolean isGlobalBooleanFeatureActive() {
+        return launchdarklyClient.boolVariation("global-boolean-flag", getLaunchdarklyUserFromSession(), false);
+    }
+
+    @Override
+    public Boolean isPercentageRolloutActive() {
+        return launchdarklyClient.boolVariation("user-based-percentage-rollout", getLaunchdarklyUserFromSession(), false);
+    }
+
+    @Override
+    public Integer getNumberFlag() {
+        return null;
+    }
+
+    @Override
+    public Boolean isUserActionTargetedFeatureActive() {
+        return launchdarklyClient.boolVariation("user-clicked-flag", getLaunchdarklyUserFromSession(), false);
+    }
+
+    private LDUser getLaunchdarklyUserFromSession() {
+        return new LDUser.Builder(userSession.getUsername())
+                .custom("clicked", userSession.hasClicked())
+                .build();
+    }
+}

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

@@ -0,0 +1,27 @@
+package io.reflectoring.featureflags.togglz;
+
+import org.togglz.core.Feature;
+import org.togglz.core.activation.GradualActivationStrategy;
+import org.togglz.core.annotation.ActivationParameter;
+import org.togglz.core.annotation.DefaultActivationStrategy;
+import org.togglz.core.annotation.EnabledByDefault;
+import org.togglz.core.context.FeatureContext;
+
+public enum Features implements Feature {
+
+    GLOBAL_BOOLEAN_FLAG,
+
+    @EnabledByDefault
+    @DefaultActivationStrategy(id = GradualActivationStrategy.ID, parameters = {
+            @ActivationParameter(name = GradualActivationStrategy.PARAM_PERCENTAGE, value = "50")
+    })
+    USER_BASED_PERCENTAGE_ROLLOUT,
+
+    @EnabledByDefault
+    @DefaultActivationStrategy(id = "clicked")
+    USER_ACTION_TARGETED_FEATURE;
+
+    public boolean isActive() {
+        return FeatureContext.getFeatureManager().isActive(this);
+    }
+}

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

@@ -0,0 +1,40 @@
+package io.reflectoring.featureflags.togglz;
+
+import io.reflectoring.featureflags.web.UserSession;
+import org.springframework.stereotype.Component;
+import org.togglz.core.user.FeatureUser;
+import org.togglz.core.user.UserProvider;
+
+@Component
+public class TogglzUserProvider implements UserProvider {
+
+    private final UserSession userSession;
+
+    public TogglzUserProvider(UserSession userSession) {
+        this.userSession = userSession;
+    }
+
+    @Override
+    public FeatureUser getCurrentUser() {
+        return new FeatureUser() {
+            @Override
+            public String getName() {
+                return userSession.getUsername();
+            }
+
+            @Override
+            public boolean isFeatureAdmin() {
+                return false;
+            }
+
+            @Override
+            public Object getAttribute(String attributeName) {
+                if (attributeName.equals("clicked")) {
+                    return userSession.hasClicked();
+                }
+                return null;
+            }
+        };
+    }
+
+}

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

@@ -0,0 +1,29 @@
+package io.reflectoring.featureflags.togglz;
+
+import io.reflectoring.featureflags.FeatureFlagService;
+import org.springframework.stereotype.Component;
+
+@Component("togglz")
+public class TooglzFeatureFlagService implements FeatureFlagService {
+
+    @Override
+    public Boolean isGlobalBooleanFeatureActive() {
+        return Features.GLOBAL_BOOLEAN_FLAG.isActive();
+    }
+
+    @Override
+    public Boolean isPercentageRolloutActive() {
+        return Features.USER_BASED_PERCENTAGE_ROLLOUT.isActive();
+    }
+
+    @Override
+    public Integer getNumberFlag() {
+        return null;
+    }
+
+    @Override
+    public Boolean isUserActionTargetedFeatureActive() {
+        return Features.USER_ACTION_TARGETED_FEATURE.isActive();
+    }
+
+}

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

@@ -0,0 +1,29 @@
+package io.reflectoring.featureflags.togglz;
+
+import org.togglz.core.activation.Parameter;
+import org.togglz.core.repository.FeatureState;
+import org.togglz.core.spi.ActivationStrategy;
+import org.togglz.core.user.FeatureUser;
+
+public class UserClickedActivationStrategy implements ActivationStrategy {
+
+    @Override
+    public String getId() {
+        return "clicked";
+    }
+
+    @Override
+    public String getName() {
+        return "Rollout based on user click";
+    }
+
+    @Override
+    public boolean isActive(FeatureState featureState, FeatureUser user) {
+        return (Boolean) user.getAttribute("clicked");
+    }
+
+    @Override
+    public Parameter[] getParameters() {
+        return new Parameter[0];
+    }
+}

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

@@ -0,0 +1,49 @@
+package io.reflectoring.featureflags.web;
+
+import org.springframework.context.annotation.Scope;
+import org.springframework.context.annotation.ScopedProxyMode;
+import org.springframework.stereotype.Component;
+import org.springframework.web.context.WebApplicationContext;
+
+import java.io.Serializable;
+import java.util.HashMap;
+import java.util.Map;
+
+@Component("userSession")
+@Scope(value = WebApplicationContext.SCOPE_SESSION, proxyMode = ScopedProxyMode.TARGET_CLASS)
+public class UserSession implements Serializable {
+
+    private static ThreadLocal<UserSession> threadLocalUserSession;
+
+    public static void setThreadLocalSession(UserSession userSession){
+        threadLocalUserSession.set(userSession);
+    }
+
+    public static UserSession get(){
+        return threadLocalUserSession.get();
+    }
+
+    private Map<String, Boolean> userClicked = new HashMap<>();
+    private String username;
+
+    public void login(String username){
+        this.username = username;
+    }
+
+    public String getUsername(){
+        return this.username;
+    }
+
+    public boolean hasClicked(){
+        if(!userClicked.containsKey(this.username)){
+            return false;
+        }
+        return userClicked.get(username);
+    }
+
+    public void recordClick(){
+        userClicked.put(this.username, Boolean.TRUE);
+    }
+
+
+}

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

@@ -0,0 +1,46 @@
+package io.reflectoring.featureflags.web;
+
+import org.springframework.stereotype.Controller;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.servlet.ModelAndView;
+
+@Controller
+class WebController {
+
+    private final UserSession userSession;
+
+    WebController(UserSession userSession) {
+        this.userSession = userSession;
+    }
+
+    @GetMapping(path = {"/"})
+    ModelAndView chooseUser() {
+        return new ModelAndView("/choose-user.html");
+    }
+
+    @GetMapping(path = {"/alice"})
+    ModelAndView alice() {
+        userSession.login("alice");
+        return new ModelAndView("/features.html");
+    }
+
+    @GetMapping(path = {"/bob"})
+    ModelAndView bob() {
+        userSession.login("bob");
+        return new ModelAndView("/features.html");
+    }
+
+    @GetMapping(path = {"/charlie"})
+    ModelAndView charlie() {
+        userSession.login("charlie");
+        return new ModelAndView("/features.html");
+    }
+
+    @PostMapping(path = {"/click"})
+    ModelAndView click() {
+        userSession.recordClick();
+        return new ModelAndView("/features.html");
+    }
+
+}

spring-boot/feature-flags/src/main/resources/META-INF/services/org.togglz.core.spi.ActivationStrategy

@@ -0,0 +1 @@
+io.reflectoring.featureflags.togglz.UserClickedActivationStrategy

spring-boot/feature-flags/src/main/resources/application.yml

@@ -0,0 +1,18 @@
+launchdarkly:
+  sdkKey: <YOUR-SDK-KEY>
+
+logging:
+  level:
+    org.togglz: DEBUG
+    com.launchdarkly: TRACE
+
+togglz:
+  feature-enums: io.reflectoring.featureflags.togglz.Features
+  features:
+    GLOBAL_BOOLEAN_FLAG:
+      enabled: true
+  console:
+    enabled: true
+    secured: false
+    path: /togglz
+    use-management-port: false

spring-boot/feature-flags/src/main/resources/ff4j.xml

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<ff4j xmlns="http://www.ff4j.org/schema/ff4j"
+      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+      xsi:schemaLocation="http://www.ff4j.org/schema/ff4j http://ff4j.org/schema/ff4j-1.4.0.xsd">
+
+    <features>
+        <feature uid="global-boolean-flag" enable="true"  description="A global boolean flag" />
+
+        <feature uid="global-percentage-rollout" enable="true" description="A global percentage rollout">
+            <flipstrategy class="org.ff4j.strategy.PonderationStrategy" >
+                <param name="weight" value="0.5" />
+            </flipstrategy>
+        </feature>
+
+    </features>
+
+
+</ff4j>

spring-boot/feature-flags/src/main/resources/templates/choose-user.html

@@ -0,0 +1,20 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <meta charset="utf-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+
+    <title>Who are you?</title>
+
+  </head>
+
+  <body>
+    <h1>Who are you?</h1>
+    <ul>
+      <li><a href="/alice">Alice</a></li>
+      <li><a href="/bob">Bob</a></li>
+      <li><a href="/charlie">Charlie</a></li>
+    </ul>
+
+  </body>
+</html>

spring-boot/feature-flags/src/main/resources/templates/features.html

@@ -0,0 +1,61 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <meta charset="utf-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+
+    <title>Your features</title>
+    <style>
+    td {
+      padding:10px;
+    }
+    </style>
+
+  </head>
+
+  <body>
+
+  <h1>Who are you?</h1>
+  <ul>
+    <li><a href="/alice">Alice</a></li>
+    <li><a href="/bob">Bob</a></li>
+    <li><a href="/charlie">Charlie</a></li>
+  </ul>
+
+  <h1><span th:text="${@userSession.username}">Bob</span>'s features</h1>
+    <table>
+      <tr>
+        <td></td>
+        <th>Togglz</th>
+        <th>FF4J</th>
+        <th>Launchdarkly</th>
+      </tr>
+      <tr>
+        <th>global boolean feature</th>
+        <td th:text="${@togglz.isGlobalBooleanFeatureActive()}"></td>
+        <td th:text="${@ff4j.isGlobalBooleanFeatureActive()}"></td>
+        <td th:text="${@launchdarkly.isGlobalBooleanFeatureActive()}"></td>
+      </tr>
+      <tr>
+        <th>user-based percentage rollout (50%)</th>
+        <td th:text="${@togglz.isPercentageRolloutActive()}"></td>
+        <td th:text="${@ff4j.isPercentageRolloutActive()}"></td>
+        <td th:text="${@launchdarkly.isPercentageRolloutActive()}"></td>
+      </tr>
+      <tr>
+        <th>rollout based on user click</th>
+        <td th:text="${@togglz.isUserActionTargetedFeatureActive()}"></td>
+        <td>N/A</td>
+        <td th:text="${@launchdarkly.isUserActionTargetedFeatureActive()}"></td>
+      </tr>
+    </table>
+
+  <form action="/click" method="post">
+    <input type="submit" value="Click to enable User-Action targeted feature"/>
+  </form>
+
+  <form action="/test" method="post">
+    <input type="submit" value="testuser"/>
+  </form>
+  </body>
+</html>

spring-boot/feature-flags/src/test/java/io/reflectoring/featureflags/FeatureFlagsApplicationTests.java

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