Merge remote-tracking branch 'upstream/master'

core-java-modules/core-java-collections-maps-2/src/main/java/com/baeldung/map/Product.java

@@ -26,7 +26,7 @@ public class Product {
         return tags;
     }
 
-    public Product addTagsOfOtherProdcut(Product product) {
+    public Product addTagsOfOtherProduct(Product product) {
         this.tags.addAll(product.getTags());
         return this;
     }
@@ -100,11 +100,11 @@ public class Product {
         HashMap<String, Product> productsByName = new HashMap<>();
         Product eBike2 = new Product("E-Bike", "A bike with a battery");
         eBike2.getTags().add("sport");
-        productsByName.merge("E-Bike", eBike2, Product::addTagsOfOtherProdcut);
+        productsByName.merge("E-Bike", eBike2, Product::addTagsOfOtherProduct);
 
         //Prior to Java 8:
         if(productsByName.containsKey("E-Bike")) {
-            productsByName.get("E-Bike").addTagsOfOtherProdcut(eBike2);
+            productsByName.get("E-Bike").addTagsOfOtherProduct(eBike2);
         } else {
             productsByName.put("E-Bike", eBike2);
         }
@@ -117,7 +117,7 @@ public class Product {
 
         productsByName.compute("E-Bike", (k,v) -> {
             if(v != null) {
-                return v.addTagsOfOtherProdcut(eBike2);
+                return v.addTagsOfOtherProduct(eBike2);
             } else {
                 return eBike2;
             }
@@ -125,7 +125,7 @@ public class Product {
 
         //Prior to Java 8:
         if(productsByName.containsKey("E-Bike")) {
-            productsByName.get("E-Bike").addTagsOfOtherProdcut(eBike2);
+            productsByName.get("E-Bike").addTagsOfOtherProduct(eBike2);
         } else {
             productsByName.put("E-Bike", eBike2);
         }

core-java-modules/core-java-concurrency-advanced-4/README.md

@@ -1,3 +1,4 @@
 ### Relevant Articles:
 
 - [Binary Semaphore vs Reentrant Lock](https://www.baeldung.com/java-binary-semaphore-vs-reentrant-lock)
+- [Bad Practices With Synchronization](https://www.baeldung.com/java-synchronization-bad-practices)

core-java-modules/core-java-concurrency-advanced-4/src/main/java/com/baeldung/synchronizationbadpractices/AnimalBadPractice.java

@@ -0,0 +1,35 @@
+package com.baeldung.synchronizationbadpractices;
+
+public class AnimalBadPractice {
+    
+    private String name;
+    private String owner;
+    
+    public String getName() {
+        return name;
+    }
+
+    public String getOwner() {
+        return owner;
+    }
+
+    public synchronized void setName(String name) {
+        this.name = name;
+    }
+    
+    public void setOwner(String owner) {
+        synchronized(this) {
+            this.owner = owner;
+        }
+    }
+    
+    public AnimalBadPractice() {
+        
+    }
+    
+    public AnimalBadPractice(String name, String owner) {
+        this.name = name;
+        this.owner = owner;
+    }
+    
+}

core-java-modules/core-java-concurrency-advanced-4/src/main/java/com/baeldung/synchronizationbadpractices/AnimalSolution.java

@@ -0,0 +1,42 @@
+package com.baeldung.synchronizationbadpractices;
+
+public class AnimalSolution { 
+    
+    private final Object objLock1 = new Object();
+    private final Object objLock2 = new Object();
+    
+    private String name;
+    private String owner;
+    
+    public String getName() {
+        return name;
+    }
+
+    public String getOwner() {
+        return owner;
+    }
+    
+    
+    public void setName(String name) {
+        synchronized(objLock1) {
+            this.name = name;
+        }
+    }
+     
+    public void setOwner(String owner) {
+        synchronized(objLock2) {
+            this.owner = owner;
+        }
+    }
+    
+    public AnimalSolution() {
+        
+    }
+    
+    public AnimalSolution(String name, String owner) {
+        this.name = name;
+        this.owner = owner;
+    }
+    
+
+}

core-java-modules/core-java-concurrency-advanced-4/src/main/java/com/baeldung/synchronizationbadpractices/SynchronizationBadPracticeExample.java

@@ -0,0 +1,51 @@
+package com.baeldung.synchronizationbadpractices;
+
+public class SynchronizationBadPracticeExample {
+
+    public void stringBadPractice1() { 
+        String stringLock = "LOCK_STRING"; 
+        synchronized (stringLock) { 
+            // ... 
+        }
+    }
+
+    private final String stringLock = "LOCK_STRING"; 
+    public void stringBadPractice2() { 
+        synchronized (stringLock) { 
+            // ... 
+        }
+    }
+
+    private final String internedStringLock = new String("LOCK_STRING").intern(); 
+    public void stringBadPractice3() { 
+        synchronized (internedStringLock) { 
+            // ... 
+        }
+    }
+
+    private final Boolean booleanLock = Boolean.FALSE; 
+    public void booleanBadPractice() { 
+        synchronized (booleanLock) { 
+            // ...
+        }
+    }
+
+    private int count = 0; 
+    private final Integer intLock = count; 
+    public void boxedPrimitiveBadPractice() { 
+        synchronized (intLock) { 
+            count++; 
+            // ...
+        }
+    }
+
+    public void classBadPractice() throws InterruptedException {
+        AnimalBadPractice animalObj = new AnimalBadPractice("Tommy", "John");
+        synchronized(animalObj) {
+            while (true) {
+                Thread.sleep(Integer.MAX_VALUE);
+            }
+        } 
+    }
+
+}

core-java-modules/core-java-concurrency-advanced-4/src/main/java/com/baeldung/synchronizationbadpractices/SynchronizationSolutionExample.java

@@ -0,0 +1,30 @@
+package com.baeldung.synchronizationbadpractices;
+
+public class SynchronizationSolutionExample {
+
+    private final String stringLock = new String("LOCK_STRING"); 
+    public void stringSolution() { 
+        synchronized (stringLock) { 
+            // ... 
+        }
+    }
+
+    private int count = 0;
+    private final Integer intLock = new Integer(count);
+    public void boxedPrimitiveSolution() {
+        synchronized(intLock) {
+            count++; 
+            // ... 
+        } 
+    }
+
+    private static int staticCount = 0;
+    private static final Object staticObjLock = new Object();
+    public void staticVariableSolution() {
+        synchronized(staticObjLock) {
+            staticCount++; 
+            // ... 
+        } 
+    }
+
+}

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

@@ -11,4 +11,5 @@ This module contains articles about working with the Java Virtual Machine (JVM).
 - [Where Is the Array Length Stored in JVM?](https://www.baeldung.com/java-jvm-array-length)
 - [Memory Address of Objects in Java](https://www.baeldung.com/java-object-memory-address)
 - [List All Classes Loaded in a Specific Class Loader](https://www.baeldung.com/java-list-classes-class-loader)
+- [An Introduction to the Constant Pool in the JVM](https://www.baeldung.com/jvm-constant-pool)
 - More articles: [[<-- prev]](/core-java-modules/core-java-jvm)

core-java-modules/core-java-lang-3/src/main/java/com/baeldung/compareto/BankAccount.java

@@ -0,0 +1,16 @@
+package com.baeldung.compareto;
+
+public class BankAccount implements Comparable<BankAccount> {
+
+    private final int balance;
+
+    public BankAccount(int balance) {
+        this.balance = balance;
+    }
+
+    @Override
+    public int compareTo(BankAccount anotherAccount) {
+        return this.balance - anotherAccount.balance;
+    }
+
+}

core-java-modules/core-java-lang-3/src/main/java/com/baeldung/compareto/BankAccountFix.java

@@ -0,0 +1,16 @@
+package com.baeldung.compareto;
+
+public class BankAccountFix implements Comparable<BankAccountFix> {
+
+    private final int balance;
+
+    public BankAccountFix(int balance) {
+        this.balance = balance;
+    }
+
+    @Override
+    public int compareTo(BankAccountFix anotherAccount) {
+        return Integer.compare(this.balance, anotherAccount.balance);
+    }
+
+}

core-java-modules/core-java-lang-3/src/main/java/com/baeldung/compareto/FootballPlayer.java

@@ -0,0 +1,32 @@
+package com.baeldung.compareto;
+
+public class FootballPlayer implements Comparable<FootballPlayer> {
+
+    private final String name;
+    private final int goalsScored;
+
+    public FootballPlayer(String name, int goalsScored) {
+        this.name = name;
+        this.goalsScored = goalsScored;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    @Override
+    public int compareTo(FootballPlayer anotherPlayer) {
+        return Integer.compare(this.goalsScored, anotherPlayer.goalsScored);
+    }
+
+    @Override
+    public boolean equals(Object object) {
+        if (this == object)
+            return true;
+        if (object == null || getClass() != object.getClass())
+            return false;
+        FootballPlayer player = (FootballPlayer) object;
+        return name.equals(player.name);
+    }
+
+}

core-java-modules/core-java-lang-3/src/main/java/com/baeldung/compareto/HandballPlayer.java

@@ -0,0 +1,12 @@
+package com.baeldung.compareto;
+
+public class HandballPlayer {
+
+    private final String name;
+    private final int height;
+
+    public HandballPlayer(String name, int height) {
+        this.name = name;
+        this.height = height;
+    }
+}

core-java-modules/core-java-lang-3/src/test/java/com/baeldung/compareto/ArraysSortingUnitTest.java

@@ -0,0 +1,25 @@
+package com.baeldung.compareto;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.Arrays;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class ArraysSortingUnitTest {
+
+    @Test
+    public void givenArrayOfNumbers_whenSortingArray_thenNumbersAreSortedAscending() {
+        int[] numbers = new int[] {5, 3, 9, 11, 1, 7};
+        Arrays.sort(numbers);
+        assertThat(numbers).containsExactly(1, 3, 5, 7, 9, 11);
+    }
+
+    @Test
+    public void givenArrayOfStrings_whenSortingArray_thenStringsAreSortedAlphabetically() {
+        String[] players = new String[] {"ronaldo",  "modric", "ramos", "messi"};
+        Arrays.sort(players);
+        assertThat(players).containsExactly("messi", "modric", "ramos", "ronaldo");
+    }
+
+}

core-java-modules/core-java-lang-3/src/test/java/com/baeldung/compareto/BankAccountFixUnitTest.java

@@ -0,0 +1,25 @@
+package com.baeldung.compareto;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class BankAccountFixUnitTest {
+
+    @Test
+    public void givenComparisonBasedImpl_whenUsingSmallIntegers_thenComparisonWorks() {
+        BankAccountFix accountOne = new BankAccountFix(5000);
+        BankAccountFix accountTwo = new BankAccountFix(1000);
+        int comparison = accountOne.compareTo(accountTwo);
+        assertThat(comparison).isPositive();
+    }
+
+    @Test
+    public void givenComparisonBasedImpl_whenUsingLargeIntegers_thenComparisonWorks() {
+        BankAccountFix accountOne = new BankAccountFix(1900000000);
+        BankAccountFix accountTwo = new BankAccountFix(-2000000000);
+        int comparison = accountOne.compareTo(accountTwo);
+        assertThat(comparison).isPositive();
+    }
+
+}

core-java-modules/core-java-lang-3/src/test/java/com/baeldung/compareto/BankAccountUnitTest.java

@@ -0,0 +1,25 @@
+package com.baeldung.compareto;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.*;
+
+public class BankAccountUnitTest {
+
+    @Test
+    public void givenSubtractionBasedImpl_whenUsingSmallIntegers_thenComparisonWorks() {
+        BankAccount accountOne = new BankAccount(5000);
+        BankAccount accountTwo = new BankAccount(1000);
+        int comparison = accountOne.compareTo(accountTwo);
+        assertThat(comparison).isPositive();
+    }
+
+    @Test
+    public void givenSubtractionBasedImpl_whenUsingLargeIntegers_thenComparisonBreaks() {
+        BankAccount accountOne = new BankAccount(1900000000);
+        BankAccount accountTwo = new BankAccount(-2000000000);
+        int comparison = accountOne.compareTo(accountTwo);
+        assertThat(comparison).isNegative();
+    }
+
+}

core-java-modules/core-java-lang-3/src/test/java/com/baeldung/compareto/FootballPlayerUnitTest.java

@@ -0,0 +1,57 @@
+package com.baeldung.compareto;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.List;
+import java.util.Map;
+import java.util.TreeMap;
+import java.util.TreeSet;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class FootballPlayerUnitTest {
+
+    @Test
+    public void givenInconsistentCompareToAndEqualsImpl_whenUsingSortedSet_thenSomeElementsAreNotAdded() {
+        FootballPlayer messi = new FootballPlayer("Messi", 800);
+        FootballPlayer ronaldo = new FootballPlayer("Ronaldo", 800);
+
+        TreeSet<FootballPlayer> set = new TreeSet<>();
+        set.add(messi);
+        set.add(ronaldo);
+
+        assertThat(set).hasSize(1);
+        assertThat(set).doesNotContain(ronaldo);
+    }
+
+    @Test
+    public void givenCompareToImpl_whenUsingCustomComparator_thenComparatorLogicIsApplied() {
+        FootballPlayer ronaldo = new FootballPlayer("Ronaldo", 900);
+        FootballPlayer messi = new FootballPlayer("Messi", 800);
+        FootballPlayer modric = new FootballPlayer("Modric", 100);
+
+        List<FootballPlayer> players = Arrays.asList(ronaldo, messi, modric);
+        Comparator<FootballPlayer> nameComparator = Comparator.comparing(FootballPlayer::getName);
+        Collections.sort(players, nameComparator);
+
+        assertThat(players).containsExactly(messi, modric, ronaldo);
+    }
+
+    @Test
+    public void givenCompareToImpl_whenSavingElementsInTreeMap_thenKeysAreSortedUsingCompareTo() {
+        FootballPlayer ronaldo = new FootballPlayer("Ronaldo", 900);
+        FootballPlayer messi = new FootballPlayer("Messi", 800);
+        FootballPlayer modric = new FootballPlayer("Modric", 100);
+
+        Map<FootballPlayer, String> players = new TreeMap<>();
+        players.put(ronaldo, "forward");
+        players.put(messi, "forward");
+        players.put(modric, "midfielder");
+
+        assertThat(players.keySet()).containsExactly(modric, messi, ronaldo);
+    }
+
+}

core-java-modules/core-java-lang-3/src/test/java/com/baeldung/compareto/HandballPlayerUnitTest.java

@@ -0,0 +1,20 @@
+package com.baeldung.compareto;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.Arrays;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
+
+public class HandballPlayerUnitTest {
+
+    @Test
+    public void givenComparableIsNotImplemented_whenSortingArray_thenExceptionIsThrown() {
+        HandballPlayer duvnjak = new HandballPlayer("Duvnjak", 197);
+        HandballPlayer hansen = new HandballPlayer("Hansen", 196);
+
+        HandballPlayer[] players = new HandballPlayer[] {duvnjak, hansen};
+
+        assertThatExceptionOfType(ClassCastException.class).isThrownBy(() -> Arrays.sort(players));
+    }
+
+}

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

@@ -7,3 +7,4 @@ This module contains articles about generics in Java
 - [Type Erasure in Java Explained](https://www.baeldung.com/java-type-erasure)
 - [Raw Types in Java](https://www.baeldung.com/raw-types-java)
 - [Super Type Tokens in Java Generics](https://www.baeldung.com/java-super-type-tokens)
+- [Java Warning “unchecked conversion”](https://www.baeldung.com/java-unchecked-conversion)

core-java-modules/core-java-lang-oop-generics/pom.xml

@@ -13,4 +13,32 @@
     <name>core-java-lang-oop-generics</name>
     <packaging>jar</packaging>
 
+    <build>
+        <resources>
+            <resource>
+                <directory>src/main/resources</directory>
+                <filtering>true</filtering>
+            </resource>
+        </resources>
+
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>${maven-compiler-plugin.version}</version>
+                <configuration>
+                    <source>${maven.compiler.source}</source>
+                    <target>${maven.compiler.target}</target>
+                    <compilerArguments>
+                        <Xlint:unchecked/>
+                    </compilerArguments>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+    <properties>
+        <maven.compiler.source>1.8</maven.compiler.source>
+        <maven.compiler.target>1.8</maven.compiler.target>
+    </properties>
+
 </project>

core-java-modules/core-java-lang-oop-generics/src/main/java/com/baeldung/uncheckedconversion/UncheckedConversion.java

@@ -0,0 +1,45 @@
+package com.baeldung.uncheckedconversion;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Date;
+import java.util.List;
+
+public class UncheckedConversion {
+    public static List getRawList() {
+        List result = new ArrayList();
+        result.add("I am the 1st String.");
+        result.add("I am the 2nd String.");
+        result.add("I am the 3rd String.");
+        return result;
+    }
+
+    public static List getRawListWithMixedTypes() {
+        List result = new ArrayList();
+        result.add("I am the 1st String.");
+        result.add("I am the 2nd String.");
+        result.add("I am the 3rd String.");
+        result.add(new Date());
+        return result;
+    }
+
+    public static <T> List<T> castList(Class<? extends T> clazz, Collection<?> rawCollection) {
+        List<T> result = new ArrayList<>(rawCollection.size());
+        for (Object o : rawCollection) {
+            try {
+                result.add(clazz.cast(o));
+            } catch (ClassCastException e) {
+                // log the exception or other error handling
+            }
+        }
+        return result;
+    }
+
+    public static <T> List<T> castList2(Class<? extends T> clazz, Collection<?> rawCollection) throws ClassCastException {
+        List<T> result = new ArrayList<>(rawCollection.size());
+        for (Object o : rawCollection) {
+            result.add(clazz.cast(o));
+        }
+        return result;
+    }
+}

core-java-modules/core-java-lang-oop-generics/src/test/java/com/baeldung/uncheckedconversion/UncheckedConversionUnitTest.java

@@ -0,0 +1,39 @@
+package com.baeldung.uncheckedconversion;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.util.List;
+
+public class UncheckedConversionUnitTest {
+
+    @Test
+    public void givenRawList_whenAssignToTypedList_shouldHaveCompilerWarning() {
+        List<String> fromRawList = UncheckedConversion.getRawList();
+        Assert.assertEquals(3, fromRawList.size());
+        Assert.assertEquals("I am the 1st String.", fromRawList.get(0));
+    }
+
+    @Test(expected = ClassCastException.class)
+    public void givenRawList_whenListHasMixedType_shouldThrowClassCastException() {
+        List<String> fromRawList = UncheckedConversion.getRawListWithMixedTypes();
+        Assert.assertEquals(4, fromRawList.size());
+        Assert.assertFalse(fromRawList.get(3).endsWith("String."));
+    }
+
+    @Test
+    public void givenRawList_whenAssignToTypedListAfterCallingCastList_shouldOnlyHaveElementsWithExpectedType() {
+        List rawList = UncheckedConversion.getRawListWithMixedTypes();
+        List<String> strList = UncheckedConversion.castList(String.class, rawList);
+        Assert.assertEquals(4, rawList.size());
+        Assert.assertEquals("One element with the wrong type has been filtered out.", 3, strList.size());
+        Assert.assertTrue(strList.stream().allMatch(el -> el.endsWith("String.")));
+    }
+
+    @Test(expected = ClassCastException.class)
+    public void givenRawListWithWrongType_whenAssignToTypedListAfterCallingCastList2_shouldThrowException() {
+        List rawList = UncheckedConversion.getRawListWithMixedTypes();
+        UncheckedConversion.castList2(String.class, rawList);
+    }
+
+}

core-java-modules/core-java-reflection-2/src/main/java/com/baeldung/reflection/check/abstractclass/InterfaceExample.java

@@ -0,0 +1,4 @@
+package com.baeldung.reflection.check.abstractclass;
+
+public interface InterfaceExample {
+}

core-java-modules/core-java-reflection-2/src/test/java/com/baeldung/reflection/check/abstractclass/AbstractExampleUnitTest.java

@@ -1,16 +1,36 @@
 package com.baeldung.reflection.check.abstractclass;
 
-import java.lang.reflect.Modifier;
-
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
 
+import java.lang.reflect.Modifier;
+import java.util.Date;
+
 class AbstractExampleUnitTest {
 
     @Test
-    void givenAbstractClass_whenCheckModifierIsAbstract_thenTrue() throws Exception {
+    void givenAbstractClass_whenCheckModifierIsAbstract_thenTrue() {
         Class<AbstractExample> clazz = AbstractExample.class;
         Assertions.assertTrue(Modifier.isAbstract(clazz.getModifiers()));
     }
 
+    @Test
+    void givenInterface_whenCheckModifierIsAbstract_thenTrue() {
+        Class<InterfaceExample> clazz = InterfaceExample.class;
+        Assertions.assertTrue(Modifier.isAbstract(clazz.getModifiers()));
+    }
+
+    @Test
+    void givenAbstractClass_whenCheckIsAbstractClass_thenTrue() {
+        Class<AbstractExample> clazz = AbstractExample.class;
+        int mod = clazz.getModifiers();
+        Assertions.assertTrue(Modifier.isAbstract(mod) && !Modifier.isInterface(mod));
+    }
+
+    @Test
+    void givenConcreteClass_whenCheckIsAbstractClass_thenFalse() {
+        Class<Date> clazz = Date.class;
+        int mod = clazz.getModifiers();
+        Assertions.assertFalse(Modifier.isAbstract(mod) && !Modifier.isInterface(mod));
+    }
 }

core-java-modules/core-java-security-2/src/main/java/com/baeldung/egd/JavaSecurityEgdTester.java

@@ -0,0 +1,23 @@
+package com.baeldung.egd;
+
+import java.security.SecureRandom;
+
+/**
+ * JavaSecurityEgdTester - run this with JVM parameter java.security.egd, e.g.:
+ *     java -Djava.security.egd=file:/dev/urandom -cp . com.baeldung.egd.JavaSecurityEgdTester
+ */
+public class JavaSecurityEgdTester {
+    public static final double NANOSECS = 1000000000.0;
+    public static final String JAVA_SECURITY_EGD = "java.security.egd";
+
+    public static void main(String[] args) {
+        SecureRandom secureRandom = new SecureRandom();
+        long start = System.nanoTime();
+        byte[] randomBytes = new byte[256];
+        secureRandom.nextBytes(randomBytes);
+        double duration = (System.nanoTime() - start) / NANOSECS;
+
+        String message = String.format("java.security.egd=%s took %.3f seconds and used the %s algorithm", System.getProperty(JAVA_SECURITY_EGD), duration, secureRandom.getAlgorithm());
+        System.out.println(message);
+    }
+}

java-collections-maps-3/README.md

@@ -2,3 +2,4 @@
 
 - [Java Map With Case-Insensitive Keys](https://www.baeldung.com/java-map-with-case-insensitive-keys)
 - [Using a Byte Array as Map Key in Java](https://www.baeldung.com/java-map-key-byte-array)
+- [Using the Map.Entry Java Class](https://www.baeldung.com/java-map-entry)

java-collections-maps-3/src/main/java/com/baeldung/map/entry/Book.java

@@ -0,0 +1,35 @@
+package com.baeldung.map.entry;
+
+public class Book {
+    private String title;
+    private String author;
+
+    public Book(String title, String author) {
+        this.title = title;
+        this.author = author;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public void setTitle(String title) {
+        this.title = title;
+    }
+
+    public String getAuthor() {
+        return author;
+    }
+
+    public void setAuthor(String author) {
+        this.author = author;
+    }
+
+    @Override
+    public String toString() {
+        return "Book{" +
+                "title='" + title + '\'' +
+                ", author='" + author + '\'' +
+                '}';
+    }
+}

java-collections-maps-3/src/main/java/com/baeldung/map/entry/MapEntryEfficiencyExample.java

@@ -0,0 +1,34 @@
+package com.baeldung.map.entry;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class MapEntryEfficiencyExample {
+
+    public static void main(String[] args) {
+        MapEntryEfficiencyExample mapEntryEfficiencyExample = new MapEntryEfficiencyExample();
+        Map<String, String> map = new HashMap<>();
+
+        map.put("Robert C. Martin", "Clean Code");
+        map.put("Joshua Bloch", "Effective Java");
+
+        System.out.println("Iterating Using Map.KeySet - 2 operations");
+        mapEntryEfficiencyExample.usingKeySet(map);
+
+        System.out.println("Iterating Using Map.Entry - 1 operation");
+        mapEntryEfficiencyExample.usingEntrySet(map);
+
+    }
+
+    public void usingKeySet(Map<String, String> bookMap) {
+        for (String key : bookMap.keySet()) {
+            System.out.println("key: " + key + " value: " + bookMap.get(key));
+        }
+    }
+
+    public void usingEntrySet(Map<String, String> bookMap) {
+        for (Map.Entry<String, String> book: bookMap.entrySet()) {
+            System.out.println("key: " + book.getKey() + " value: " + book.getValue());
+        }
+    }
+}

java-collections-maps-3/src/main/java/com/baeldung/map/entry/MapEntryTupleExample.java

@@ -0,0 +1,25 @@
+package com.baeldung.map.entry;
+
+import java.util.*;
+
+public class MapEntryTupleExample {
+
+    public static void main(String[] args) {
+        Map.Entry<String, Book> tuple1;
+        Map.Entry<String, Book> tuple2;
+        Map.Entry<String, Book> tuple3;
+
+        tuple1 = new AbstractMap.SimpleEntry<>("9780134685991", new Book("Effective Java 3d Edition", "Joshua Bloch"));
+        tuple2 = new AbstractMap.SimpleEntry<>("9780132350884", new Book("Clean Code", "Robert C Martin"));
+        tuple3 = new AbstractMap.SimpleEntry<>("9780132350884", new Book("Clean Code", "Robert C Martin"));
+
+        List<Map.Entry<String, Book>> orderedTuples = new ArrayList<>();
+        orderedTuples.add(tuple1);
+        orderedTuples.add(tuple2);
+        orderedTuples.add(tuple3);
+
+        for (Map.Entry<String, Book> tuple : orderedTuples) {
+            System.out.println("key: " + tuple.getKey() + " value: " + tuple.getValue());
+        }
+    }
+}

java-collections-maps-3/src/test/java/com/baeldung/map/entry/MapEntryUnitTest.java

@@ -0,0 +1,33 @@
+package com.baeldung.map.entry;
+
+import org.junit.Test;
+
+import java.util.*;
+
+import static org.junit.Assert.assertEquals;
+
+public class MapEntryUnitTest {
+
+    @Test
+    public void givenSimpleEntryList_whenAddDuplicateKey_thenDoesNotOverwriteExistingKey() {
+        List<Map.Entry<String, Book>> orderedTuples = new ArrayList<>();
+        orderedTuples.add(new AbstractMap.SimpleEntry<>("9780134685991", new Book("Effective Java 3d Edition", "Joshua Bloch")));
+        orderedTuples.add(new AbstractMap.SimpleEntry<>("9780132350884", new Book("Clean Code", "Robert C Martin")));
+        orderedTuples.add(new AbstractMap.SimpleEntry<>("9780132350884", new Book("Clean Code", "Robert C Martin")));
+
+        assertEquals(3, orderedTuples.size());
+        assertEquals("9780134685991", orderedTuples.get(0).getKey());
+        assertEquals("9780132350884", orderedTuples.get(1).getKey());
+        assertEquals("9780132350884", orderedTuples.get(2).getKey());
+    }
+
+    @Test
+    public void givenRegularMap_whenAddDuplicateKey_thenOverwritesExistingKey() {
+        Map<String, Book> entries = new HashMap<>();
+        entries.put("9780134685991", new Book("Effective Java 3d Edition", "Joshua Bloch"));
+        entries.put("9780132350884", new Book("Clean Code", "Robert C Martin"));
+        entries.put("9780132350884", new Book("Clean Code", "Robert C Martin"));
+
+        assertEquals(2, entries.size());
+    }
+}

libraries-http/pom.xml

@@ -120,7 +120,7 @@
         <httpclient.version>4.5.3</httpclient.version>
 <!--        <jackson.version>2.9.8</jackson.version>-->
         <assertj.version>3.6.2</assertj.version>
-        <com.squareup.okhttp3.version>3.14.2</com.squareup.okhttp3.version>
+        <com.squareup.okhttp3.version>4.9.1</com.squareup.okhttp3.version>
         <googleclient.version>1.23.0</googleclient.version>
         <async.http.client.version>2.2.0</async.http.client.version>
         <retrofit.version>2.3.0</retrofit.version>

performance-tests/README.md

@@ -6,6 +6,7 @@ This module contains articles about performance testing.
 
 - [Performance of Java Mapping Frameworks](https://www.baeldung.com/java-performance-mapping-frameworks)
 - [Performance Effects of Exceptions in Java](https://www.baeldung.com/java-exceptions-performance)
+- [Is Java a Compiled or Interpreted Language?](https://www.baeldung.com/java-compiled-interpreted)
 
 ### Running
 

persistence-modules/spring-boot-persistence-mongodb/src/main/java/com/baeldung/zoneddatetime/config/MongoConfig.java

@@ -1,11 +1,8 @@
 package com.baeldung.zoneddatetime.config;
 
 import java.util.ArrayList;
-import java.util.Collection;
-import java.util.Collections;
 import java.util.List;
 
-import org.springframework.context.annotation.Configuration;
 import org.springframework.core.convert.converter.Converter;
 import org.springframework.data.mongodb.config.AbstractMongoClientConfiguration;
 import org.springframework.data.mongodb.core.convert.MongoCustomConversions;
@@ -13,12 +10,7 @@ import org.springframework.data.mongodb.repository.config.EnableMongoRepositorie
 
 import com.baeldung.zoneddatetime.converter.ZonedDateTimeReadConverter;
 import com.baeldung.zoneddatetime.converter.ZonedDateTimeWriteConverter;
-import com.mongodb.ConnectionString;
-import com.mongodb.MongoClientSettings;
-import com.mongodb.client.MongoClient;
-import com.mongodb.client.MongoClients;
 
-@Configuration
 @EnableMongoRepositories(basePackages = { "com.baeldung" })
 public class MongoConfig extends AbstractMongoClientConfiguration {
 
@@ -29,20 +21,6 @@ public class MongoConfig extends AbstractMongoClientConfiguration {
         return "test";
     }
 
-    @Override
-    public MongoClient mongoClient() {
-        final ConnectionString connectionString = new ConnectionString("mongodb://localhost:27017/test");
-        final MongoClientSettings mongoClientSettings = MongoClientSettings.builder()
-            .applyConnectionString(connectionString)
-            .build();
-        return MongoClients.create(mongoClientSettings);
-    }
-
-    @Override
-    public Collection<String> getMappingBasePackages() {
-        return Collections.singleton("com.baeldung");
-    }
-
     @Override
     public MongoCustomConversions customConversions() {
         converters.add(new ZonedDateTimeReadConverter());

persistence-modules/spring-boot-persistence-mongodb/src/main/resources/mongoConfig.xml

@@ -24,8 +24,8 @@
         <constructor-arg ref="mongoConverter" />
     </bean>
 
-    <mongo:mapping-converter id="mongoConverter" base-package="com.baeldung.converter">
-        <mongo:custom-converters base-package="com.baeldung.converter" />
+    <mongo:mapping-converter id="mongoConverter" base-package="com.baeldung.zoneddatetime.converter">
+        <mongo:custom-converters base-package="com.baeldung.zoneddatetime.converter" />
     </mongo:mapping-converter>
 
 </beans>

spring-5-reactive-client/README.md

@@ -11,3 +11,4 @@ The "REST With Spring" Classes: http://bit.ly/restwithspring
 - [Logging Spring WebClient Calls](https://www.baeldung.com/spring-log-webclient-calls)
 - [Mocking a WebClient in Spring](https://www.baeldung.com/spring-mocking-webclient)
 - [Spring WebClient Filters](https://www.baeldung.com/spring-webclient-filters)
+- [Get List of JSON Objects with WebClient](https://www.baeldung.com/spring-webclient-json-list)

spring-5-reactive-client/src/main/java/com/baeldung/webclient/json/ReaderConsumerService.java

@@ -0,0 +1,18 @@
+package com.baeldung.webclient.json;
+
+import com.baeldung.webclient.json.model.Book;
+
+import java.util.List;
+
+public interface ReaderConsumerService {
+
+    List<Book> processReaderDataFromObjectArray();
+
+    List<Book> processReaderDataFromReaderArray();
+
+    List<Book> processReaderDataFromReaderList();
+
+    List<String> processNestedReaderDataFromReaderArray();
+
+    List<String> processNestedReaderDataFromReaderList();
+}

spring-5-reactive-client/src/main/java/com/baeldung/webclient/json/ReaderConsumerServiceImpl.java

@@ -0,0 +1,90 @@
+package com.baeldung.webclient.json;
+
+import com.baeldung.webclient.json.model.Book;
+import com.baeldung.webclient.json.model.Reader;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.springframework.core.ParameterizedTypeReference;
+import org.springframework.http.MediaType;
+import org.springframework.web.reactive.function.client.WebClient;
+import reactor.core.publisher.Mono;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class ReaderConsumerServiceImpl implements ReaderConsumerService {
+
+    private final WebClient webClient;
+    private static final ObjectMapper mapper = new ObjectMapper();
+
+    public ReaderConsumerServiceImpl(WebClient webClient) {
+        this.webClient = webClient;
+    }
+    @Override
+    public List<Book> processReaderDataFromObjectArray() {
+        Mono<Object[]> response = webClient.get()
+          .accept(MediaType.APPLICATION_JSON)
+          .retrieve()
+          .bodyToMono(Object[].class).log();
+        Object[] objects = response.block();
+        return Arrays.stream(objects)
+          .map(object -> mapper.convertValue(object, Reader.class))
+          .map(Reader::getFavouriteBook)
+          .collect(Collectors.toList());
+    }
+
+    @Override
+    public List<Book> processReaderDataFromReaderArray() {
+        Mono<Reader[]> response =
+          webClient.get()
+          .accept(MediaType.APPLICATION_JSON)
+          .retrieve()
+          .bodyToMono(Reader[].class).log();
+
+        Reader[] readers = response.block();
+        return Arrays.stream(readers)
+          .map(Reader::getFavouriteBook)
+          .collect(Collectors.toList());
+    }
+
+    @Override
+    public List<Book> processReaderDataFromReaderList() {
+        Mono<List<Reader>> response = webClient.get()
+          .accept(MediaType.APPLICATION_JSON)
+          .retrieve()
+          .bodyToMono(new ParameterizedTypeReference<List<Reader>>() {});
+        List<Reader> readers = response.block();
+
+        return readers.stream()
+          .map(Reader::getFavouriteBook)
+          .collect(Collectors.toList());
+    }
+
+    @Override
+    public List<String> processNestedReaderDataFromReaderArray() {
+        Mono<Reader[]> response = webClient.get()
+          .accept(MediaType.APPLICATION_JSON)
+          .retrieve()
+          .bodyToMono(Reader[].class).log();
+        Reader[] readers = response.block();
+
+        return Arrays.stream(readers)
+          .flatMap(reader -> reader.getBooksRead().stream())
+          .map(Book::getAuthor)
+          .collect(Collectors.toList());
+    }
+
+    @Override
+    public List<String> processNestedReaderDataFromReaderList() {
+        Mono<List<Reader>> response = webClient.get()
+          .accept(MediaType.APPLICATION_JSON)
+          .retrieve()
+          .bodyToMono(new ParameterizedTypeReference<List<Reader>>() {});
+
+        List<Reader> readers = response.block();
+        return readers.stream()
+          .flatMap(reader -> reader.getBooksRead().stream())
+          .map(Book::getAuthor)
+          .collect(Collectors.toList());
+    }
+}

spring-5-reactive-client/src/main/java/com/baeldung/webclient/json/model/Book.java

@@ -0,0 +1,22 @@
+package com.baeldung.webclient.json.model;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+@JsonInclude(JsonInclude.Include.NON_NULL)
+public class Book {
+    private final String author;
+    private final String title;
+
+    @JsonCreator
+    public Book(
+            @JsonProperty("author") String author,
+            @JsonProperty("title") String title) {
+        this.author = author;
+        this.title  = title;
+    }
+    public String getAuthor() {
+        return this.author;
+    }
+}

spring-5-reactive-client/src/main/java/com/baeldung/webclient/json/model/Reader.java

@@ -0,0 +1,33 @@
+package com.baeldung.webclient.json.model;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+import java.util.List;
+
+@JsonInclude(JsonInclude.Include.NON_NULL)
+public class Reader {
+    private final int id;
+    private final String name;
+    private final Book favouriteBook;
+    private final List<Book> booksRead;
+
+    @JsonCreator
+    public Reader(
+      @JsonProperty("id") int id,
+      @JsonProperty("name") String name,
+      @JsonProperty("favouriteBook") Book favouriteBook,
+      @JsonProperty("booksRead") List<Book> booksRead) {
+        this.id = id;
+        this.name = name;
+        this.favouriteBook = favouriteBook;
+        this.booksRead =booksRead;
+    }
+
+    public Book getFavouriteBook() {
+        return favouriteBook;
+    }
+
+    public List<Book> getBooksRead() { return booksRead; }
+}

spring-5-reactive-client/src/test/java/com/baeldung/webclient/json/ReaderConsumerServiceImplUnitTest.java

@@ -0,0 +1,88 @@
+package com.baeldung.webclient.json;
+
+import com.baeldung.webclient.json.model.Book;
+import org.junit.jupiter.api.Test;
+import org.springframework.http.HttpStatus;
+import org.springframework.web.reactive.function.client.ClientResponse;
+import org.springframework.web.reactive.function.client.WebClient;
+import reactor.core.publisher.Mono;
+
+import java.util.Arrays;
+import java.util.List;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.CoreMatchers.hasItems;
+import static org.hamcrest.CoreMatchers.is;
+import static org.hamcrest.Matchers.hasProperty;
+
+public class ReaderConsumerServiceImplUnitTest {
+
+    private static String READER_JSON = "[{\"id\":1,\"name\":\"reader1\",\"favouriteBook\":{\"author\":\"Milan Kundera\",\"title\":\"The Unbearable Lightness of Being\"}," +
+      "\"booksRead\":[{\"author\":\"Charles Dickens\",\"title\":\"Oliver Twist\"},{\"author\":\"Milan Kundera\",\"title\":\"The Unbearable Lightness of Being\"}]}," +
+      "{\"id\":2,\"name\":\"reader2\",\"favouriteBook\":{\"author\":\"Douglas Adams\",\"title\":\"The Hitchhiker\'s Guide to the Galaxy\"}," +
+      "\"booksRead\":[{\"author\":\"J.R.R. Tolkien\",\"title\":\"Lord of the Rings\"}, " +
+      "{\"author\":\"Douglas Adams\",\"title\":\"The Hitchhiker\'s Guide to the Galaxy\"}]}]";
+
+    private static String BASE_URL = "http://localhost:8080/readers";
+
+    WebClient webClientMock = WebClient.builder().baseUrl(BASE_URL)
+      .exchangeFunction(clientRequest -> Mono.just(ClientResponse.create(HttpStatus.OK)
+        .header("content-type", "application/json")
+        .body(READER_JSON)
+        .build()))
+      .build();
+
+    private final ReaderConsumerService tested = new ReaderConsumerServiceImpl(webClientMock);
+
+    @Test
+    void when_processReaderDataFromObjectArray_then_OK() {
+        String expectedAuthor1 = "Milan Kundera";
+        String expectedAuthor2 = "Douglas Adams";
+        List<Book> actual = tested.processReaderDataFromObjectArray();
+        assertThat(actual, hasItems(hasProperty("author", is(expectedAuthor1)),
+          hasProperty("author", is(expectedAuthor2))));
+    }
+
+    @Test
+    void when_processReaderDataFromReaderArray_then_OK() {
+        String expectedAuthor1 = "Milan Kundera";
+        String expectedAuthor2 = "Douglas Adams";
+        List<Book> actual = tested.processReaderDataFromReaderArray();
+        assertThat(actual, hasItems(hasProperty("author", is(expectedAuthor1)),
+          hasProperty("author", is(expectedAuthor2))));
+    }
+
+    @Test
+    void when_processReaderDataFromReaderList_then_OK() {
+        String expectedAuthor1 = "Milan Kundera";
+        String expectedAuthor2 = "Douglas Adams";
+        List<Book> actual = tested.processReaderDataFromReaderList();
+        assertThat(actual, hasItems(hasProperty("author", is(expectedAuthor1)),
+          hasProperty("author", is(expectedAuthor2))));
+
+    }
+
+    @Test
+    void when_processNestedReaderDataFromReaderArray_then_OK() {
+        List<String> expected = Arrays.asList(
+          "Milan Kundera",
+          "Charles Dickens",
+          "J.R.R. Tolkien",
+          "Douglas Adams");
+
+        List<String> actual = tested.processNestedReaderDataFromReaderArray();
+        assertThat(actual, hasItems(expected.get(0), expected.get(1), expected.get(2), expected.get(3)));
+    }
+
+    @Test
+    void when_processNestedReaderDataFromReaderList_then_OK() {
+        List<String> expected = Arrays.asList(
+          "Milan Kundera",
+          "Charles Dickens",
+          "J.R.R. Tolkien",
+          "Douglas Adams");
+
+        List<String> actual = tested.processNestedReaderDataFromReaderList();
+        assertThat(actual, hasItems(expected.get(0), expected.get(1), expected.get(2), expected.get(3)));
+    }
+}

spring-5-reactive/pom.xml

@@ -1,6 +1,7 @@
 <?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">
+<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>spring-5-reactive</artifactId>
     <version>0.0.1-SNAPSHOT</version>
@@ -73,6 +74,12 @@
             <artifactId>spring-security-test</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>io.projectreactor</groupId>
+            <artifactId>reactor-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+
 
         <!-- Spring WebFlux WebSession -->
         <dependency>

spring-5-reactive/src/main/java/com/baeldung/functional/FormHandler.java

@@ -11,7 +11,7 @@ import java.util.concurrent.atomic.AtomicLong;
 
 import static org.springframework.web.reactive.function.BodyExtractors.toDataBuffers;
 import static org.springframework.web.reactive.function.BodyExtractors.toFormData;
-import static org.springframework.web.reactive.function.BodyInserters.fromObject;
+import static org.springframework.web.reactive.function.BodyInserters.fromValue;
 import static org.springframework.web.reactive.function.server.ServerResponse.ok;
 
 public class FormHandler {
@@ -29,7 +29,7 @@ public class FormHandler {
     Mono<ServerResponse> handleUpload(ServerRequest request) {
         return request.body(toDataBuffers())
             .collectList()
-            .flatMap(dataBuffers -> ok().body(fromObject(extractData(dataBuffers).toString())));
+            .flatMap(dataBuffers -> ok().body(fromValue(extractData(dataBuffers).toString())));
     }
 
     private AtomicLong extractData(List<DataBuffer> dataBuffers) {

spring-5-reactive/src/main/java/com/baeldung/functional/FunctionalSpringBootApplication.java

@@ -1,6 +1,6 @@
 package com.baeldung.functional;
 
-import static org.springframework.web.reactive.function.BodyInserters.fromObject;
+import static org.springframework.web.reactive.function.BodyInserters.fromValue;
 import static org.springframework.web.reactive.function.server.RequestPredicates.GET;
 import static org.springframework.web.reactive.function.server.RequestPredicates.POST;
 import static org.springframework.web.reactive.function.server.RequestPredicates.path;
@@ -44,7 +44,7 @@ public class FunctionalSpringBootApplication {
                     .doOnNext(actors::add)
                     .then(ok().build()));
 
-        return route(GET("/test"), serverRequest -> ok().body(fromObject("helloworld")))
+        return route(GET("/test"), serverRequest -> ok().body(fromValue("helloworld")))
             .andRoute(POST("/login"), formHandler::handleLogin)
             .andRoute(POST("/upload"), formHandler::handleUpload)
             .and(RouterFunctions.resources("/files/**", new ClassPathResource("files/")))

spring-5-reactive/src/main/java/com/baeldung/functional/FunctionalWebApplication.java

@@ -1,6 +1,6 @@
 package com.baeldung.functional;
 
-import static org.springframework.web.reactive.function.BodyInserters.fromObject;
+import static org.springframework.web.reactive.function.BodyInserters.fromValue;
 import static org.springframework.web.reactive.function.server.RequestPredicates.GET;
 import static org.springframework.web.reactive.function.server.RequestPredicates.POST;
 import static org.springframework.web.reactive.function.server.RequestPredicates.accept;
@@ -42,7 +42,7 @@ public class FunctionalWebApplication {
             .doOnNext(actors::add)
             .then(ok().build()));
 
-        return route(GET("/test"), serverRequest -> ok().body(fromObject("helloworld"))).andRoute(POST("/login"), formHandler::handleLogin)
+        return route(GET("/test"), serverRequest -> ok().body(fromValue("helloworld"))).andRoute(POST("/login"), formHandler::handleLogin)
             .andRoute(POST("/upload"), formHandler::handleUpload)
             .and(RouterFunctions.resources("/files/**", new ClassPathResource("files/")))
             .andNest(accept(MediaType.APPLICATION_JSON), restfulRouter)

spring-5-reactive/src/main/java/com/baeldung/functional/RootServlet.java

@@ -2,7 +2,7 @@ package com.baeldung.functional;
 
 import static org.springframework.web.reactive.function.BodyExtractors.toDataBuffers;
 import static org.springframework.web.reactive.function.BodyExtractors.toFormData;
-import static org.springframework.web.reactive.function.BodyInserters.fromObject;
+import static org.springframework.web.reactive.function.BodyInserters.fromValue;
 import static org.springframework.web.reactive.function.server.RequestPredicates.GET;
 import static org.springframework.web.reactive.function.server.RequestPredicates.POST;
 import static org.springframework.web.reactive.function.server.RequestPredicates.path;
@@ -46,7 +46,7 @@ public class RootServlet extends ServletHttpHandlerAdapter {
 
     private static RouterFunction<?> routingFunction() {
 
-        return route(GET("/test"), serverRequest -> ok().body(fromObject("helloworld"))).andRoute(POST("/login"), serverRequest -> serverRequest.body(toFormData())
+        return route(GET("/test"), serverRequest -> ok().body(fromValue("helloworld"))).andRoute(POST("/login"), serverRequest -> serverRequest.body(toFormData())
             .map(MultiValueMap::toSingleValueMap)
             .map(formData -> {
                 System.out.println("form data: " + formData.toString());
@@ -65,7 +65,7 @@ public class RootServlet extends ServletHttpHandlerAdapter {
                     dataBuffers.forEach(d -> atomicLong.addAndGet(d.asByteBuffer()
                         .array().length));
                     System.out.println("data length:" + atomicLong.get());
-                    return ok().body(fromObject(atomicLong.toString()))
+                    return ok().body(fromValue(atomicLong.toString()))
                         .block();
                 }))
             .and(RouterFunctions.resources("/files/**", new ClassPathResource("files/")))

spring-5-reactive/src/main/java/com/baeldung/reactive/errorhandling/GlobalErrorWebExceptionHandler.java

@@ -2,7 +2,8 @@
 package com.baeldung.reactive.errorhandling;
 
 import java.util.Map;
-import org.springframework.boot.autoconfigure.web.ResourceProperties;
+
+import org.springframework.boot.autoconfigure.web.WebProperties;
 import org.springframework.boot.autoconfigure.web.reactive.error.AbstractErrorWebExceptionHandler;
 import org.springframework.boot.web.error.ErrorAttributeOptions;
 import org.springframework.boot.web.reactive.error.ErrorAttributes;
@@ -18,6 +19,7 @@ import org.springframework.web.reactive.function.server.RouterFunction;
 import org.springframework.web.reactive.function.server.RouterFunctions;
 import org.springframework.web.reactive.function.server.ServerRequest;
 import org.springframework.web.reactive.function.server.ServerResponse;
+
 import reactor.core.publisher.Mono;
 
 @Component
@@ -26,7 +28,7 @@ public class GlobalErrorWebExceptionHandler extends AbstractErrorWebExceptionHan
 
     public GlobalErrorWebExceptionHandler(GlobalErrorAttributes g, ApplicationContext applicationContext, 
             ServerCodecConfigurer serverCodecConfigurer) {
-        super(g, new ResourceProperties(), applicationContext);
+        super(g, new WebProperties.Resources(), applicationContext);
         super.setMessageWriters(serverCodecConfigurer.getWriters());
         super.setMessageReaders(serverCodecConfigurer.getReaders());
     }
@@ -41,8 +43,8 @@ public class GlobalErrorWebExceptionHandler extends AbstractErrorWebExceptionHan
         final Map<String, Object> errorPropertiesMap = getErrorAttributes(request, ErrorAttributeOptions.defaults());
 
         return ServerResponse.status(HttpStatus.BAD_REQUEST)
-            .contentType(MediaType.APPLICATION_JSON_UTF8)
-            .body(BodyInserters.fromObject(errorPropertiesMap));
+            .contentType(MediaType.APPLICATION_JSON)
+            .body(BodyInserters.fromValue(errorPropertiesMap));
     }
 
 }

spring-5-reactive/src/main/java/com/baeldung/reactive/errorhandling/handlers/Handler1.java

@@ -14,7 +14,7 @@ public class Handler1 {
         return sayHello(request).onErrorReturn("Hello, Stranger")
             .flatMap(s -> ServerResponse.ok()
                 .contentType(MediaType.TEXT_PLAIN)
-                .syncBody(s));
+                .bodyValue(s));
     }
 
     private Mono<String> sayHello(ServerRequest request) {

spring-5-reactive/src/main/java/com/baeldung/reactive/errorhandling/handlers/Handler2.java

@@ -15,11 +15,11 @@ public Mono<ServerResponse> handleRequest2(ServerRequest request) {
         sayHello(request)
             .flatMap(s -> ServerResponse.ok()
                 .contentType(MediaType.TEXT_PLAIN)
-                .syncBody(s))
+                .bodyValue(s))
             .onErrorResume(e -> sayHelloFallback()
                 .flatMap(s -> ServerResponse.ok()
                     .contentType(MediaType.TEXT_PLAIN)
-                    .syncBody(s)));
+                    .bodyValue(s)));
 }
 
     private Mono<String> sayHello(ServerRequest request) {

spring-5-reactive/src/main/java/com/baeldung/reactive/errorhandling/handlers/Handler3.java

@@ -15,11 +15,11 @@ public class Handler3 {
             sayHello(request)
               .flatMap(s -> ServerResponse.ok()
                         .contentType(MediaType.TEXT_PLAIN)
-                        .syncBody(s))
+                        .bodyValue(s))
               .onErrorResume(e -> (Mono.just("Hi, I looked around for your name but found: " + 
                     e.getMessage())).flatMap(s -> ServerResponse.ok()
                 .contentType(MediaType.TEXT_PLAIN)
-                .syncBody(s)));
+                .bodyValue(s)));
     }
 
     private Mono<String> sayHello(ServerRequest request) {

spring-5-reactive/src/main/java/com/baeldung/reactive/urlmatch/ExploreSpring5URLPatternUsingRouterFunctions.java

@@ -1,6 +1,6 @@
 package com.baeldung.reactive.urlmatch;
 
-import static org.springframework.web.reactive.function.BodyInserters.fromObject;
+import static org.springframework.web.reactive.function.BodyInserters.fromValue;
 import static org.springframework.web.reactive.function.server.RequestPredicates.GET;
 import static org.springframework.web.reactive.function.server.RouterFunctions.route;
 import static org.springframework.web.reactive.function.server.RouterFunctions.toHttpHandler;
@@ -24,10 +24,10 @@ public class ExploreSpring5URLPatternUsingRouterFunctions {
 
     private RouterFunction<ServerResponse> routingFunction() {
 
-        return route(GET("/p?ths"), serverRequest -> ok().body(fromObject("/p?ths"))).andRoute(GET("/test/{*id}"), serverRequest -> ok().body(fromObject(serverRequest.pathVariable("id"))))
-            .andRoute(GET("/*card"), serverRequest -> ok().body(fromObject("/*card path was accessed")))
-            .andRoute(GET("/{var1}_{var2}"), serverRequest -> ok().body(fromObject(serverRequest.pathVariable("var1") + " , " + serverRequest.pathVariable("var2"))))
-            .andRoute(GET("/{baeldung:[a-z]+}"), serverRequest -> ok().body(fromObject("/{baeldung:[a-z]+} was accessed and baeldung=" + serverRequest.pathVariable("baeldung"))))
+        return route(GET("/p?ths"), serverRequest -> ok().body(fromValue("/p?ths"))).andRoute(GET("/test/{*id}"), serverRequest -> ok().body(fromValue(serverRequest.pathVariable("id"))))
+            .andRoute(GET("/*card"), serverRequest -> ok().body(fromValue("/*card path was accessed")))
+            .andRoute(GET("/{var1}_{var2}"), serverRequest -> ok().body(fromValue(serverRequest.pathVariable("var1") + " , " + serverRequest.pathVariable("var2"))))
+            .andRoute(GET("/{baeldung:[a-z]+}"), serverRequest -> ok().body(fromValue("/{baeldung:[a-z]+} was accessed and baeldung=" + serverRequest.pathVariable("baeldung"))))
             .and(RouterFunctions.resources("/files/{*filepaths}", new ClassPathResource("files/")));
     }
 

spring-5-reactive/src/main/java/com/baeldung/reactive/urlmatch/FormHandler.java

@@ -11,7 +11,7 @@ import java.util.concurrent.atomic.AtomicLong;
 
 import static org.springframework.web.reactive.function.BodyExtractors.toDataBuffers;
 import static org.springframework.web.reactive.function.BodyExtractors.toFormData;
-import static org.springframework.web.reactive.function.BodyInserters.fromObject;
+import static org.springframework.web.reactive.function.BodyInserters.fromValue;
 import static org.springframework.web.reactive.function.server.ServerResponse.ok;
 
 public class FormHandler {
@@ -29,7 +29,7 @@ public class FormHandler {
     Mono<ServerResponse> handleUpload(ServerRequest request) {
         return request.body(toDataBuffers())
             .collectList()
-            .flatMap(dataBuffers -> ok().body(fromObject(extractData(dataBuffers).toString())));
+            .flatMap(dataBuffers -> ok().body(fromValue(extractData(dataBuffers).toString())));
     }
 
     private AtomicLong extractData(List<DataBuffer> dataBuffers) {

spring-5-reactive/src/main/java/com/baeldung/reactive/urlmatch/FunctionalWebApplication.java

@@ -1,6 +1,6 @@
 package com.baeldung.reactive.urlmatch;
 
-import static org.springframework.web.reactive.function.BodyInserters.fromObject;
+import static org.springframework.web.reactive.function.BodyInserters.fromValue;
 import static org.springframework.web.reactive.function.server.RequestPredicates.GET;
 import static org.springframework.web.reactive.function.server.RequestPredicates.POST;
 import static org.springframework.web.reactive.function.server.RequestPredicates.path;
@@ -40,7 +40,7 @@ public class FunctionalWebApplication {
             .doOnNext(actors::add)
             .then(ok().build()));
 
-        return route(GET("/test"), serverRequest -> ok().body(fromObject("helloworld"))).andRoute(POST("/login"), formHandler::handleLogin)
+        return route(GET("/test"), serverRequest -> ok().body(fromValue("helloworld"))).andRoute(POST("/login"), formHandler::handleLogin)
             .andRoute(POST("/upload"), formHandler::handleUpload)
             .and(RouterFunctions.resources("/files/**", new ClassPathResource("files/")))
             .andNest(path("/actor"), restfulRouter)

spring-5-reactive/src/main/java/com/baeldung/web/reactive/client/Foo.java

@@ -0,0 +1,24 @@
+package com.baeldung.web.reactive.client;
+
+public class Foo {
+
+    private String name;
+
+    public Foo() {
+        super();
+    }
+
+    public Foo(String name) {
+        super();
+        this.name = name;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+}

spring-5-reactive/src/main/java/com/baeldung/web/reactive/client/WebClientApplication.java

@@ -2,9 +2,10 @@ package com.baeldung.web.reactive.client;
 
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.autoconfigure.security.reactive.ReactiveSecurityAutoConfiguration;
 
-@SpringBootApplication
-public class WebClientApplication{
+@SpringBootApplication(exclude = { ReactiveSecurityAutoConfiguration.class })
+public class WebClientApplication {
 
     public static void main(String[] args) {
         SpringApplication.run(WebClientApplication.class, args);

spring-5-reactive/src/main/java/com/baeldung/web/reactive/client/WebClientController.java

@@ -1,36 +1,18 @@
 package com.baeldung.web.reactive.client;
 
-import java.net.URI;
-import java.nio.charset.Charset;
-import java.time.ZonedDateTime;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
-import java.util.concurrent.TimeUnit;
 
-import org.reactivestreams.Publisher;
-import org.reactivestreams.Subscriber;
-import org.springframework.http.HttpHeaders;
-import org.springframework.http.HttpMethod;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.MediaType;
-import org.springframework.http.ReactiveHttpOutputMessage;
-import org.springframework.http.client.reactive.ClientHttpRequest;
-import org.springframework.http.client.reactive.ReactorClientHttpConnector;
-import org.springframework.util.LinkedMultiValueMap;
-import org.springframework.util.MultiValueMap;
 import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestPart;
 import org.springframework.web.bind.annotation.ResponseStatus;
 import org.springframework.web.bind.annotation.RestController;
-import org.springframework.web.reactive.function.BodyInserter;
-import org.springframework.web.reactive.function.BodyInserters;
-import org.springframework.web.reactive.function.client.WebClient;
 
-import io.netty.channel.ChannelOption;
-import io.netty.handler.timeout.ReadTimeoutHandler;
-import io.netty.handler.timeout.WriteTimeoutHandler;
 import reactor.core.publisher.Mono;
-import reactor.netty.http.client.HttpClient;
 
 @RestController
 public class WebClientController {
@@ -43,74 +25,18 @@ public class WebClientController {
         return response;
     }
 
-    public void demonstrateWebClient() {
-        // request
-        WebClient.UriSpec<WebClient.RequestBodySpec> request1 = createWebClientWithServerURLAndDefaultValues().method(HttpMethod.POST);
-        WebClient.UriSpec<WebClient.RequestBodySpec> request2 = createWebClientWithServerURLAndDefaultValues().post();
-
-        // request body specifications
-        WebClient.RequestBodySpec uri1 = createWebClientWithServerURLAndDefaultValues().method(HttpMethod.POST)
-            .uri("/resource");
-        WebClient.RequestBodySpec uri2 = createWebClientWithServerURLAndDefaultValues().post()
-            .uri(URI.create("/resource"));
-
-        // request header specification
-        WebClient.RequestHeadersSpec<?> requestSpec1 = uri1.body(BodyInserters.fromPublisher(Mono.just("data"), String.class));
-        WebClient.RequestHeadersSpec<?> requestSpec2 = uri2.body(BodyInserters.fromValue("data"));
-
-        // inserters
-        BodyInserter<Publisher<String>, ReactiveHttpOutputMessage> inserter1 = BodyInserters.fromPublisher(Subscriber::onComplete, String.class);
-
-        LinkedMultiValueMap<String, String> map = new LinkedMultiValueMap<>();
-        map.add("key1", "value1");
-        map.add("key2", "value2");
-
-        BodyInserter<MultiValueMap<String, Object>, ClientHttpRequest> inserter2 = BodyInserters.fromMultipartData(map);
-        BodyInserter<Object, ReactiveHttpOutputMessage> inserter3 = BodyInserters.fromValue(new Object());
-        BodyInserter<String, ReactiveHttpOutputMessage> inserter4 = BodyInserters.fromValue("body");
-
-        // responses
-        WebClient.ResponseSpec response1 = uri1.body(inserter3)
-            .header(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_JSON_VALUE)
-            .accept(MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML)
-            .acceptCharset(Charset.forName("UTF-8"))
-            .ifNoneMatch("*")
-            .ifModifiedSince(ZonedDateTime.now())
-            .retrieve();
-        String response2 = uri1.exchangeToMono(response -> response.bodyToMono(String.class))
-            .block();
-        String response3 = uri2.retrieve()
-            .bodyToMono(String.class)
-            .block();
-        WebClient.ResponseSpec response4 = requestSpec2.retrieve();
+    @PostMapping("/resource")
+    public Mono<String> postStringResource(@RequestBody Mono<String> bodyString) {
+        return bodyString.map(body -> "processed-" + body);
     }
 
-    private WebClient createWebClient() {
-        return WebClient.create();
+    @PostMapping("/resource-foo")
+    public Mono<String> postFooResource(@RequestBody Mono<Foo> bodyFoo) {
+        return bodyFoo.map(foo -> "processedFoo-" + foo.getName());
     }
 
-    private WebClient createWebClientWithServerURL() {
-        return WebClient.create("http://localhost:8081");
+    @PostMapping(value = "/resource-multipart", consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
+    public String handleFormUpload(@RequestPart("key1") String value1, @RequestPart("key2") String value2) {
+        return "processed-" + value1 + "-" + value2;
     }
-
-    private WebClient createWebClientConfiguringTimeout() {
-        HttpClient httpClient = HttpClient.create()
-            .option(ChannelOption.CONNECT_TIMEOUT_MILLIS, 5000)
-            .doOnConnected(conn -> conn.addHandlerLast(new ReadTimeoutHandler(5000, TimeUnit.MILLISECONDS))
-                .addHandlerLast(new WriteTimeoutHandler(5000, TimeUnit.MILLISECONDS)));
-
-        return WebClient.builder()
-            .clientConnector(new ReactorClientHttpConnector(httpClient))
-            .build();
-    }
-
-    private WebClient createWebClientWithServerURLAndDefaultValues() {
-        return WebClient.builder()
-            .baseUrl("http://localhost:8081")
-            .defaultCookie("cookieKey", "cookieValue")
-            .defaultHeader(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_JSON_VALUE)
-            .defaultUriVariables(Collections.singletonMap("url", "http://localhost:8080"))
-            .build();
-    }
-
 }

spring-5-reactive/src/test/java/com/baeldung/functional/FunctionalWebApplicationIntegrationTest.java

@@ -1,17 +1,15 @@
 package com.baeldung.functional;
 
-import static org.springframework.web.reactive.function.BodyInserters.fromObject;
+import static org.springframework.web.reactive.function.BodyInserters.fromValue;
 import static org.springframework.web.reactive.function.BodyInserters.fromResource;
 
 import org.junit.AfterClass;
 import org.junit.BeforeClass;
-import org.junit.Ignore;
 import org.junit.Test;
 import org.springframework.boot.web.server.WebServer;
 import org.springframework.core.io.ClassPathResource;
 import org.springframework.core.io.Resource;
 import org.springframework.http.MediaType;
-import org.springframework.security.test.context.support.WithMockUser;
 import org.springframework.test.web.reactive.server.WebTestClient;
 import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.util.MultiValueMap;
@@ -115,7 +113,7 @@ public class FunctionalWebApplicationIntegrationTest {
 
         client.post()
             .uri("/actor")
-            .body(fromObject(new Actor("Clint", "Eastwood")))
+            .body(fromValue(new Actor("Clint", "Eastwood")))
             .exchange()
             .expectStatus()
             .isOk();

spring-5-reactive/src/test/java/com/baeldung/reactive/errorhandling/ErrorHandlingIntegrationTest.java

@@ -133,7 +133,7 @@ public class ErrorHandlingIntegrationTest {
             .expectStatus()
             .isBadRequest()
             .expectHeader()
-            .contentType(MediaType.APPLICATION_JSON_UTF8)
+            .contentType(MediaType.APPLICATION_JSON)
             .expectBody()
             .jsonPath("$.message")
             .isNotEmpty()
@@ -164,7 +164,7 @@ public class ErrorHandlingIntegrationTest {
             .expectStatus()
             .isBadRequest()
             .expectHeader()
-            .contentType(MediaType.APPLICATION_JSON_UTF8)
+            .contentType(MediaType.APPLICATION_JSON)
             .expectBody()
             .jsonPath("$.message")
             .isNotEmpty()

spring-5-reactive/src/test/java/com/baeldung/web/client/WebClientIntegrationTest.java

@@ -0,0 +1,331 @@
+package com.baeldung.web.client;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.net.URI;
+import java.nio.charset.StandardCharsets;
+import java.time.Duration;
+import java.time.ZonedDateTime;
+import java.util.Collections;
+import java.util.Map;
+import java.util.concurrent.TimeUnit;
+
+import org.junit.jupiter.api.Test;
+import org.reactivestreams.Publisher;
+import org.reactivestreams.Subscriber;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
+import org.springframework.boot.web.server.LocalServerPort;
+import org.springframework.core.ParameterizedTypeReference;
+import org.springframework.core.codec.CodecException;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpMethod;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
+import org.springframework.http.ReactiveHttpOutputMessage;
+import org.springframework.http.client.reactive.ClientHttpRequest;
+import org.springframework.http.client.reactive.ReactorClientHttpConnector;
+import org.springframework.util.LinkedMultiValueMap;
+import org.springframework.util.MultiValueMap;
+import org.springframework.web.reactive.function.BodyInserter;
+import org.springframework.web.reactive.function.BodyInserters;
+import org.springframework.web.reactive.function.client.WebClient;
+import org.springframework.web.reactive.function.client.WebClient.RequestBodySpec;
+import org.springframework.web.reactive.function.client.WebClient.RequestBodyUriSpec;
+import org.springframework.web.reactive.function.client.WebClient.RequestHeadersSpec;
+import org.springframework.web.reactive.function.client.WebClient.RequestHeadersUriSpec;
+import org.springframework.web.reactive.function.client.WebClient.ResponseSpec;
+import org.springframework.web.reactive.function.client.WebClientRequestException;
+
+import com.baeldung.web.reactive.client.Foo;
+import com.baeldung.web.reactive.client.WebClientApplication;
+
+import io.netty.channel.ChannelOption;
+import io.netty.handler.timeout.ReadTimeoutHandler;
+import io.netty.handler.timeout.WriteTimeoutHandler;
+import reactor.core.publisher.Mono;
+import reactor.netty.http.client.HttpClient;
+import reactor.test.StepVerifier;
+
+@SpringBootTest(classes = WebClientApplication.class, webEnvironment = WebEnvironment.RANDOM_PORT)
+public class WebClientIntegrationTest {
+
+    @LocalServerPort
+    private int port;
+
+    private static final String BODY_VALUE = "bodyValue";
+    private static final ParameterizedTypeReference<Map<String, String>> MAP_RESPONSE_REF = new ParameterizedTypeReference<Map<String, String>>() {
+    };
+
+    @Test
+    public void givenDifferentWebClientCreationMethods_whenUsed_thenObtainExpectedResponse() {
+        // WebClient creation
+        WebClient client1 = WebClient.create();
+        WebClient client2 = WebClient.create("http://localhost:" + port);
+        WebClient client3 = WebClient.builder()
+            .baseUrl("http://localhost:" + port)
+            .defaultCookie("cookieKey", "cookieValue")
+            .defaultHeader(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_JSON_VALUE)
+            .defaultUriVariables(Collections.singletonMap("url", "http://localhost:8080"))
+            .build();
+
+        // response assertions
+        StepVerifier.create(retrieveResponse(client1.post()
+            .uri("http://localhost:" + port + "/resource")))
+            .expectNext("processed-bodyValue")
+            .verifyComplete();
+        StepVerifier.create(retrieveResponse(client2))
+            .expectNext("processed-bodyValue")
+            .verifyComplete();
+        StepVerifier.create(retrieveResponse(client3))
+            .expectNext("processed-bodyValue")
+            .verifyComplete();
+        // assert response without specifying URI
+        StepVerifier.create(retrieveResponse(client1))
+            .expectErrorMatches(ex -> WebClientRequestException.class.isAssignableFrom(ex.getClass()) && ex.getMessage()
+                .contains("Connection refused"))
+            .verify();
+    }
+
+    @Test
+    public void givenDifferentMethodSpecifications_whenUsed_thenObtainExpectedResponse() {
+        // request specification
+        RequestBodyUriSpec uriSpecPost1 = createDefaultClient().method(HttpMethod.POST);
+        RequestBodyUriSpec uriSpecPost2 = createDefaultClient().post();
+        RequestHeadersUriSpec<?> requestGet = createDefaultClient().get();
+
+        // response assertions
+        StepVerifier.create(retrieveResponse(uriSpecPost1))
+            .expectNext("processed-bodyValue")
+            .verifyComplete();
+        StepVerifier.create(retrieveResponse(uriSpecPost2))
+            .expectNext("processed-bodyValue")
+            .verifyComplete();
+        StepVerifier.create(retrieveGetResponse(requestGet))
+            .expectNextMatches(nextMap -> nextMap.get("field")
+                .equals("value"))
+            .verifyComplete();
+    }
+
+    @Test
+    public void givenDifferentUriSpecifications_whenUsed_thenObtainExpectedResponse() {
+        // uri specification
+        RequestBodySpec bodySpecUsingString = createDefaultPostRequest().uri("/resource");
+        RequestBodySpec bodySpecUsingUriBuilder = createDefaultPostRequest().uri(uriBuilder -> uriBuilder.pathSegment("resource")
+            .build());
+        RequestBodySpec bodySpecusingURI = createDefaultPostRequest().uri(URI.create("http://localhost:" + port + "/resource"));
+        RequestBodySpec bodySpecOverridenBaseUri = createDefaultPostRequest().uri(URI.create("/resource"));
+        RequestBodySpec bodySpecOverridenBaseUri2 = WebClient.builder()
+            .baseUrl("http://localhost:" + port)
+            .build()
+            .post()
+            .uri(URI.create("/resource"));
+
+        // response assertions
+        StepVerifier.create(retrieveResponse(bodySpecUsingString))
+            .expectNext("processed-bodyValue")
+            .verifyComplete();
+        StepVerifier.create(retrieveResponse(bodySpecUsingUriBuilder))
+            .expectNext("processed-bodyValue")
+            .verifyComplete();
+        StepVerifier.create(retrieveResponse(bodySpecusingURI))
+            .expectNext("processed-bodyValue")
+            .verifyComplete();
+        // assert sending request overriding base URI
+        StepVerifier.create(retrieveResponse(bodySpecOverridenBaseUri))
+            .expectErrorMatches(ex -> WebClientRequestException.class.isAssignableFrom(ex.getClass()) && ex.getMessage()
+                .contains("Connection refused"))
+            .verify();
+        StepVerifier.create(retrieveResponse(bodySpecOverridenBaseUri2))
+            .expectErrorMatches(ex -> WebClientRequestException.class.isAssignableFrom(ex.getClass()) && ex.getMessage()
+                .contains("Connection refused"))
+            .verify();
+    }
+
+    @Test
+    public void givenDifferentBodySpecifications_whenUsed_thenObtainExpectedResponse() {
+        // request body specifications
+        RequestHeadersSpec<?> headersSpecPost1 = createDefaultPostResourceRequest().body(BodyInserters.fromPublisher(Mono.just(BODY_VALUE), String.class));
+        RequestHeadersSpec<?> headersSpecPost2 = createDefaultPostResourceRequest().body(BodyInserters.fromValue(BODY_VALUE));
+        RequestHeadersSpec<?> headersSpecPost3 = createDefaultPostResourceRequest().bodyValue(BODY_VALUE);
+        RequestHeadersSpec<?> headersSpecFooPost = createDefaultPostRequest().uri("/resource-foo")
+            .body(Mono.just(new Foo("fooName")), Foo.class);
+        BodyInserter<Object, ReactiveHttpOutputMessage> inserterPlainObject = BodyInserters.fromValue(new Object());
+        RequestHeadersSpec<?> headersSpecPlainObject = createDefaultPostResourceRequest().body(inserterPlainObject);
+
+        // request body specifications - using other inserter method (multipart request)
+        LinkedMultiValueMap<String, String> map = new LinkedMultiValueMap<>();
+        map.add("key1", "multipartValue1");
+        map.add("key2", "multipartValue2");
+        BodyInserter<MultiValueMap<String, Object>, ClientHttpRequest> inserterMultipart = BodyInserters.fromMultipartData(map);
+        RequestHeadersSpec<?> headersSpecInserterMultipart = createDefaultPostRequest().uri("/resource-multipart")
+            .body(inserterMultipart);
+
+        // response assertions
+        StepVerifier.create(retrieveResponse(headersSpecPost1))
+            .expectNext("processed-bodyValue")
+            .verifyComplete();
+        StepVerifier.create(retrieveResponse(headersSpecPost2))
+            .expectNext("processed-bodyValue")
+            .verifyComplete();
+        StepVerifier.create(retrieveResponse(headersSpecPost3))
+            .expectNext("processed-bodyValue")
+            .verifyComplete();
+        StepVerifier.create(retrieveResponse(headersSpecFooPost))
+            .expectNext("processedFoo-fooName")
+            .verifyComplete();
+        StepVerifier.create(retrieveResponse(headersSpecInserterMultipart))
+            .expectNext("processed-multipartValue1-multipartValue2")
+            .verifyComplete();
+        // assert error plain `new Object()` as request body
+        StepVerifier.create(retrieveResponse(headersSpecPlainObject))
+            .expectError(CodecException.class)
+            .verify();
+        // assert response for request with no body
+        Mono<Map<String, String>> responsePostWithNoBody = createDefaultPostResourceRequest().exchangeToMono(responseHandler -> {
+            assertThat(responseHandler.statusCode()).isEqualTo(HttpStatus.BAD_REQUEST);
+            return responseHandler.bodyToMono(MAP_RESPONSE_REF);
+        });
+        StepVerifier.create(responsePostWithNoBody)
+            .expectNextMatches(nextMap -> nextMap.get("error")
+                .equals("Bad Request"))
+            .verifyComplete();
+    }
+
+    @Test
+    public void givenPostSpecifications_whenHeadersAdded_thenObtainExpectedResponse() {
+        // request header specification
+        RequestHeadersSpec<?> headersSpecInserterStringWithHeaders = createDefaultPostResourceRequestResponse().header(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_JSON_VALUE)
+            .accept(MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML)
+            .acceptCharset(StandardCharsets.UTF_8)
+            .ifNoneMatch("*")
+            .ifModifiedSince(ZonedDateTime.now());
+
+        // response assertions
+        StepVerifier.create(retrieveResponse(headersSpecInserterStringWithHeaders))
+            .expectNext("processed-bodyValue")
+            .verifyComplete();
+    }
+
+    @Test
+    public void givenDifferentResponseSpecifications_whenUsed_thenObtainExpectedResponse() {
+        ResponseSpec responseSpecPostString = createDefaultPostResourceRequestResponse().retrieve();
+        Mono<String> responsePostString = responseSpecPostString.bodyToMono(String.class);
+        Mono<String> responsePostString2 = createDefaultPostResourceRequestResponse().exchangeToMono(response -> {
+            if (response.statusCode()
+                .equals(HttpStatus.OK)) {
+                return response.bodyToMono(String.class);
+            } else if (response.statusCode()
+                .is4xxClientError()) {
+                return Mono.just("Error response");
+            } else {
+                return response.createException()
+                    .flatMap(Mono::error);
+            }
+        });
+        Mono<String> responsePostNoBody = createDefaultPostResourceRequest().exchangeToMono(response -> {
+            if (response.statusCode()
+                .equals(HttpStatus.OK)) {
+                return response.bodyToMono(String.class);
+            } else if (response.statusCode()
+                .is4xxClientError()) {
+                return Mono.just("Error response");
+            } else {
+                return response.createException()
+                    .flatMap(Mono::error);
+            }
+        });
+        Mono<Map<String, String>> responseGet = createDefaultClient().get()
+            .uri("/resource")
+            .retrieve()
+            .bodyToMono(MAP_RESPONSE_REF);
+
+        // response assertions
+        StepVerifier.create(responsePostString)
+            .expectNext("processed-bodyValue")
+            .verifyComplete();
+        StepVerifier.create(responsePostString2)
+            .expectNext("processed-bodyValue")
+            .verifyComplete();
+        StepVerifier.create(responsePostNoBody)
+            .expectNext("Error response")
+            .verifyComplete();
+        StepVerifier.create(responseGet)
+            .expectNextMatches(nextMap -> nextMap.get("field")
+                .equals("value"))
+            .verifyComplete();
+    }
+
+    @Test
+    public void givenWebClientWithTimeoutConfigurations_whenRequestUsingWronglyConfiguredPublisher_thenObtainTimeout() {
+        HttpClient httpClient = HttpClient.create()
+            .option(ChannelOption.CONNECT_TIMEOUT_MILLIS, 1000)
+            .responseTimeout(Duration.ofMillis(1000))
+            .doOnConnected(conn -> conn.addHandlerLast(new ReadTimeoutHandler(1000, TimeUnit.MILLISECONDS))
+                .addHandlerLast(new WriteTimeoutHandler(1000, TimeUnit.MILLISECONDS)));
+
+        WebClient timeoutClient = WebClient.builder()
+            .clientConnector(new ReactorClientHttpConnector(httpClient))
+            .build();
+
+        BodyInserter<Publisher<String>, ReactiveHttpOutputMessage> inserterCompleteSuscriber = BodyInserters.fromPublisher(Subscriber::onComplete, String.class);
+        RequestHeadersSpec<?> headersSpecInserterCompleteSuscriber = timeoutClient.post()
+            .uri("/resource")
+            .body(inserterCompleteSuscriber);
+
+        StepVerifier.create(headersSpecInserterCompleteSuscriber.retrieve()
+            .bodyToMono(String.class))
+            .expectTimeout(Duration.ofMillis(2000))
+            .verify();
+    }
+
+    // helper methods to create default instances
+    private WebClient createDefaultClient() {
+        return WebClient.create("http://localhost:" + port);
+    }
+
+    private RequestBodyUriSpec createDefaultPostRequest() {
+        return createDefaultClient().post();
+    }
+
+    private RequestBodySpec createDefaultPostResourceRequest() {
+        return createDefaultPostRequest().uri("/resource");
+    }
+
+    private RequestHeadersSpec<?> createDefaultPostResourceRequestResponse() {
+        return createDefaultPostResourceRequest().bodyValue(BODY_VALUE);
+    }
+
+    // helper methods to retrieve a response based on different steps of the process (specs)
+    private Mono<String> retrieveResponse(WebClient client) {
+        return client.post()
+            .uri("/resource")
+            .bodyValue(BODY_VALUE)
+            .retrieve()
+            .bodyToMono(String.class);
+    }
+
+    private Mono<String> retrieveResponse(RequestBodyUriSpec spec) {
+        return spec.uri("/resource")
+            .bodyValue(BODY_VALUE)
+            .retrieve()
+            .bodyToMono(String.class);
+    }
+
+    private Mono<Map<String, String>> retrieveGetResponse(RequestHeadersUriSpec<?> spec) {
+        return spec.uri("/resource")
+            .retrieve()
+            .bodyToMono(MAP_RESPONSE_REF);
+    }
+
+    private Mono<String> retrieveResponse(RequestBodySpec spec) {
+        return spec.bodyValue(BODY_VALUE)
+            .retrieve()
+            .bodyToMono(String.class);
+    }
+
+    private Mono<String> retrieveResponse(RequestHeadersSpec<?> spec) {
+        return spec.retrieve()
+            .bodyToMono(String.class);
+    }
+}

spring-aop/README.md

@@ -11,3 +11,4 @@ This module contains articles about Spring aspect oriented programming (AOP)
 - [Introduction to Pointcut Expressions in Spring](https://www.baeldung.com/spring-aop-pointcut-tutorial)
 - [Introduction to Advice Types in Spring](https://www.baeldung.com/spring-aop-advice-tutorial)
 - [When Does Java Throw UndeclaredThrowableException?](https://www.baeldung.com/java-undeclaredthrowableexception)
+- [Get Advised Method Info in Spring AOP](https://www.baeldung.com/spring-aop-get-advised-method-info)

spring-boot-modules/pom.xml

@@ -62,6 +62,7 @@
         <module>spring-boot-properties-3</module>
         <module>spring-boot-property-exp</module>
         <module>spring-boot-runtime</module>
+        <module>spring-boot-runtime-2</module>
         <module>spring-boot-security</module>
         <module>spring-boot-springdoc</module>
         <module>spring-boot-swagger</module>

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

@@ -11,7 +11,7 @@
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
-        <version>2.3.0.RELEASE</version>
+        <version>2.3.2.RELEASE</version>
         <relativePath/> <!-- lookup parent from repository -->
     </parent>
 

spring-boot-modules/spring-boot-actuator/src/main/resources/application.properties

@@ -1,4 +1,6 @@
-management.health.probes.enabled=true
+management.endpoint.health.probes.enabled=true
+management.health.livenessState.enabled=true
+management.health.readinessState.enabled=true
 management.endpoint.health.show-details=always
 management.endpoint.health.status.http-mapping.down=500
 management.endpoint.health.status.http-mapping.out_of_service=503
@@ -8,4 +10,4 @@ management.endpoint.health.status.http-mapping.warning=500
 info.app.name=Spring Sample Application
 info.app.description=This is my first spring boot application G1
 info.app.version=1.0.0
-info.java-vendor = ${java.specification.vendor}
+info.java-vendor = ${java.specification.vendor}

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

@@ -10,3 +10,4 @@ This module contains articles about Spring Boot annotations
 - [Spring Core Annotations](https://www.baeldung.com/spring-core-annotations)
 - [Spring Bean Annotations](https://www.baeldung.com/spring-bean-annotations)
 - [Difference Between @ComponentScan and @EnableAutoConfiguration in Spring Boot](https://www.baeldung.com/spring-componentscan-vs-enableautoconfiguration)
+- [Where Should the Spring @Service Annotation Be Kept?](https://www.baeldung.com/spring-service-annotation-placement)

spring-boot-modules/spring-boot-annotations/src/main/java/com/baeldung/annotations/service/AuthApplication.java

@@ -0,0 +1,22 @@
+package com.baeldung.annotations.service;
+
+import com.baeldung.annotations.service.abstracts.AbstractAuthenticationService;
+import com.baeldung.annotations.service.interfaces.AuthenticationService;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class AuthApplication {
+
+    @Autowired
+    private AuthenticationService inMemoryAuthService;
+
+    @Autowired
+    private AbstractAuthenticationService ldapAuthService;
+
+    public static void main(String[] args) {
+        SpringApplication.run(AuthApplication.class, args);
+    }
+
+}

spring-boot-modules/spring-boot-annotations/src/main/java/com/baeldung/annotations/service/abstracts/AbstractAuthenticationService.java

@@ -0,0 +1,12 @@
+package com.baeldung.annotations.service.abstracts;
+
+import org.springframework.stereotype.Service;
+
+@Service
+public abstract class AbstractAuthenticationService {
+
+    public boolean authenticate(String username, String password) {
+        return false;
+    }
+
+}

spring-boot-modules/spring-boot-annotations/src/main/java/com/baeldung/annotations/service/concretes/InMemoryAuthenticationService.java

@@ -0,0 +1,14 @@
+package com.baeldung.annotations.service.concretes;
+
+import com.baeldung.annotations.service.interfaces.AuthenticationService;
+import org.springframework.stereotype.Service;
+
+@Service
+public class InMemoryAuthenticationService implements AuthenticationService {
+
+    @Override
+    public boolean authenticate(String username, String password) {
+        return false;
+    }
+
+}

spring-boot-modules/spring-boot-annotations/src/main/java/com/baeldung/annotations/service/concretes/LdapAuthenticationService.java

@@ -0,0 +1,14 @@
+package com.baeldung.annotations.service.concretes;
+
+import com.baeldung.annotations.service.abstracts.AbstractAuthenticationService;
+import org.springframework.stereotype.Service;
+
+@Service
+public class LdapAuthenticationService extends AbstractAuthenticationService {
+
+    @Override
+    public boolean authenticate(String username, String password) {
+        return true;
+    }
+
+}

spring-boot-modules/spring-boot-annotations/src/main/java/com/baeldung/annotations/service/interfaces/AuthenticationService.java

@@ -0,0 +1,10 @@
+package com.baeldung.annotations.service.interfaces;
+
+import org.springframework.stereotype.Service;
+
+@Service
+public interface AuthenticationService {
+
+    boolean authenticate(String username, String password);
+
+}

spring-boot-modules/spring-boot-annotations/src/test/java/com.baeldung.annotations/EmployeeApplicationUnitTest.java

@@ -6,7 +6,7 @@ import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 import static org.junit.jupiter.api.Assertions.assertAll;
 
-public class EmployeeApplicationTest {
+public class EmployeeApplicationUnitTest {
     private final ApplicationContextRunner contextRunner = new ApplicationContextRunner()
             .withUserConfiguration(EmployeeApplication.class);
 

spring-boot-modules/spring-boot-annotations/src/test/java/com.baeldung.annotations/service/AuthApplicationUnitTest.java

@@ -0,0 +1,51 @@
+package com.baeldung.annotations.service;
+
+import com.baeldung.annotations.service.abstracts.AbstractAuthenticationService;
+import com.baeldung.annotations.service.config.AbstractsAnnotatedTestConfiguration;
+import com.baeldung.annotations.service.config.ConcreteClassesAnnotatedTestConfiguration;
+import com.baeldung.annotations.service.config.InterfacesAnnotatedTestConfiguration;
+import com.baeldung.annotations.service.interfaces.AuthenticationService;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.NoSuchBeanDefinitionException;
+import org.springframework.boot.test.context.runner.ApplicationContextRunner;
+
+public class AuthApplicationUnitTest {
+
+    private final ApplicationContextRunner contextRunner = new ApplicationContextRunner();
+
+    @Test
+    void whenOnlyInterfacesAnnotated_noSuchBeanDefinitionExceptionThrown() {
+        contextRunner
+          .withUserConfiguration(InterfacesAnnotatedTestConfiguration.class)
+          .run(context -> {
+              Assertions.assertThrows(NoSuchBeanDefinitionException.class, () -> {
+                  context.getBean(AuthenticationService.class);
+              });
+          });
+    }
+
+    @Test
+    void whenOnlyAbstractClassesAnnotated_noSuchBeanDefinitionExceptionThrown() {
+        contextRunner
+          .withUserConfiguration(AbstractsAnnotatedTestConfiguration.class)
+          .run(context -> {
+              Assertions.assertThrows(NoSuchBeanDefinitionException.class, () -> {
+                  context.getBean(AbstractAuthenticationService.class);
+              });
+          });
+    }
+
+    @Test
+    void whenConcreteClassesAnnotated_noExceptionThrown() {
+        contextRunner
+          .withUserConfiguration(ConcreteClassesAnnotatedTestConfiguration.class)
+          .run(context -> {
+              AuthenticationService inMemoryAuthService = context.getBean(AuthenticationService.class);
+              AbstractAuthenticationService ldapAuthService = context.getBean(AbstractAuthenticationService.class);
+
+              Assertions.assertNotNull(inMemoryAuthService);
+              Assertions.assertNotNull(ldapAuthService);
+          });
+    }
+}

spring-boot-modules/spring-boot-annotations/src/test/java/com.baeldung.annotations/service/config/AbstractsAnnotatedTestConfiguration.java

@@ -0,0 +1,10 @@
+package com.baeldung.annotations.service.config;
+
+import org.springframework.boot.test.context.TestConfiguration;
+import org.springframework.context.annotation.ComponentScan;
+
+@TestConfiguration
+@ComponentScan("com.baeldung.annotations.service.abstracts")
+public class AbstractsAnnotatedTestConfiguration {
+
+}

spring-boot-modules/spring-boot-annotations/src/test/java/com.baeldung.annotations/service/config/ConcreteClassesAnnotatedTestConfiguration.java

@@ -0,0 +1,10 @@
+package com.baeldung.annotations.service.config;
+
+import org.springframework.boot.test.context.TestConfiguration;
+import org.springframework.context.annotation.ComponentScan;
+
+@TestConfiguration
+@ComponentScan("com.baeldung.annotations.service.concretes")
+public class ConcreteClassesAnnotatedTestConfiguration {
+
+}

spring-boot-modules/spring-boot-annotations/src/test/java/com.baeldung.annotations/service/config/InterfacesAnnotatedTestConfiguration.java

@@ -0,0 +1,10 @@
+package com.baeldung.annotations.service.config;
+
+import org.springframework.boot.test.context.TestConfiguration;
+import org.springframework.context.annotation.ComponentScan;
+
+@TestConfiguration
+@ComponentScan("com.baeldung.annotations.service.interfaces")
+public class InterfacesAnnotatedTestConfiguration {
+
+}

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

@@ -0,0 +1,6 @@
+## Spring Boot Runtime 2
+
+This module contains articles about administering a Spring Boot runtime
+
+### Relevant Articles:									
+ - 

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

@@ -0,0 +1,66 @@
+<?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>
+
+    <parent>
+        <groupId>com.baeldung.spring-boot-modules</groupId>
+        <artifactId>spring-boot-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+        <relativePath>../</relativePath>
+    </parent>
+
+    <artifactId>spring-boot-runtime-2</artifactId>
+    <packaging>jar</packaging>
+
+    <name>spring-boot-runtime-2</name>
+    <description>Demo project for Spring Boot</description>
+
+    <dependencies>
+
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <finalName>${project.artifactId}</finalName>
+        <resources>
+            <resource>
+                <directory>src/main/resources/heap</directory>
+                <targetPath>${project.build.directory}</targetPath>
+                <filtering>true</filtering>
+                <includes>
+                    <include>${project.name}.conf</include>
+                </includes>
+            </resource>
+        </resources>
+        <plugins>
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <configuration>
+                            <mainClass>com.baeldung.heap.HeapSizeDemoApplication</mainClass>
+                        </configuration>
+                    </execution>
+                </executions>
+                <configuration>
+                    <executable>true</executable>
+                    <jvmArguments>
+                        -Xms256m
+                        -Xmx1g
+                    </jvmArguments>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+</project>

spring-boot-modules/spring-boot-runtime-2/src/main/java/com/baeldung/heap/HeapSizeDemoApplication.java

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

spring-boot-modules/spring-boot-runtime-2/src/main/java/com/baeldung/heap/MemoryStats.java

@@ -0,0 +1,31 @@
+package com.baeldung.heap;
+
+public class MemoryStats {
+    private long heapSize;
+    private long heapMaxSize;
+    private long heapFreeSize;
+    
+    public long getHeapSize() {
+        return heapSize;
+    }
+    
+    public void setHeapSize(long heapSize) {
+        this.heapSize = heapSize;
+    }
+    
+    public long getHeapMaxSize() {
+        return heapMaxSize;
+    }
+    
+    public void setHeapMaxSize(long heapMaxSize) {
+        this.heapMaxSize = heapMaxSize;
+    }
+    
+    public long getHeapFreeSize() {
+        return heapFreeSize;
+    }
+    
+    public void setHeapFreeSize(long heapFreeSize) {
+        this.heapFreeSize = heapFreeSize;
+    }
+}

spring-boot-modules/spring-boot-runtime-2/src/main/java/com/baeldung/heap/MemoryStatusController.java

@@ -0,0 +1,20 @@
+package com.baeldung.heap;
+
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+public class MemoryStatusController {
+
+    @GetMapping("memory-status")
+    public MemoryStats getMemoryStatistics() {
+        MemoryStats stats = new MemoryStats();
+        stats.setHeapSize(Runtime.getRuntime()
+            .totalMemory());
+        stats.setHeapMaxSize(Runtime.getRuntime()
+            .maxMemory());
+        stats.setHeapFreeSize(Runtime.getRuntime()
+            .freeMemory());
+        return stats;
+    }
+}

spring-boot-modules/spring-boot-runtime-2/src/main/resources/heap/spring-boot-runtime-2.conf

@@ -0,0 +1 @@
+JAVA_OPTS="-Xms512m -Xmx1024m"

spring-boot-modules/spring-boot-runtime-2/src/test/java/com/baeldung/heap/MemoryStatusControllerIntegrationTest.java

@@ -0,0 +1,32 @@
+package com.baeldung.heap;
+
+import static org.hamcrest.Matchers.notANumber;
+import static org.hamcrest.Matchers.not;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest;
+import org.springframework.http.MediaType;
+import org.springframework.test.context.junit4.SpringRunner;
+import org.springframework.test.web.servlet.MockMvc;
+
+@RunWith(SpringRunner.class)
+@WebMvcTest(MemoryStatusController.class)
+public class MemoryStatusControllerIntegrationTest {
+
+    @Autowired
+    private MockMvc mvc;
+
+    @Test
+    public void whenGetMemoryStatistics_thenReturnJsonArray() throws Exception {
+        mvc.perform(get("/memory-status").contentType(MediaType.APPLICATION_JSON))
+            .andExpect(status().isOk())
+            .andExpect(jsonPath("heapSize", not(notANumber())))
+            .andExpect(jsonPath("heapMaxSize", not(notANumber())))
+            .andExpect(jsonPath("heapFreeSize", not(notANumber())));
+    }
+}

spring-boot-modules/spring-boot-springdoc/src/main/java/com/baeldung/springdoc/controller/RegularRestController.java

@@ -0,0 +1,31 @@
+package com.baeldung.springdoc.controller;
+
+import java.time.LocalDate;
+import java.time.LocalTime;
+
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import io.swagger.v3.oas.annotations.Hidden;
+
+@Hidden
+@RestController
+public class RegularRestController {
+
+    @Hidden
+    @GetMapping("/getAuthor")
+    public String getAuthor() {
+        return "Umang Budhwar";
+    }
+
+    @GetMapping("/getDate")
+    public LocalDate getDate() {
+        return LocalDate.now();
+    }
+
+    @GetMapping("/getTime")
+    public LocalTime getTime() {
+        return LocalTime.now();
+    }
+
+}

spring-web-modules/spring-mvc-forms-jsp/README.md

@@ -7,3 +7,4 @@ This module contains articles about Spring MVC Forms using JSP
 - [Getting Started with Forms in Spring MVC](https://www.baeldung.com/spring-mvc-form-tutorial)
 - [Form Validation with AngularJS and Spring MVC](https://www.baeldung.com/validation-angularjs-spring-mvc)
 - [A Guide to the JSTL Library](https://www.baeldung.com/jstl)
+- [Multiple Submit Buttons on a Form](https://www.baeldung.com/spring-form-multiple-submit-buttons)

spring-web-modules/spring-mvc-forms-jsp/src/main/java/com/baeldung/springmvcforms/controller/EmployeeController.java

@@ -26,7 +26,7 @@ public class EmployeeController {
         return employeeMap.get(Id);
     }
 
-    @RequestMapping(value = "/addEmployee", method = RequestMethod.POST)
+    @RequestMapping(value = "/addEmployee", method = RequestMethod.POST, params = "submit")
     public String submit(@Valid @ModelAttribute("employee") final Employee employee, final BindingResult result, final ModelMap model) {
         if (result.hasErrors()) {
             return "error";
@@ -37,5 +37,11 @@ public class EmployeeController {
         employeeMap.put(employee.getId(), employee);
         return "employeeView";
     }
+    
+    @RequestMapping(value = "/addEmployee", method = RequestMethod.POST, params = "cancel")
+    public String cancel(@Valid @ModelAttribute("employee") final Employee employee, final BindingResult result, final ModelMap model) {
+        model.addAttribute("message", "You clicked cancel, please re-enter employee details:");
+        return "employeeHome";
+    }
 
 }

spring-web-modules/spring-mvc-forms-jsp/src/main/webapp/WEB-INF/views/employeeHome.jsp

@@ -7,6 +7,7 @@
 </head>
 <body>
 	<h3>Welcome, Enter The Employee Details</h3>
+	<h4>${message}</h4>
 
 	<form:form method="POST" action="${pageContext.request.contextPath}/addEmployee" modelAttribute="employee">
 		<table>
@@ -23,7 +24,8 @@
 				<td><form:input path="contactNumber" /></td>
 			</tr>
 			<tr>
-				<td><input type="submit" value="Submit" /></td>
+				<td><input type="submit" name="submit" value="Submit" /></td>
+				<td><input type="submit" name="cancel" value="Cancel" /></td>
 			</tr>
 		</table>
 	</form:form>

spring-web-modules/spring-rest-http-2/README.md

@@ -8,3 +8,4 @@ The "REST With Spring 2" Classes: http://bit.ly/restwithspring
 ### Relevant Articles:
 
 - [How to Turn Off Swagger-ui in Production](https://www.baeldung.com/swagger-ui-turn-off-in-production)
+- [Setting a Request Timeout for a Spring REST API](https://www.baeldung.com/spring-rest-timeout)

spring-web-modules/spring-resttemplate-2/README.md

@@ -10,3 +10,5 @@ This module contains articles about Spring RestTemplate
 - [RestTemplate Post Request with JSON](https://www.baeldung.com/spring-resttemplate-post-json)
 - [How to Compress Requests Using the Spring RestTemplate](https://www.baeldung.com/spring-resttemplate-compressing-requests)
 - [Get list of JSON objects with Spring RestTemplate](https://www.baeldung.com/spring-resttemplate-json-list)
+- [A Guide To Spring Redirects](https://www.baeldung.com/spring-redirect-and-forward)
+- [Spring RestTemplate Exception: “Not enough variables available to expand”](https://www.baeldung.com/spring-not-enough-variables-available)

spring-web-modules/spring-resttemplate-2/pom.xml

@@ -11,7 +11,7 @@
         <groupId>com.baeldung</groupId>
         <artifactId>parent-boot-2</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>parent-boot-2/pom.xml</relativePath>
+        <relativePath>../../parent-boot-2/pom.xml</relativePath>
     </parent>
 
     <dependencies>

spring-web-modules/spring-resttemplate-2/src/main/java/com/baeldung/resttemplateexception/RestTemplateExceptionApplication.java

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

spring-web-modules/spring-resttemplate-2/src/main/java/com/baeldung/resttemplateexception/controller/ProductApi.java

@@ -0,0 +1,46 @@
+package com.baeldung.resttemplateexception.controller;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+import com.baeldung.resttemplateexception.model.Criterion;
+import com.baeldung.resttemplateexception.model.Product;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.JsonMappingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+@RestController
+@RequestMapping("/api")
+public class ProductApi {
+
+    private List<Product> productList = new ArrayList<>(Arrays.asList(new Product(1, "Acer Aspire 5", 437), new Product(2, "ASUS VivoBook", 650), new Product(3, "Lenovo Legion", 990)));
+
+    @GetMapping("/get")
+    public Product get(@RequestParam String criterion) throws JsonMappingException, JsonProcessingException {
+        ObjectMapper objectMapper = new ObjectMapper();
+        Criterion crt = objectMapper.readValue(criterion, Criterion.class);
+        if (crt.getProp().equals("name"))
+            return findByName(crt.getValue());
+
+        // Search by other properties (id,price)
+
+        return null;
+    }
+
+    private Product findByName(String name) {
+        for (Product product : this.productList) {
+            if (product.getName().equals(name)) {
+                return product;
+            }
+        }
+        return null;
+    }
+
+    // Other methods
+}

spring-web-modules/spring-resttemplate-2/src/main/java/com/baeldung/resttemplateexception/model/Criterion.java

@@ -0,0 +1,28 @@
+package com.baeldung.resttemplateexception.model;
+
+public class Criterion {
+
+    private String prop;
+    private String value;
+
+    public Criterion() {
+
+    }
+
+    public String getProp() {
+        return prop;
+    }
+
+    public void setProp(String prop) {
+        this.prop = prop;
+    }
+
+    public String getValue() {
+        return value;
+    }
+
+    public void setValue(String value) {
+        this.value = value;
+    }
+
+}

spring-web-modules/spring-resttemplate-2/src/main/java/com/baeldung/resttemplateexception/model/Product.java

@@ -0,0 +1,43 @@
+package com.baeldung.resttemplateexception.model;
+
+public class Product {
+
+    private int id;
+    private String name;
+    private double price;
+
+    public Product() {
+
+    }
+
+    public Product(int id, String name, double price) {
+        this.id = id;
+        this.name = name;
+        this.price = price;
+    }
+
+    public int getId() {
+        return id;
+    }
+
+    public void setId(int id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public double getPrice() {
+        return price;
+    }
+
+    public void setPrice(double price) {
+        this.price = price;
+    }
+
+}

spring-web-modules/spring-resttemplate-2/src/main/webapp/WEB-INF/api-servlet.xml

@@ -0,0 +1,36 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xmlns:context="http://www.springframework.org/schema/context"
+    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd 
+    http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd 
+    http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd"
+>
+
+    <context:component-scan base-package="com.baeldung.sampleapp.web" />
+
+    <mvc:annotation-driven content-negotiation-manager="contentNegotiationManager" >
+        <mvc:message-converters register-defaults="true">
+           <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter"/>
+<!-- <bean class="org.springframework.http.converter.protobuf.ProtobufHttpMessageConverter"/>         -->      
+  </mvc:message-converters>
+    </mvc:annotation-driven>
+    
+
+    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" />
+    <bean class="org.springframework.web.servlet.view.XmlViewResolver">
+        <property name="location">
+            <value>/WEB-INF/spring-views.xml</value>
+        </property>
+        <property name="order" value="0" />
+    </bean>
+
+    
+    <bean id="contentNegotiationManager"
+             class="org.springframework.web.accept.ContentNegotiationManagerFactoryBean">
+       <property name="defaultContentType" value="application/json" />
+  </bean>
+
+
+</beans>
+
+

spring-web-modules/spring-resttemplate-2/src/main/webapp/WEB-INF/spring-views.xml

@@ -0,0 +1,10 @@
+<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://www.springframework.org/schema/beans 
+	http://www.springframework.org/schema/beans/spring-beans-2.5.xsd"
+>
+
+    <bean id="RedirectedUrl" class="org.springframework.web.servlet.view.RedirectView">
+        <property name="url" value="redirectedUrl" />
+    </bean>
+
+</beans>

spring-web-modules/spring-resttemplate-2/src/test/java/com/baeldung/resttemplateexception/RestTemplateExceptionLiveTest.java

@@ -0,0 +1,47 @@
+package com.baeldung.resttemplateexception;
+
+import static org.junit.Assert.assertEquals;
+
+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.test.context.junit4.SpringRunner;
+import org.springframework.web.client.RestTemplate;
+import org.springframework.web.util.UriComponentsBuilder;
+
+import com.baeldung.resttemplateexception.model.Product;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest(classes = { RestTemplate.class, RestTemplateExceptionApplication.class })
+public class RestTemplateExceptionLiveTest {
+
+    @Autowired
+    RestTemplate restTemplate;
+
+    @Test(expected = IllegalArgumentException.class)
+    public void givenGetUrl_whenJsonIsPassed_thenThrowException() {
+        String url = "http://localhost:8080/spring-rest/api/get?criterion={\"prop\":\"name\",\"value\":\"ASUS VivoBook\"}";
+        Product product = restTemplate.getForObject(url, Product.class);
+    }
+
+    @Test
+    public void givenGetUrl_whenJsonIsPassed_thenGetProduct() {
+        String criterion = "{\"prop\":\"name\",\"value\":\"ASUS VivoBook\"}";
+        String url = "http://localhost:8080/spring-rest/api/get?criterion={criterion}";
+        Product product = restTemplate.getForObject(url, Product.class, criterion);
+
+        assertEquals(product.getPrice(), 650, 0);
+    }
+
+    @Test
+    public void givenGetUrl_whenJsonIsPassed_thenReturnProduct() {
+        String criterion = "{\"prop\":\"name\",\"value\":\"Acer Aspire 5\"}";
+        String url = "http://localhost:8080/spring-rest/api/get";
+
+        UriComponentsBuilder builder = UriComponentsBuilder.fromUriString(url).queryParam("criterion", criterion);
+        Product product = restTemplate.getForObject(builder.build().toUri(), Product.class);
+
+        assertEquals(product.getId(), 1, 0);
+    }
+}

spring-web-modules/spring-resttemplate/pom.xml

@@ -188,7 +188,7 @@
                 <artifactId>cargo-maven2-plugin</artifactId>
                 <version>${cargo-maven2-plugin.version}</version>
                 <configuration>
-                    <!--<wait>true</wait> caused errors on commit -->
+                    <wait>true</wait>
                     <container>
                         <containerId>tomcat8x</containerId>
                         <type>embedded</type>
@@ -297,7 +297,7 @@
         <guava.version>20.0</guava.version>
 
         <!-- Maven plugins -->
-        <cargo-maven2-plugin.version>1.6.0</cargo-maven2-plugin.version>
+        <cargo-maven2-plugin.version>1.6.1</cargo-maven2-plugin.version>
         <findbugs-maven-plugin.version>3.0.4</findbugs-maven-plugin.version>
 
         <!-- okhttp -->

spring-web-modules/spring-resttemplate/src/main/java/com/baeldung/mock/EmployeeService.java

@@ -1,4 +1,4 @@
-package com.baeldung.resttemplate.web.service;
+package com.baeldung.mock;
 
 import com.baeldung.resttemplate.web.model.Employee;
 import org.slf4j.Logger;

spring-web-modules/spring-resttemplate/src/test/java/com/baeldung/client/TestRestTemplateBasicLiveTest.java

@@ -18,6 +18,7 @@ import org.springframework.web.client.RestTemplate;
 import okhttp3.Request;
 import okhttp3.RequestBody;
 
+// This test needs RestTemplateConfigurationApplication to be up and running
 public class TestRestTemplateBasicLiveTest {
 
     private RestTemplate restTemplate;

spring-web-modules/spring-resttemplate/src/test/java/com/baeldung/mock/EmployeeServiceMockRestServiceServerUnitTest.java

@@ -1,4 +1,4 @@
-package com.baeldung.web.service;
+package com.baeldung.mock;
 
 import static org.springframework.test.web.client.match.MockRestRequestMatchers.method;
 import static org.springframework.test.web.client.match.MockRestRequestMatchers.requestTo;
@@ -7,8 +7,9 @@ import static org.springframework.test.web.client.response.MockRestResponseCreat
 import java.net.URI;
 
 import com.baeldung.SpringTestConfig;
+import com.baeldung.mock.EmployeeService;
 import com.baeldung.resttemplate.web.model.Employee;
-import com.baeldung.resttemplate.web.service.EmployeeService;
+
 import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;

spring-web-modules/spring-resttemplate/src/test/java/com/baeldung/mock/EmployeeServiceUnitTest.java

@@ -1,7 +1,8 @@
-package com.baeldung.web.service;
+package com.baeldung.mock;
 
+import com.baeldung.mock.EmployeeService;
 import com.baeldung.resttemplate.web.model.Employee;
-import com.baeldung.resttemplate.web.service.EmployeeService;
+
 import org.junit.Assert;
 import org.junit.Test;
 import org.junit.runner.RunWith;

spring-web-modules/spring-resttemplate/src/test/java/com/baeldung/resttemplate/RestTemplateBasicLiveTest.java

@@ -38,6 +38,7 @@ import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.dataformat.xml.XmlMapper;
 import com.google.common.base.Charsets;
 
+// This test needs RestTemplateConfigurationApplication to be up and running
 public class RestTemplateBasicLiveTest {
 
     private RestTemplate restTemplate;