argumentresolver example

Reflect-76 ISP explained added code examples

build-all.sh

@@ -30,6 +30,9 @@ build_gradle_module() {
 
 chmod +x gradlew
 
+build_gradle_module "spring-boot/argumentresolver"
+build_gradle_module "solid"
+build_gradle_module "spring-boot/data-migration/flyway"
 build_gradle_module "reactive"
 build_gradle_module "junit/assumptions"
 build_gradle_module "logging"

solid/build.gradle

@@ -0,0 +1,25 @@
+buildscript {
+	repositories {
+		jcenter()
+	}
+}
+
+apply plugin: 'java'
+apply plugin: 'java-library'
+
+version = '0.0.1-SNAPSHOT'
+sourceCompatibility = 8
+
+repositories {
+	mavenLocal()
+	mavenCentral()
+}
+
+dependencies {
+	testImplementation 'org.junit.jupiter:junit-jupiter-engine:5.0.1'
+	testImplementation 'org.assertj:assertj-core:2.6.0'
+}
+
+test {
+	useJUnitPlatform()
+}

solid/gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.10.1-bin.zip

solid/gradlew

@@ -0,0 +1,172 @@
+#!/usr/bin/env sh
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+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"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS=""
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+    echo "$*"
+}
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+# Determine the Java command to use to start the JVM.
+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
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+    JAVACMD=`cygpath --unix "$JAVACMD"`
+
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
+    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=$((i+1))
+    done
+    case $i in
+        (0) set -- ;;
+        (1) set -- "$args0" ;;
+        (2) set -- "$args0" "$args1" ;;
+        (3) set -- "$args0" "$args1" "$args2" ;;
+        (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
+fi
+
+# Escape application args
+save () {
+    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
+    echo " "
+}
+APP_ARGS=$(save "$@")
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+# by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong
+if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then
+  cd "$(dirname "$0")"
+fi
+
+exec "$JAVACMD" "$@"

solid/gradlew.bat

@@ -0,0 +1,84 @@
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS=
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto init
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto init
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:init
+@rem Get command-line arguments, handling Windows variants
+
+if not "%OS%" == "Windows_NT" goto win9xME_args
+
+:win9xME_args
+@rem Slurp the command line arguments.
+set CMD_LINE_ARGS=
+set _SKIP=2
+
+:win9xME_args_slurp
+if "x%~1" == "x" goto execute
+
+set CMD_LINE_ARGS=%*
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega

solid/src/main/java/io/reflectoring/solid/isp/BetterOrderService.java

@@ -0,0 +1,5 @@
+package io.reflectoring.solid.isp;
+
+interface BetterOrderService {
+    void submitOrder(Order order);
+}

solid/src/main/java/io/reflectoring/solid/isp/BurgerOrderService.java

@@ -0,0 +1,18 @@
+package io.reflectoring.solid.isp;
+
+class BurgerOrderService implements OrderService {
+    @Override
+    public void orderBurger(int quantity) {
+        System.out.println("Received order of "+quantity+" burgers");
+    }
+
+    @Override
+    public void orderFries(int fries) {
+        throw new UnsupportedOperationException("No fries in burger only order");
+    }
+
+    @Override
+    public void orderCombo(int quantity, int fries) {
+        throw new UnsupportedOperationException("No combo in burger only order");
+    }
+}

solid/src/main/java/io/reflectoring/solid/isp/ComboOrderService.java

@@ -0,0 +1,18 @@
+package io.reflectoring.solid.isp;
+
+class ComboOrderService implements OrderService{
+    @Override
+    public void orderBurger(int quantity) {
+        System.out.println("Received order of "+quantity+" burgers");
+    }
+
+    @Override
+    public void orderFries(int fries) {
+        System.out.println("Received order of "+fries+ " fries");
+    }
+
+    @Override
+    public void orderCombo(int quantity, int fries) {
+        System.out.println("Received order of "+quantity+" burgers and "+ fries+" fries");
+    }
+}

solid/src/main/java/io/reflectoring/solid/isp/FriesOrderService.java

@@ -0,0 +1,19 @@
+package io.reflectoring.solid.isp;
+
+class FriesOrderService implements OrderService {
+    @Override
+    public void orderBurger(int quantity) {
+        throw new UnsupportedOperationException("No burger in fries only order");
+    }
+
+    @Override
+    public void orderFries(int fries) {
+        System.out.println("Received order of "+fries+ " fries");
+    }
+
+    @Override
+    public void orderCombo(int quantity, int fries) {
+        throw new UnsupportedOperationException("No combo in fries only order");
+    }
+}
+

solid/src/main/java/io/reflectoring/solid/isp/Main.java

@@ -0,0 +1,10 @@
+package io.reflectoring.solid.isp;
+
+class Main{
+    public static void main(String[] args){
+        OrderService comboOrderService = new ComboOrderService();
+        NewBurgerOrderService burgerService =
+            new OrderServiceObjectAdapter(new ComboOrderService());
+        burgerService.orderBurger(4);
+    }
+}

solid/src/main/java/io/reflectoring/solid/isp/NewBurgerOrderService.java

@@ -0,0 +1,5 @@
+package io.reflectoring.solid.isp;
+
+interface NewBurgerOrderService {
+    void orderBurger(int quantity);
+}

solid/src/main/java/io/reflectoring/solid/isp/NewFriesOrderService.java

@@ -0,0 +1,5 @@
+package io.reflectoring.solid.isp;
+
+interface NewFriesOrderService {
+    void orderFries(int fries);
+}

solid/src/main/java/io/reflectoring/solid/isp/Order.java

@@ -0,0 +1,5 @@
+package io.reflectoring.solid.isp;
+
+class Order {
+    // define order
+}

solid/src/main/java/io/reflectoring/solid/isp/OrderService.java

@@ -0,0 +1,7 @@
+package io.reflectoring.solid.isp;
+
+interface OrderService {
+    void orderBurger(int quantity);
+    void orderFries(int fries);
+    void orderCombo(int quantity, int fries);
+}

solid/src/main/java/io/reflectoring/solid/isp/OrderServiceObjectAdapter.java

@@ -0,0 +1,14 @@
+package io.reflectoring.solid.isp;
+
+class OrderServiceObjectAdapter implements NewBurgerOrderService {
+    private OrderService adaptee;
+    public OrderServiceObjectAdapter(OrderService adaptee) {
+        super();
+        this.adaptee = adaptee;
+    }
+
+    @Override
+    public void orderBurger(int quantity) {
+        adaptee.orderBurger(quantity);
+    }
+}

spring-boot/argumentresolver/.gitignore

@@ -0,0 +1,32 @@
+HELP.md
+.gradle
+build/
+!gradle/wrapper/gradle-wrapper.jar
+!**/src/main/**
+!**/src/test/**
+
+### STS ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+
+### IntelliJ IDEA ###
+.idea
+*.iws
+*.iml
+*.ipr
+out/
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+
+### VS Code ###
+.vscode/

spring-boot/argumentresolver/build.gradle

@@ -0,0 +1,28 @@
+plugins {
+	id 'org.springframework.boot' version '2.2.5.RELEASE'
+	id 'io.spring.dependency-management' version '1.0.9.RELEASE'
+	id 'java'
+}
+
+group = 'io.reflectoring'
+version = '0.0.1-SNAPSHOT'
+sourceCompatibility = '11'
+
+repositories {
+	mavenCentral()
+}
+
+dependencies {
+	implementation 'org.springframework.boot:spring-boot-starter'
+	implementation 'org.springframework.boot:spring-boot-starter-web'
+	testImplementation('org.springframework.boot:spring-boot-starter-test') {
+		exclude group: 'org.junit.vintage', module: 'junit-vintage-engine'
+	}
+
+	compileOnly 'org.projectlombok:lombok'
+	annotationProcessor 'org.projectlombok:lombok'
+}
+
+test {
+	useJUnitPlatform()
+}

spring-boot/argumentresolver/gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.0.1-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists

spring-boot/argumentresolver/gradlew

@@ -0,0 +1,172 @@
+#!/usr/bin/env sh
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+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"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS=""
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+    echo "$*"
+}
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+# Determine the Java command to use to start the JVM.
+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
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+    JAVACMD=`cygpath --unix "$JAVACMD"`
+
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
+    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=$((i+1))
+    done
+    case $i in
+        (0) set -- ;;
+        (1) set -- "$args0" ;;
+        (2) set -- "$args0" "$args1" ;;
+        (3) set -- "$args0" "$args1" "$args2" ;;
+        (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
+fi
+
+# Escape application args
+save () {
+    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
+    echo " "
+}
+APP_ARGS=$(save "$@")
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+# by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong
+if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then
+  cd "$(dirname "$0")"
+fi
+
+exec "$JAVACMD" "$@"

spring-boot/argumentresolver/gradlew.bat

@@ -0,0 +1,84 @@
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS=
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto init
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto init
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:init
+@rem Get command-line arguments, handling Windows variants
+
+if not "%OS%" == "Windows_NT" goto win9xME_args
+
+:win9xME_args
+@rem Slurp the command line arguments.
+set CMD_LINE_ARGS=
+set _SKIP=2
+
+:win9xME_args_slurp
+if "x%~1" == "x" goto execute
+
+set CMD_LINE_ARGS=%*
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega

spring-boot/argumentresolver/settings.gradle

@@ -0,0 +1 @@
+rootProject.name = 'argumentresolver'

spring-boot/argumentresolver/src/main/java/io/reflectoring/argumentresolver/ArgumentresolverApplication.java

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

spring-boot/argumentresolver/src/main/java/io/reflectoring/argumentresolver/ErrorHandler.java

@@ -0,0 +1,15 @@
+package io.reflectoring.argumentresolver;
+
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.ControllerAdvice;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+
+@ControllerAdvice
+class ErrorHandler {
+
+  @ExceptionHandler(NotFoundException.class)
+  ResponseEntity<?> handleHttpStatusCodeException(NotFoundException e) {
+    return ResponseEntity.status(e.getStatusCode()).build();
+  }
+
+}

spring-boot/argumentresolver/src/main/java/io/reflectoring/argumentresolver/NotFoundException.java

@@ -0,0 +1,11 @@
+package io.reflectoring.argumentresolver;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.web.client.HttpStatusCodeException;
+
+public class NotFoundException extends HttpStatusCodeException {
+
+  protected NotFoundException() {
+    super(HttpStatus.NOT_FOUND);
+  }
+}

spring-boot/argumentresolver/src/main/java/io/reflectoring/argumentresolver/Repository.java

@@ -0,0 +1,12 @@
+package io.reflectoring.argumentresolver;
+
+
+import lombok.Value;
+
+@Value
+class Repository {
+
+  private final Long id;
+  private final String slug;
+
+}

spring-boot/argumentresolver/src/main/java/io/reflectoring/argumentresolver/RepositoryArgumentResolver.java

@@ -0,0 +1,44 @@
+package io.reflectoring.argumentresolver;
+
+import java.util.Optional;
+import java.util.regex.Pattern;
+import lombok.RequiredArgsConstructor;
+import org.springframework.core.MethodParameter;
+import org.springframework.web.bind.support.WebDataBinderFactory;
+import org.springframework.web.context.request.NativeWebRequest;
+import org.springframework.web.context.request.ServletWebRequest;
+import org.springframework.web.method.support.HandlerMethodArgumentResolver;
+import org.springframework.web.method.support.ModelAndViewContainer;
+
+@RequiredArgsConstructor
+class RepositoryArgumentResolver implements HandlerMethodArgumentResolver {
+
+  private final RepositoryFinder repositoryFinder;
+
+  @Override
+  public boolean supportsParameter(MethodParameter parameter) {
+    return parameter.getParameter().getType() == Repository.class;
+  }
+
+  @Override
+  public Object resolveArgument(
+      MethodParameter parameter,
+      ModelAndViewContainer mavContainer,
+      NativeWebRequest webRequest,
+      WebDataBinderFactory binderFactory) {
+
+    String requestPath = ((ServletWebRequest) webRequest).getRequest().getPathInfo();
+
+    String slug = requestPath
+        .substring(0, requestPath.indexOf("/", 1))
+        .replaceAll("^/", "");
+
+    Optional<Repository> repository = repositoryFinder.findBySlug(slug);
+
+    if (repository.isEmpty()) {
+      throw new NotFoundException();
+    }
+
+    return repository.get();
+  }
+}

spring-boot/argumentresolver/src/main/java/io/reflectoring/argumentresolver/RepositoryArgumentResolverConfiguration.java

@@ -0,0 +1,20 @@
+package io.reflectoring.argumentresolver;
+
+import java.util.List;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Component;
+import org.springframework.web.method.support.HandlerMethodArgumentResolver;
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
+
+@Component
+@RequiredArgsConstructor
+class RepositoryArgumentResolverConfiguration implements WebMvcConfigurer {
+
+  private final RepositoryFinder repositoryFinder;
+
+  @Override
+  public void addArgumentResolvers(List<HandlerMethodArgumentResolver> resolvers) {
+    resolvers.add(new RepositoryArgumentResolver(repositoryFinder));
+  }
+
+}

spring-boot/argumentresolver/src/main/java/io/reflectoring/argumentresolver/RepositoryFinder.java

@@ -0,0 +1,9 @@
+package io.reflectoring.argumentresolver;
+
+import java.util.Optional;
+
+public interface RepositoryFinder {
+
+  Optional<Repository> findBySlug(String slug);
+
+}

spring-boot/argumentresolver/src/main/java/io/reflectoring/argumentresolver/RepositoryId.java

@@ -0,0 +1,10 @@
+package io.reflectoring.argumentresolver;
+
+import lombok.Value;
+
+@Value
+class RepositoryId {
+
+  private final long value;
+
+}

spring-boot/argumentresolver/src/main/java/io/reflectoring/argumentresolver/RepositoryIdConverter.java

@@ -0,0 +1,13 @@
+package io.reflectoring.argumentresolver;
+
+import org.springframework.core.convert.converter.Converter;
+import org.springframework.stereotype.Component;
+
+@Component
+class RepositoryIdConverter implements Converter<String, RepositoryId> {
+
+  @Override
+  public RepositoryId convert(String source) {
+    return new RepositoryId(Long.parseLong(source));
+  }
+}

spring-boot/argumentresolver/src/test/java/io/reflectoring/argumentresolver/RepositoryArgumentResolverTest.java

@@ -0,0 +1,43 @@
+package io.reflectoring.argumentresolver;
+
+import static org.mockito.BDDMockito.given;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+import java.util.Optional;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest;
+import org.springframework.boot.test.mock.mockito.MockBean;
+import org.springframework.test.web.servlet.MockMvc;
+
+@WebMvcTest(controllers = RepositoryArgumentResolverTestController.class)
+class RepositoryArgumentResolverTest {
+
+  @Autowired
+  private MockMvc mockMvc;
+
+  @MockBean
+  private RepositoryFinder repositoryFinder;
+
+  @Test
+  void resolvesSiteSuccessfully() throws Exception {
+
+    given(repositoryFinder.findBySlug("my-repo"))
+        .willReturn(Optional.of(new Repository(1L, "my-repo")));
+
+    mockMvc.perform(get("/my-repo/listContributors"))
+        .andExpect(status().isOk());
+  }
+
+  @Test
+  void notFoundOnUnknownSlug() throws Exception {
+
+    given(repositoryFinder.findBySlug("unknownSlug"))
+        .willReturn(Optional.empty());
+
+    mockMvc.perform(get("/unknownSlug/listContributors"))
+        .andExpect(status().isNotFound());
+  }
+
+}

spring-boot/argumentresolver/src/test/java/io/reflectoring/argumentresolver/RepositoryArgumentResolverTestController.java

@@ -0,0 +1,19 @@
+package io.reflectoring.argumentresolver;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+@RequestMapping(path = "/{repositorySlug}")
+class RepositoryArgumentResolverTestController {
+
+  @GetMapping("/listContributors")
+  String listContributors(Repository repository) {
+    assertThat(repository.getId()).isEqualTo(1L);
+    return "test";
+  }
+
+}

spring-boot/argumentresolver/src/test/java/io/reflectoring/argumentresolver/RepositoryIdConverterTest.java

@@ -0,0 +1,27 @@
+package io.reflectoring.argumentresolver;
+
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest;
+import org.springframework.boot.test.mock.mockito.MockBean;
+import org.springframework.test.web.servlet.MockMvc;
+
+@WebMvcTest(controllers = RepositoryIdConverterTestController.class)
+class RepositoryIdConverterTest {
+
+  @Autowired
+  private MockMvc mockMvc;
+
+  @MockBean
+  private RepositoryFinder repositoryFinder;
+
+  @Test
+  void resolvesRepositoryId() throws Exception {
+    mockMvc.perform(get("/repositories/42"))
+        .andExpect(status().isOk());
+  }
+
+}

spring-boot/argumentresolver/src/test/java/io/reflectoring/argumentresolver/RepositoryIdConverterTestController.java

@@ -0,0 +1,18 @@
+package io.reflectoring.argumentresolver;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+class RepositoryIdConverterTestController {
+
+  @GetMapping("/repositories/{repositoryId}")
+  String getRepository(@PathVariable("repositoryId") RepositoryId repositoryId) {
+    assertThat(repositoryId).isNotNull();
+    return "test";
+  }
+
+}

spring-boot/data-migration/flyway/.gitignore

@@ -0,0 +1,31 @@
+.gradle
+build/
+!gradle/wrapper/gradle-wrapper.jar
+!**/src/main/**
+!**/src/test/**
+
+### STS ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+
+### IntelliJ IDEA ###
+.idea
+*.iws
+*.iml
+*.ipr
+out/
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+
+### VS Code ###
+.vscode/

spring-boot/data-migration/flyway/Jenkinsfile-build

@@ -0,0 +1,19 @@
+pipeline {
+	agent any
+
+	stages {
+		checkout scm
+
+		stage('Gradle Build') {
+      steps {
+        script {
+          if (isUnix()) {
+            sh './gradlew clean build --info'
+          } else {
+            bat 'gradlew.bat clean build --info'
+          }
+        }
+      }
+    }
+	}
+}

spring-boot/data-migration/flyway/Jenkinsfile-db-migration

@@ -0,0 +1,19 @@
+pipeline {
+	agent any
+
+	stages {
+		checkout scm
+
+		stage('Apply Database Migrations') {
+      steps {
+        script {
+          if (isUnix()) {
+            sh '/gradlew flywayMigrate --info'
+          } else {
+            bat 'gradlew.bat flywayMigrate --info'
+          }
+        }
+      }
+    }
+	}
+}

spring-boot/data-migration/flyway/build.gradle

@@ -0,0 +1,49 @@
+plugins {
+	id 'org.springframework.boot' version '2.2.3.RELEASE'
+	id 'io.spring.dependency-management' version '1.0.8.RELEASE'
+	id 'java'
+    id "org.flywaydb.flyway" version "6.2.3"
+}
+
+group = 'io.reflectoring'
+version = '0.0.1-SNAPSHOT'
+sourceCompatibility = '11'
+
+repositories {
+	mavenCentral()
+}
+
+dependencies {
+
+	compileOnly 'org.projectlombok:lombok'
+
+    // Spring
+	implementation 'org.springframework.boot:spring-boot-starter-web'
+	implementation 'org.springframework.boot:spring-boot-starter-jdbc'
+
+    // Database
+    implementation 'org.flywaydb:flyway-core'
+	runtimeOnly 'com.h2database:h2'
+
+	// Add jaxb since it's no longer available in Java 11
+	runtime 'javax.xml.bind:jaxb-api:2.3.1'
+
+    // Test
+    testCompile 'org.assertj:assertj-core'
+    testImplementation('org.springframework.boot:spring-boot-starter-test') {
+        exclude group: 'org.junit.vintage', module: 'junit-vintage-engine'
+    }
+	testImplementation('org.junit.jupiter:junit-jupiter:5.5.1')
+}
+
+test {
+	useJUnitPlatform()
+}
+
+flyway {
+	url = 'jdbc:h2:mem:'
+	locations = [
+		// Add this if you have Java-based migrations
+		'classpath:db/migration'
+	]
+}

spring-boot/data-migration/flyway/gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,6 @@
+#Tue Jan 21 16:55:51 EET 2020
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.0.1-all.zip
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+zipStorePath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME

spring-boot/data-migration/flyway/gradlew

@@ -0,0 +1,172 @@
+#!/usr/bin/env sh
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+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"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS=""
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+    echo "$*"
+}
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+# Determine the Java command to use to start the JVM.
+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
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+    JAVACMD=`cygpath --unix "$JAVACMD"`
+
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
+    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=$((i+1))
+    done
+    case $i in
+        (0) set -- ;;
+        (1) set -- "$args0" ;;
+        (2) set -- "$args0" "$args1" ;;
+        (3) set -- "$args0" "$args1" "$args2" ;;
+        (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
+fi
+
+# Escape application args
+save () {
+    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
+    echo " "
+}
+APP_ARGS=$(save "$@")
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+# by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong
+if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then
+  cd "$(dirname "$0")"
+fi
+
+exec "$JAVACMD" "$@"

spring-boot/data-migration/flyway/gradlew.bat

@@ -0,0 +1,84 @@
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS=
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto init
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto init
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:init
+@rem Get command-line arguments, handling Windows variants
+
+if not "%OS%" == "Windows_NT" goto win9xME_args
+
+:win9xME_args
+@rem Slurp the command line arguments.
+set CMD_LINE_ARGS=
+set _SKIP=2
+
+:win9xME_args_slurp
+if "x%~1" == "x" goto execute
+
+set CMD_LINE_ARGS=%*
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega

spring-boot/data-migration/flyway/settings.gradle

@@ -0,0 +1 @@
+rootProject.name = 'flyway'

spring-boot/data-migration/flyway/src/main/java/db/migration/V2__InsertRandomUsers.java

@@ -0,0 +1,23 @@
+package db.migration;
+
+import org.flywaydb.core.api.migration.BaseJavaMigration;
+import org.flywaydb.core.api.migration.Context;
+import org.springframework.jdbc.core.JdbcTemplate;
+import org.springframework.jdbc.datasource.SingleConnectionDataSource;
+
+/**
+ * Example of a Java-based migration using Spring {@link JdbcTemplate}.
+ */
+public class V2__InsertRandomUsers extends BaseJavaMigration {
+
+  public void migrate(Context context) {
+
+    final JdbcTemplate jdbcTemplate = new JdbcTemplate(new SingleConnectionDataSource(context.getConnection(), true));
+
+    // Create 10 random users
+    for (int i = 1; i <= 10; i++) {
+      jdbcTemplate.execute(String.format("insert into test_user(username, first_name, last_name) "
+                                             + "values('%d@reflectoring.io', 'Elvis_%d', 'Presley_%d')", i, i, i));
+    }
+  }
+}

spring-boot/data-migration/flyway/src/main/java/io/reflectoring/flyway/FlywayApplication.java

@@ -0,0 +1,12 @@
+package io.reflectoring.flyway;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class FlywayApplication {
+
+	public static void main(String[] args) {
+		SpringApplication.run(FlywayApplication.class, args);
+	}
+}

spring-boot/data-migration/flyway/src/main/resources/db/migration/U1__Undo_Init.sql

@@ -0,0 +1 @@
+DROP TABLE test_user;

spring-boot/data-migration/flyway/src/main/resources/db/migration/V1__Init.sql

@@ -0,0 +1,9 @@
+-- Init script
+
+-- DDL
+CREATE TABLE test_user(
+    id INT AUTO_INCREMENT PRIMARY KEY,
+    username VARCHAR(255) NOT NULL UNIQUE,
+    first_name VARCHAR(255) NOT NULL,
+    last_name VARCHAR(255) NOT NULL
+);

spring-boot/data-migration/flyway/src/test/java/io/reflectoring/flyway/FlywayWithH2Test.java

@@ -0,0 +1,43 @@
+package io.reflectoring.flyway;
+
+import java.util.List;
+import org.assertj.core.api.Assertions;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
+import org.springframework.jdbc.core.JdbcTemplate;
+
+@DataJpaTest
+class FlywayWithH2Test {
+
+  @Autowired
+  private JdbcTemplate jdbcTemplate;
+
+  @Test
+  void databaseHasBeenInitialized() {
+
+    jdbcTemplate.execute("insert into test_user (username, first_name, last_name) values('reflectoring', 'Elvis', 'Presley')");
+
+    final List<AuthUser> authUsers = jdbcTemplate
+        .query("SELECT username, first_name, last_name FROM test_user", (rs, rowNum) -> new AuthUser(
+            rs.getString("username"),
+            rs.getString("first_name"),
+            rs.getString("last_name")
+        ));
+
+    Assertions.assertThat(authUsers).isNotEmpty();
+  }
+
+  private static class AuthUser {
+    public String username;
+    public String firstName;
+    public String lastName;
+
+    public AuthUser(final String username, final String firstName, final String lastName) {
+
+      this.username = username;
+      this.firstName = firstName;
+      this.lastName = lastName;
+    }
+  }
+}