First version Commit

.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/

.mvn/wrapper/maven-wrapper.properties

@@ -0,0 +1,2 @@
+distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.9.2/apache-maven-3.9.2-bin.zip
+wrapperUrl=https://repo.maven.apache.org/maven2/org/apache/maven/wrapper/maven-wrapper/3.2.0/maven-wrapper-3.2.0.jar

README.md

@@ -0,0 +1,8 @@
+# Spring-Boot REST API validations
+
+### Required Tools:
+* JDK 20
+* Maven 3.x.x
+
+Complete source code accompanying the article on the Medium Blog.
+

mvnw

@@ -0,0 +1,308 @@
+#!/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.
+# ----------------------------------------------------------------------------
+
+# ----------------------------------------------------------------------------
+# Apache Maven Wrapper startup batch script, version 3.2.0
+#
+# Required ENV vars:
+# ------------------
+#   JAVA_HOME - location of a JDK home dir
+#
+# Optional ENV vars
+# -----------------
+#   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 "$MAVEN_SKIP_RC" ] ; then
+
+  if [ -f /usr/local/etc/mavenrc ] ; then
+    . /usr/local/etc/mavenrc
+  fi
+
+  if [ -f /etc/mavenrc ] ; then
+    . /etc/mavenrc
+  fi
+
+  if [ -f "$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 "$JAVA_HOME" ]; then
+      if [ -x "/usr/libexec/java_home" ]; then
+        JAVA_HOME="$(/usr/libexec/java_home)"; export JAVA_HOME
+      else
+        JAVA_HOME="/Library/Java/Home"; export JAVA_HOME
+      fi
+    fi
+    ;;
+esac
+
+if [ -z "$JAVA_HOME" ] ; then
+  if [ -r /etc/gentoo-release ] ; then
+    JAVA_HOME=$(java-config --jre-home)
+  fi
+fi
+
+# For Cygwin, ensure paths are in UNIX format before anything is touched
+if $cygwin ; then
+  [ -n "$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 $mingw ; then
+  [ -n "$JAVA_HOME" ] && [ -d "$JAVA_HOME" ] &&
+    JAVA_HOME="$(cd "$JAVA_HOME" || (echo "cannot cd into $JAVA_HOME."; exit 1); pwd)"
+fi
+
+if [ -z "$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="$(\unset -f command 2>/dev/null; \command -v java)"
+  fi
+fi
+
+if [ ! -x "$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
+
+# 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 "$wdir/.." || exit 1; pwd)
+    fi
+    # end of workaround
+  done
+  printf '%s' "$(cd "$basedir" || exit 1; pwd)"
+}
+
+# concatenates all lines of a file
+concat_lines() {
+  if [ -f "$1" ]; then
+    # Remove \r in case we run on Windows within Git Bash
+    # and check out the repository with auto CRLF management
+    # enabled. Otherwise, we may read lines that are delimited with
+    # \r\n and produce $'-Xarg\r' rather than -Xarg due to word
+    # splitting rules.
+    tr -s '\r\n' ' ' < "$1"
+  fi
+}
+
+log() {
+  if [ "$MVNW_VERBOSE" = true ]; then
+    printf '%s\n' "$1"
+  fi
+}
+
+BASE_DIR=$(find_maven_basedir "$(dirname "$0")")
+if [ -z "$BASE_DIR" ]; then
+  exit 1;
+fi
+
+MAVEN_PROJECTBASEDIR=${MAVEN_BASEDIR:-"$BASE_DIR"}; export MAVEN_PROJECTBASEDIR
+log "$MAVEN_PROJECTBASEDIR"
+
+##########################################################################################
+# Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+# This allows using the maven wrapper in projects that prohibit checking in binary data.
+##########################################################################################
+wrapperJarPath="$MAVEN_PROJECTBASEDIR/.mvn/wrapper/maven-wrapper.jar"
+if [ -r "$wrapperJarPath" ]; then
+    log "Found $wrapperJarPath"
+else
+    log "Couldn't find $wrapperJarPath, downloading it ..."
+
+    if [ -n "$MVNW_REPOURL" ]; then
+      wrapperUrl="$MVNW_REPOURL/org/apache/maven/wrapper/maven-wrapper/3.2.0/maven-wrapper-3.2.0.jar"
+    else
+      wrapperUrl="https://repo.maven.apache.org/maven2/org/apache/maven/wrapper/maven-wrapper/3.2.0/maven-wrapper-3.2.0.jar"
+    fi
+    while IFS="=" read -r key value; do
+      # Remove '\r' from value to allow usage on windows as IFS does not consider '\r' as a separator ( considers space, tab, new line ('\n'), and custom '=' )
+      safeValue=$(echo "$value" | tr -d '\r')
+      case "$key" in (wrapperUrl) wrapperUrl="$safeValue"; break ;;
+      esac
+    done < "$MAVEN_PROJECTBASEDIR/.mvn/wrapper/maven-wrapper.properties"
+    log "Downloading from: $wrapperUrl"
+
+    if $cygwin; then
+      wrapperJarPath=$(cygpath --path --windows "$wrapperJarPath")
+    fi
+
+    if command -v wget > /dev/null; then
+        log "Found wget ... using wget"
+        [ "$MVNW_VERBOSE" = true ] && QUIET="" || QUIET="--quiet"
+        if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+            wget $QUIET "$wrapperUrl" -O "$wrapperJarPath" || rm -f "$wrapperJarPath"
+        else
+            wget $QUIET --http-user="$MVNW_USERNAME" --http-password="$MVNW_PASSWORD" "$wrapperUrl" -O "$wrapperJarPath" || rm -f "$wrapperJarPath"
+        fi
+    elif command -v curl > /dev/null; then
+        log "Found curl ... using curl"
+        [ "$MVNW_VERBOSE" = true ] && QUIET="" || QUIET="--silent"
+        if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+            curl $QUIET -o "$wrapperJarPath" "$wrapperUrl" -f -L || rm -f "$wrapperJarPath"
+        else
+            curl $QUIET --user "$MVNW_USERNAME:$MVNW_PASSWORD" -o "$wrapperJarPath" "$wrapperUrl" -f -L || rm -f "$wrapperJarPath"
+        fi
+    else
+        log "Falling back to using Java to download"
+        javaSource="$MAVEN_PROJECTBASEDIR/.mvn/wrapper/MavenWrapperDownloader.java"
+        javaClass="$MAVEN_PROJECTBASEDIR/.mvn/wrapper/MavenWrapperDownloader.class"
+        # For Cygwin, switch paths to Windows format before running javac
+        if $cygwin; then
+          javaSource=$(cygpath --path --windows "$javaSource")
+          javaClass=$(cygpath --path --windows "$javaClass")
+        fi
+        if [ -e "$javaSource" ]; then
+            if [ ! -e "$javaClass" ]; then
+                log " - Compiling MavenWrapperDownloader.java ..."
+                ("$JAVA_HOME/bin/javac" "$javaSource")
+            fi
+            if [ -e "$javaClass" ]; then
+                log " - Running MavenWrapperDownloader.java ..."
+                ("$JAVA_HOME/bin/java" -cp .mvn/wrapper MavenWrapperDownloader "$wrapperUrl" "$wrapperJarPath") || rm -f "$wrapperJarPath"
+            fi
+        fi
+    fi
+fi
+##########################################################################################
+# End of extension
+##########################################################################################
+
+# If specified, validate the SHA-256 sum of the Maven wrapper jar file
+wrapperSha256Sum=""
+while IFS="=" read -r key value; do
+  case "$key" in (wrapperSha256Sum) wrapperSha256Sum=$value; break ;;
+  esac
+done < "$MAVEN_PROJECTBASEDIR/.mvn/wrapper/maven-wrapper.properties"
+if [ -n "$wrapperSha256Sum" ]; then
+  wrapperSha256Result=false
+  if command -v sha256sum > /dev/null; then
+    if echo "$wrapperSha256Sum  $wrapperJarPath" | sha256sum -c > /dev/null 2>&1; then
+      wrapperSha256Result=true
+    fi
+  elif command -v shasum > /dev/null; then
+    if echo "$wrapperSha256Sum  $wrapperJarPath" | shasum -a 256 -c > /dev/null 2>&1; then
+      wrapperSha256Result=true
+    fi
+  else
+    echo "Checksum validation was requested but neither 'sha256sum' or 'shasum' are available."
+    echo "Please install either command, or disable validation by removing 'wrapperSha256Sum' from your maven-wrapper.properties."
+    exit 1
+  fi
+  if [ $wrapperSha256Result = false ]; then
+    echo "Error: Failed to validate Maven wrapper SHA-256, your Maven wrapper might be compromised." >&2
+    echo "Investigate or delete $wrapperJarPath to attempt a clean download." >&2
+    echo "If you updated your Maven version, you need to update the specified wrapperSha256Sum property." >&2
+    exit 1
+  fi
+fi
+
+MAVEN_OPTS="$(concat_lines "$MAVEN_PROJECTBASEDIR/.mvn/jvm.config") $MAVEN_OPTS"
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin; then
+  [ -n "$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 $*"
+export MAVEN_CMD_LINE_ARGS
+
+WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+# shellcheck disable=SC2086 # safe args
+exec "$JAVACMD" \
+  $MAVEN_OPTS \
+  $MAVEN_DEBUG_OPTS \
+  -classpath "$MAVEN_PROJECTBASEDIR/.mvn/wrapper/maven-wrapper.jar" \
+  "-Dmaven.multiModuleProjectDirectory=${MAVEN_PROJECTBASEDIR}" \
+  ${WRAPPER_LAUNCHER} $MAVEN_CONFIG "$@"

mvnw.cmd

@@ -0,0 +1,205 @@
+@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 Apache Maven Wrapper startup batch script, version 3.2.0
+@REM
+@REM Required ENV vars:
+@REM JAVA_HOME - location of a JDK home dir
+@REM
+@REM Optional ENV vars
+@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 "%USERPROFILE%\mavenrc_pre.bat" call "%USERPROFILE%\mavenrc_pre.bat" %*
+if exist "%USERPROFILE%\mavenrc_pre.cmd" call "%USERPROFILE%\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 WRAPPER_URL="https://repo.maven.apache.org/maven2/org/apache/maven/wrapper/maven-wrapper/3.2.0/maven-wrapper-3.2.0.jar"
+
+FOR /F "usebackq tokens=1,2 delims==" %%A IN ("%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.properties") DO (
+    IF "%%A"=="wrapperUrl" SET WRAPPER_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 WRAPPER_URL="%MVNW_REPOURL%/org/apache/maven/wrapper/maven-wrapper/3.2.0/maven-wrapper-3.2.0.jar"
+    )
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Couldn't find %WRAPPER_JAR%, downloading it ...
+        echo Downloading from: %WRAPPER_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; $webclient.DownloadFile('%WRAPPER_URL%', '%WRAPPER_JAR%')"^
+		"}"
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Finished downloading %WRAPPER_JAR%
+    )
+)
+@REM End of extension
+
+@REM If specified, validate the SHA-256 sum of the Maven wrapper jar file
+SET WRAPPER_SHA_256_SUM=""
+FOR /F "usebackq tokens=1,2 delims==" %%A IN ("%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.properties") DO (
+    IF "%%A"=="wrapperSha256Sum" SET WRAPPER_SHA_256_SUM=%%B
+)
+IF NOT %WRAPPER_SHA_256_SUM%=="" (
+    powershell -Command "&{"^
+       "$hash = (Get-FileHash \"%WRAPPER_JAR%\" -Algorithm SHA256).Hash.ToLower();"^
+       "If('%WRAPPER_SHA_256_SUM%' -ne $hash){"^
+       "  Write-Output 'Error: Failed to validate Maven wrapper SHA-256, your Maven wrapper might be compromised.';"^
+       "  Write-Output 'Investigate or delete %WRAPPER_JAR% to attempt a clean download.';"^
+       "  Write-Output 'If you updated your Maven version, you need to update the specified wrapperSha256Sum property.';"^
+       "  exit 1;"^
+       "}"^
+       "}"
+    if ERRORLEVEL 1 goto error
+)
+
+@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 "%USERPROFILE%\mavenrc_post.bat" call "%USERPROFILE%\mavenrc_post.bat"
+if exist "%USERPROFILE%\mavenrc_post.cmd" call "%USERPROFILE%\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%
+
+cmd /C exit /B %ERROR_CODE%

pom.xml

@@ -0,0 +1,100 @@
+<?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>3.1.0</version>
+        <relativePath/> <!-- lookup parent from repository -->
+    </parent>
+    <groupId>demo</groupId>
+    <artifactId>springboot-api-validations</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <name>springboot-api-validations</name>
+    <description>Demo project for API validations in Clean Architecture</description>
+    <properties>
+        <java.version>20</java.version>
+        <vavr.version>0.10.4</vavr.version>
+        <assertj-vavr.version>0.4.3</assertj-vavr.version>
+    </properties>
+    <dependencies>
+        <!-- Web -->
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-validation</artifactId>
+        </dependency>
+
+        <!-- Libs -->
+        <dependency>
+            <groupId>io.vavr</groupId>
+            <artifactId>vavr</artifactId>
+            <version>${vavr.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <optional>true</optional>
+        </dependency>
+
+        <!-- Testing -->
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-vavr</artifactId>
+            <version>${assertj-vavr.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.skyscreamer</groupId>
+            <artifactId>jsonassert</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <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>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <compilerArgs>
+                        <arg>--enable-preview</arg>
+                    </compilerArgs>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-surefire-plugin</artifactId>
+                <configuration>
+                    <argLine>--enable-preview</argLine>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+</project>

src/main/java/demo/Application.java

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

src/main/java/demo/album/javax/adapter/in/web/AlbumController.java

@@ -0,0 +1,44 @@
+package demo.album.javax.adapter.in.web;
+
+import demo.album.javax.application.port.in.CreateAlbumUseCase;
+import lombok.RequiredArgsConstructor;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.math.BigDecimal;
+import java.util.UUID;
+
+import static demo.album.javax.application.port.in.CreateAlbumUseCase.CreateAlbumCommand;
+import static org.springframework.http.MediaType.APPLICATION_JSON_VALUE;
+import static org.springframework.http.ResponseEntity.created;
+import static org.springframework.web.servlet.support.ServletUriComponentsBuilder.fromCurrentRequest;
+
+@RestController("jAlbumController")
+@RequiredArgsConstructor
+@RequestMapping(value = "/javax/albums")
+final class AlbumController {
+
+    private final CreateAlbumUseCase jCreateAlbumUseCase;
+
+    @PostMapping(consumes = APPLICATION_JSON_VALUE, produces = APPLICATION_JSON_VALUE)
+    ResponseEntity<?> create(@RequestBody AlbumResource resource) {
+        var command = CreateAlbumCommand.builder()
+                .title(resource.title())
+                .artist(resource.artist())
+                .price(resource.price())
+                .build(); // validations are applied on build
+
+        var albumId = jCreateAlbumUseCase.add(command);
+
+        return created(fromCurrentRequest().path("/{id}").build(albumId)).build();
+    }
+
+    private record AlbumResource(UUID id,
+                                 String title,
+                                 String artist,
+                                 BigDecimal price) {
+    }
+}

src/main/java/demo/album/javax/adapter/in/web/AlbumControllerAdvice.java

@@ -0,0 +1,21 @@
+package demo.album.javax.adapter.in.web;
+
+import jakarta.validation.ConstraintViolationException;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.RestControllerAdvice;
+
+import static demo.shared.ApiError.fieldApiError;
+import static demo.shared.ApiErrorResponse.unprocessableEntity;
+
+@RestControllerAdvice
+class AlbumControllerAdvice {
+
+    @ExceptionHandler(value = ConstraintViolationException.class)
+    ResponseEntity<?> handle(ConstraintViolationException ex) {
+        var apiErrors = ex.getConstraintViolations().stream()
+                .map(c -> fieldApiError(c.getPropertyPath().toString(), c.getMessage(), c.getInvalidValue()))
+                .toList();
+        return unprocessableEntity(apiErrors, "Schema validation failure.");
+    }
+}

src/main/java/demo/album/javax/application/port/in/CreateAlbumUseCase.java

@@ -0,0 +1,38 @@
+package demo.album.javax.application.port.in;
+
+import demo.shared.SelfValidating;
+import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.NotNull;
+import jakarta.validation.constraints.Positive;
+import lombok.Builder;
+import lombok.Getter;
+
+import java.math.BigDecimal;
+import java.util.UUID;
+
+public interface CreateAlbumUseCase {
+
+    UUID add(CreateAlbumCommand command);
+
+    @Getter
+    class CreateAlbumCommand extends SelfValidating<CreateAlbumCommand> {
+
+        @NotBlank(message = "title cannot be blank.")
+        private final String title;
+
+        @NotBlank(message = "artist cannot be blank.")
+        private final String artist;
+
+        @NotNull(message = "price cannot be null.")
+        @Positive(message = "price must be greater than 0.")
+        private final BigDecimal price;
+
+        @Builder
+        public CreateAlbumCommand(String title, String artist, BigDecimal price) {
+            this.title = title;
+            this.artist = artist;
+            this.price = price;
+            this.validateSelf();
+        }
+    }
+}

src/main/java/demo/album/javax/application/service/CreateAlbumService.java

@@ -0,0 +1,29 @@
+package demo.album.javax.application.service;
+
+import demo.album.javax.application.port.in.CreateAlbumUseCase;
+import demo.album.javax.domain.Album;
+import org.springframework.stereotype.Service;
+
+import java.util.UUID;
+
+@Service("jCreateAlbumUseCase")
+class CreateAlbumService implements CreateAlbumUseCase {
+
+    @Override
+    public UUID add(CreateAlbumCommand command) {
+        // TODO: validate business rules
+        // requireUniqueTitle(command.title());
+
+        // TODO: manipulate model state
+        var album = Album.builder()
+                .id(UUID.randomUUID())
+                .title(command.getTitle())
+                .artist(command.getArtist())
+                .price(command.getPrice())
+                .build();
+
+
+        // TODO: return output
+        return album.id();
+    }
+}

src/main/java/demo/album/javax/domain/Album.java

@@ -0,0 +1,22 @@
+package demo.album.javax.domain;
+
+import lombok.Builder;
+import demo.shared.Guards;
+
+import java.math.BigDecimal;
+import java.util.UUID;
+
+@Builder
+public record Album(UUID id,
+                    String title,
+                    String artist,
+                    BigDecimal price) {
+
+    public Album {
+        Guards.notNull(id, "id cannot be null.");
+        Guards.notBlank(title, "title cannot be blank.");
+        Guards.notBlank(artist, "artist cannot be blank.");
+        Guards.notNull(price, "price cannot be null.");
+        Guards.positive(price, "price must be greater than 0.");
+    }
+}

src/main/java/demo/album/vavr/adapter/in/web/AlbumController.java

@@ -0,0 +1,44 @@
+package demo.album.vavr.adapter.in.web;
+
+import demo.album.vavr.application.port.in.CreateAlbumUseCase;
+import lombok.RequiredArgsConstructor;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.math.BigDecimal;
+import java.util.UUID;
+
+import static demo.album.vavr.application.port.in.CreateAlbumUseCase.CreateAlbumCommand;
+import static org.springframework.http.MediaType.APPLICATION_JSON_VALUE;
+import static org.springframework.http.ResponseEntity.created;
+import static org.springframework.web.servlet.support.ServletUriComponentsBuilder.fromCurrentRequest;
+
+@RestController("vAlbumController")
+@RequiredArgsConstructor
+@RequestMapping(value = "/vavr/albums")
+final class AlbumController {
+
+    private final CreateAlbumUseCase vCreateAlbumUseCase;
+    private final ApiFailureHandler apiFailureHandler;
+
+    @PostMapping(consumes = APPLICATION_JSON_VALUE, produces = APPLICATION_JSON_VALUE)
+    ResponseEntity<?> create(@RequestBody AlbumResource resource) {
+        var command = CreateAlbumCommand.builder()
+                .title(resource.title())
+                .artist(resource.artist())
+                .price(resource.price())
+                .build();
+
+        return vCreateAlbumUseCase.create(command)
+                .fold(apiFailureHandler::handle, albumId -> created(fromCurrentRequest().path("/{id}").build(albumId)).build());
+    }
+
+    private record AlbumResource(UUID id,
+                                 String title,
+                                 String artist,
+                                 BigDecimal price) {
+    }
+}

src/main/java/demo/album/vavr/adapter/in/web/ApiFailureHandler.java

@@ -0,0 +1,39 @@
+package demo.album.vavr.adapter.in.web;
+
+import org.springframework.http.ResponseEntity;
+import org.springframework.stereotype.Component;
+import demo.shared.ApiError;
+import demo.shared.Failure;
+import demo.shared.Failure.ConflictFailure;
+import demo.shared.Failure.NotFoundFailure;
+import demo.shared.Failure.ValidationFailure;
+import demo.shared.FieldViolation;
+
+import java.util.Collection;
+
+import static demo.shared.ApiError.fieldApiError;
+import static demo.shared.ApiErrorResponse.*;
+
+@Component
+final class ApiFailureHandler {
+
+    private final ValidationFailureToApiMapper apiMapper = new ValidationFailureToApiMapper();
+
+    ResponseEntity<?> handle(Failure failure) {
+        return switch (failure) {
+            case NotFoundFailure notFoundFailure -> notFound(notFoundFailure.message());
+            case ConflictFailure conflictFailure -> conflict(conflictFailure.message());
+            case ValidationFailure validFailure -> unprocessableEntity(apiMapper.map(failure.fieldViolations()), validFailure.message());
+            default -> throw new IllegalArgumentException("Unsupported failure type");
+        };
+    }
+
+    private static class ValidationFailureToApiMapper {
+
+        private Collection<ApiError> map(Collection<FieldViolation> violations) {
+            return violations.stream()
+                    .map(violation -> fieldApiError(violation.field(), violation.message(), violation.rejValue()))
+                    .toList();
+        }
+    }
+}

src/main/java/demo/album/vavr/application/port/in/CreateAlbumUseCase.java

@@ -0,0 +1,24 @@
+package demo.album.vavr.application.port.in;
+
+import io.vavr.control.Either;
+import lombok.Builder;
+import demo.shared.Failure;
+
+import java.math.BigDecimal;
+import java.util.UUID;
+
+public interface CreateAlbumUseCase {
+
+    Either<Failure, UUID> create(CreateAlbumCommand command);
+
+    @Builder
+    record CreateAlbumCommand(String title,
+                              String artist,
+                              BigDecimal price) {
+
+        public static final String FIELD_TITLE = "title";
+        public static final String FIELD_ARTIST = "artist";
+        public static final String FIELD_PRICE = "price";
+
+    }
+}

src/main/java/demo/album/vavr/application/service/CreateAlbumService.java

@@ -0,0 +1,102 @@
+package demo.album.vavr.application.service;
+
+import demo.album.vavr.application.port.in.CreateAlbumUseCase;
+import demo.album.vavr.domain.Album;
+import demo.shared.Failure;
+import demo.shared.FieldViolation;
+import io.micrometer.common.util.StringUtils;
+import io.vavr.collection.Seq;
+import io.vavr.control.Either;
+import io.vavr.control.Validation;
+import org.springframework.stereotype.Service;
+
+import java.math.BigDecimal;
+import java.util.UUID;
+
+import static demo.shared.Failure.validatonFailure;
+import static io.vavr.API.Invalid;
+import static io.vavr.API.Valid;
+import static java.util.Objects.isNull;
+
+@Service("vCreateAlbumUseCase")
+class CreateAlbumService implements CreateAlbumUseCase {
+
+    static final String VALIDATION_FAILURE_MESSAGE = "Schema validation failure.";
+
+    private final CreateAlbumCommandValidator validator = new CreateAlbumCommandValidator();
+
+    @Override
+    public Either<Failure, UUID> create(CreateAlbumCommand command) {
+        // TODO: validate input schema
+        var validation = validator.validate(command);
+        if (validation.isInvalid())
+            return Either.left(validatonFailure(VALIDATION_FAILURE_MESSAGE, validation.getError().toJavaList()));
+
+        // TODO: validate business rules
+//        if (!uniqueTitle(command.title()))
+//            return Either.left(conflictFailure("title '%s' already exists.".formatted(command.title())));
+
+        // TODO: manipulate model state
+        var album = Album.builder()
+                .id(UUID.randomUUID())
+                .title(command.title())
+                .artist(command.artist())
+                .price(command.price())
+                .build();
+
+        // TODO: return output
+        return Either.right(album.id());
+    }
+
+
+    private static final class CreateAlbumCommandValidator {
+
+        Validation<Seq<FieldViolation>, CreateAlbumCommand> validate(CreateAlbumCommand command) {
+            return Validation.combine(
+                    validateTitle(command.title()),
+                    validateArtist(command.artist()),
+                    validatePrice(command.price())
+            ).ap((title, artist, price) -> command);
+        }
+
+        private Validation<FieldViolation, String> validateTitle(String title) {
+            if (StringUtils.isBlank(title))
+                return Invalid(FieldViolation.builder()
+                        .field(CreateAlbumCommand.FIELD_TITLE)
+                        .message("title cannot be blank.")
+                        .rejValue(title)
+                        .build());
+
+            return Valid(title);
+        }
+
+        private Validation<FieldViolation, String> validateArtist(String artist) {
+            if (StringUtils.isBlank(artist))
+                return Invalid(FieldViolation.builder()
+                        .field(CreateAlbumCommand.FIELD_ARTIST)
+                        .message("artist cannot be blank.")
+                        .rejValue(artist)
+                        .build());
+
+            return Valid(artist);
+        }
+
+        private Validation<FieldViolation, BigDecimal> validatePrice(BigDecimal price) {
+            if (isNull(price))
+                return Invalid(FieldViolation.builder()
+                        .field(CreateAlbumCommand.FIELD_PRICE)
+                        .message("price cannot be null.")
+                        .rejValue(price)
+                        .build());
+
+            if (price.compareTo(BigDecimal.ZERO) <= 0)
+                return Invalid(FieldViolation.builder()
+                        .field(CreateAlbumCommand.FIELD_PRICE)
+                        .message("price must be greater than 0.")
+                        .rejValue(price)
+                        .build());
+
+            return Valid(price);
+        }
+    }
+}

src/main/java/demo/album/vavr/domain/Album.java

@@ -0,0 +1,22 @@
+package demo.album.vavr.domain;
+
+import lombok.Builder;
+import demo.shared.Guards;
+
+import java.math.BigDecimal;
+import java.util.UUID;
+
+@Builder
+public record Album(UUID id,
+                    String title,
+                    String artist,
+                    BigDecimal price) {
+
+    public Album {
+        Guards.notNull(id, "id cannot be null.");
+        Guards.notBlank(title, "title cannot be blank.");
+        Guards.notBlank(artist, "artist cannot be blank.");
+        Guards.notNull(price, "price cannot be null.");
+        Guards.positive(price, "price must be greater than 0.");
+    }
+}

src/main/java/demo/shared/ApiError.java

@@ -0,0 +1,13 @@
+package demo.shared;
+
+public interface ApiError {
+
+    String message();
+
+    static ApiError fieldApiError(String field, String message, Object rejectedValue) {
+        return new ApiErrorField(field, message, rejectedValue);
+    }
+
+    record ApiErrorField(String field, String message, Object rejectedValue) implements ApiError {
+    }
+}

src/main/java/demo/shared/ApiErrorResponse.java

@@ -0,0 +1,112 @@
+package demo.shared;
+
+import lombok.Builder;
+import lombok.Getter;
+import lombok.ToString;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+
+import java.time.Instant;
+import java.util.Collection;
+
+import static java.util.Collections.emptyList;
+import static java.util.Objects.isNull;
+import static org.springframework.http.HttpStatus.*;
+import static org.springframework.http.MediaType.APPLICATION_JSON;
+import static org.springframework.http.ResponseEntity.status;
+
+@ToString
+@Getter
+public final class ApiErrorResponse {
+
+    private final Instant timestamp;
+    private final int status;
+    private final HttpStatus errorCode;
+    private final String message;
+    private final Collection<ApiError> errors;
+
+    @Builder
+    private ApiErrorResponse(HttpStatus httpStatus, String message, Collection<ApiError> errors) {
+        this.timestamp = Instant.now();
+        this.status = httpStatus.value();
+        this.errorCode = httpStatus;
+        this.message = message;
+        this.errors = isNull(errors) ? emptyList() : errors;
+    }
+
+    public static ResponseEntity<ApiErrorResponse> badRequest(String message) {
+        return ResponseEntity.badRequest()
+                .contentType(APPLICATION_JSON)
+                .body(ApiErrorResponse.builder()
+                        .httpStatus(BAD_REQUEST)
+                        .message(message)
+                        .build());
+    }
+
+    public static ResponseEntity<ApiErrorResponse> notFound(String message) {
+        return status(NOT_FOUND)
+                .contentType(APPLICATION_JSON)
+                .body(ApiErrorResponse.builder()
+                        .httpStatus(NOT_FOUND)
+                        .message(message)
+                        .build());
+    }
+
+    public static ResponseEntity<ApiErrorResponse> unprocessableEntity(Collection<ApiError> errors, String message) {
+        return ResponseEntity.unprocessableEntity()
+                .contentType(APPLICATION_JSON)
+                .body(ApiErrorResponse.builder()
+                        .httpStatus(UNPROCESSABLE_ENTITY)
+                        .message(message)
+                        .errors(errors)
+                        .build());
+    }
+
+    public static ResponseEntity<ApiErrorResponse> conflict(String message) {
+        return status(CONFLICT)
+                .contentType(APPLICATION_JSON)
+                .body(ApiErrorResponse.builder()
+                        .httpStatus(CONFLICT)
+                        .message(message)
+                        .build());
+    }
+
+    public static ResponseEntity<ApiErrorResponse> methodNotAllowed(HttpHeaders headers, String message) {
+        return status(METHOD_NOT_ALLOWED)
+                .headers(headers)
+                .contentType(APPLICATION_JSON)
+                .body(ApiErrorResponse.builder()
+                        .httpStatus(METHOD_NOT_ALLOWED)
+                        .message(message)
+                        .build());
+    }
+
+    public static ResponseEntity<ApiErrorResponse> notAcceptable(String message) {
+        return status(NOT_ACCEPTABLE)
+                .contentType(APPLICATION_JSON)
+                .body(ApiErrorResponse.builder()
+                        .httpStatus(NOT_ACCEPTABLE)
+                        .message(message)
+                        .build());
+    }
+
+    public static ResponseEntity<ApiErrorResponse> unsupportedMediaType(HttpHeaders headers, String message) {
+        return status(UNSUPPORTED_MEDIA_TYPE)
+                .headers(headers)
+                .contentType(APPLICATION_JSON)
+                .body(ApiErrorResponse.builder()
+                        .httpStatus(UNSUPPORTED_MEDIA_TYPE)
+                        .message(message)
+                        .build());
+    }
+
+    public static ResponseEntity<ApiErrorResponse> internalServerError(String message) {
+        return ResponseEntity.internalServerError()
+                .contentType(APPLICATION_JSON)
+                .body(ApiErrorResponse.builder()
+                        .httpStatus(INTERNAL_SERVER_ERROR)
+                        .message(message)
+                        .build());
+    }
+}

src/main/java/demo/shared/ApiExceptionHandler.java

@@ -0,0 +1,79 @@
+package demo.shared;
+
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.beans.TypeMismatchException;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpStatusCode;
+import org.springframework.http.ResponseEntity;
+import org.springframework.http.converter.HttpMessageNotReadableException;
+import org.springframework.util.CollectionUtils;
+import org.springframework.web.HttpMediaTypeNotAcceptableException;
+import org.springframework.web.HttpMediaTypeNotSupportedException;
+import org.springframework.web.HttpRequestMethodNotSupportedException;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.RestControllerAdvice;
+import org.springframework.web.context.request.WebRequest;
+import org.springframework.web.servlet.NoHandlerFoundException;
+import org.springframework.web.servlet.mvc.method.annotation.ResponseEntityExceptionHandler;
+
+import static demo.shared.ApiErrorResponse.*;
+
+@RestControllerAdvice
+@Slf4j
+class ApiExceptionHandler extends ResponseEntityExceptionHandler {
+
+    @Override
+    protected ResponseEntity handleHttpMessageNotReadable(HttpMessageNotReadableException ex,
+                                                          HttpHeaders headers, HttpStatusCode status, WebRequest request) {
+        return badRequest("Malformed JSON request");
+    }
+
+    @Override
+    protected ResponseEntity handleTypeMismatch(TypeMismatchException ex,
+                                                HttpHeaders headers, HttpStatusCode status, WebRequest request) {
+        return badRequest("Type mismatch request");
+    }
+
+    @Override
+    protected ResponseEntity handleNoHandlerFoundException(NoHandlerFoundException exception,
+                                                           HttpHeaders headers, HttpStatusCode status, WebRequest request) {
+        return notFound("Resource '" + exception.getRequestURL() + "' not found");
+    }
+
+    @Override
+    protected ResponseEntity handleHttpRequestMethodNotSupported(HttpRequestMethodNotSupportedException exception,
+                                                                 HttpHeaders headers, HttpStatusCode status, WebRequest request) {
+
+        var supportedMethods = exception.getSupportedHttpMethods();
+
+        if (!CollectionUtils.isEmpty(supportedMethods)) {
+            headers.setAllow(supportedMethods);
+        }
+
+        return methodNotAllowed(headers, "Request method '" + exception.getMethod() + "' not supported");
+    }
+
+    @Override
+    protected ResponseEntity handleHttpMediaTypeNotAcceptable(HttpMediaTypeNotAcceptableException exception,
+                                                              HttpHeaders headers, HttpStatusCode status, WebRequest request) {
+        return notAcceptable("Could not find acceptable representation");
+    }
+
+    @Override
+    protected ResponseEntity handleHttpMediaTypeNotSupported(HttpMediaTypeNotSupportedException exception,
+                                                             HttpHeaders headers, HttpStatusCode status, WebRequest request) {
+
+        var mediaTypes = exception.getSupportedMediaTypes();
+        if (!CollectionUtils.isEmpty(mediaTypes)) {
+            headers.setAccept(mediaTypes);
+        }
+
+        return unsupportedMediaType(headers, "Content type '" + exception.getContentType() + "' not supported");
+    }
+
+    @ExceptionHandler(Throwable.class)
+    ResponseEntity<ApiErrorResponse> handleThrowable(Throwable throwable) {
+        log.error("Request handling failed", throwable);
+        return internalServerError("An unexpected error occurred");
+    }
+}

src/main/java/demo/shared/Failure.java

@@ -0,0 +1,46 @@
+package demo.shared;
+
+import java.util.Collection;
+
+import static java.util.Objects.requireNonNull;
+
+public interface Failure {
+
+    String message();
+
+    Collection<FieldViolation> fieldViolations();
+
+    static Failure validatonFailure(String message, Collection<FieldViolation> fieldViolations) {
+        return new ValidationFailure(message, fieldViolations);
+    }
+
+    static Failure notFoundFailure(String message) {
+        return new NotFoundFailure(message);
+    }
+
+    static Failure conflictFailure(String message) {
+        return new ConflictFailure(message);
+    }
+
+    record ValidationFailure(String message,
+                             Collection<FieldViolation> fieldViolations) implements Failure {
+
+        public ValidationFailure {
+            requireNonNull(fieldViolations, "fieldViolations cannot be null");
+        }
+    }
+
+    record NotFoundFailure(String message) implements Failure {
+
+        public Collection<FieldViolation> fieldViolations() {
+            throw new UnsupportedOperationException();
+        }
+    }
+
+    record ConflictFailure(String message) implements Failure {
+
+        public Collection<FieldViolation> fieldViolations() {
+            throw new UnsupportedOperationException();
+        }
+    }
+}

src/main/java/demo/shared/FieldViolation.java

@@ -0,0 +1,9 @@
+package demo.shared;
+
+import lombok.Builder;
+
+@Builder
+public record FieldViolation(String field,
+                             String message,
+                             Object rejValue) {
+}

src/main/java/demo/shared/Guards.java

@@ -0,0 +1,28 @@
+package demo.shared;
+
+import lombok.NoArgsConstructor;
+
+import java.math.BigDecimal;
+
+import static io.micrometer.common.util.StringUtils.isBlank;
+import static java.math.BigDecimal.ZERO;
+import static lombok.AccessLevel.PRIVATE;
+
+@NoArgsConstructor(access = PRIVATE)
+public final class Guards {
+
+    public static void notNull(Object object, String message) {
+        if (object == null)
+            throw new NullPointerException(message);
+    }
+
+    public static void notBlank(String text, String message) {
+        if (isBlank(text))
+            throw new IllegalArgumentException(message);
+    }
+
+    public static void positive(BigDecimal value, String message) {
+        if (value.compareTo(ZERO) <= 0)
+            throw new IllegalArgumentException(message);
+    }
+}

src/main/java/demo/shared/SelfValidating.java

@@ -0,0 +1,25 @@
+package demo.shared;
+
+import jakarta.validation.ConstraintViolation;
+import jakarta.validation.ConstraintViolationException;
+import jakarta.validation.Validation;
+import jakarta.validation.Validator;
+
+import java.util.Set;
+
+public abstract class SelfValidating<T> {
+
+    private final Validator validator;
+
+    public SelfValidating() {
+        var factory = Validation.buildDefaultValidatorFactory();
+        validator = factory.getValidator();
+    }
+
+    protected void validateSelf() {
+        Set<ConstraintViolation<T>> violations = validator.validate((T) this);
+        if (!violations.isEmpty()) {
+            throw new ConstraintViolationException(violations);
+        }
+    }
+}

src/main/resources/application.yml

@@ -0,0 +1,11 @@
+spring:
+  # disable default exception handling, enforce @RestControllerAdvice invocation
+  autoconfigure:
+    exclude: org.springframework.boot.autoconfigure.web.servlet.error.ErrorMvcAutoConfiguration
+  mvc:
+    throw-exception-if-no-handler-found: true
+  jackson:
+    default-property-inclusion: non_empty
+  web:
+    resources:
+      add-mappings: false

src/test/java/demo/album/DataSamples.java

@@ -0,0 +1,54 @@
+package demo.album;
+
+import lombok.NoArgsConstructor;
+
+import static lombok.AccessLevel.PRIVATE;
+
+@NoArgsConstructor(access = PRIVATE)
+public final class DataSamples {
+
+    public static String newValidRequest() {
+        return """
+                {
+                    "title": "Jeru",
+                    "artist": "Gerry Mulligan",
+                    "price": 17.99
+                }
+                """;
+    }
+
+    public static String newInvalidRequest() {
+        return """
+                {
+                    "title": "",
+                    "artist": null,
+                    "price": -17.99
+                }
+                """;
+    }
+
+    public static String expectedValidationFailure() {
+        return """
+                {
+                  "status": 422,
+                  "errorCode": "UNPROCESSABLE_ENTITY",
+                  "message": "Schema validation failure.",
+                  "errors": [
+                    {
+                      "field": "title",
+                      "message": "title cannot be blank."
+                    },
+                    {
+                      "field": "artist",
+                      "message": "artist cannot be blank."
+                    },
+                    {
+                      "field": "price",
+                      "message": "price must be greater than 0."
+                    }
+                    
+                  ]
+                }
+                """;
+    }
+}

src/test/java/demo/album/javax/adapter/in/web/AlbumControllerTest.java

@@ -0,0 +1,70 @@
+package demo.album.javax.adapter.in.web;
+
+import org.json.JSONException;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Tag;
+import org.junit.jupiter.api.Test;
+import org.skyscreamer.jsonassert.JSONAssert;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.web.client.TestRestTemplate;
+import org.springframework.http.HttpEntity;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.ResponseEntity;
+
+import static demo.album.DataSamples.*;
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.skyscreamer.jsonassert.JSONCompareMode.LENIENT;
+import static org.springframework.boot.test.context.SpringBootTest.WebEnvironment.RANDOM_PORT;
+import static org.springframework.http.HttpStatus.CREATED;
+import static org.springframework.http.HttpStatus.UNPROCESSABLE_ENTITY;
+import static org.springframework.http.MediaType.APPLICATION_JSON;
+
+@Tag("integration")
+@SpringBootTest(webEnvironment = RANDOM_PORT)
+class AlbumControllerTest {
+
+    @Autowired
+    TestRestTemplate restTemplate;
+
+    @Test
+    @DisplayName("Should create a new album successfully")
+    void createNewAlbum() {
+        // given
+        var request = newValidRequest();
+
+        // when
+        var resp = postNewAlbum(request);
+
+        // then
+        assertThat(resp.getStatusCode())
+                .isEqualTo(CREATED);
+
+        // and
+        assertThat(resp.getHeaders().getLocation())
+                .isNotNull();
+    }
+
+    @Test
+    @DisplayName("Should fail album creation when request has validation failures")
+    void failCreationWhenRequestHasValidationFailures() throws JSONException {
+        // given
+        var request = newInvalidRequest();
+
+        // when
+        var resp = postNewAlbum(request);
+
+        // then
+        assertThat(resp.getStatusCode())
+                .isEqualTo(UNPROCESSABLE_ENTITY);
+
+        // and
+        JSONAssert.assertEquals(expectedValidationFailure(), resp.getBody(), LENIENT);
+    }
+
+    private ResponseEntity<String> postNewAlbum(String request) {
+        var headers = new HttpHeaders();
+        headers.setContentType(APPLICATION_JSON);
+        return restTemplate.postForEntity("/javax/albums", new HttpEntity<>(request, headers), String.class);
+    }
+}

src/test/java/demo/album/javax/application/service/CreateAlbumServiceTest.java

@@ -0,0 +1,99 @@
+package demo.album.javax.application.service;
+
+import jakarta.validation.ConstraintViolationException;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Tag;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.NullSource;
+import org.junit.jupiter.params.provider.ValueSource;
+
+import java.math.BigDecimal;
+import java.util.UUID;
+
+import static demo.album.javax.application.port.in.CreateAlbumUseCase.CreateAlbumCommand;
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.AssertionsForClassTypes.catchThrowable;
+
+@Tag("unit")
+class CreateAlbumServiceTest {
+
+    CreateAlbumService service;
+
+    @BeforeEach
+    void setUp() {
+        service = new CreateAlbumService();
+    }
+
+    @Test
+    @DisplayName("Should create a new album successfully")
+    void createNewAlbum() {
+        // when
+        var albumId = service.add(validAlbum().build());
+
+        // then
+        assertThat(albumId).isNotNull();
+        assertThat(albumId).isInstanceOf(UUID.class);
+    }
+
+    @ParameterizedTest
+    @ValueSource(strings = {"", "  "})
+    @NullSource
+    @DisplayName("Should fail album creation when 'title' is blank")
+    void failWhenTitleIsBlank(String title) {
+        // when
+        var thrown = catchThrowable(() -> validAlbum().title(title).build());
+
+        // then
+        assertThat(thrown)
+                .isInstanceOf(ConstraintViolationException.class)
+                .hasMessageContaining("title: title cannot be blank.");
+    }
+
+    @ParameterizedTest
+    @ValueSource(strings = {"", "  "})
+    @NullSource
+    @DisplayName("Should fail album creation when 'artist' is blank")
+    void failWhenArtistIsBlank(String artist) {
+        // when
+        var thrown = catchThrowable(() -> validAlbum().artist(artist).build());
+
+        // then
+        assertThat(thrown)
+                .isInstanceOf(ConstraintViolationException.class)
+                .hasMessageContaining("artist: artist cannot be blank.");
+    }
+
+    @Test
+    @DisplayName("Should fail album creation when 'price' is null")
+    void failWhenPriceIsNull() {
+        // when
+        var thrown = catchThrowable(() -> validAlbum().price(null).build());
+
+        // then
+        assertThat(thrown)
+                .isInstanceOf(ConstraintViolationException.class)
+                .hasMessageContaining("price: price cannot be null.");
+    }
+
+    @ParameterizedTest
+    @ValueSource(doubles = {-10, 0})
+    @DisplayName("Should fail album creation when 'price' is negative")
+    void failWhenPriceIsNegative(Double price) {
+        // when
+        var thrown = catchThrowable(() -> validAlbum().price(BigDecimal.valueOf(price)).build());
+
+        // then
+        assertThat(thrown)
+                .isInstanceOf(ConstraintViolationException.class)
+                .hasMessageContaining("price: price must be greater than 0.");
+    }
+
+    private CreateAlbumCommand.CreateAlbumCommandBuilder validAlbum() {
+        return CreateAlbumCommand.builder()
+                .title("Blue Train")
+                .artist("John Coltrane")
+                .price(BigDecimal.valueOf(56.99));
+    }
+}

src/test/java/demo/album/vavr/adapter/in/web/AlbumControllerTest.java

@@ -0,0 +1,70 @@
+package demo.album.vavr.adapter.in.web;
+
+import org.json.JSONException;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Tag;
+import org.junit.jupiter.api.Test;
+import org.skyscreamer.jsonassert.JSONAssert;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.web.client.TestRestTemplate;
+import org.springframework.http.HttpEntity;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.ResponseEntity;
+
+import static demo.album.DataSamples.*;
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.skyscreamer.jsonassert.JSONCompareMode.LENIENT;
+import static org.springframework.boot.test.context.SpringBootTest.WebEnvironment.RANDOM_PORT;
+import static org.springframework.http.HttpStatus.CREATED;
+import static org.springframework.http.HttpStatus.UNPROCESSABLE_ENTITY;
+import static org.springframework.http.MediaType.APPLICATION_JSON;
+
+@Tag("integration")
+@SpringBootTest(webEnvironment = RANDOM_PORT)
+class AlbumControllerTest {
+
+    @Autowired
+    TestRestTemplate restTemplate;
+
+    @Test
+    @DisplayName("Should create a new album successfully")
+    void createNewAlbum() {
+        // given
+        var request = newValidRequest();
+
+        // when
+        var resp = postNewAlbum(request);
+
+        // then
+        assertThat(resp.getStatusCode())
+                .isEqualTo(CREATED);
+
+        // and
+        assertThat(resp.getHeaders().getLocation())
+                .isNotNull();
+    }
+
+    @Test
+    @DisplayName("Should fail album creation when request has validation failures")
+    void failCreationWhenRequestHasValidationFailures() throws JSONException {
+        // given
+        var request = newInvalidRequest();
+
+        // when
+        var resp = postNewAlbum(request);
+
+        // then
+        assertThat(resp.getStatusCode())
+                .isEqualTo(UNPROCESSABLE_ENTITY);
+
+        // and
+        JSONAssert.assertEquals(expectedValidationFailure(), resp.getBody(), LENIENT);
+    }
+
+    private ResponseEntity<String> postNewAlbum(String request) {
+        var headers = new HttpHeaders();
+        headers.setContentType(APPLICATION_JSON);
+        return restTemplate.postForEntity("/vavr/albums", new HttpEntity<>(request, headers), String.class);
+    }
+}

src/test/java/demo/album/vavr/application/service/CreateAlbumServiceTest.java

@@ -0,0 +1,123 @@
+package demo.album.vavr.application.service;
+
+import demo.shared.Failure;
+import demo.shared.FieldViolation;
+import org.assertj.vavr.api.VavrAssertions;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Tag;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.NullSource;
+import org.junit.jupiter.params.provider.ValueSource;
+
+import java.math.BigDecimal;
+import java.util.List;
+import java.util.UUID;
+
+import static demo.album.vavr.application.port.in.CreateAlbumUseCase.CreateAlbumCommand;
+import static demo.album.vavr.application.port.in.CreateAlbumUseCase.CreateAlbumCommand.*;
+import static demo.album.vavr.application.service.CreateAlbumService.VALIDATION_FAILURE_MESSAGE;
+import static demo.shared.Failure.validatonFailure;
+
+@Tag("unit")
+class CreateAlbumServiceTest {
+
+    CreateAlbumService service;
+
+    @BeforeEach
+    void setUp() {
+        service = new CreateAlbumService();
+    }
+
+    @Test
+    @DisplayName("Should create a new album successfully")
+    void createNewAlbum() {
+        // given
+        var command = validAlbum().build();
+
+        // when
+        var either = service.create(command);
+
+        // then
+        VavrAssertions.assertThat(either)
+                .isRight()
+                .containsRightInstanceOf(UUID.class);
+    }
+
+    @ParameterizedTest
+    @ValueSource(strings = {"", "  "})
+    @NullSource
+    @DisplayName("Should fail album creation when 'title' is blank")
+    void failWhenTitleIsBlank(String title) {
+        // given
+        var command = validAlbum().title(title).build();
+
+        // when
+        var either = service.create(command);
+
+        // then
+        VavrAssertions.assertThat(either)
+                .isLeft()
+                .containsOnLeft(failure(new FieldViolation(FIELD_TITLE, "title cannot be blank.", title)));
+    }
+
+    @ParameterizedTest
+    @ValueSource(strings = {"", "  "})
+    @NullSource
+    @DisplayName("Should fail album creation when 'artist' is blank")
+    void failWhenArtistIsBlank(String artist) {
+        // given
+        var command = validAlbum().artist(artist).build();
+
+        // when
+        var either = service.create(command);
+
+        // then
+        VavrAssertions.assertThat(either)
+                .isLeft()
+                .containsOnLeft(failure(new FieldViolation(FIELD_ARTIST, "artist cannot be blank.", artist)));
+    }
+
+    @Test
+    @DisplayName("Should fail album creation when 'price' is null")
+    void failWhenPriceIsNull() {
+        // given
+        var command = validAlbum().price(null).build();
+
+        // when
+        var either = service.create(command);
+
+        // then
+        VavrAssertions.assertThat(either)
+                .isLeft()
+                .containsOnLeft(failure(new FieldViolation(FIELD_PRICE, "price cannot be null.", null)));
+    }
+
+    @ParameterizedTest
+    @ValueSource(doubles = {-10, 0})
+    @DisplayName("Should fail album creation when 'price' is negative")
+    void failWhenPriceIsNegative(Double price) {
+        // given
+        var command = validAlbum().price(BigDecimal.valueOf(price)).build();
+
+        // when
+        var either = service.create(command);
+
+        // then
+        VavrAssertions.assertThat(either)
+                .isLeft()
+                .containsOnLeft(failure(new FieldViolation(FIELD_PRICE, "price must be greater than 0.", BigDecimal.valueOf(price))));
+    }
+
+    private Failure failure(FieldViolation fieldViolation) {
+        return validatonFailure(VALIDATION_FAILURE_MESSAGE, List.of(fieldViolation));
+    }
+
+    private CreateAlbumCommand.CreateAlbumCommandBuilder validAlbum() {
+        return CreateAlbumCommand.builder()
+                .title("Blue Train")
+                .artist("John Coltrane")
+                .price(BigDecimal.valueOf(56.99));
+    }
+}

src/test/java/demo/shared/ApiExceptionHandlerTest.java

@@ -0,0 +1,196 @@
+package demo.shared;
+
+import demo.shared.ApiExceptionHandlerTest.Config.TestResource;
+import org.junit.jupiter.api.Tag;
+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.context.TestConfiguration;
+import org.springframework.context.annotation.Import;
+import org.springframework.http.ResponseEntity;
+import org.springframework.test.web.servlet.MockMvc;
+import org.springframework.web.bind.annotation.*;
+
+import java.util.UUID;
+
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.matchesPattern;
+import static org.springframework.http.HttpHeaders.ALLOW;
+import static org.springframework.http.HttpHeaders.CONTENT_TYPE;
+import static org.springframework.http.HttpMethod.GET;
+import static org.springframework.http.MediaType.*;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.*;
+
+/*
+    Error Response Format:
+    ---------------------
+    {
+      "timestamp": "2022-07-23T15:04:04.320363Z",
+      "status": 400,
+      "errorCode": "BAD_REQUEST",
+      "message": "Malformed JSON request"
+      "errors" : []
+    }
+ */
+
+@Tag("integration")
+@WebMvcTest(controllers = TestResource.class)
+@Import(ApiExceptionHandler.class)
+class ApiExceptionHandlerTest {
+
+    private static final String ISO_8601 = "^\\d{4}-[01]\\d-[0-3]\\dT[0-2]\\d:[0-5]\\d:[0-5]\\d\\.\\d{3,}([+-][0-2]\\d(:?[0-5]\\d)?|Z)$";
+
+    @Autowired
+    private MockMvc mockMvc;
+
+    @Test
+    void messageNotReadable() throws Exception {
+        var lenientJSONRes = """
+                {
+                  "status": 400,
+                  "errorCode": "BAD_REQUEST",
+                  "message": "Malformed JSON request"
+                }""";
+
+        mockMvc.perform(post("/test-url2")
+                        .contentType(APPLICATION_JSON)
+                        .content("{\"value\": "))
+                .andExpect(status().isBadRequest())
+                .andExpect(content().json(lenientJSONRes))
+                .andExpect(jsonPath("$.timestamp").value(matchesPattern(ISO_8601)));
+    }
+
+    @Test
+    void typeMismatch() throws Exception {
+        var lenientJSONRes = """
+                {
+                  "status": 400,
+                  "errorCode": "BAD_REQUEST",
+                  "message": "Type mismatch request"
+                }""";
+
+        mockMvc.perform(post("/test-url3/1234")
+                        .contentType(APPLICATION_JSON))
+                .andExpect(status().isBadRequest())
+                .andExpect(header().string(CONTENT_TYPE, is(APPLICATION_JSON_VALUE)))
+                .andExpect(content().json(lenientJSONRes))
+                .andExpect(jsonPath("$.timestamp").value(matchesPattern(ISO_8601)));
+    }
+
+    @Test
+    void notFound() throws Exception {
+        var lenientJSONRes = """
+                {
+                  "status": 404,
+                  "errorCode": "NOT_FOUND",
+                  "message": "Resource '/unknown' not found"
+                }""";
+
+        mockMvc.perform(get("/unknown"))
+                .andExpect(status().isNotFound())
+                .andExpect(header().string(CONTENT_TYPE, is(APPLICATION_JSON_VALUE)))
+                .andExpect(content().json(lenientJSONRes))
+                .andExpect(jsonPath("$.timestamp").value(matchesPattern(ISO_8601)));
+    }
+
+    @Test
+    void methodNotSupported() throws Exception {
+        var lenientJSONRes = """
+                {
+                  "status": 405,
+                  "errorCode": "METHOD_NOT_ALLOWED",
+                  "message": "Request method 'POST' not supported"
+                }""";
+
+        mockMvc.perform(post("/test-url"))
+                .andExpect(status().isMethodNotAllowed())
+                .andExpect(header().string(CONTENT_TYPE, is(APPLICATION_JSON_VALUE)))
+                .andExpect(header().string(ALLOW, is(GET.name())))
+                .andExpect(content().json(lenientJSONRes))
+                .andExpect(jsonPath("$.timestamp").value(matchesPattern(ISO_8601)));
+    }
+
+    @Test
+    void mediaTypeNotAcceptable() throws Exception {
+        var lenientJSONRes = """
+                {
+                  "status": 406,
+                  "errorCode": "NOT_ACCEPTABLE",
+                  "message": "Could not find acceptable representation"
+                }""";
+
+        mockMvc.perform(get("/test-url")
+                        .accept(APPLICATION_JSON))
+                .andExpect(status().isNotAcceptable())
+                .andExpect(header().string(CONTENT_TYPE, is(APPLICATION_JSON_VALUE)))
+                .andExpect(content().json(lenientJSONRes))
+                .andExpect(jsonPath("$.timestamp").value(matchesPattern(ISO_8601)));
+    }
+
+    @Test
+    void mediaTypeNotSupported() throws Exception {
+        var lenientJSONRes = """
+                {
+                  "status": 415,
+                  "errorCode": "UNSUPPORTED_MEDIA_TYPE",
+                  "message": "Content type 'application/xml' not supported"
+                }""";
+
+        mockMvc.perform(post("/test-url3/" + UUID.randomUUID())
+                        .contentType(APPLICATION_XML))
+                .andExpect(status().isUnsupportedMediaType())
+                .andExpect(header().string(CONTENT_TYPE, is(APPLICATION_JSON_VALUE)))
+                .andExpect(content().json(lenientJSONRes))
+                .andExpect(jsonPath("$.timestamp").value(matchesPattern(ISO_8601)));
+    }
+
+    @Test
+    void internalServerError() throws Exception {
+        var lenientJSONRes = """
+                {
+                  "status": 500,
+                  "errorCode": "INTERNAL_SERVER_ERROR",
+                  "message": "An unexpected error occurred"
+                }""";
+
+        mockMvc.perform(post("/test-url3/" + UUID.randomUUID())
+                        .contentType(APPLICATION_JSON))
+                .andExpect(status().isInternalServerError())
+                .andExpect(header().string(CONTENT_TYPE, is(APPLICATION_JSON_VALUE)))
+                .andExpect(content().json(lenientJSONRes))
+                .andExpect(jsonPath("$.timestamp").value(matchesPattern(ISO_8601)));
+    }
+
+    @TestConfiguration
+    static class Config {
+
+        @RestController
+        static class TestResource {
+
+            @GetMapping(path = "/test-url", produces = TEXT_HTML_VALUE)
+            String get() {
+                return "test";
+            }
+
+            @GetMapping(path = "/test-url2", produces = APPLICATION_JSON_VALUE)
+            ResponseEntity<?> getQuery(Request request) {
+                return ResponseEntity.ok("{}");
+            }
+
+            @PostMapping(path = "/test-url2", consumes = APPLICATION_JSON_VALUE)
+            void post(@RequestBody Request request) {
+                throw new UnsupportedOperationException("Not implemented");
+            }
+
+            @PostMapping(path = "/test-url3/{id}", consumes = APPLICATION_JSON_VALUE)
+            void post(@PathVariable UUID id) {
+                throw new UnsupportedOperationException("Not implemented");
+            }
+        }
+
+        record Request(Integer value, String value2) {
+        }
+    }
+}