Merge pull request #1 from eugenp/master

merge

algorithms-miscellaneous-6/src/main/java/com/baeldung/algorithms/linkedlist/LinkedListReversal.java

@@ -0,0 +1,30 @@
+package com.baeldung.algorithms.linkedlist;
+
+public class LinkedListReversal {
+
+    ListNode reverseList(ListNode head) {
+        ListNode previous = null;
+        ListNode current = head;
+        while (current != null) {
+            ListNode nextElement = current.getNext();
+            current.setNext(previous);
+            previous = current;
+            current = nextElement;
+        }
+        return previous;
+    }
+
+    ListNode reverseListRecursive(ListNode head) {
+        if (head == null) {
+            return null;
+        }
+        if (head.getNext() == null) {
+            return head;
+        }
+        ListNode node = reverseListRecursive(head.getNext());
+        head.getNext().setNext(head);
+        head.setNext(null);
+        return node;
+    }
+
+}

algorithms-miscellaneous-6/src/main/java/com/baeldung/algorithms/linkedlist/ListNode.java

@@ -0,0 +1,28 @@
+package com.baeldung.algorithms.linkedlist;
+
+public class ListNode {
+
+    private int data;
+    private ListNode next;
+
+    ListNode(int data) {
+        this.data = data;
+        this.next = null;
+    }
+
+    public int getData() {
+        return data;
+    }
+
+    public ListNode getNext() {
+        return next;
+    }
+
+    public void setData(int data) {
+        this.data = data;
+    }
+
+    public void setNext(ListNode next) {
+        this.next = next;
+    }
+}

algorithms-miscellaneous-6/src/test/java/com/baeldung/algorithms/linkedlist/LinkedListReversalUnitTest.java

@@ -0,0 +1,59 @@
+package com.baeldung.algorithms.linkedlist;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+public class LinkedListReversalUnitTest {
+    @Test
+    public void givenLinkedList_whenIterativeReverse_thenOutputCorrectResult() {
+        ListNode head = constructLinkedList();
+        ListNode node = head;
+        for (int i = 1; i <= 5; i++) {
+            assertNotNull(node);
+            assertEquals(i, node.getData());
+            node = node.getNext();
+        }
+        LinkedListReversal reversal = new LinkedListReversal();
+        node = reversal.reverseList(head);
+        for (int i = 5; i >= 1; i--) {
+            assertNotNull(node);
+            assertEquals(i, node.getData());
+            node = node.getNext();
+        }
+    }
+
+    @Test
+    public void givenLinkedList_whenRecursiveReverse_thenOutputCorrectResult() {
+        ListNode head = constructLinkedList();
+        ListNode node = head;
+        for (int i = 1; i <= 5; i++) {
+            assertNotNull(node);
+            assertEquals(i, node.getData());
+            node = node.getNext();
+        }
+        LinkedListReversal reversal = new LinkedListReversal();
+        node = reversal.reverseListRecursive(head);
+        for (int i = 5; i >= 1; i--) {
+            assertNotNull(node);
+            assertEquals(i, node.getData());
+            node = node.getNext();
+        }
+    }
+
+    private ListNode constructLinkedList() {
+        ListNode head = null;
+        ListNode tail = null;
+        for (int i = 1; i <= 5; i++) {
+            ListNode node = new ListNode(i);
+            if (head == null) {
+                head = node;
+            } else {
+                tail.setNext(node);
+            }
+            tail = node;
+        }
+        return head;
+    }
+}

core-groovy-strings/README.md

@@ -0,0 +1,3 @@
+### Relevant Articles:
+
+- [How to Remove a Prefix From Strings in Groovy](https://www.baeldung.com/groovy-remove-string-prefix)

core-java-modules/core-java-io-3/src/main/java/com/baeldung/lastmodifiedfile/LastModifiedFileApp.java

@@ -0,0 +1,61 @@
+package com.baeldung.lastmodifiedfile;
+
+import java.io.File;
+import java.io.FileFilter;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.Arrays;
+import java.util.Optional;
+
+import org.apache.commons.io.comparator.LastModifiedFileComparator;
+import org.apache.commons.io.filefilter.FileFilterUtils;
+
+public class LastModifiedFileApp {
+
+    public static File findUsingIOApi(String sdir) {
+        File dir = new File(sdir);
+        if (dir.isDirectory()) {
+            Optional<File> opFile = Arrays.stream(dir.listFiles(File::isFile))
+              .max((f1, f2) -> Long.compare(f1.lastModified(), f2.lastModified()));
+
+            if (opFile.isPresent()) {
+                return opFile.get();
+            }
+        }
+
+        return null;
+    }
+
+    public static Path findUsingNIOApi(String sdir) throws IOException {
+        Path dir = Paths.get(sdir);
+        if (Files.isDirectory(dir)) {
+            Optional<Path> opPath = Files.list(dir)
+              .filter(p -> !Files.isDirectory(p))
+              .sorted((p1, p2) -> Long.valueOf(p2.toFile().lastModified())
+                .compareTo(p1.toFile().lastModified()))
+              .findFirst();
+
+            if (opPath.isPresent()) {
+                return opPath.get();
+            }
+        }
+
+        return null;
+    }
+
+    public static File findUsingCommonsIO(String sdir) {
+        File dir = new File(sdir);
+        if (dir.isDirectory()) {
+            File[] dirFiles = dir.listFiles((FileFilter) FileFilterUtils.fileFileFilter());
+            if (dirFiles != null && dirFiles.length > 0) {
+                Arrays.sort(dirFiles, LastModifiedFileComparator.LASTMODIFIED_REVERSE);
+                return dirFiles[0];
+            }
+        }
+
+        return null;
+    }
+
+}

core-java-modules/core-java-io-3/src/test/java/com/baeldung/lastmodifiedfile/LastModifiedFileAppUnitTest.java

@@ -0,0 +1,78 @@
+package com.baeldung.lastmodifiedfile;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+
+import org.apache.commons.io.FileUtils;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+public class LastModifiedFileAppUnitTest {
+
+    private final static String SOURCEDIRECTORY = "src/test/resources/lastmodfiles";
+
+    @BeforeAll
+    public static void setUpFiles() throws IOException, InterruptedException {
+        File srcDir = new File(SOURCEDIRECTORY);
+        if (!srcDir.exists()) {
+            srcDir.mkdir();
+        }
+
+        FileUtils.cleanDirectory(srcDir);
+
+        File file01 = new File(SOURCEDIRECTORY + "/file01.txt");
+        file01.createNewFile();
+
+        Thread.sleep(2000);
+
+        File file02 = new File(SOURCEDIRECTORY + "/file02.txt");
+        file02.createNewFile();
+
+        Thread.sleep(2000);
+
+        File file03 = new File(SOURCEDIRECTORY + "/file03.txt");
+        file03.createNewFile();
+
+        Thread.sleep(2000);
+
+        Files.write(Paths.get(SOURCEDIRECTORY + "/file02.txt"), "Hello File02".getBytes());
+
+    }
+
+    @Test
+    public void givenDirectory_whenUsingIoApi_thenFindLastModfile() throws IOException {
+        File lastModFile = LastModifiedFileApp.findUsingIOApi(SOURCEDIRECTORY);
+
+        assertThat(lastModFile).isNotNull();
+        assertThat(lastModFile.getName()).isEqualTo("file02.txt");
+    }
+
+    @Test
+    public void givenDirectory_whenUsingNioApi_thenFindLastModfile() throws IOException {
+        Path lastModPath = LastModifiedFileApp.findUsingNIOApi(SOURCEDIRECTORY);
+
+        assertThat(lastModPath).isNotNull();
+        assertThat(lastModPath.toFile().getName()).isEqualTo("file02.txt");
+    }
+
+    @Test
+    public void givenDirectory_whenUsingApacheCommons_thenFindLastModfile() throws IOException {
+        File lastModFile = LastModifiedFileApp.findUsingCommonsIO(SOURCEDIRECTORY);
+
+        assertThat(lastModFile).isNotNull();
+        assertThat(lastModFile.getName()).isEqualTo("file02.txt");
+    }
+
+    @AfterAll
+    public static void cleanUp() throws IOException {
+        File srcDir = new File(SOURCEDIRECTORY);
+        FileUtils.deleteDirectory(srcDir);
+    }
+
+}

core-java-modules/core-java-lang-3/src/main/java/com/baeldung/getclassobject/Animal.java

@@ -0,0 +1,5 @@
+package com.baeldung.getclassobject;
+
+public class Animal {
+    protected int numberOfEyes;
+}

core-java-modules/core-java-lang-3/src/main/java/com/baeldung/getclassobject/Monkey.java

@@ -0,0 +1,4 @@
+package com.baeldung.getclassobject;
+
+public class Monkey extends Animal {
+}

core-java-modules/core-java-lang-3/src/main/java/com/baeldung/getclassobject/SomeAbstractClass.java

@@ -0,0 +1,4 @@
+package com.baeldung.getclassobject;
+
+public abstract class SomeAbstractClass {
+}

core-java-modules/core-java-lang-3/src/main/java/com/baeldung/getclassobject/SomeInterface.java

@@ -0,0 +1,4 @@
+package com.baeldung.getclassobject;
+
+interface SomeInterface {
+}

core-java-modules/core-java-lang-3/src/main/java/com/baeldung/getclassobject/SomeUtils.java

@@ -0,0 +1,9 @@
+package com.baeldung.getclassobject;
+
+public class SomeUtils {
+    private SomeUtils() {
+        throw new RuntimeException("This Util class is not allowed to be instantiated!");
+    }
+    //  public static utilMethods
+    //  ...
+}

core-java-modules/core-java-lang-3/src/test/java/com/baeldung/getclassobject/GetClassObjectUnitTest.java

@@ -0,0 +1,55 @@
+package com.baeldung.getclassobject;
+
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+public class GetClassObjectUnitTest {
+    @Test
+    public void givenObjectAndType_whenGettingClassObject_thenTwoMethodsHaveTheSameResult() {
+        String str = "I am an object of the String class";
+        Class fromStrObject = str.getClass();
+        Class clazz = String.class;
+        assertSame(fromStrObject, clazz);
+    }
+
+    @Test
+    public void givenClassInheritance_whenGettingRuntimeTypeAndStaticType_thenGetDifferentResult() {
+        Animal animal = new Monkey();
+        Class runtimeType = animal.getClass();
+        Class staticType = Animal.class;
+        //Not equals
+        assertNotEquals(staticType, runtimeType);
+
+        Class monkeyClass = Monkey.class;
+        assertSame(runtimeType, monkeyClass);
+    }
+
+    @Test
+    public void givenPrimitiveType_whenGettingClassObject_thenOnlyStaticTypeWorks() {
+        int number = 7;
+        // Class numberClass = number.getClass();   <-- compilation error
+        Class intType = int.class;
+
+        assertNotNull(intType);
+        assertEquals("int", intType.getName());
+        assertTrue(intType.isPrimitive());
+    }
+
+    @Test
+    public void givenTypeCannotInstantiate_whenGetTypeStatically_thenGetTypesSuccefully() {
+        Class interfaceType = SomeInterface.class;
+        Class abstractClassType = SomeAbstractClass.class;
+        Class utilClassType = SomeUtils.class;
+
+        assertNotNull(interfaceType);
+        assertTrue(interfaceType.isInterface());
+        assertEquals("SomeInterface", interfaceType.getSimpleName());
+
+        assertNotNull(abstractClassType);
+        assertEquals("SomeAbstractClass", abstractClassType.getSimpleName());
+
+        assertNotNull(utilClassType);
+        assertEquals("SomeUtils", utilClassType.getSimpleName());
+    }
+}

core-java-modules/core-java-lang-oop-methods/README.md

@@ -9,3 +9,4 @@ This module contains articles about methods in Java
 - [Java equals() and hashCode() Contracts](https://www.baeldung.com/java-equals-hashcode-contracts)
 - [Guide to hashCode() in Java](https://www.baeldung.com/java-hashcode)
 - [The Covariant Return Type in Java](https://www.baeldung.com/java-covariant-return-type)
+- [Does a Method’s Signature Include the Return Type in Java?](https://www.baeldung.com/java-method-signature-return-type)

core-java-modules/core-java-networking-2/README.md

@@ -13,4 +13,5 @@ This module contains articles about networking in Java
 - [Download a File from an URL in Java](https://www.baeldung.com/java-download-file)
 - [Handling java.net.ConnectException](https://www.baeldung.com/java-net-connectexception)
 - [Getting MAC addresses in Java](https://www.baeldung.com/java-mac-address)
+- [Sending Emails with Attachments in Java](https://www.baeldung.com/java-send-emails-attachments)
 - [[<-- Prev]](/core-java-modules/core-java-networking)

core-java-modules/core-java-reflection-2/README.md

@@ -2,3 +2,4 @@
 
 - [Reading the Value of ‘private’ Fields from a Different Class in Java](https://www.baeldung.com/java-reflection-read-private-field-value)
 - [Set Field Value With Reflection](https://www.baeldung.com/java-set-private-field-value)
+- [Checking If a Method is Static Using Reflection in Java](https://www.baeldung.com/java-check-method-is-static)

gradle/gradle-wrapper/gradle/wrapper/README.md

@@ -0,0 +1,35 @@
+The files in this project were generated using gradle wrapper command.
+`gradle wrapper`
+
+To test, download this project on your machine and run the following:
+`./wrapper tasks`
+
+This should generate output similar to:
+```
+> Task :tasks
+
+------------------------------------------------------------
+Tasks runnable from root project
+------------------------------------------------------------
+
+Build Setup tasks
+-----------------
+init - Initializes a new Gradle build.
+wrapper - Generates Gradle wrapper files.
+
+Help tasks
+----------
+buildEnvironment - Displays all buildscript dependencies declared in root project 'gradle-wrapper'.
+components - Displays the components produced by root project 'gradle-wrapper'. [incubating]
+dependencies - Displays all dependencies declared in root project 'gradle-wrapper'.
+dependencyInsight - Displays the insight into a specific dependency in root project 'gradle-wrapper'.
+dependentComponents - Displays the dependent components of components in root project 'gradle-wrapper'. [incubating]
+help - Displays a help message.
+model - Displays the configuration model of root project 'gradle-wrapper'. [incubating]
+outgoingVariants - Displays the outgoing variants of root project 'gradle-wrapper'.
+projects - Displays the sub-projects of root project 'gradle-wrapper'.
+properties - Displays the properties of root project 'gradle-wrapper'.
+tasks - Displays the tasks runnable from root project 'gradle-wrapper'.
+
+To see all tasks and more detail, run gradlew tasks --all
+```

gradle/gradle-wrapper/gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.3-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists

gradle/gradle-wrapper/gradlew

@@ -0,0 +1,183 @@
+#!/usr/bin/env sh
+
+#
+# Copyright 2015 the original author or authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      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.
+#
+
+##############################################################################
+##
+##  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 "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+    echo "$*"
+}
+
+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 or MSYS, switch paths to Windows format before running java
+if [ "$cygwin" = "true" -o "$msys" = "true" ] ; 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=`expr $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"
+
+exec "$JAVACMD" "$@"

gradle/gradle-wrapper/gradlew.bat

@@ -0,0 +1,103 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem 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, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+
+@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 Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@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="-Xmx64m" "-Xms64m"
+
+@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

httpclient-2/.gitignore

@@ -0,0 +1,13 @@
+*.class
+
+#folders#
+/target
+/neoDb*
+/data
+/src/main/webapp/WEB-INF/classes
+*/META-INF/*
+
+# Packaged files #
+*.jar
+*.war
+*.ear

httpclient-2/README.md

@@ -0,0 +1,12 @@
+## HttpClient 4.x
+
+This module contains articles about HttpClient 4.x
+
+### The Course
+
+The "REST With Spring" Classes: http://bit.ly/restwithspring
+
+### Relevant Articles: 
+
+- [How to Set TLS Version in Apache HttpClient](https://www.baeldung.com/TODO)
+- More articles: [[<-- prev]](../httpclient)

httpclient-2/pom.xml

@@ -0,0 +1,43 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>httpclient-2</artifactId>
+    <version>0.1-SNAPSHOT</version>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-java</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../parent-java</relativePath>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.apache.httpcomponents</groupId>
+            <artifactId>httpclient</artifactId>
+            <version>${httpclient.version}</version>
+            <exclusions>
+                <exclusion>
+                    <artifactId>commons-logging</artifactId>
+                    <groupId>commons-logging</groupId>
+                </exclusion>
+            </exclusions>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <finalName>httpclient-2</finalName>
+        <resources>
+            <resource>
+                <directory>src/main/resources</directory>
+                <filtering>true</filtering>
+            </resource>
+        </resources>
+    </build>
+
+    <properties>
+        <httpclient.version>4.5.8</httpclient.version>
+    </properties>
+
+</project>

httpclient-2/src/main/java/com/baeldung/tlsversion/ClientTlsVersionExamples.java

@@ -0,0 +1,64 @@
+package com.baeldung.tlsversion;
+
+import javax.net.ssl.SSLSocket;
+
+import org.apache.http.HttpEntity;
+import org.apache.http.client.methods.CloseableHttpResponse;
+import org.apache.http.client.methods.HttpGet;
+import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
+import org.apache.http.impl.client.CloseableHttpClient;
+import org.apache.http.impl.client.HttpClients;
+import org.apache.http.ssl.SSLContexts;
+import org.apache.http.util.EntityUtils;
+
+import java.io.IOException;
+
+public class ClientTlsVersionExamples {
+
+    public static CloseableHttpClient setViaSocketFactory() {
+        SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(
+          SSLContexts.createDefault(),
+          new String[] { "TLSv1.2", "TLSv1.3" },
+          null,
+          SSLConnectionSocketFactory.getDefaultHostnameVerifier());
+
+        return HttpClients.custom().setSSLSocketFactory(sslsf).build();
+    }
+
+    public static CloseableHttpClient setTlsVersionPerConnection() {
+        SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(SSLContexts.createDefault()) {
+
+            @Override
+            protected void prepareSocket(SSLSocket socket) {
+                String hostname = socket.getInetAddress().getHostName();
+                if (hostname.endsWith("internal.system.com")) {
+                    socket.setEnabledProtocols(new String[] { "TLSv1", "TLSv1.1", "TLSv1.2", "TLSv1.3" });
+                } else {
+                    socket.setEnabledProtocols(new String[] { "TLSv1.3" });
+                }
+            }
+        };
+
+        return HttpClients.custom().setSSLSocketFactory(sslsf).build();
+    }
+
+    // To configure the TLS versions for the client, set the https.protocols system property during runtime.
+    // For example: java -Dhttps.protocols=TLSv1.1,TLSv1.2,TLSv1.3 -jar webClient.jar
+    public static CloseableHttpClient setViaSystemProperties() {
+        return HttpClients.createSystem();
+        // Alternatively:
+        // return HttpClients.custom().useSystemProperties().build();
+    }
+
+    public static void main(String[] args) throws IOException {
+        // Alternatively:
+        // CloseableHttpClient httpClient = setTlsVersionPerConnection();
+        // CloseableHttpClient httpClient = setViaSystemProperties();
+        try (CloseableHttpClient httpClient = setViaSocketFactory();
+           CloseableHttpResponse response = httpClient.execute(new HttpGet("https://httpbin.org/"))) {
+
+            HttpEntity entity = response.getEntity();
+            EntityUtils.consume(entity);
+        }
+    }
+}

httpclient/README.md

@@ -18,3 +18,4 @@ The "REST With Spring" Classes: http://bit.ly/restwithspring
 - [Advanced HttpClient Configuration](https://www.baeldung.com/httpclient-advanced-config)
 - [HttpClient 4 – Do Not Follow Redirects](https://www.baeldung.com/httpclient-stop-follow-redirect)
 - [Custom User-Agent in HttpClient 4](https://www.baeldung.com/httpclient-user-agent-header)
+- More articles: [[next -->]](../httpclient-2)

java-collections-conversions-2/README.md

@@ -7,4 +7,5 @@ This module contains articles about conversions among Collection types and array
 - [Array to String Conversions](https://www.baeldung.com/java-array-to-string)
 - [Mapping Lists with ModelMapper](https://www.baeldung.com/java-modelmapper-lists)
 - [Converting List to Map With a Custom Supplier](https://www.baeldung.com/list-to-map-supplier)
+- [Arrays.asList vs new ArrayList(Arrays.asList())](https://www.baeldung.com/java-arrays-aslist-vs-new-arraylist)
 - More articles: [[<-- prev]](../java-collections-conversions)

json/README.md

@@ -13,3 +13,4 @@ This module contains articles about JSON.
 - [Get a Value by Key in a JSONArray](https://www.baeldung.com/java-jsonarray-get-value-by-key)
 - [Iterating Over an Instance of org.json.JSONObject](https://www.baeldung.com/jsonobject-iteration)
 - [Escape JSON String in Java](https://www.baeldung.com/java-json-escaping)
+- [Reducing JSON Data Size](https://www.baeldung.com/json-reduce-data-size)

mapstruct/pom.xml

@@ -71,7 +71,7 @@
     </build>
 
     <properties>
-        <org.mapstruct.version>1.4.0.Beta1</org.mapstruct.version>
+        <org.mapstruct.version>1.3.1.Final</org.mapstruct.version>
         <springframework.version>4.3.4.RELEASE</springframework.version>
         <maven.compiler.source>1.8</maven.compiler.source>
         <maven.compiler.target>1.8</maven.compiler.target>

mapstruct/src/main/java/com/baeldung/mapstruct/mappingCollections/mapper/CompanyMapperAdderPreferred.java

@@ -5,7 +5,8 @@ import com.baeldung.mapstruct.mappingCollections.model.Company;
 import org.mapstruct.CollectionMappingStrategy;
 import org.mapstruct.Mapper;
 
-@Mapper(collectionMappingStrategy = CollectionMappingStrategy.ADDER_PREFERRED)
+@Mapper(collectionMappingStrategy = CollectionMappingStrategy.ADDER_PREFERRED,
+        uses = EmployeeMapper.class)
 public interface CompanyMapperAdderPreferred {
 
     CompanyDTO map(Company company);

mapstruct/src/main/java/com/baeldung/mapstruct/mappingCollections/mapper/EmployeeMapper.java

@@ -11,6 +11,8 @@ import java.util.Set;
 @Mapper
 public interface EmployeeMapper {
 
+    EmployeeDTO map(Employee employee);
+
     List<EmployeeDTO> map(List<Employee> employees);
 
     Set<EmployeeDTO> map(Set<Employee> employees);

persistence-modules/jooq/pom.xml

@@ -0,0 +1,46 @@
+<?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>
+    <artifactId>jooq</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <name>jooq-examples</name>
+    <packaging>jar</packaging>
+    <description>jOOQ Examples</description>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>persistence-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.jooq</groupId>
+            <artifactId>jooq</artifactId>
+            <version>3.13.4</version>
+        </dependency>
+        <dependency>
+            <groupId>org.jooq</groupId>
+            <artifactId>jooq-meta</artifactId>
+            <version>3.13.4</version>
+        </dependency>
+        <dependency>
+            <groupId>org.jooq</groupId>
+            <artifactId>jooq-codegen</artifactId>
+            <version>3.13.4</version>
+        </dependency>
+        <dependency>
+            <groupId>org.postgresql</groupId>
+            <artifactId>postgresql</artifactId>
+            <version>42.2.16</version>
+        </dependency>
+        <dependency>
+            <groupId>com.h2database</groupId>
+            <artifactId>h2</artifactId>
+            <version>1.4.200</version>
+        </dependency>
+    </dependencies>
+
+</project>

persistence-modules/jooq/src/main/java/com/baeldung/jooq/Crud.java

@@ -0,0 +1,57 @@
+package com.baeldung.jooq;
+
+import org.jooq.Condition;
+import org.jooq.DSLContext;
+import org.jooq.Field;
+import org.jooq.Record;
+import org.jooq.Result;
+import org.jooq.SelectFieldOrAsterisk;
+import org.jooq.Table;
+import org.jooq.UpdatableRecord;
+
+import java.util.Map;
+
+public class Crud {
+
+    public static <R extends UpdatableRecord<R>> void save(UpdatableRecord<R> record) {
+        record.store();
+    }
+
+    public static Result<Record> getAll(DSLContext context, Table<? extends Record> table) {
+        return context.select()
+                .from(table)
+                .fetch();
+    }
+
+    public static Result<Record> getFields(DSLContext context, Table<? extends Record> table, SelectFieldOrAsterisk... fields) {
+        return context.select(fields)
+                .from(table)
+                .fetch();
+    }
+
+    public static <R extends Record> R getOne(DSLContext context, Table<R> table, Condition condition) {
+        return context.fetchOne(table, condition);
+    }
+
+    public static <T> void update(DSLContext context, Table<? extends Record> table, Map<Field<T>, T> values, Condition condition) {
+        context.update(table)
+                .set(values)
+                .where(condition)
+                .execute();
+    }
+
+    public static <R extends UpdatableRecord<R>> void update(UpdatableRecord<R> record) {
+        record.update();
+    }
+
+    public static void delete(DSLContext context, Table<? extends Record> table, Condition condition) {
+        context.delete(table)
+                .where(condition)
+                .execute();
+    }
+
+    public static <R extends UpdatableRecord<R>> void delete(UpdatableRecord<R> record) {
+        record.delete();
+    }
+
+}

persistence-modules/jooq/src/main/java/com/baeldung/jooq/CrudExamples.java

@@ -0,0 +1,117 @@
+package com.baeldung.jooq;
+
+import com.baeldung.jooq.model.tables.Article;
+import com.baeldung.jooq.model.tables.Author;
+import com.baeldung.jooq.model.tables.records.ArticleRecord;
+import com.baeldung.jooq.model.tables.records.AuthorRecord;
+import org.jooq.DSLContext;
+import org.jooq.Field;
+import org.jooq.Record;
+import org.jooq.Result;
+import org.jooq.SQLDialect;
+import org.jooq.impl.DSL;
+
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.SQLException;
+import java.util.HashMap;
+
+import static com.baeldung.jooq.Crud.delete;
+import static com.baeldung.jooq.Crud.getAll;
+import static com.baeldung.jooq.Crud.getFields;
+import static com.baeldung.jooq.Crud.getOne;
+import static com.baeldung.jooq.Crud.save;
+import static com.baeldung.jooq.Crud.update;
+
+public class CrudExamples {
+
+    public void crudExamples() throws SQLException {
+        String userName = "username";
+        String password = "password";
+        String url = "jdbc:postgresql://db_url:5432/baeldung_database";
+
+        Connection conn = DriverManager.getConnection(url, userName, password);
+        DSLContext context = DSL.using(conn, SQLDialect.POSTGRES);
+
+        createValues(context);
+        readValues(context);
+        updateValues(context);
+        deleteValues(context);
+    }
+
+    private void createValues(DSLContext context) {
+        ArticleRecord article = context.newRecord(Article.ARTICLE);
+
+        article.setId(2);
+        article.setTitle("jOOQ examples");
+        article.setDescription("A few examples of jOOQ CRUD operations");
+        article.setAuthorId(1);
+
+        save(article);
+
+        AuthorRecord author = context.newRecord(Author.AUTHOR);
+        author.setId(1);
+        author.setFirstName("John");
+        author.setLastName("Smith");
+        author.setAge(40);
+
+        save(author);
+    }
+
+    private void readValues(DSLContext context) {
+        Result<Record> authors = getAll(
+                context,
+                Author.AUTHOR
+        );
+
+        authors.forEach(author -> {
+            Integer id = author.getValue(Author.AUTHOR.ID);
+            String firstName = author.getValue(Author.AUTHOR.FIRST_NAME);
+            String lastName = author.getValue(Author.AUTHOR.LAST_NAME);
+            Integer age = author.getValue(Author.AUTHOR.AGE);
+            System.out.printf("Author %s %s has id: %d and age: %d%n", firstName, lastName, id, age);
+        });
+
+        Result<Record> articles = getFields(
+                context,
+                Author.AUTHOR,
+                Article.ARTICLE.ID, Article.ARTICLE.TITLE
+        );
+
+        AuthorRecord author = getOne(
+                context,
+                Author.AUTHOR,
+                Author.AUTHOR.ID.eq(1)
+        );
+    }
+
+    private void updateValues(DSLContext context) {
+        HashMap<Field<String>, String> fieldsToUpdate = new HashMap<>();
+        fieldsToUpdate.put(Author.AUTHOR.FIRST_NAME, "David");
+        fieldsToUpdate.put(Author.AUTHOR.LAST_NAME, "Brown");
+        update(
+                context,
+                Author.AUTHOR,
+                fieldsToUpdate,
+                Author.AUTHOR.ID.eq(1)
+        );
+
+        ArticleRecord article = context.fetchOne(Article.ARTICLE, Article.ARTICLE.ID.eq(1));
+        article.setTitle("A New Article Title");
+        update(
+                article
+        );
+    }
+
+    private void deleteValues(DSLContext context) {
+        delete(
+                context,
+                Article.ARTICLE,
+                Article.ARTICLE.ID.eq(1)
+        );
+
+        AuthorRecord author = context.fetchOne(Author.AUTHOR, Author.AUTHOR.ID.eq(1));
+        delete(author);
+    }
+
+}

persistence-modules/jooq/src/main/java/com/baeldung/jooq/model/DefaultCatalog.java

@@ -0,0 +1,44 @@
+/*
+ * This file is generated by jOOQ.
+ */
+package com.baeldung.jooq.model;
+
+
+import org.jooq.Schema;
+import org.jooq.impl.CatalogImpl;
+
+import java.util.Arrays;
+import java.util.List;
+
+
+/**
+ * This class is generated by jOOQ.
+ */
+@SuppressWarnings({ "all", "unchecked", "rawtypes" })
+public class DefaultCatalog extends CatalogImpl {
+
+    private static final long serialVersionUID = 1035293962;
+
+    /**
+     * The reference instance of <code>DEFAULT_CATALOG</code>
+     */
+    public static final DefaultCatalog DEFAULT_CATALOG = new DefaultCatalog();
+
+    /**
+     * The schema <code>public</code>.
+     */
+    public final Public PUBLIC = Public.PUBLIC;
+
+    /**
+     * No further instances allowed
+     */
+    private DefaultCatalog() {
+        super("");
+    }
+
+    @Override
+    public final List<Schema> getSchemas() {
+        return Arrays.<Schema>asList(
+            Public.PUBLIC);
+    }
+}

persistence-modules/jooq/src/main/java/com/baeldung/jooq/model/Keys.java

@@ -0,0 +1,48 @@
+/*
+ * This file is generated by jOOQ.
+ */
+package com.baeldung.jooq.model;
+
+
+import com.baeldung.jooq.model.tables.Article;
+import com.baeldung.jooq.model.tables.Author;
+import com.baeldung.jooq.model.tables.records.ArticleRecord;
+import com.baeldung.jooq.model.tables.records.AuthorRecord;
+import org.jooq.ForeignKey;
+import org.jooq.TableField;
+import org.jooq.UniqueKey;
+import org.jooq.impl.Internal;
+
+
+/**
+ * A class modelling foreign key relationships and constraints of tables of
+ * the <code>public</code> schema.
+ */
+@SuppressWarnings({"all", "unchecked", "rawtypes"})
+public class Keys {
+
+    // -------------------------------------------------------------------------
+    // UNIQUE and PRIMARY KEY definitions
+    // -------------------------------------------------------------------------
+
+    public static final UniqueKey<ArticleRecord> ARTICLE_PKEY = UniqueKeys0.ARTICLE_PKEY;
+    public static final UniqueKey<AuthorRecord> AUTHOR_PKEY = UniqueKeys0.AUTHOR_PKEY;
+
+    // -------------------------------------------------------------------------
+    // FOREIGN KEY definitions
+    // -------------------------------------------------------------------------
+    public static final ForeignKey<ArticleRecord, AuthorRecord> ARTICLE__XXX = ForeignKeys0.ARTICLE__XXX;
+
+    // -------------------------------------------------------------------------
+    // [#1459] distribute members to avoid static initialisers > 64kb
+    // -------------------------------------------------------------------------
+
+    private static class UniqueKeys0 {
+        public static final UniqueKey<ArticleRecord> ARTICLE_PKEY = Internal.createUniqueKey(Article.ARTICLE, "article_pkey", new TableField[]{Article.ARTICLE.ID}, true);
+        public static final UniqueKey<AuthorRecord> AUTHOR_PKEY = Internal.createUniqueKey(Author.AUTHOR, "author_pkey", new TableField[]{Author.AUTHOR.ID}, true);
+    }
+
+    private static class ForeignKeys0 {
+        public static final ForeignKey<ArticleRecord, AuthorRecord> ARTICLE__XXX = Internal.createForeignKey(Keys.AUTHOR_PKEY, Article.ARTICLE, "xxx", new TableField[]{Article.ARTICLE.AUTHOR_ID}, true);
+    }
+}

persistence-modules/jooq/src/main/java/com/baeldung/jooq/model/Public.java

@@ -0,0 +1,59 @@
+/*
+ * This file is generated by jOOQ.
+ */
+package com.baeldung.jooq.model;
+
+import com.baeldung.jooq.model.tables.Article;
+import com.baeldung.jooq.model.tables.Author;
+import org.jooq.Catalog;
+import org.jooq.Table;
+import org.jooq.impl.SchemaImpl;
+
+import java.util.Arrays;
+import java.util.List;
+
+
+/**
+ * This class is generated by jOOQ.
+ */
+@SuppressWarnings({"all", "unchecked", "rawtypes"})
+public class Public extends SchemaImpl {
+
+    private static final long serialVersionUID = -2049410122;
+
+    /**
+     * The reference instance of <code>public</code>
+     */
+    public static final Public PUBLIC = new Public();
+
+    /**
+     * The table <code>public.article</code>.
+     */
+    public final Article ARTICLE = Article.ARTICLE;
+
+    /**
+     * The table <code>public.author</code>.
+     */
+    public final Author AUTHOR = Author.AUTHOR;
+
+    /**
+     * No further instances allowed
+     */
+    private Public() {
+        super("public", null);
+    }
+
+
+    @Override
+    public Catalog getCatalog() {
+        return DefaultCatalog.DEFAULT_CATALOG;
+    }
+
+    @Override
+    public final List<Table<?>> getTables() {
+        return Arrays.<Table<?>>asList(
+                Article.ARTICLE,
+                Author.AUTHOR
+        );
+    }
+}

persistence-modules/jooq/src/main/java/com/baeldung/jooq/model/Tables.java

@@ -0,0 +1,25 @@
+/*
+ * This file is generated by jOOQ.
+ */
+package com.baeldung.jooq.model;
+
+import com.baeldung.jooq.model.tables.Article;
+import com.baeldung.jooq.model.tables.Author;
+
+/**
+ * Convenience access to all tables in public
+ */
+@SuppressWarnings({"all", "unchecked", "rawtypes"})
+public class Tables {
+
+    /**
+     * The table <code>public.article</code>.
+     */
+    public static final Article ARTICLE = Article.ARTICLE;
+
+    /**
+     * The table <code>public.author</code>.
+     */
+    public static final Author AUTHOR = Author.AUTHOR;
+
+}

persistence-modules/jooq/src/main/java/com/baeldung/jooq/model/tables/Article.java

@@ -0,0 +1,159 @@
+/*
+ * This file is generated by jOOQ.
+ */
+package com.baeldung.jooq.model.tables;
+
+
+import com.baeldung.jooq.model.Keys;
+import com.baeldung.jooq.model.Public;
+import com.baeldung.jooq.model.tables.records.ArticleRecord;
+import org.jooq.Field;
+import org.jooq.ForeignKey;
+import org.jooq.Name;
+import org.jooq.Record;
+import org.jooq.Row4;
+import org.jooq.Schema;
+import org.jooq.Table;
+import org.jooq.TableField;
+import org.jooq.TableOptions;
+import org.jooq.UniqueKey;
+import org.jooq.impl.DSL;
+import org.jooq.impl.TableImpl;
+
+import java.util.Arrays;
+import java.util.List;
+
+
+/**
+ * This class is generated by jOOQ.
+ */
+@SuppressWarnings({ "all", "unchecked", "rawtypes" })
+public class Article extends TableImpl<ArticleRecord> {
+
+    private static final long serialVersionUID = -1401275800;
+
+    /**
+     * The reference instance of <code>public.article</code>
+     */
+    public static final Article ARTICLE = new Article();
+
+    /**
+     * The class holding records for this type
+     */
+    @Override
+    public Class<ArticleRecord> getRecordType() {
+        return ArticleRecord.class;
+    }
+
+    /**
+     * The column <code>public.article.id</code>.
+     */
+    public final TableField<ArticleRecord, Integer> ID = createField(DSL.name("id"), org.jooq.impl.SQLDataType.INTEGER.nullable(false), this, "");
+
+    /**
+     * The column <code>public.article.title</code>.
+     */
+    public final TableField<ArticleRecord, String> TITLE = createField(DSL.name("title"), org.jooq.impl.SQLDataType.VARCHAR(255).nullable(false), this, "");
+
+    /**
+     * The column <code>public.article.description</code>.
+     */
+    public final TableField<ArticleRecord, String> DESCRIPTION = createField(DSL.name("description"), org.jooq.impl.SQLDataType.VARCHAR(255), this, "");
+
+    /**
+     * The column <code>public.article.author_id</code>.
+     */
+    public final TableField<ArticleRecord, Integer> AUTHOR_ID = createField(DSL.name("author_id"), org.jooq.impl.SQLDataType.INTEGER, this, "");
+
+    /**
+     * Create a <code>public.article</code> table reference
+     */
+    public Article() {
+        this(DSL.name("article"), null);
+    }
+
+    /**
+     * Create an aliased <code>public.article</code> table reference
+     */
+    public Article(String alias) {
+        this(DSL.name(alias), ARTICLE);
+    }
+
+    /**
+     * Create an aliased <code>public.article</code> table reference
+     */
+    public Article(Name alias) {
+        this(alias, ARTICLE);
+    }
+
+    private Article(Name alias, Table<ArticleRecord> aliased) {
+        this(alias, aliased, null);
+    }
+
+    private Article(Name alias, Table<ArticleRecord> aliased, Field<?>[] parameters) {
+        super(alias, null, aliased, parameters, DSL.comment(""), TableOptions.table());
+    }
+
+    public <O extends Record> Article(Table<O> child, ForeignKey<O, ArticleRecord> key) {
+        super(child, key, ARTICLE);
+    }
+
+    @Override
+    public Schema getSchema() {
+        return Public.PUBLIC;
+    }
+
+    @Override
+    public UniqueKey<ArticleRecord> getPrimaryKey() {
+        return Keys.ARTICLE_PKEY;
+    }
+
+    @Override
+    public List<UniqueKey<ArticleRecord>> getKeys() {
+        return Arrays.<UniqueKey<ArticleRecord>>asList(Keys.ARTICLE_PKEY);
+    }
+
+    @Override
+    public List<ForeignKey<ArticleRecord, ?>> getReferences() {
+        return Arrays.<ForeignKey<ArticleRecord, ?>>asList(Keys.ARTICLE__XXX);
+    }
+
+    public Author author() {
+        return new Author(this, Keys.ARTICLE__XXX);
+    }
+
+    @Override
+    public Article as(String alias) {
+        return new Article(DSL.name(alias), this);
+    }
+
+    @Override
+    public Article as(Name alias) {
+        return new Article(alias, this);
+    }
+
+    /**
+     * Rename this table
+     */
+    @Override
+    public Article rename(String name) {
+        return new Article(DSL.name(name), null);
+    }
+
+    /**
+     * Rename this table
+     */
+    @Override
+    public Article rename(Name name) {
+        return new Article(name, null);
+    }
+
+    // -------------------------------------------------------------------------
+    // Row4 type methods
+    // -------------------------------------------------------------------------
+
+    @Override
+    public Row4<Integer, String, String, Integer> fieldsRow() {
+        return (Row4) super.fieldsRow();
+    }
+}

persistence-modules/jooq/src/main/java/com/baeldung/jooq/model/tables/Author.java

@@ -0,0 +1,149 @@
+/*
+ * This file is generated by jOOQ.
+ */
+package com.baeldung.jooq.model.tables;
+
+import com.baeldung.jooq.model.Keys;
+import com.baeldung.jooq.model.Public;
+import com.baeldung.jooq.model.tables.records.AuthorRecord;
+import org.jooq.Field;
+import org.jooq.ForeignKey;
+import org.jooq.Name;
+import org.jooq.Record;
+import org.jooq.Row4;
+import org.jooq.Schema;
+import org.jooq.Table;
+import org.jooq.TableField;
+import org.jooq.TableOptions;
+import org.jooq.UniqueKey;
+import org.jooq.impl.DSL;
+import org.jooq.impl.TableImpl;
+
+import java.util.Arrays;
+import java.util.List;
+
+
+/**
+ * This class is generated by jOOQ.
+ */
+@SuppressWarnings({ "all", "unchecked", "rawtypes" })
+public class Author extends TableImpl<AuthorRecord> {
+
+    private static final long serialVersionUID = -798376522;
+
+    /**
+     * The reference instance of <code>public.author</code>
+     */
+    public static final Author AUTHOR = new Author();
+
+    /**
+     * The class holding records for this type
+     */
+    @Override
+    public Class<AuthorRecord> getRecordType() {
+        return AuthorRecord.class;
+    }
+
+    /**
+     * The column <code>public.author.id</code>.
+     */
+    public final TableField<AuthorRecord, Integer> ID = createField(DSL.name("id"), org.jooq.impl.SQLDataType.INTEGER.nullable(false), AUTHOR, "");
+
+    /**
+     * The column <code>public.author.first_name</code>.
+     */
+    public final TableField<AuthorRecord, String> FIRST_NAME = createField(DSL.name("first_name"), org.jooq.impl.SQLDataType.VARCHAR(255), this, "");
+
+    /**
+     * The column <code>public.author.last_name</code>.
+     */
+    public final TableField<AuthorRecord, String> LAST_NAME = createField(DSL.name("last_name"), org.jooq.impl.SQLDataType.VARCHAR(255), this, "");
+
+    /**
+     * The column <code>public.author.age</code>.
+     */
+    public final TableField<AuthorRecord, Integer> AGE = createField(DSL.name("age"), org.jooq.impl.SQLDataType.INTEGER, this, "");
+
+    /**
+     * Create a <code>public.author</code> table reference
+     */
+    public Author() {
+        this(DSL.name("author"), null);
+    }
+
+    /**
+     * Create an aliased <code>public.author</code> table reference
+     */
+    public Author(String alias) {
+        this(DSL.name(alias), AUTHOR);
+    }
+
+    /**
+     * Create an aliased <code>public.author</code> table reference
+     */
+    public Author(Name alias) {
+        this(alias, AUTHOR);
+    }
+
+    private Author(Name alias, Table<AuthorRecord> aliased) {
+        this(alias, aliased, null);
+    }
+
+    private Author(Name alias, Table<AuthorRecord> aliased, Field<?>[] parameters) {
+        super(alias, null, aliased, parameters, DSL.comment(""), TableOptions.table());
+    }
+
+    public <O extends Record> Author(Table<O> child, ForeignKey<O, AuthorRecord> key) {
+        super(child, key, AUTHOR);
+    }
+
+    @Override
+    public Schema getSchema() {
+        return Public.PUBLIC;
+    }
+
+    @Override
+    public UniqueKey<AuthorRecord> getPrimaryKey() {
+        return Keys.AUTHOR_PKEY;
+    }
+
+    @Override
+    public List<UniqueKey<AuthorRecord>> getKeys() {
+        return Arrays.<UniqueKey<AuthorRecord>>asList(Keys.AUTHOR_PKEY);
+    }
+
+    @Override
+    public Author as(String alias) {
+        return new Author(DSL.name(alias), this);
+    }
+
+    @Override
+    public Author as(Name alias) {
+        return new Author(alias, this);
+    }
+
+    /**
+     * Rename this table
+     */
+    @Override
+    public Author rename(String name) {
+        return new Author(DSL.name(name), null);
+    }
+
+    /**
+     * Rename this table
+     */
+    @Override
+    public Author rename(Name name) {
+        return new Author(name, null);
+    }
+
+    // -------------------------------------------------------------------------
+    // Row4 type methods
+    // -------------------------------------------------------------------------
+
+    @Override
+    public Row4<Integer, String, String, Integer> fieldsRow() {
+        return (Row4) super.fieldsRow();
+    }
+}

persistence-modules/jooq/src/main/java/com/baeldung/jooq/model/tables/records/ArticleRecord.java

@@ -0,0 +1,218 @@
+/*
+ * This file is generated by jOOQ.
+ */
+package com.baeldung.jooq.model.tables.records;
+
+
+import com.baeldung.jooq.model.tables.Article;
+
+import org.jooq.Field;
+import org.jooq.Record1;
+import org.jooq.Record4;
+import org.jooq.Row4;
+import org.jooq.impl.UpdatableRecordImpl;
+
+
+/**
+ * This class is generated by jOOQ.
+ */
+@SuppressWarnings({ "all", "unchecked", "rawtypes" })
+public class ArticleRecord extends UpdatableRecordImpl<ArticleRecord> implements Record4<Integer, String, String, Integer> {
+
+    private static final long serialVersionUID = 1297442421;
+
+    /**
+     * Setter for <code>public.article.id</code>.
+     */
+    public void setId(Integer value) {
+        set(0, value);
+    }
+
+    /**
+     * Getter for <code>public.article.id</code>.
+     */
+    public Integer getId() {
+        return (Integer) get(0);
+    }
+
+    /**
+     * Setter for <code>public.article.title</code>.
+     */
+    public void setTitle(String value) {
+        set(1, value);
+    }
+
+    /**
+     * Getter for <code>public.article.title</code>.
+     */
+    public String getTitle() {
+        return (String) get(1);
+    }
+
+    /**
+     * Setter for <code>public.article.description</code>.
+     */
+    public void setDescription(String value) {
+        set(2, value);
+    }
+
+    /**
+     * Getter for <code>public.article.description</code>.
+     */
+    public String getDescription() {
+        return (String) get(2);
+    }
+
+    /**
+     * Setter for <code>public.article.author_id</code>.
+     */
+    public void setAuthorId(Integer value) {
+        set(3, value);
+    }
+
+    /**
+     * Getter for <code>public.article.author_id</code>.
+     */
+    public Integer getAuthorId() {
+        return (Integer) get(3);
+    }
+
+    // -------------------------------------------------------------------------
+    // Primary key information
+    // -------------------------------------------------------------------------
+
+    @Override
+    public Record1<Integer> key() {
+        return (Record1) super.key();
+    }
+
+    // -------------------------------------------------------------------------
+    // Record4 type implementation
+    // -------------------------------------------------------------------------
+
+    @Override
+    public Row4<Integer, String, String, Integer> fieldsRow() {
+        return (Row4) super.fieldsRow();
+    }
+
+    @Override
+    public Row4<Integer, String, String, Integer> valuesRow() {
+        return (Row4) super.valuesRow();
+    }
+
+    @Override
+    public Field<Integer> field1() {
+        return Article.ARTICLE.ID;
+    }
+
+    @Override
+    public Field<String> field2() {
+        return Article.ARTICLE.TITLE;
+    }
+
+    @Override
+    public Field<String> field3() {
+        return Article.ARTICLE.DESCRIPTION;
+    }
+
+    @Override
+    public Field<Integer> field4() {
+        return Article.ARTICLE.AUTHOR_ID;
+    }
+
+    @Override
+    public Integer component1() {
+        return getId();
+    }
+
+    @Override
+    public String component2() {
+        return getTitle();
+    }
+
+    @Override
+    public String component3() {
+        return getDescription();
+    }
+
+    @Override
+    public Integer component4() {
+        return getAuthorId();
+    }
+
+    @Override
+    public Integer value1() {
+        return getId();
+    }
+
+    @Override
+    public String value2() {
+        return getTitle();
+    }
+
+    @Override
+    public String value3() {
+        return getDescription();
+    }
+
+    @Override
+    public Integer value4() {
+        return getAuthorId();
+    }
+
+    @Override
+    public ArticleRecord value1(Integer value) {
+        setId(value);
+        return this;
+    }
+
+    @Override
+    public ArticleRecord value2(String value) {
+        setTitle(value);
+        return this;
+    }
+
+    @Override
+    public ArticleRecord value3(String value) {
+        setDescription(value);
+        return this;
+    }
+
+    @Override
+    public ArticleRecord value4(Integer value) {
+        setAuthorId(value);
+        return this;
+    }
+
+    @Override
+    public ArticleRecord values(Integer value1, String value2, String value3, Integer value4) {
+        value1(value1);
+        value2(value2);
+        value3(value3);
+        value4(value4);
+        return this;
+    }
+
+    // -------------------------------------------------------------------------
+    // Constructors
+    // -------------------------------------------------------------------------
+
+    /**
+     * Create a detached ArticleRecord
+     */
+    public ArticleRecord() {
+        super(Article.ARTICLE);
+    }
+
+    /**
+     * Create a detached, initialised ArticleRecord
+     */
+    public ArticleRecord(Integer id, String title, String description, Integer authorId) {
+        super(Article.ARTICLE);
+
+        set(0, id);
+        set(1, title);
+        set(2, description);
+        set(3, authorId);
+    }
+}

persistence-modules/jooq/src/main/java/com/baeldung/jooq/model/tables/records/AuthorRecord.java

@@ -0,0 +1,217 @@
+/*
+ * This file is generated by jOOQ.
+ */
+package com.baeldung.jooq.model.tables.records;
+
+
+import com.baeldung.jooq.model.tables.Author;
+import org.jooq.Field;
+import org.jooq.Record1;
+import org.jooq.Record4;
+import org.jooq.Row4;
+import org.jooq.impl.UpdatableRecordImpl;
+
+
+/**
+ * This class is generated by jOOQ.
+ */
+@SuppressWarnings({ "all", "unchecked", "rawtypes" })
+public class AuthorRecord extends UpdatableRecordImpl<AuthorRecord> implements Record4<Integer, String, String, Integer> {
+
+    private static final long serialVersionUID = -2120822720;
+
+    /**
+     * Setter for <code>public.author.id</code>.
+     */
+    public void setId(Integer value) {
+        set(0, value);
+    }
+
+    /**
+     * Getter for <code>public.author.id</code>.
+     */
+    public Integer getId() {
+        return (Integer) get(0);
+    }
+
+    /**
+     * Setter for <code>public.author.first_name</code>.
+     */
+    public void setFirstName(String value) {
+        set(1, value);
+    }
+
+    /**
+     * Getter for <code>public.author.first_name</code>.
+     */
+    public String getFirstName() {
+        return (String) get(1);
+    }
+
+    /**
+     * Setter for <code>public.author.last_name</code>.
+     */
+    public void setLastName(String value) {
+        set(2, value);
+    }
+
+    /**
+     * Getter for <code>public.author.last_name</code>.
+     */
+    public String getLastName() {
+        return (String) get(2);
+    }
+
+    /**
+     * Setter for <code>public.author.age</code>.
+     */
+    public void setAge(Integer value) {
+        set(3, value);
+    }
+
+    /**
+     * Getter for <code>public.author.age</code>.
+     */
+    public Integer getAge() {
+        return (Integer) get(3);
+    }
+
+    // -------------------------------------------------------------------------
+    // Primary key information
+    // -------------------------------------------------------------------------
+
+    @Override
+    public Record1<Integer> key() {
+        return (Record1) super.key();
+    }
+
+    // -------------------------------------------------------------------------
+    // Record4 type implementation
+    // -------------------------------------------------------------------------
+
+    @Override
+    public Row4<Integer, String, String, Integer> fieldsRow() {
+        return (Row4) super.fieldsRow();
+    }
+
+    @Override
+    public Row4<Integer, String, String, Integer> valuesRow() {
+        return (Row4) super.valuesRow();
+    }
+
+    @Override
+    public Field<Integer> field1() {
+        return Author.AUTHOR.ID;
+    }
+
+    @Override
+    public Field<String> field2() {
+        return Author.AUTHOR.FIRST_NAME;
+    }
+
+    @Override
+    public Field<String> field3() {
+        return Author.AUTHOR.LAST_NAME;
+    }
+
+    @Override
+    public Field<Integer> field4() {
+        return Author.AUTHOR.AGE;
+    }
+
+    @Override
+    public Integer component1() {
+        return getId();
+    }
+
+    @Override
+    public String component2() {
+        return getFirstName();
+    }
+
+    @Override
+    public String component3() {
+        return getLastName();
+    }
+
+    @Override
+    public Integer component4() {
+        return getAge();
+    }
+
+    @Override
+    public Integer value1() {
+        return getId();
+    }
+
+    @Override
+    public String value2() {
+        return getFirstName();
+    }
+
+    @Override
+    public String value3() {
+        return getLastName();
+    }
+
+    @Override
+    public Integer value4() {
+        return getAge();
+    }
+
+    @Override
+    public AuthorRecord value1(Integer value) {
+        setId(value);
+        return this;
+    }
+
+    @Override
+    public AuthorRecord value2(String value) {
+        setFirstName(value);
+        return this;
+    }
+
+    @Override
+    public AuthorRecord value3(String value) {
+        setLastName(value);
+        return this;
+    }
+
+    @Override
+    public AuthorRecord value4(Integer value) {
+        setAge(value);
+        return this;
+    }
+
+    @Override
+    public AuthorRecord values(Integer value1, String value2, String value3, Integer value4) {
+        value1(value1);
+        value2(value2);
+        value3(value3);
+        value4(value4);
+        return this;
+    }
+
+    // -------------------------------------------------------------------------
+    // Constructors
+    // -------------------------------------------------------------------------
+
+    /**
+     * Create a detached AuthorRecord
+     */
+    public AuthorRecord() {
+        super(Author.AUTHOR);
+    }
+
+    /**
+     * Create a detached, initialised AuthorRecord
+     */
+    public AuthorRecord(Integer id, String firstName, String lastName, Integer age) {
+        super(Author.AUTHOR);
+
+        set(0, id);
+        set(1, firstName);
+        set(2, lastName);
+        set(3, age);
+    }
+}

persistence-modules/jooq/src/test/java/com/baeldung/jooq/CrudLiveTest.java

@@ -0,0 +1,257 @@
+package com.baeldung.jooq;
+
+import com.baeldung.jooq.model.tables.Article;
+import com.baeldung.jooq.model.tables.Author;
+import com.baeldung.jooq.model.tables.records.ArticleRecord;
+import org.jooq.DSLContext;
+import org.jooq.Field;
+import org.jooq.Record;
+import org.jooq.Result;
+import org.jooq.SQLDialect;
+import org.jooq.impl.DSL;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.SQLException;
+import java.util.HashMap;
+
+import static com.baeldung.jooq.Crud.delete;
+import static com.baeldung.jooq.Crud.getAll;
+import static com.baeldung.jooq.Crud.getFields;
+import static com.baeldung.jooq.Crud.getOne;
+import static com.baeldung.jooq.Crud.save;
+import static com.baeldung.jooq.Crud.update;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
+
+public class CrudLiveTest {
+
+    static DSLContext context;
+
+    @BeforeClass
+    public static void setup() throws SQLException {
+        Connection conn = DriverManager.getConnection("jdbc:h2:mem:tes;INIT=CREATE SCHEMA IF NOT EXISTS \"public\"");
+        context = DSL.using(conn, SQLDialect.H2);
+
+        context.createTable(Author.AUTHOR)
+                .columns(
+                        Author.AUTHOR.ID,
+                        Author.AUTHOR.FIRST_NAME,
+                        Author.AUTHOR.LAST_NAME,
+                        Author.AUTHOR.AGE
+                )
+                .execute();
+        context.createTable(Article.ARTICLE)
+                .columns(
+                        Article.ARTICLE.ID,
+                        Article.ARTICLE.TITLE,
+                        Article.ARTICLE.DESCRIPTION,
+                        Article.ARTICLE.AUTHOR_ID
+                )
+                .execute();
+    }
+
+    @Before
+    public void cleanup() {
+        context.truncateTable(Article.ARTICLE)
+                .execute();
+        context.truncateTable(Author.AUTHOR)
+                .execute();
+    }
+
+    @Test
+    public void givenArticleRecord_whenSave_thenNewRecordInDb() {
+        // given
+        ArticleRecord article = article();
+
+        // when
+        save(article);
+
+        // then
+        ArticleRecord savedArticle = getOne(
+                context,
+                Article.ARTICLE,
+                Article.ARTICLE.ID.eq(1)
+        );
+        assertEquals(savedArticle.getId().intValue(), 1);
+        assertEquals(savedArticle.getTitle(), "jOOQ examples");
+        assertEquals(savedArticle.getDescription(), "A few examples of jOOQ CRUD operations");
+        assertEquals(savedArticle.getAuthorId().intValue(), 1);
+    }
+
+    @Test
+    public void givenArticleRecord_whenGetAll_thenValidOneRecord() {
+        // given
+        ArticleRecord article = article();
+        save(article);
+
+        // when
+        Result<Record> articles = getAll(
+                context,
+                Article.ARTICLE
+        );
+
+        // then
+        assertEquals(articles.size(), 1);
+
+        Record record = articles.get(0);
+        ArticleRecord savedArticle = record.into(Article.ARTICLE);
+
+        assertEquals(savedArticle.getId().intValue(), 1);
+        assertEquals(savedArticle.getTitle(), "jOOQ examples");
+        assertEquals(savedArticle.getDescription(), "A few examples of jOOQ CRUD operations");
+        assertEquals(savedArticle.getAuthorId().intValue(), 1);
+    }
+
+    @Test
+    public void givenArticleRecord_whenGetOnlyTitles_thenValidOneValue() {
+        // given
+        ArticleRecord article = article();
+        save(article);
+
+        // when
+        Result<Record> articles = getFields(
+                context,
+                Article.ARTICLE,
+                Article.ARTICLE.TITLE
+        );
+
+        // then
+        assertEquals(articles.size(), 1);
+
+        Record record = articles.get(0);
+        ArticleRecord savedArticle = record.into(Article.ARTICLE);
+
+        assertNull(savedArticle.getId());
+        assertEquals(savedArticle.getTitle(), "jOOQ examples");
+        assertNull(savedArticle.getDescription());
+        assertNull(savedArticle.getAuthorId());
+    }
+
+    @Test
+    public void givenArticleRecord_whenGetOne_thenValidRecord() {
+        // given
+        ArticleRecord article = article();
+        save(article);
+
+        // when
+        ArticleRecord savedArticle = getOne(
+                context,
+                Article.ARTICLE,
+                Article.ARTICLE.ID.eq(1)
+        );
+
+        // then
+        assertEquals(savedArticle.getId().intValue(), 1);
+        assertEquals(savedArticle.getTitle(), "jOOQ examples");
+        assertEquals(savedArticle.getDescription(), "A few examples of jOOQ CRUD operations");
+        assertEquals(savedArticle.getAuthorId().intValue(), 1);
+    }
+
+    @Test
+    public void givenArticleRecord_whenUpdateById_thenChangedValuesDbTable() {
+        // given
+        ArticleRecord article = article();
+        save(article);
+
+        HashMap<Field<String>, String> updateFields = new HashMap<>();
+        updateFields.put(Article.ARTICLE.TITLE, "new title");
+        updateFields.put(Article.ARTICLE.DESCRIPTION, "new description");
+
+        // when
+        update(
+                context,
+                Article.ARTICLE,
+                updateFields,
+                Article.ARTICLE.ID.eq(1)
+        );
+
+        // then
+        ArticleRecord updatedArticle = getOne(
+                context,
+                Article.ARTICLE,
+                Article.ARTICLE.ID.eq(1)
+        );
+        assertEquals(updatedArticle.getId().intValue(), 1);
+        assertEquals(updatedArticle.getTitle(), "new title");
+        assertEquals(updatedArticle.getDescription(), "new description");
+        assertEquals(updatedArticle.getAuthorId().intValue(), 1);
+    }
+
+    @Test
+    public void givenArticleRecord_whenUpdate_thenChangedValuesDbTable() {
+        // given
+        ArticleRecord article = article();
+        save(article);
+
+        article.setTitle("new title");
+        article.setDescription("new description");
+
+        // when
+        update(article);
+
+        // then
+        ArticleRecord updatedArticle = getOne(
+                context,
+                Article.ARTICLE,
+                Article.ARTICLE.ID.eq(1)
+        );
+        assertEquals(updatedArticle.getId().intValue(), 1);
+        assertEquals(updatedArticle.getTitle(), "new title");
+        assertEquals(updatedArticle.getDescription(), "new description");
+        assertEquals(updatedArticle.getAuthorId().intValue(), 1);
+    }
+
+    @Test
+    public void givenArticleRecord_whenDelete_thenEmptyDbTable() {
+        // given
+        ArticleRecord article = article();
+        save(article);
+
+        // when
+        delete(article);
+
+        // then
+        Result<Record> articles = getAll(
+                context,
+                Article.ARTICLE
+        );
+        assertTrue(articles.isEmpty());
+    }
+
+    @Test
+    public void givenArticleRecord_whenDeleteById_thenEmptyDbTable() {
+        // given
+        ArticleRecord article = article();
+        save(article);
+
+        // when
+        delete(
+                context,
+                Article.ARTICLE,
+                Article.ARTICLE.ID.eq(1)
+        );
+
+        // then
+        Result<Record> articles = getAll(
+                context,
+                Article.ARTICLE
+        );
+        assertTrue(articles.isEmpty());
+    }
+
+    private ArticleRecord article() {
+        ArticleRecord article = context.newRecord(Article.ARTICLE);
+        article.setId(1);
+        article.setTitle("jOOQ examples");
+        article.setDescription("A few examples of jOOQ CRUD operations");
+        article.setAuthorId(1);
+
+        return article;
+    }
+
+}

persistence-modules/pom.xml

@@ -39,6 +39,7 @@
         <module>java-jpa-2</module> <!-- long running -->
         <module>java-mongodb</module> <!-- long running -->
         <module>jnosql</module> <!-- long running -->
+        <module>jooq</module>
         <module>jpa-hibernate-cascade-type</module>
         <module>liquibase</module>
         <module>orientdb</module>

persistence-modules/spring-data-jpa-enterprise/pom.xml

@@ -95,10 +95,6 @@
     </build>
 
     <properties>
-        <spring-boot-version>2.1.9.RELEASE</spring-boot-version>
-        <start-class>com.baeldung.springdatageode.app.ClientCacheApp</start-class>
-        <spring-geode-starter-version>1.1.1.RELEASE</spring-geode-starter-version>
-        <spring.boot.starter.version>2.1.9.RELEASE</spring.boot.starter.version>
         <mapstruct.version>1.3.1.Final</mapstruct.version>
         <guava.version>21.0</guava.version>
         <testcontainers.version>1.12.2</testcontainers.version>

persistence-modules/spring-jpa-2/pom.xml

@@ -66,6 +66,11 @@
             <artifactId>guava</artifactId>
             <version>${guava.version}</version>
         </dependency>
+        <dependency>
+            <groupId>net.bytebuddy</groupId>
+            <artifactId>byte-buddy</artifactId>
+            <version>${byte-buddy.version}</version>
+        </dependency>
 
         <!-- test scoped -->
         <dependency>
@@ -85,13 +90,14 @@
     <properties>
         <!-- Spring -->
         <org.springframework.version>5.1.5.RELEASE</org.springframework.version>
+        <spring-boot.version>2.2.6.RELEASE</spring-boot.version>
 
         <!-- persistence -->
         <tomcat-dbcp.version>9.0.0.M26</tomcat-dbcp.version>
 
         <!-- utilities -->
         <guava.version>21.0</guava.version>
-        <spring-boot.version>2.2.6.RELEASE</spring-boot.version>
+        <byte-buddy.version>1.10.16</byte-buddy.version>
     </properties>
 
 </project>

pom.xml

@@ -424,6 +424,7 @@
                 <module>hazelcast</module>
                 <module>helidon</module>
                 <module>httpclient</module>
+                <module>httpclient-2</module>
                 <module>httpclient-simple</module>
                 <module>hystrix</module>
 
@@ -935,6 +936,7 @@
                 <module>hazelcast</module>
                 <module>helidon</module>
                 <module>httpclient</module>
+                <module>httpclient-2</module>
                 <module>httpclient-simple</module>
                 <module>hystrix</module>
 

spring-boot-modules/pom.xml

@@ -46,6 +46,7 @@
         <module>spring-boot-jasypt</module>
         <module>spring-boot-keycloak</module>
         <module>spring-boot-libraries</module>
+        <module>spring-boot-libraries-2</module>
         <module>spring-boot-logging-log4j2</module>
         <module>spring-boot-kotlin</module>
         <module>spring-boot-mvc</module>

spring-boot-modules/spring-boot-environment/src/main/java/com/baeldung/serverport/GetServerPortApplication.java

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

spring-boot-modules/spring-boot-environment/src/main/java/com/baeldung/serverport/ServerPortService.java

@@ -0,0 +1,20 @@
+package com.baeldung.serverport;
+
+import org.springframework.boot.web.servlet.context.ServletWebServerInitializedEvent;
+import org.springframework.context.event.EventListener;
+import org.springframework.stereotype.Service;
+
+@Service
+public class ServerPortService {
+    private int port;
+
+    public int getPort() {
+        return port;
+    }
+
+    @EventListener
+    public void onApplicationEvent(final ServletWebServerInitializedEvent event) {
+        port = event.getWebServer().getPort();
+    }
+
+}

spring-boot-modules/spring-boot-environment/src/test/java/com/baeldung/serverport/GetServerFixedPortUnitTest.java

@@ -0,0 +1,37 @@
+package com.baeldung.serverport;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.boot.autoconfigure.web.ServerProperties;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.ActiveProfiles;
+import org.springframework.test.context.junit4.SpringRunner;
+
+import static org.junit.Assert.assertEquals;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest(classes = GetServerPortApplication.class, webEnvironment = SpringBootTest.WebEnvironment.DEFINED_PORT)
+@ActiveProfiles("fixedport")
+public class GetServerFixedPortUnitTest {
+    private final static int EXPECTED_PORT = 7777;
+
+    @Value("${server.port}")
+    private int serverPort;
+
+    @Autowired
+    private ServerProperties serverProperties;
+
+    @Test
+    public void givenFixedPortAsServerPort_whenReadServerPort_thenGetThePort() {
+        assertEquals("Reading fixed port by @Value(\"${server.port}\") will get the port.", EXPECTED_PORT, serverPort);
+    }
+
+    @Test
+    public void givenFixedPortAsServerPort_whenReadServerProps_thenGetThePort() {
+        int port = serverProperties.getPort();
+        assertEquals("Reading fixed port from serverProperties will get the port.", EXPECTED_PORT, port);
+    }
+
+}

spring-boot-modules/spring-boot-environment/src/test/java/com/baeldung/serverport/GetServerRandomPortUnitTest.java

@@ -0,0 +1,55 @@
+package com.baeldung.serverport;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.boot.autoconfigure.web.ServerProperties;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext;
+import org.springframework.test.context.ActiveProfiles;
+import org.springframework.test.context.junit4.SpringRunner;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest(classes = GetServerPortApplication.class, webEnvironment = SpringBootTest.WebEnvironment.DEFINED_PORT)
+@ActiveProfiles("randomport")
+public class GetServerRandomPortUnitTest {
+
+    @Value("${server.port}")
+    private int randomServerPort;
+
+    @Autowired
+    private ServerPortService serverPortService;
+
+    @Autowired
+    private ServerProperties serverProperties;
+
+    @Autowired
+    private ServletWebServerApplicationContext webServerAppCtxt;
+
+    @Test
+    public void given0AsServerPort_whenReadServerPort_thenGet0() {
+        assertEquals("Reading random port by @Value(\"${server.port}\") will get 0.", 0, randomServerPort);
+    }
+
+    @Test
+    public void given0AsServerPort_whenReadServerProps_thenGet0() {
+        int port = serverProperties.getPort();
+        assertEquals("Reading random port by serverProperties will get 0.", 0, port);
+    }
+
+    @Test
+    public void given0AsServerPort_whenReadWebAppCtxt_thenGetThePort() {
+        int port = webServerAppCtxt.getWebServer().getPort();
+        assertTrue("The random port should be greater than 1023", port > 1023);
+    }
+
+    @Test
+    public void given0AsServerPort_whenReadFromListener_thenGetThePort() {
+        int port = serverPortService.getPort();
+        assertTrue("The random port should be greater than 1023", port > 1023);
+    }
+}

spring-boot-modules/spring-boot-environment/src/test/resources/application-fixedport.properties

@@ -0,0 +1 @@
+server.port=7777

spring-boot-modules/spring-boot-environment/src/test/resources/application-randomport.properties

@@ -0,0 +1 @@
+server.port=0

spring-boot-modules/spring-boot-libraries-2/README.md

@@ -0,0 +1,7 @@
+## Spring Boot Libraries
+
+This module contains articles about various Spring Boot libraries
+
+### Relevant Articles:
+
+- Running background jobs in Spring with JobRunr

spring-boot-modules/spring-boot-libraries-2/pom.xml

@@ -0,0 +1,46 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <artifactId>spring-boot-modules</artifactId>
+        <groupId>com.baeldung.spring-boot-modules</groupId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>spring-boot-libraries-2</artifactId>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+
+        <!-- JobRunr -->
+        <dependency>
+            <groupId>org.jobrunr</groupId>
+            <artifactId>jobrunr-spring-boot-starter</artifactId>
+            <version>${jobrunr.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>org.awaitility</groupId>
+            <artifactId>awaitility</artifactId>
+            <version>${awaitility.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <properties>
+        <jobrunr.version>1.0.0</jobrunr.version>
+        <awaitility.version>4.0.3</awaitility.version>
+    </properties>
+
+</project>

spring-boot-modules/spring-boot-libraries-2/src/main/java/com/baeldung/jobrunr/JobRunrSpringBootApp.java

@@ -0,0 +1,37 @@
+package com.baeldung.jobrunr;
+
+import com.baeldung.jobrunr.service.SampleJobService;
+import org.jobrunr.jobs.mappers.JobMapper;
+import org.jobrunr.scheduling.JobScheduler;
+import org.jobrunr.scheduling.cron.Cron;
+import org.jobrunr.storage.InMemoryStorageProvider;
+import org.jobrunr.storage.StorageProvider;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.Bean;
+
+import javax.annotation.PostConstruct;
+
+@SpringBootApplication
+public class JobRunrSpringBootApp {
+
+    @Autowired
+    private JobScheduler jobScheduler;
+
+    public static void main(String[] args) {
+        SpringApplication.run(JobRunrSpringBootApp.class, args);
+    }
+
+    @Bean
+    public StorageProvider storageProvider(JobMapper jobMapper) {
+        InMemoryStorageProvider storageProvider = new InMemoryStorageProvider();
+        storageProvider.setJobMapper(jobMapper);
+        return storageProvider;
+    }
+
+    @PostConstruct
+    public void scheduleRecurrently() {
+        jobScheduler.<SampleJobService>scheduleRecurrently(x -> x.executeSampleJob("a recurring job"), Cron.every5minutes());
+    }
+}

spring-boot-modules/spring-boot-libraries-2/src/main/java/com/baeldung/jobrunr/controller/JobRunrController.java

@@ -0,0 +1,43 @@
+package com.baeldung.jobrunr.controller;
+
+import com.baeldung.jobrunr.service.SampleJobService;
+import org.jobrunr.scheduling.JobScheduler;
+import org.springframework.boot.context.properties.bind.DefaultValue;
+import org.springframework.format.annotation.DateTimeFormat;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.*;
+
+import java.time.LocalDateTime;
+
+@RestController
+@RequestMapping("/jobrunr")
+public class JobRunrController {
+
+    private JobScheduler jobScheduler;
+    private SampleJobService sampleJobService;
+
+    private JobRunrController(JobScheduler jobScheduler, SampleJobService sampleJobService) {
+        this.jobScheduler = jobScheduler;
+        this.sampleJobService = sampleJobService;
+    }
+
+    @GetMapping(value = "/enqueue/{input}", produces = MediaType.APPLICATION_JSON_VALUE)
+    public ResponseEntity<String> enqueue(@PathVariable("input") @DefaultValue("default-input") String input) {
+        jobScheduler.enqueue(() -> sampleJobService.executeSampleJob(input));
+        return okResponse("job enqueued successfully");
+    }
+
+    @GetMapping(value = "/schedule/{input}", produces = MediaType.APPLICATION_JSON_VALUE)
+    public ResponseEntity<String> schedule(
+            @PathVariable("input") @DefaultValue("default-input") String input,
+            @RequestParam("scheduleAt") @DateTimeFormat(iso = DateTimeFormat.ISO.DATE_TIME) LocalDateTime scheduleAt) {
+        jobScheduler.schedule(() -> sampleJobService.executeSampleJob(input), scheduleAt);
+        return okResponse("job scheduled successfully");
+    }
+
+    private ResponseEntity<String> okResponse(String feedback) {
+        return new ResponseEntity<>(feedback, HttpStatus.OK);
+    }
+}

spring-boot-modules/spring-boot-libraries-2/src/main/java/com/baeldung/jobrunr/service/SampleJobService.java

@@ -0,0 +1,36 @@
+package com.baeldung.jobrunr.service;
+
+import org.jobrunr.jobs.annotations.Job;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Service;
+
+import java.util.concurrent.atomic.AtomicInteger;
+
+@Service
+public class SampleJobService {
+
+    public static final long EXECUTION_TIME = 5000L;
+
+    private Logger logger = LoggerFactory.getLogger(getClass());
+
+    private AtomicInteger count = new AtomicInteger();
+
+    @Job(name = "The sample job with variable %0", retries = 2)
+    public void executeSampleJob(String variable) {
+
+        logger.info("The sample job has begun. The variable you passed is {}", variable);
+        try {
+            Thread.sleep(EXECUTION_TIME);
+        } catch (InterruptedException e) {
+            logger.error("Error while executing sample job", e);
+        } finally {
+            count.incrementAndGet();
+            logger.info("Sample job has finished...");
+        }
+    }
+
+    public int getNumberOfInvocations() {
+        return count.get();
+    }
+}

spring-boot-modules/spring-boot-libraries-2/src/main/resources/application.properties

@@ -0,0 +1,2 @@
+org.jobrunr.background_job_server=true
+org.jobrunr.dashboard=true

spring-boot-modules/spring-boot-libraries-2/src/test/java/com/baeldung/jobrunr/JobRunrLiveTest.java

@@ -0,0 +1,46 @@
+package com.baeldung.jobrunr;
+
+import org.awaitility.Awaitility;
+import org.jobrunr.jobs.states.StateName;
+import org.jobrunr.storage.StorageProvider;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+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.test.context.junit4.SpringRunner;
+
+import java.net.URI;
+import java.util.concurrent.TimeUnit;
+
+import static org.awaitility.Awaitility.await;
+import static org.junit.Assert.assertEquals;
+import static org.springframework.boot.test.context.SpringBootTest.WebEnvironment.DEFINED_PORT;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest(webEnvironment = DEFINED_PORT, classes = JobRunrSpringBootApp.class)
+public class JobRunrLiveTest {
+
+    @Autowired
+    TestRestTemplate restTemplate;
+
+    @Autowired
+    StorageProvider storageProvider;
+
+    @Test
+    public void givenEndpoint_whenJobEnqueued_thenJobIsProcessedWithin30Seconds() {
+        String response = enqueueJobViaRest("some-input");
+        assertEquals("job enqueued successfully", response);
+
+        await().atMost(30, TimeUnit.SECONDS).until(() -> storageProvider.countJobs(StateName.SUCCEEDED) == 1);
+    }
+
+    private String enqueueJobViaRest(String input) {
+        try {
+            return restTemplate.getForObject(new URI("http://localhost:8080/jobrunr/enqueue/" + input), String.class);
+        } catch (Exception ignored) {
+            ignored.printStackTrace();
+        }
+        return null;
+    }
+}

spring-boot-modules/spring-boot-mvc-3/README.md

@@ -7,4 +7,5 @@ This module contains articles about Spring Web MVC in Spring Boot projects.
 - [Circular View Path Error](https://www.baeldung.com/spring-circular-view-path-error)
 - [Download an Image or a File with Spring MVC](https://www.baeldung.com/spring-controller-return-image-file)
 - [Spring MVC Async vs Spring WebFlux](https://www.baeldung.com/spring-mvc-async-vs-webflux)
+- [Differences in @Valid and @Validated Annotations in Spring](https://www.baeldung.com/spring-valid-vs-validated)
 - More articles: [[prev -->]](/spring-boot-modules/spring-boot-mvc-2)

testing-modules/testing-libraries-2/README.md

@@ -0,0 +1,3 @@
+### Relevant Articles:
+
+- [Guide to the System Rules Library](https://www.baeldung.com/java-system-rules-junit)