Merge branch 'eugenp:master' into master

aws-lambda/README.md

@@ -6,3 +6,4 @@ This module contains articles about AWS Lambda
 - [Using AWS Lambda with API Gateway](https://www.baeldung.com/aws-lambda-api-gateway)
 - [Introduction to AWS Serverless Application Model](https://www.baeldung.com/aws-serverless)
 - [How to Implement Hibernate in an AWS Lambda Function in Java](https://www.baeldung.com/java-aws-lambda-hibernate)
+- [Writing an Enterprise-Grade AWS Lambda in Java](https://www.baeldung.com/java-enterprise-aws-lambda)

core-java-modules/core-java-9/src/main/java/com/baeldung/java9/interfaces/CustomFoo.java

@@ -0,0 +1,10 @@
+package com.baeldung.java9.interfaces;
+
+public class CustomFoo implements Foo {
+
+    public static void main(String... args) {
+        Foo customFoo = new CustomFoo();
+        customFoo.bar(); // 'Hello world!'
+        Foo.buzz(); // 'Hello static world!'
+    }
+}

core-java-modules/core-java-9/src/main/java/com/baeldung/java9/interfaces/Foo.java

@@ -0,0 +1,22 @@
+package com.baeldung.java9.interfaces;
+
+public interface Foo {
+
+    public default void bar() {
+        System.out.print("Hello");
+        baz();
+    }
+
+    public static void buzz() {
+        System.out.print("Hello");
+        staticBaz();
+    }
+
+    private void baz() {
+        System.out.print(" world!");
+    }
+
+    private static void staticBaz() {
+        System.out.print(" static world!");
+    }
+}

core-java-modules/core-java-9/src/test/java/com/baeldung/java9/interfaces/CustomFooUnitTest.java

@@ -0,0 +1,38 @@
+package com.baeldung.java9.interfaces;
+
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.io.ByteArrayOutputStream;
+import java.io.PrintStream;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class CustomFooUnitTest {
+    private ByteArrayOutputStream outContent = new ByteArrayOutputStream();
+    private PrintStream originalOut = System.out;
+
+    @BeforeEach
+    void setup() {
+        System.setOut(new PrintStream(outContent));
+    }
+
+    @AfterEach
+    void tearDown() {
+        System.setOut(originalOut);
+    }
+
+    @Test
+    void givenACustomFooObject_whenCallingDefaultMethodBar_thenExpectedStringIsWrittenToSystemOut() {
+        CustomFoo customFoo = new CustomFoo();
+        customFoo.bar();
+        assertThat(outContent.toString()).isEqualTo("Hello world!");
+    }
+
+    @Test
+    void givenAFooInterface_whenCallingStaticMethodBuzz_thenExpectedStringIsWrittenToSystemOut() {
+        Foo.buzz();
+        assertThat(outContent.toString()).isEqualTo("Hello static world!");
+    }
+}

core-java-modules/core-java-arrays-guides/README.md

@@ -8,3 +8,4 @@ This module contains complete guides about arrays in Java
 - [What is \[Ljava.lang.Object;?](https://www.baeldung.com/java-tostring-array)
 - [Guide to ArrayStoreException](https://www.baeldung.com/java-arraystoreexception)
 - [Creating a Generic Array in Java](https://www.baeldung.com/java-generic-array)
+- [Maximum Size of Java Arrays](https://www.baeldung.com/java-arrays-max-size)

core-java-modules/core-java-exceptions-3/README.md

@@ -8,3 +8,4 @@
 - [Localizing Exception Messages in Java](https://www.baeldung.com/java-localize-exception-messages)
 - [Explanation of ClassCastException in Java](https://www.baeldung.com/java-classcastexception)
 - [NoSuchFieldError in Java](https://www.baeldung.com/java-nosuchfielderror)
+- [IllegalAccessError in Java](https://www.baeldung.com/java-illegalaccesserror)

core-java-modules/core-java-networking-3/README.md

@@ -5,4 +5,5 @@ This module contains articles about networking in Java
 ### Relevant Articles
 
 - [Finding a Free Port in Java](https://www.baeldung.com/java-free-port)
+- [Downloading Email Attachments in Java](https://www.baeldung.com/java-download-email-attachments)
 - [[<-- Prev]](/core-java-modules/core-java-networking-2)

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

@@ -5,3 +5,4 @@
 - [Checking If a Method is Static Using Reflection in Java](https://www.baeldung.com/java-check-method-is-static)
 - [Checking if a Java Class is ‘abstract’ Using Reflection](https://www.baeldung.com/java-reflection-is-class-abstract)
 - [Invoking a Private Method in Java](https://www.baeldung.com/java-call-private-method)
+- [Finding All Classes in a Java Package](https://www.baeldung.com/java-find-all-classes-in-package)

core-java-modules/core-java-regex/README.md

@@ -13,3 +13,5 @@
 - [Regular Expressions \s and \s+ in Java](https://www.baeldung.com/java-regex-s-splus)
 - [Validate Phone Numbers With Java Regex](https://www.baeldung.com/java-regex-validate-phone-numbers)
 - [How to Count the Number of Matches for a Regex?](https://www.baeldung.com/java-count-regex-matches)
+- [Find All Numbers in a String in Java](https://www.baeldung.com/java-find-numbers-in-string)
+- [Understanding the Pattern.quote Method](https://www.baeldung.com/java-pattern-quote)

core-java-modules/core-java-regex/src/test/java/com/baeldung/ignore/pattern/metacharacters/IgnoringPatternMetacharactersUnitTest.java

@@ -12,7 +12,7 @@ public class IgnoringPatternMetacharactersUnitTest {
     private static final String patternStr = "$100.50";
 
     @Test
-    public void givenPatternStringHasMetacharacters_whenPatternMatchedWithoutEscapingMetacharacters_thenNoMatchesFound() {
+    public void whenMetacharactersNotEscaped_thenNoMatchesFound() {
         Pattern pattern = Pattern.compile(patternStr);
         Matcher matcher = pattern.matcher(dollarAmounts);
 
@@ -25,7 +25,7 @@ public class IgnoringPatternMetacharactersUnitTest {
     }
 
     @Test
-    public void givenPatternStringHasMetacharacters_whenPatternCompiledUsingManuallyMetaEscapedPattern_thenMatchingSuccessful() {
+    public void whenMetacharactersManuallyEscaped_thenMatchingSuccessful() {
         String metaEscapedPatternStr = "\\Q" + patternStr + "\\E";
         Pattern pattern = Pattern.compile(metaEscapedPatternStr);
         Matcher matcher = pattern.matcher(dollarAmounts);
@@ -39,7 +39,7 @@ public class IgnoringPatternMetacharactersUnitTest {
     }
 
     @Test
-    public void givenPatternStringHasMetacharacters_whenPatternCompiledUsingLiteralPatternFromQuote_thenMatchingSuccessful() {
+    public void whenMetacharactersEscapedUsingPatternQuote_thenMatchingSuccessful() {
         String literalPatternStr = Pattern.quote(patternStr);
         Pattern pattern = Pattern.compile(literalPatternStr);
         Matcher matcher = pattern.matcher(dollarAmounts);

core-java-modules/core-java-security-3/README.md

@@ -4,5 +4,5 @@ This module contains articles about core Java Security
 
 ### Relevant Articles:
 
-- [Secret Key and String Conversion in Java](https://www.baeldung.com/secret-key-and-string-conversion-in-java/)
+- [Secret Key and String Conversion in Java](https://www.baeldung.com/java-secret-key-to-string)
 - More articles: [[<-- prev]](/core-java-modules/core-java-security-2)

gradle/gradle-cucumber/README.md

@@ -0,0 +1,3 @@
+### Relevant Articles:
+
+- [Using Cucumber with Gradle](https://www.baeldung.com/java-cucumber-gradle)

gradle/gradle-jacoco/build.gradle

@@ -0,0 +1,54 @@
+
+plugins {
+    id 'java'
+    id 'jacoco'
+}
+
+ext {
+    junitVersion = '5.7.2'
+    lombokVersion = '1.18.20'
+}
+
+group 'com.com.baeldung'
+version '1.0-SNAPSHOT'
+
+repositories {
+    mavenCentral()
+}
+
+java {
+    sourceCompatibility = JavaVersion.VERSION_11
+    targetCompatibility = JavaVersion.VERSION_11
+}
+
+dependencies {
+    testImplementation "org.junit.jupiter:junit-jupiter-api:${junitVersion}"
+    testRuntimeOnly "org.junit.jupiter:junit-jupiter-engine:${junitVersion}"
+
+    compileOnly "org.projectlombok:lombok:${lombokVersion}"
+    annotationProcessor "org.projectlombok:lombok:${lombokVersion}"
+}
+
+test {
+    useJUnitPlatform()
+
+    finalizedBy jacocoTestReport // report is always generated after tests run
+}
+
+jacocoTestReport {
+    dependsOn test // tests are required to run before generating the report
+
+    afterEvaluate {
+        classDirectories.setFrom(files(classDirectories.files.collect {
+            fileTree(dir: it, exclude: [
+                "com/baeldung/**/ExcludedPOJO.class",
+                "com/baeldung/**/*DTO.*",
+                "**/config/*"
+            ])
+        }))
+    }
+}
+
+jacoco {
+    toolVersion = "0.8.6"
+}

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

@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.8-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists

gradle/gradle-jacoco/gradlew

@@ -0,0 +1,185 @@
+#!/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-jacoco/gradlew.bat

@@ -0,0 +1,89 @@
+@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 execute
+
+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 execute
+
+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
+
+: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 %*
+
+: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

gradle/gradle-jacoco/lombok.config

@@ -0,0 +1 @@
+lombok.addLombokGeneratedAnnotation = true

gradle/gradle-jacoco/settings.gradle

@@ -0,0 +1 @@
+rootProject.name = 'gradle-jacoco'

gradle/gradle-jacoco/src/main/java/com/baeldung/config/AppConfig.java

@@ -0,0 +1,11 @@
+package com.baeldung.config;
+
+import com.baeldung.service.ProductService;
+
+public class AppConfig {
+
+    public ProductService productService() {
+        return new ProductService();
+    }
+
+}

gradle/gradle-jacoco/src/main/java/com/baeldung/domain/Product.java

@@ -0,0 +1,12 @@
+package com.baeldung.domain;
+
+import lombok.Builder;
+import lombok.Data;
+
+@Builder
+@Data
+public class Product {
+    private int id;
+    private String name;
+
+}

gradle/gradle-jacoco/src/main/java/com/baeldung/dto/ExcludedPOJO.java

@@ -0,0 +1,4 @@
+package com.baeldung.dto;
+
+public class ExcludedPOJO {
+}

gradle/gradle-jacoco/src/main/java/com/baeldung/dto/ProductDTO.java

@@ -0,0 +1,4 @@
+package com.baeldung.dto;
+
+public class ProductDTO {
+}

gradle/gradle-jacoco/src/main/java/com/baeldung/generated/Customer.java

@@ -0,0 +1,11 @@
+package com.baeldung.generated;
+
+@Generated
+public class Customer {
+    // everything in this class will be excluded from jacoco report because of @Generated
+
+    @Override
+    public String toString() {
+        return "Customer{}";
+    }
+}

gradle/gradle-jacoco/src/main/java/com/baeldung/generated/Generated.java

@@ -0,0 +1,15 @@
+package com.baeldung.generated;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+import static java.lang.annotation.ElementType.METHOD;
+import static java.lang.annotation.ElementType.TYPE;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+
+@Documented
+@Retention(RUNTIME)
+@Target({TYPE, METHOD})
+public @interface Generated {
+}

gradle/gradle-jacoco/src/main/java/com/baeldung/service/CustomerService.java

@@ -0,0 +1,16 @@
+package com.baeldung.service;
+
+import com.baeldung.generated.Generated;
+
+public class CustomerService {
+
+    //this method will be excluded from coverage due to @Generated.
+    @Generated
+    public String getProductId() {
+        return "An ID";
+    }
+
+    public String getCustomerName() {
+        return "some name";
+    }
+}

gradle/gradle-jacoco/src/main/java/com/baeldung/service/ProductService.java

@@ -0,0 +1,9 @@
+package com.baeldung.service;
+
+public class ProductService {
+    private static final double DISCOUNT = 0.25;
+
+    public double getSalePrice(double originalPrice) {
+        return originalPrice - originalPrice * DISCOUNT;
+    }
+}

gradle/gradle-jacoco/src/test/java/com/baeldung/service/CustomerServiceUnitTest.java

@@ -0,0 +1,14 @@
+package com.baeldung.service;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+
+class CustomerServiceUnitTest {
+
+    @Test
+    public void givenCustomer_whenGetCustomer_thenReturnNewCustomer() {
+        CustomerService customerService = new CustomerService();
+        assertNotNull(customerService.getCustomerName());
+    }
+}

gradle/gradle-jacoco/src/test/java/com/baeldung/service/ProductServiceUnitTest.java

@@ -0,0 +1,15 @@
+package com.baeldung.service;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class ProductServiceUnitTest {
+
+    @Test
+    public void givenOriginalPrice_whenGetSalePrice_thenReturnsDiscountedPrice() {
+        ProductService productService = new ProductService();
+        double salePrice = productService.getSalePrice(100);
+        assertEquals(salePrice, 75);
+    }
+}

gradle/gradle-jacoco/src/test/resources/features/account_credited.feature

@@ -0,0 +1,6 @@
+Feature: Account is credited with amount
+
+  Scenario: Credit amount
+    Given account balance is 0.0
+    When the account is credited with 10.0
+    Then account should have a balance of 10.0

java-collections-conversions-2/pom.xml

@@ -44,6 +44,12 @@
             <version>${hamcrest.version}</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>io.vavr</groupId>
+            <artifactId>vavr</artifactId>
+            <version>0.10.3</version>
+        </dependency>
+
     </dependencies>
 
     <build>

java-collections-conversions-2/src/test/java/com/baeldung/setiteration/SetIteration.java

@@ -0,0 +1,74 @@
+package com.baeldung.setiteration;
+
+import com.google.common.collect.Sets;
+import io.vavr.collection.Stream;
+import org.junit.jupiter.api.Test;
+
+import java.util.Iterator;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+class SetIteration {
+
+    @Test
+    void givenSet_whenIteratorUsed_shouldIterateOverElements() {
+        // given
+        Set<String> names = Sets.newHashSet("Tom", "Jane", "Karen");
+
+        // when
+        Iterator<String> namesIterator1 = names.iterator();
+        Iterator<String> namesIterator2 = names.iterator();
+
+        // then
+        namesIterator1.forEachRemaining(System.out::println);
+        while(namesIterator2.hasNext()) {
+            System.out.println(namesIterator2.next());
+        }
+    }
+
+    @Test
+    void givenSet_whenStreamUsed_shouldIterateOverElements() {
+        // given
+        Set<String> names = Sets.newHashSet("Tom", "Jane", "Karen");
+
+        // when & then
+        String namesJoined = names.stream()
+                .map(String::toUpperCase)
+                .peek(System.out::println)
+                .collect(Collectors.joining());
+    }
+
+    @Test
+    void givenSet_whenEnhancedLoopUsed_shouldIterateOverElements() {
+        // given
+        Set<String> names = Sets.newHashSet("Tom", "Jane", "Karen");
+
+        // when & then
+        for (String name : names) {
+            System.out.println(name);
+        }
+    }
+
+    @Test
+    void givenSet_whenMappedToArray_shouldIterateOverElements() {
+        // given
+        Set<String> names = Sets.newHashSet("Tom", "Jane", "Karen");
+
+        // when & then
+        Object[] namesArray = names.toArray();
+        for (int i = 0; i < namesArray.length; i++) {
+            System.out.println(i + ": " + namesArray[i]);
+        }
+    }
+
+    @Test
+    void givenSet_whenZippedWithIndex_shouldIterateOverElements() {
+        // given
+        Set<String> names = Sets.newHashSet("Tom", "Jane", "Karen");
+
+        // when & then
+        Stream.ofAll(names)
+                .zipWithIndex()
+                .forEach(t -> System.out.println(t._2() + ": " + t._1()));
+    }
+}

kubernetes/k8s-intro/README.md

@@ -17,3 +17,4 @@ If you get a valid response, then you're good to go.
 - [Paging and Async Calls with the Kubernetes API](https://www.baeldung.com/java-kubernetes-paging-async)
 - [Using Watch with the Kubernetes API](https://www.baeldung.com/java-kubernetes-watch)
 - [Using Namespaces and Selectors With the Kubernetes Java API](https://www.baeldung.com/java-kubernetes-namespaces-selectors)
+- [Creating, Updating and Deleting Resources with the Java Kubernetes API](https://www.baeldung.com/java-kubernetes-api-crud)

libraries-data-3/README.md

@@ -3,7 +3,7 @@
 This module contains articles about libraries for data processing in Java.
 
 ### Relevant articles
-- [Kafka Streams vs Kafka Consumer]()
+- [Kafka Streams vs Kafka Consumer](https://www.baeldung.com/java-kafka-streams-vs-kafka-consumer)
 - More articles: [[<-- prev]](/../libraries-data-2)
 
 ##### Building the project

logging-modules/log4j/README.md

@@ -3,3 +3,4 @@
 - [Introduction to SLF4J](http://www.baeldung.com/slf4j-with-log4j2-logback)
 - [A Guide to Rolling File Appenders](http://www.baeldung.com/java-logging-rolling-file-appenders)
 - [Logging Exceptions Using SLF4J](https://www.baeldung.com/slf4j-log-exceptions)
+- [Log4j Warning: "No Appenders Could Be Found for Logger"](https://www.baeldung.com/log4j-no-appenders-found)

logging-modules/log4j/src/main/java/com/baeldung/log4j/NoAppenderExample.java

@@ -0,0 +1,18 @@
+package com.baeldung.log4j;
+
+import org.apache.log4j.Logger;
+
+public class NoAppenderExample {
+
+    private final static Logger logger = Logger.getLogger(NoAppenderExample.class);
+
+    public static void main(String[] args) {
+
+        //Setup default appender
+        //BasicConfigurator.configure();
+
+        //Define path to configuration file
+        //PropertyConfigurator.configure("src\\main\\resources\\log4j.properties");
+        logger.info("Info log message");
+    }
+}

logging-modules/log4j/src/main/resources/log4j.properties

@@ -0,0 +1,5 @@
+log4j.rootLogger=INFO, stdout
+log4j.appender.stdout=org.apache.log4j.ConsoleAppender
+log4j.appender.stdout.Target=System.out
+log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
+log4j.appender.stdout.layout.ConversionPattern=%d{yy/MM/dd HH:mm:ss} %p %c{2}: %m%n

logging-modules/log4j/src/main/resources/log4j.xml

@@ -90,6 +90,8 @@
         <appender-ref ref="roll-by-time-and-size"/>
     </category>
 
+    <logger name="com.baeldung.log4j.NoAppenderExample"/>
+
     <root>
         <level value="DEBUG"/>
         <appender-ref ref="stdout"/>

mapstruct/pom.xml

@@ -34,7 +34,12 @@
         <dependency>
             <groupId>org.projectlombok</groupId>
             <artifactId>lombok</artifactId>
-            <version>${org.projectlombok.version}</version>
+            <version>${lombok.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok-mapstruct-binding</artifactId>
+            <version>${lombok.mapstruct.binding.version}</version>
         </dependency>
         <dependency>
             <groupId>org.assertj</groupId>
@@ -63,7 +68,12 @@
                         <path>
                             <groupId>org.projectlombok</groupId>
                             <artifactId>lombok</artifactId>
-                            <version>${org.projectlombok.version}</version>
+                            <version>${lombok.version}</version>
+                        </path>
+                        <path>
+                            <groupId>org.projectlombok</groupId>
+                            <artifactId>lombok-mapstruct-binding</artifactId>
+                            <version>${lombok.mapstruct.binding.version}</version>
                         </path>
                     </annotationProcessorPaths>
                 </configuration>
@@ -72,11 +82,11 @@
     </build>
 
     <properties>
-        <org.mapstruct.version>1.3.1.Final</org.mapstruct.version>
+        <org.mapstruct.version>1.4.2.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>
-        <org.projectlombok.version>1.18.4</org.projectlombok.version>
+        <lombok.mapstruct.binding.version>0.2.0</lombok.mapstruct.binding.version>
         <assertj.version>3.16.1</assertj.version>
     </properties>
 

persistence-modules/core-java-persistence-2/src/main/java/com/baeldung/insertnull/DBConfig.java

@@ -0,0 +1,26 @@
+package com.baeldung.insertnull;
+
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.SQLException;
+import java.sql.Statement;
+
+public class DBConfig {
+
+    private static Connection INSTANCE;
+
+    public static Connection getConnection() throws SQLException {
+        if (INSTANCE == null) {
+            INSTANCE = DriverManager.getConnection("jdbc:h2:mem:insertnull", "user", "password");
+            createPersonTable();
+        }
+        return INSTANCE;
+    }
+
+    private static void createPersonTable() throws SQLException {
+        try(Statement statement = INSTANCE.createStatement()) {
+            String sql = "CREATE TABLE Person (id INTEGER not null, name VARCHAR(50), lastName VARCHAR(50), age INTEGER, PRIMARY KEY (id))";
+            statement.executeUpdate(sql);
+        }
+    }
+}

persistence-modules/core-java-persistence-2/src/main/java/com/baeldung/insertnull/Person.java

@@ -0,0 +1,48 @@
+package com.baeldung.insertnull;
+
+public class Person {
+
+    private Integer id;
+    private String name;
+    private String lastName;
+    private Integer age;
+
+    public Person(Integer id, String name, String lastName, Integer age) {
+        this.id = id;
+        this.name = name;
+        this.lastName = lastName;
+        this.age = age;
+    }
+
+    public Integer getId() {
+        return id;
+    }
+
+    public void setId(Integer id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getLastName() {
+        return lastName;
+    }
+
+    public void setLastName(String lastName) {
+        this.lastName = lastName;
+    }
+
+    public Integer getAge() {
+        return age;
+    }
+
+    public void setAge(Integer age) {
+        this.age = age;
+    }
+}

persistence-modules/core-java-persistence-2/src/test/java/com/baeldung/insertnull/InsertNullUnitTest.java

@@ -0,0 +1,50 @@
+package com.baeldung.insertnull;
+
+import org.junit.jupiter.api.Test;
+
+import java.sql.PreparedStatement;
+import java.sql.SQLException;
+import java.sql.Types;
+
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.hamcrest.MatcherAssert.assertThat;
+
+public class InsertNullUnitTest {
+
+    private final String SQL = "INSERT INTO Person VALUES(?,?,?,?)";
+
+    @Test
+    public void givenNewPerson_whenSetNullIsUsed_thenNewRecordIsCreated() throws SQLException {
+        Person person = new Person(1, "John", "Doe", null);
+
+        try (PreparedStatement preparedStatement = DBConfig.getConnection().prepareStatement(SQL)) {
+            preparedStatement.setInt(1, person.getId());
+            preparedStatement.setString(2, person.getName());
+            preparedStatement.setString(3, person.getLastName());
+            if (person.getAge() == null) {
+                preparedStatement.setNull(4, Types.INTEGER);
+            }
+            else {
+                preparedStatement.setInt(4, person.getAge());
+            }
+            int noOfRows = preparedStatement.executeUpdate();
+
+            assertThat(noOfRows, equalTo(1));
+        }
+    }
+
+    @Test
+    public void givenNewPerson_whenSetObjectIsUsed_thenNewRecordIsCreated() throws SQLException {
+        Person person = new Person(2, "John", "Doe", null);
+
+        try (PreparedStatement preparedStatement = DBConfig.getConnection().prepareStatement(SQL)) {
+            preparedStatement.setInt(1, person.getId());
+            preparedStatement.setString(2, person.getName());
+            preparedStatement.setString(3, person.getLastName());
+            preparedStatement.setObject(4, person.getAge(), Types.INTEGER);
+            int noOfRows = preparedStatement.executeUpdate();
+
+            assertThat(noOfRows, equalTo(1));
+        }
+    }
+}

persistence-modules/java-jpa-3/README.md

@@ -11,3 +11,5 @@ This module contains articles about the Java Persistence API (JPA) in Java.
 - [A Guide to MultipleBagFetchException in Hibernate](https://www.baeldung.com/java-hibernate-multiplebagfetchexception)
 - [How to Convert a Hibernate Proxy to a Real Entity Object](https://www.baeldung.com/hibernate-proxy-to-real-entity-object)
 - [Returning an Auto-Generated Id with JPA](https://www.baeldung.com/jpa-get-auto-generated-id)
+- [How to Return Multiple Entities In JPA Query](https://www.baeldung.com/jpa-return-multiple-entities)
+- [Defining Unique Constraints in JPA](https://www.baeldung.com/jpa-unique-constraints)

persistence-modules/java-jpa-3/src/main/java/com/baeldung/jpa/uniqueconstraints/Address.java

@@ -0,0 +1,37 @@
+package com.baeldung.jpa.uniqueconstraints;
+
+import java.io.Serializable;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+import javax.persistence.Table;
+
+@Entity
+@Table
+public class Address implements Serializable {
+    
+    private static final long serialVersionUID = 1L;
+
+    @Id
+    @GeneratedValue
+    private Long id;
+    
+    private String streetAddress;
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getStreetAddress() {
+        return streetAddress;
+    }
+
+    public void setStreetAddress(String streetAddress) {
+        this.streetAddress = streetAddress;
+    }
+}

persistence-modules/java-jpa-3/src/main/java/com/baeldung/jpa/uniqueconstraints/Person.java

@@ -0,0 +1,116 @@
+package com.baeldung.jpa.uniqueconstraints;
+
+import java.io.Serializable;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+import javax.persistence.JoinColumn;
+import javax.persistence.Table;
+import javax.persistence.UniqueConstraint;
+
+@Entity
+@Table(uniqueConstraints = { @UniqueConstraint(name = "UniqueNumberAndStatus", columnNames = { "personNumber", "isActive" }),
+                             @UniqueConstraint(name = "UniqueSecurityAndDepartment", columnNames = { "securityNumber", "departmentCode" }),
+                             @UniqueConstraint(name = "UniqueNumberAndAddress", columnNames = { "personNumber", "address" }) })
+public class Person implements Serializable {
+
+    private static final long serialVersionUID = 1L;
+
+    @Id
+    @GeneratedValue
+    private Long id;
+    
+    private String name;
+    
+    private String password;
+
+    @Column(unique = true)
+    private String email;
+
+    @Column(unique = true)
+    private Long personNumber;
+
+    private Boolean isActive;
+    
+    private String securityNumber;
+    
+    private String departmentCode;
+
+    @Column(unique = true)
+    @JoinColumn(name = "addressId", referencedColumnName = "id")
+    private Address address;
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getPassword() {
+        return password;
+    }
+
+    public void setPassword(String password) {
+        this.password = password;
+    }
+
+    public String getEmail() {
+        return email;
+    }
+
+    public void setEmail(String email) {
+        this.email = email;
+    }
+
+    public Long getPersonNumber() {
+        return personNumber;
+    }
+
+    public void setPersonNumber(Long personNumber) {
+        this.personNumber = personNumber;
+    }
+
+    public Boolean getIsActive() {
+        return isActive;
+    }
+
+    public void setIsActive(Boolean isActive) {
+        this.isActive = isActive;
+    }
+
+    public String getScode() {
+        return securityNumber;
+    }
+
+    public void setScode(String scode) {
+        this.securityNumber = scode;
+    }
+
+    public String getDcode() {
+        return departmentCode;
+    }
+
+    public void setDcode(String dcode) {
+        this.departmentCode = dcode;
+    }
+
+    public Address getAddress() {
+        return address;
+    }
+
+    public void setAddress(Address address) {
+        this.address = address;
+    }
+}

persistence-modules/java-jpa-3/src/main/resources/META-INF/persistence.xml

@@ -113,6 +113,22 @@
             <property name="hibernate.temp.use_jdbc_metadata_defaults" value="false"/>
         </properties>
     </persistence-unit>
+    <persistence-unit name="jpa-unique-constraints">
+        <provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
+        <class>com.baeldung.jpa.uniqueconstraints.Person</class>
+        <class>com.baeldung.jpa.uniqueconstraints.Address</class>
+        <exclude-unlisted-classes>true</exclude-unlisted-classes>
+        <properties>
+            <property name="javax.persistence.jdbc.driver" value="org.h2.Driver" />
+            <property name="javax.persistence.jdbc.url" value="jdbc:h2:mem:test" />
+            <property name="javax.persistence.jdbc.user" value="sa" />
+            <property name="javax.persistence.jdbc.password" value="" />
+            <property name="hibernate.dialect" value="org.hibernate.dialect.H2Dialect" />
+            <property name="hibernate.hbm2ddl.auto" value="create-drop" />
+            <property name="show_sql" value="true" />
+            <property name="hibernate.temp.use_jdbc_metadata_defaults" value="false" />
+        </properties>
+	</persistence-unit>
     <persistence-unit name="jpa-h2-return-multiple-entities">
         <provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
         <class>com.baeldung.jpa.returnmultipleentities.Channel</class>

persistence-modules/java-jpa-3/src/test/java/com/baeldung/jpa/uniqueconstraints/UniqueColumnIntegrationTest.java

@@ -0,0 +1,119 @@
+package com.baeldung.jpa.uniqueconstraints;
+
+import java.util.Optional;
+
+import javax.persistence.EntityManager;
+import javax.persistence.EntityManagerFactory;
+import javax.persistence.Persistence;
+
+import org.hibernate.exception.ConstraintViolationException;
+import org.junit.Assert;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+public class UniqueColumnIntegrationTest {
+    
+    private static EntityManagerFactory factory;
+    private static EntityManager entityManager;
+
+    @BeforeAll
+    public static void setup() {
+        factory = Persistence.createEntityManagerFactory("jpa-unique-constraints");
+        entityManager = factory.createEntityManager();
+    }
+
+    @Test
+    public void whenPersistPersonWithSameNumber_thenConstraintViolationException() {
+        Person person1 = new Person();
+        person1.setPersonNumber(2000L);
+        person1.setEmail("john.beth@gmail.com");
+
+        Person person2 = new Person();
+        person2.setPersonNumber(2000L);
+        person2.setEmail("anthony.green@gmail.com");
+
+        entityManager.getTransaction().begin();
+        entityManager.persist(person1);
+        entityManager.getTransaction().commit();
+        
+        entityManager.getTransaction().begin();
+        try {
+            entityManager.persist(person2);
+            entityManager.getTransaction().commit();
+            Assert.fail("Should raise an exception - unique key violation");
+        } catch (Exception ex) {
+            Assert.assertTrue(Optional.of(ex)
+                .map(Throwable::getCause)
+                .map(Throwable::getCause)
+                .filter(x -> x instanceof ConstraintViolationException)
+                .isPresent());
+        } finally {
+            entityManager.getTransaction().rollback();
+        }
+    }
+
+    @Test
+    public void whenPersistPersonWithSameEmail_thenConstraintViolationException() {
+        Person person1 = new Person();
+        person1.setPersonNumber(4000L);
+        person1.setEmail("timm.beth@gmail.com");
+
+        Person person2 = new Person();
+        person2.setPersonNumber(3000L);
+        person2.setEmail("timm.beth@gmail.com");
+
+        entityManager.getTransaction().begin();
+        entityManager.persist(person1);
+        entityManager.getTransaction().commit();
+
+        entityManager.getTransaction().begin();
+        try {
+            entityManager.persist(person2);
+            entityManager.getTransaction().commit();
+            Assert.fail("Should raise an exception - unique key violation");
+        } catch (Exception ex) {
+            Assert.assertTrue(Optional.of(ex)
+                .map(Throwable::getCause)
+                .map(Throwable::getCause)
+                .filter(x -> x instanceof ConstraintViolationException)
+                .isPresent());
+        } finally {
+            entityManager.getTransaction().rollback();
+        }
+    }
+
+    @Test
+    public void whenPersistPersonWithSameAddress_thenConstraintViolationException() {
+        Person person1 = new Person();
+        person1.setPersonNumber(5000L);
+        person1.setEmail("chris.beck@gmail.com");
+
+        Address address1 = new Address();
+        address1.setStreetAddress("20 Street");
+        person1.setAddress(address1);
+
+        Person person2 = new Person();
+        person2.setPersonNumber(6000L);
+        person2.setEmail("mark.jonson@gmail.com");
+        person2.setAddress(address1);
+
+        entityManager.getTransaction().begin();
+        entityManager.persist(person1);
+        entityManager.getTransaction().commit();
+
+        entityManager.getTransaction().begin();
+        try {
+            entityManager.persist(person2);
+            entityManager.getTransaction().commit();
+            Assert.fail("Should raise an exception - unique key violation");
+        } catch (Exception ex) {
+            Assert.assertTrue(Optional.of(ex)
+                .map(Throwable::getCause)
+                .map(Throwable::getCause)
+                .filter(x -> x instanceof ConstraintViolationException)
+                .isPresent());
+        } finally {
+            entityManager.getTransaction().rollback();
+        }
+    }
+}

persistence-modules/java-jpa-3/src/test/java/com/baeldung/jpa/uniqueconstraints/UniqueConstraintIntegrationTest.java

@@ -0,0 +1,116 @@
+package com.baeldung.jpa.uniqueconstraints;
+
+import java.util.Optional;
+
+import javax.persistence.EntityManager;
+import javax.persistence.EntityManagerFactory;
+import javax.persistence.Persistence;
+
+import org.hibernate.exception.ConstraintViolationException;
+import org.junit.Assert;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+public class UniqueConstraintIntegrationTest {
+    private static EntityManagerFactory factory;
+    private static EntityManager entityManager;
+
+    @BeforeAll
+    public static void setup() {
+        factory = Persistence.createEntityManagerFactory("jpa-unique-constraints");
+        entityManager = factory.createEntityManager();
+    }
+
+    @Test
+    public void whenPersistPersonWithSameNumberAndStatus_thenConstraintViolationException() {
+        Person person1 = new Person();
+        person1.setPersonNumber(12345L);
+        person1.setIsActive(Boolean.TRUE);
+
+        Person person2 = new Person();
+        person2.setPersonNumber(12345L);
+        person2.setIsActive(Boolean.TRUE);
+
+        entityManager.getTransaction().begin();
+        entityManager.persist(person1);
+        entityManager.getTransaction().commit();
+
+        entityManager.getTransaction().begin();
+        try {
+            entityManager.persist(person2);
+            entityManager.getTransaction().commit();
+            Assert.fail("Should raise an exception - unique key violation");
+        } catch (Exception ex) {
+            Assert.assertTrue(Optional.of(ex)
+                .map(Throwable::getCause)
+                .map(Throwable::getCause)
+                .filter(x -> x instanceof ConstraintViolationException)
+                .isPresent());
+        } finally {
+            entityManager.getTransaction().rollback();
+        }
+    }
+
+    @Test
+    public void whenPersistPersonWithSameSCodeAndDecode_thenConstraintViolationException() {
+        Person person1 = new Person();
+        person1.setDcode("Sec1");
+        person1.setScode("Axybg356");
+
+        Person person2 = new Person();
+        person2.setDcode("Sec1");
+        person2.setScode("Axybg356");
+
+        entityManager.getTransaction().begin();
+        entityManager.persist(person1);
+        entityManager.getTransaction().commit();
+
+        entityManager.getTransaction().begin();
+        try {
+            entityManager.persist(person2);
+            entityManager.getTransaction().commit();
+            Assert.fail("Should raise an exception - unique key violation");
+        } catch (Exception ex) {
+            Assert.assertTrue(Optional.of(ex)
+                .map(Throwable::getCause)
+                .map(Throwable::getCause)
+                .filter(x -> x instanceof ConstraintViolationException)
+                .isPresent());
+        } finally {
+            entityManager.getTransaction().rollback();
+        }
+    }
+
+    @Test
+    public void whenPersistPersonWithSameNumberAndAddress_thenConstraintViolationException() {
+        Address address1 = new Address();
+        address1.setStreetAddress("40 Street");
+
+        Person person1 = new Person();
+        person1.setPersonNumber(54321L);
+        person1.setAddress(address1);
+
+        Person person2 = new Person();
+        person2.setPersonNumber(99999L);
+        person2.setAddress(address1);
+
+        entityManager.getTransaction().begin();
+        entityManager.persist(person1);
+        entityManager.getTransaction().commit();
+
+        entityManager.getTransaction().begin();
+        try {
+            entityManager.persist(person2);
+            entityManager.getTransaction().commit();
+            Assert.fail("Should raise an exception - unique key violation");
+        } catch (Exception ex) {
+            Assert.assertTrue(Optional.of(ex)
+                .map(Throwable::getCause)
+                .map(Throwable::getCause)
+                .filter(x -> x instanceof ConstraintViolationException)
+                .isPresent());
+        } finally {
+            entityManager.getTransaction().rollback();
+        }
+    }
+}

reactor-core/README.md

@@ -9,3 +9,4 @@ This module contains articles about Reactor Core.
 - [Programmatically Creating Sequences with Project Reactor](https://www.baeldung.com/flux-sequences-reactor)
 - [How to Extract a Mono’s Content in Java](https://www.baeldung.com/java-string-from-mono)
 - [How to Convert Mono<List<T\>> Into Flux<T\>](https://www.baeldung.com/java-mono-list-to-flux)
+- [Project Reactor: map() vs flatMap()](https://www.baeldung.com/java-reactor-map-flatmap)

spring-boot-modules/pom.xml

@@ -73,6 +73,7 @@
         <module>spring-boot-actuator</module>
         <module>spring-boot-data-2</module>
         <module>spring-boot-react</module>
+        <module>spring-boot-validation</module>
     </modules>
 
     <dependencyManagement>

spring-boot-modules/spring-boot-exceptions/README.md

@@ -5,3 +5,4 @@ This module contains articles about Spring Boot Exceptions
 ### Relevant Articles:
 
 - [The BeanDefinitionOverrideException in Spring Boot](https://www.baeldung.com/spring-boot-bean-definition-override-exception)
+- [Spring Boot Error ApplicationContextException](https://www.baeldung.com/spring-boot-application-context-exception)

spring-boot-modules/spring-boot-exceptions/pom.xml

@@ -15,6 +15,14 @@
         <relativePath>../</relativePath>
     </parent>
 
+    <!-- Added in order to produce ApplicationContextException error -->
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+    </dependencies>
+
     <build>
         <finalName>spring-boot-exceptions</finalName>
         <resources>

spring-boot-modules/spring-boot-exceptions/src/test/java/com/baeldung/applicationcontextexception/MainEntryPoint.java

@@ -0,0 +1,14 @@
+package com.baeldung.applicationcontextexception;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+//Remove this annotation to produce ApplicationContextException error
+@SpringBootApplication
+public class MainEntryPoint {
+
+    public static void main(String[] args) {
+        SpringApplication.run(MainEntryPoint.class, args);
+    }
+
+}

spring-boot-modules/spring-boot-keycloak/pom.xml

@@ -76,7 +76,7 @@
     </build>
 
     <properties>
-        <keycloak-adapter-bom.version>11.0.2</keycloak-adapter-bom.version>
+        <keycloak-adapter-bom.version>13.0.1</keycloak-adapter-bom.version>
     </properties>
 
 </project>

spring-boot-modules/spring-boot-testing/pom.xml

@@ -147,6 +147,7 @@
         <spock.version>1.2-groovy-2.4</spock.version>
         <gmavenplus-plugin.version>1.6</gmavenplus-plugin.version>
         <redis.version>0.7.2</redis.version>
+        <spring-boot.version>2.5.0</spring-boot.version>
     </properties>
 
 </project>

spring-boot-modules/spring-boot-validation/.gitignore

@@ -0,0 +1,63 @@
+# Created by https://www.gitignore.io/api/eclipse
+
+### Eclipse ###
+
+.metadata
+target/
+bin/
+tmp/
+*.tmp
+*.bak
+*.swp
+*~.nib
+local.properties
+.settings/
+.loadpath
+.recommenders
+
+# External tool builders
+.externalToolBuilders/
+
+# Locally stored "Eclipse launch configurations"
+*.launch
+
+# PyDev specific (Python IDE for Eclipse)
+*.pydevproject
+
+# CDT-specific (C/C++ Development Tooling)
+.cproject
+
+# Java annotation processor (APT)
+.factorypath
+
+# PDT-specific (PHP Development Tools)
+.buildpath
+
+# sbteclipse plugin
+.target
+
+# Tern plugin
+.tern-project
+
+# TeXlipse plugin
+.texlipse
+
+# STS (Spring Tool Suite)
+.springBeans
+
+# Code Recommenders
+.recommenders/
+
+# Scala IDE specific (Scala & Java development for Eclipse)
+.cache-main
+.scala_dependencies
+.worksheet
+
+### Eclipse Patch ###
+# Eclipse Core      
+.project
+
+# JDT-specific (Eclipse Java Development Tools)     
+.classpath
+
+# End of https://www.gitignore.io/api/eclipse

spring-boot-modules/spring-boot-validation/README.md

@@ -0,0 +1,3 @@
+### Relevant Articles
+
+- [Spring Validation in the Service Layer](https://www.baeldung.com/spring-service-layer-validation)

spring-boot-modules/spring-boot-validation/pom.xml

@@ -0,0 +1,41 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+
+	<groupId>com.baeldung</groupId>
+	<artifactId>spring-boot-validation</artifactId>
+	<version>0.0.1-SNAPSHOT</version>
+
+	 <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-boot-2</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../../parent-boot-2</relativePath>
+    </parent>
+
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-web</artifactId>
+		</dependency>
+
+		<dependency>
+			<groupId>org.hibernate.validator</groupId>
+			<artifactId>hibernate-validator</artifactId>
+		</dependency>
+		
+		
+	</dependencies>
+
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.springframework.boot</groupId>
+				<artifactId>spring-boot-maven-plugin</artifactId>
+			</plugin>
+		</plugins>
+	</build>
+</project>

spring-boot-modules/spring-boot-validation/src/main/java/com/baeldung/spring/servicevalidation/SpringServiceLayerValidationApp.java

@@ -0,0 +1,13 @@
+package com.baeldung.spring.servicevalidation;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class SpringServiceLayerValidationApp {
+
+    public static void main(String[] args) {
+        SpringApplication.run(SpringServiceLayerValidationApp.class, args);
+    }
+
+}

spring-boot-modules/spring-boot-validation/src/main/java/com/baeldung/spring/servicevalidation/controller/UserAccountController.java

@@ -0,0 +1,22 @@
+package com.baeldung.spring.servicevalidation.controller;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RestController;
+
+import com.baeldung.spring.servicevalidation.domain.UserAccount;
+import com.baeldung.spring.servicevalidation.service.UserAccountService;
+
+@RestController
+public class UserAccountController {
+
+    @Autowired
+    private UserAccountService service;
+
+    @PostMapping("/addUserAccount")
+    public Object addUserAccount(@RequestBody UserAccount userAccount) {
+        return service.addUserAccount(userAccount);
+    }
+
+}

spring-boot-modules/spring-boot-validation/src/main/java/com/baeldung/spring/servicevalidation/dao/UserAccountDao.java

@@ -0,0 +1,31 @@
+package com.baeldung.spring.servicevalidation.dao;
+
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.Map;
+
+import org.springframework.stereotype.Service;
+
+import com.baeldung.spring.servicevalidation.domain.UserAccount;
+
+@Service
+public class UserAccountDao {
+
+    private Map<String, UserAccount> DB = new HashMap<String, UserAccount>();
+
+    public String addUserAccount(UserAccount useraccount) {
+        DB.put(useraccount.getName(), useraccount);
+        return "success";
+    }
+
+    public Collection<UserAccount> getAllUserAccounts() {
+
+        Collection<UserAccount> list = DB.values();
+        if (list.isEmpty()) {
+            list.addAll(DB.values());
+        }
+        return list;
+
+    }
+
+}

spring-boot-modules/spring-boot-validation/src/main/java/com/baeldung/spring/servicevalidation/domain/UserAccount.java

@@ -0,0 +1,77 @@
+package com.baeldung.spring.servicevalidation.domain;
+
+import javax.validation.Valid;
+import javax.validation.constraints.Min;
+import javax.validation.constraints.NotBlank;
+import javax.validation.constraints.NotNull;
+import javax.validation.constraints.Size;
+
+public class UserAccount {
+
+    @NotNull(message = "Password must be between 4 to 15 characters")
+    @Size(min = 4, max = 15)
+    private String password;
+
+    @NotBlank(message = "Name must not be blank")
+    private String name;
+
+    @Min(value = 18, message = "Age should not be less than 18")
+    private int age;
+
+    @NotBlank(message = "Phone must not be blank")
+    private String phone;
+
+    @Valid
+    @NotNull(message = "UserAddress must not be blank")
+    private UserAddress useraddress;
+
+    public UserAddress getUseraddress() {
+        return useraddress;
+    }
+
+    public void setUseraddress(UserAddress useraddress) {
+        this.useraddress = useraddress;
+    }
+
+    public UserAccount() {
+
+    }
+
+    public UserAccount(String email, String password, String name, int age) {
+        this.password = password;
+        this.name = name;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getPassword() {
+        return password;
+    }
+
+    public void setPassword(String password) {
+        this.password = password;
+    }
+
+    public int getAge() {
+        return age;
+    }
+
+    public void setAge(int age) {
+        this.age = age;
+    }
+
+    public String getPhone() {
+        return phone;
+    }
+
+    public void setPhone(String phone) {
+        this.phone = phone;
+    }
+
+}

spring-boot-modules/spring-boot-validation/src/main/java/com/baeldung/spring/servicevalidation/domain/UserAddress.java

@@ -0,0 +1,18 @@
+package com.baeldung.spring.servicevalidation.domain;
+
+import javax.validation.constraints.NotBlank;
+
+public class UserAddress {
+
+    @NotBlank
+    private String countryCode;
+
+    public String getCountryCode() {
+        return countryCode;
+    }
+
+    public void setCountryCode(String countryCode) {
+        this.countryCode = countryCode;
+    }
+
+}

spring-boot-modules/spring-boot-validation/src/main/java/com/baeldung/spring/servicevalidation/service/UserAccountService.java

@@ -0,0 +1,42 @@
+package com.baeldung.spring.servicevalidation.service;
+
+import java.util.Set;
+
+import javax.validation.ConstraintViolation;
+import javax.validation.ConstraintViolationException;
+import javax.validation.Validator;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+
+import com.baeldung.spring.servicevalidation.dao.UserAccountDao;
+import com.baeldung.spring.servicevalidation.domain.UserAccount;
+
+@Service
+public class UserAccountService {
+
+    @Autowired
+    private Validator validator;
+
+    @Autowired
+    private UserAccountDao dao;
+
+    public String addUserAccount(UserAccount useraccount) {
+
+        Set<ConstraintViolation<UserAccount>> violations = validator.validate(useraccount);
+
+        if (!violations.isEmpty()) {
+            StringBuilder sb = new StringBuilder();
+            for (ConstraintViolation<UserAccount> constraintViolation : violations) {
+                sb.append(constraintViolation.getMessage());
+            }
+
+            dao.addUserAccount(useraccount);
+
+            throw new ConstraintViolationException("Error occurred: " + sb.toString(), violations);
+        }
+
+        return "Account for " + useraccount.getName() + " Added!";
+    }
+
+}

spring-boot-modules/spring-boot-validation/src/test/java/com/baeldung/SpringContextTest.java

@@ -0,0 +1,14 @@
+package com.baeldung;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.boot.test.context.SpringBootTest;
+
+import com.baeldung.spring.servicevalidation.SpringServiceLayerValidationApp;
+
+@SpringBootTest(classes = SpringServiceLayerValidationApp.class)
+public class SpringContextTest {
+
+    @Test
+    public void whenSpringContextIsBootstrapped_thenNoExceptions() {
+    }
+}

spring-cloud/spring-cloud-openfeign/README.md

@@ -3,3 +3,4 @@
 - [Introduction to Spring Cloud OpenFeign](https://www.baeldung.com/spring-cloud-openfeign)
 - [Differences Between Netflix Feign and OpenFeign](https://www.baeldung.com/netflix-feign-vs-openfeign)
 - [File Upload With Open Feign](https://www.baeldung.com/java-feign-file-upload)
+- [Feign Logging Configuration](https://www.baeldung.com/java-feign-logging)

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

@@ -3,3 +3,4 @@
 - [Guide to the System Rules Library](https://www.baeldung.com/java-system-rules-junit)
 - [Guide to the System Stubs Library](https://www.baeldung.com/java-system-stubs)
 - [Code Coverage with SonarQube and JaCoCo](https://www.baeldung.com/sonarqube-jacoco-code-coverage)
+- [Exclusions from Jacoco Report](https://www.baeldung.com/jacoco-report-exclude)

testing-modules/testing-libraries-2/lombok.config

@@ -0,0 +1 @@
+lombok.addLombokGeneratedAnnotation = true

testing-modules/testing-libraries-2/pom.xml

@@ -13,6 +13,12 @@
     </parent>
 
     <dependencies>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <version>${lombok.version}</version>
+            <scope>provided</scope>
+        </dependency>
         <dependency>
             <groupId>org.assertj</groupId>
             <artifactId>assertj-core</artifactId>
@@ -85,6 +91,13 @@
                 <groupId>org.jacoco</groupId>
                 <artifactId>jacoco-maven-plugin</artifactId>
                 <version>${jacoco.version}</version>
+                <configuration>
+                    <excludes>
+                        <exclude>com/baeldung/**/ExcludedPOJO.class</exclude>
+                        <exclude>com/baeldung/**/*DTO.*</exclude>
+                        <exclude>**/config/*</exclude>
+                    </excludes>
+                </configuration>
                 <executions>
                     <execution>
                         <id>jacoco-initialize</id>

testing-modules/testing-libraries-2/src/main/java/com/baeldung/jacocoexclusions/config/AppConfig.java

@@ -0,0 +1,11 @@
+package com.baeldung.jacocoexclusions.config;
+
+import com.baeldung.jacocoexclusions.service.ProductService;
+
+public class AppConfig {
+
+    public ProductService productService() {
+        return new ProductService();
+    }
+
+}

testing-modules/testing-libraries-2/src/main/java/com/baeldung/jacocoexclusions/domain/Product.java

@@ -0,0 +1,12 @@
+package com.baeldung.jacocoexclusions.domain;
+
+import lombok.Builder;
+import lombok.Data;
+
+@Builder
+@Data
+public class Product {
+    private int id;
+    private String name;
+
+}

testing-modules/testing-libraries-2/src/main/java/com/baeldung/jacocoexclusions/dto/ExcludedPOJO.java

@@ -0,0 +1,4 @@
+package com.baeldung.jacocoexclusions.dto;
+
+public class ExcludedPOJO {
+}

testing-modules/testing-libraries-2/src/main/java/com/baeldung/jacocoexclusions/dto/ProductDTO.java

@@ -0,0 +1,4 @@
+package com.baeldung.jacocoexclusions.dto;
+
+public class ProductDTO {
+}

testing-modules/testing-libraries-2/src/main/java/com/baeldung/jacocoexclusions/generated/Customer.java

@@ -0,0 +1,11 @@
+package com.baeldung.jacocoexclusions.generated;
+
+@Generated
+public class Customer {
+    // everything in this class will be excluded from jacoco report because of @Generated
+
+    @Override
+    public String toString() {
+        return "Customer{}";
+    }
+}

testing-modules/testing-libraries-2/src/main/java/com/baeldung/jacocoexclusions/generated/Generated.java

@@ -0,0 +1,15 @@
+package com.baeldung.jacocoexclusions.generated;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+import static java.lang.annotation.ElementType.METHOD;
+import static java.lang.annotation.ElementType.TYPE;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+
+@Documented
+@Retention(RUNTIME)
+@Target({TYPE, METHOD})
+public @interface Generated {
+}

testing-modules/testing-libraries-2/src/main/java/com/baeldung/jacocoexclusions/service/CustomerService.java

@@ -0,0 +1,16 @@
+package com.baeldung.jacocoexclusions.service;
+
+import com.baeldung.jacocoexclusions.generated.Generated;
+
+public class CustomerService {
+
+    //this method will be excluded from coverage due to @Generated.
+    @Generated
+    public String getProductId() {
+        return "An ID";
+    }
+
+    public String getCustomerName() {
+        return "some name";
+    }
+}

testing-modules/testing-libraries-2/src/main/java/com/baeldung/jacocoexclusions/service/ProductService.java

@@ -0,0 +1,9 @@
+package com.baeldung.jacocoexclusions.service;
+
+public class ProductService {
+    private static final double DISCOUNT = 0.25;
+
+    public double getSalePrice(double originalPrice) {
+        return originalPrice - originalPrice * DISCOUNT;
+    }
+}

testing-modules/testing-libraries-2/src/test/java/com/baeldung/jacocoexclusions/service/CustomerServiceUnitTest.java

@@ -0,0 +1,14 @@
+package com.baeldung.jacocoexclusions.service;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+
+class CustomerServiceUnitTest {
+
+    @Test
+    public void givenCustomer_whenGetCustomer_thenReturnNewCustomer() {
+        CustomerService customerService = new CustomerService();
+        assertNotNull(customerService.getCustomerName());
+    }
+}

testing-modules/testing-libraries-2/src/test/java/com/baeldung/jacocoexclusions/service/ProductServiceUnitTest.java

@@ -0,0 +1,15 @@
+package com.baeldung.jacocoexclusions.service;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class ProductServiceUnitTest {
+
+    @Test
+    public void givenOriginalPrice_whenGetSalePrice_thenReturnsDiscountedPrice() {
+        ProductService productService = new ProductService();
+        double salePrice = productService.getSalePrice(100);
+        assertEquals(salePrice, 75);
+    }
+}