Merge branch 'eugenp:master' into master

core-java-modules/core-java-11-2/README.md

@@ -8,3 +8,4 @@ This module contains articles about Java 11 core features
 - [Guide to Java 8’s Collectors](https://www.baeldung.com/java-8-collectors)
 - [New Features in Java 11](https://www.baeldung.com/java-11-new-features)
 - [Getting the Java Version at Runtime](https://www.baeldung.com/get-java-version-runtime)
+- [Invoking a SOAP Web Service in Java](https://www.baeldung.com/java-soap-web-service)

core-java-modules/core-java-16/README.md

@@ -2,3 +2,6 @@
 
 - [Collect a Java Stream to an Immutable Collection](https://www.baeldung.com/java-stream-immutable-collection)
 - [Guide to mapMulti in Stream API](https://www.baeldung.com/java-mapmulti)
+- [Collecting Stream Elements into a List in Java](https://www.baeldung.com/java-stream-to-list-collecting)
+- [New Features in Java 16](https://www.baeldung.com/java-16-new-features)
+- [Guide to Java 8 groupingBy Collector](https://www.baeldung.com/java-groupingby-collector)

core-java-modules/core-java-16/pom.xml

@@ -28,6 +28,18 @@
             <artifactId>commons-lang3</artifactId>
             <version>3.12.0</version>
         </dependency>
+		<dependency>
+			<groupId>org.junit.jupiter</groupId>
+			<artifactId>junit-jupiter-engine</artifactId>
+			<version>${junit-jupiter.version}</version>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.junit.jupiter</groupId>
+			<artifactId>junit-jupiter-api</artifactId>
+			<version>${junit-jupiter.version}</version>
+			<scope>test</scope>
+		</dependency>
     </dependencies>
 
     <build>
@@ -37,17 +49,38 @@
                 <artifactId>maven-compiler-plugin</artifactId>
                 <version>${maven-compiler-plugin.version}</version>
                 <configuration>
+                    <release>${maven.compiler.release}</release>
+					<compilerArgs>--enable-preview</compilerArgs>
                     <source>${maven.compiler.source.version}</source>
                     <target>${maven.compiler.target.version}</target>
                 </configuration>
             </plugin>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-surefire-plugin</artifactId>
+				<version>${surefire.plugin.version}</version>
+				<configuration>
+					<argLine>--enable-preview</argLine>
+					<forkCount>1</forkCount>
+				</configuration>
+				<dependencies>
+					<dependency>
+						<groupId>org.apache.maven.surefire</groupId>
+						<artifactId>surefire-api</artifactId>
+						<version>${surefire.plugin.version}</version>
+					</dependency>
+				</dependencies>
+			</plugin>
         </plugins>
     </build>
 
     <properties>
         <maven.compiler.source.version>16</maven.compiler.source.version>
         <maven.compiler.target.version>16</maven.compiler.target.version>
-        <assertj.version>3.6.1</assertj.version>
+		<maven.compiler.release>16</maven.compiler.release>
+		<maven-compiler-plugin.version>3.8.1</maven-compiler-plugin.version>
+		<surefire.plugin.version>3.0.0-M5</surefire.plugin.version>
+		<assertj.version>3.17.2</assertj.version>
     </properties>
 
 </project>

core-java-modules/core-java-16/src/main/java/com/baeldung/features/HelloWorld.java

@@ -0,0 +1,7 @@
+package com.baeldung.features;
+
+interface HelloWorld {
+    default String hello() {
+        return "world";
+    }
+}

core-java-modules/core-java-16/src/main/java/com/baeldung/features/OuterClass.java

@@ -0,0 +1,9 @@
+package com.baeldung.features;
+
+import com.baeldung.features.record.Book;
+
+public class OuterClass {
+    class InnerClass {
+        Book book = new Book("Title", "author", "isbn");
+    }
+}

core-java-modules/core-java-16/src/main/java/com/baeldung/features/VectorExample.java

@@ -0,0 +1,23 @@
+package com.baeldung.features;
+
+import jdk.incubator.vector.IntVector;
+
+public class VectorExample {
+    public int[] scalarComputation(int[] a, int[] b) {
+        var c = new int[a.length];
+        for (int i = 0; i < a.length; i++) {
+            c[i] = a[i] * b[i];
+        }
+        return c;
+    }
+
+    public int[] vectorComputation(int[] a, int[] b) {
+        var c = new int[a.length];
+
+        var vectorA = IntVector.fromArray(IntVector.SPECIES_128, a, 0);
+        var vectorB = IntVector.fromArray(IntVector.SPECIES_128, b, 0);
+        var vectorC = vectorA.mul(vectorB);
+        vectorC.intoArray(c, 0);
+        return c;
+    }
+}

core-java-modules/core-java-16/src/main/java/com/baeldung/features/model/Book.java

@@ -0,0 +1,44 @@
+package com.baeldung.features.model;
+
+import java.util.Objects;
+
+public final class Book {
+    private final String title;
+    private final String author;
+    private final String isbn;
+
+    public Book(String title, String author, String isbn) {
+        this.title = title;
+        this.author = author;
+        this.isbn = isbn;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public String getAuthor() {
+        return author;
+    }
+
+    public String getIsbn() {
+        return isbn;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        Book book = (Book) o;
+        return Objects.equals(title, book.title) && Objects.equals(author, book.author) && Objects.equals(isbn, book.isbn);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(title, author, isbn);
+    }
+}

core-java-modules/core-java-16/src/main/java/com/baeldung/features/record/Book.java

@@ -0,0 +1,4 @@
+package com.baeldung.features.record;
+
+public record Book(String title, String author, String isbn) {
+}

core-java-modules/core-java-16/src/main/java/com/baeldung/features/sealed/JungleAnimal.java

@@ -0,0 +1,4 @@
+package com.baeldung.features.sealed;
+
+public sealed interface JungleAnimal permits Monkey, Snake  {
+}

core-java-modules/core-java-16/src/main/java/com/baeldung/features/sealed/Monkey.java

@@ -0,0 +1,4 @@
+package com.baeldung.features.sealed;
+
+public final class Monkey implements JungleAnimal {
+}

core-java-modules/core-java-16/src/main/java/com/baeldung/features/sealed/Sealed.java

@@ -0,0 +1,13 @@
+package com.baeldung.features.sealed;
+
+public class Sealed {
+    public static void main(String... args) {
+        JungleAnimal j = new Monkey();
+
+        if (j instanceof Monkey m) {
+            // do logic
+        } else if (j instanceof Snake s) {
+            // do logic
+        }
+    }
+}

core-java-modules/core-java-16/src/main/java/com/baeldung/features/sealed/Snake.java

@@ -0,0 +1,4 @@
+package com.baeldung.features.sealed;
+
+public non-sealed class Snake implements JungleAnimal {
+}

core-java-modules/core-java-16/src/main/java/module-info.java

@@ -0,0 +1,4 @@
+module core.java {
+    requires jdk.incubator.vector;
+    requires org.apache.commons.lang3;
+}

core-java-modules/core-java-16/src/test/java/com/baeldung/features/DayPeriodSupportUnitTest.java

@@ -0,0 +1,24 @@
+package com.baeldung.features;
+
+import org.junit.jupiter.api.Test;
+
+import java.time.LocalTime;
+import java.time.format.DateTimeFormatter;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class DayPeriodSupportUnitTest {
+
+    @Test
+    public void givenASpecificTime_whenFormattingUsingTheBSymbol_thenExpectVerbosePeriodOfDay() {
+        LocalTime date = LocalTime.parse("15:25:08.690791");
+        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("h B");
+        assertThat(date.format(formatter)).isEqualTo("3 in the afternoon");
+
+        formatter = DateTimeFormatter.ofPattern("h BBBB");
+        assertThat(date.format(formatter)).isEqualTo("3 in the afternoon");
+
+        formatter = DateTimeFormatter.ofPattern("h BBBBB");
+        assertThat(date.format(formatter)).isEqualTo("3 in the afternoon");
+    }
+}

core-java-modules/core-java-16/src/test/java/com/baeldung/features/HelloWorldUnitTest.java

@@ -0,0 +1,28 @@
+package com.baeldung.features;
+
+
+import org.junit.jupiter.api.Test;
+
+import java.lang.reflect.InvocationHandler;
+import java.lang.reflect.Method;
+import java.lang.reflect.Proxy;
+
+import static java.lang.ClassLoader.getSystemClassLoader;
+import static org.assertj.core.api.Assertions.assertThat;
+
+class HelloWorldUnitTest {
+
+    @Test
+    public void givenAnInterfaceWithDefaulMethod_whenCreatingProxyInstance_thenCanInvokeDefaultMethod() throws Exception {
+        Object proxy = Proxy.newProxyInstance(getSystemClassLoader(), new Class<?>[] { HelloWorld.class },
+            (prox, method, args) -> {
+                if (method.isDefault()) {
+                    return InvocationHandler.invokeDefault(prox, method, args);
+                }
+                return method.invoke(prox, args);
+            }
+        );
+        Method method = proxy.getClass().getMethod("hello");
+        assertThat(method.invoke(proxy)).isEqualTo("world");
+    }
+}

core-java-modules/core-java-16/src/test/java/com/baeldung/features/InstanceOfPatternMatchingUnitTest.java

@@ -0,0 +1,18 @@
+package com.baeldung.features;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class InstanceOfPatternMatchingUnitTest {
+
+    @Test
+    void givenTheNewPatternMatchingAbility_whenComparingAgainstTheTradiationalApproach_thenBothVariablesAreEqual() {
+        Object obj = "TEST";
+
+        if (obj instanceof String a) {
+            String b = (String) obj;
+            assertThat(a).isEqualTo(b);
+        }
+    }
+}

core-java-modules/core-java-16/src/test/java/com/baeldung/features/StreamToListUnitTest.java

@@ -0,0 +1,20 @@
+package com.baeldung.features;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class StreamToListUnitTest {
+
+    @Test
+    void givenAStream_whenCreatingANewListFromStream_thenCollectorsOrInbuiltFunctionAreEquivalent() {
+        List<String> integersAsString = Arrays.asList("1", "2", "3");
+        List<Integer> ints = integersAsString.stream().map(Integer::parseInt).collect(Collectors.toList());
+        List<Integer> intsEquivalent = integersAsString.stream().map(Integer::parseInt).toList();
+        assertThat(ints).isEqualTo(intsEquivalent);
+    }
+}

core-java-modules/core-java-16/src/test/java/com/baeldung/features/VectorExampleUnitTest.java

@@ -0,0 +1,21 @@
+package com.baeldung.features;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
+
+class VectorExampleUnitTest {
+
+    @Test
+    void givenAScalarComputation_whenCalculatingUsingVectorAPI_thenResultIsSameAsPreviousMethodOfComputation() {
+        VectorExample objectUnderTest = new VectorExample();
+
+        int[] a = {1, 2, 3, 4};
+        int[] b = {5, 6, 7, 8};
+
+        int[] result = objectUnderTest.scalarComputation(a, b);
+        int[] result2 = objectUnderTest.vectorComputation(a, b);
+
+        assertArrayEquals(result, result2);
+    }
+}

core-java-modules/core-java-8-2/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-8-datetime-2/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-8-datetime/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-8/README.md

@@ -4,7 +4,6 @@ This module contains articles about Java 8 core features
 
 ### Relevant Articles: 
 - [New Features in Java 8](https://www.baeldung.com/java-8-new-features)
-- [Guide to Java 8 groupingBy Collector](https://www.baeldung.com/java-groupingby-collector)
 - [Strategy Design Pattern in Java 8](https://www.baeldung.com/java-strategy-pattern)
 - [Guide to Java 8 Comparator.comparing()](https://www.baeldung.com/java-8-comparator-comparing)
 - [Guide to the Java 8 forEach](https://www.baeldung.com/foreach-java)

core-java-modules/core-java-8/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-8/src/main/java/com/baeldung/java_8_features/groupingby/BlogPost.java

@@ -1,36 +0,0 @@
-package com.baeldung.java_8_features.groupingby;
-
-public class BlogPost {
-    private String title;
-    private String author;
-    private BlogPostType type;
-    private int likes;
-
-    public BlogPost(String title, String author, BlogPostType type, int likes) {
-        this.title = title;
-        this.author = author;
-        this.type = type;
-        this.likes = likes;
-    }
-
-    public String getTitle() {
-        return title;
-    }
-
-    public String getAuthor() {
-        return author;
-    }
-
-    public BlogPostType getType() {
-        return type;
-    }
-
-    public int getLikes() {
-        return likes;
-    }
-
-    @Override
-    public String toString() {
-        return "BlogPost{" + "title='" + title + '\'' + ", type=" + type + ", likes=" + likes + '}';
-    }
-}

core-java-modules/core-java-8/src/main/java/com/baeldung/java_8_features/groupingby/BlogPostType.java

@@ -1,5 +0,0 @@
-package com.baeldung.java_8_features.groupingby;
-
-public enum BlogPostType {
-    NEWS, REVIEW, GUIDE
-}

core-java-modules/core-java-8/src/main/java/com/baeldung/java_8_features/groupingby/Tuple.java

@@ -1,41 +0,0 @@
-package com.baeldung.java_8_features.groupingby;
-
-import java.util.Objects;
-
-public class Tuple {
-    private final BlogPostType type;
-    private final String author;
-
-    public Tuple(BlogPostType type, String author) {
-        this.type = type;
-        this.author = author;
-    }
-
-    public BlogPostType getType() {
-        return type;
-    }
-
-    public String getAuthor() {
-        return author;
-    }
-
-    @Override
-    public boolean equals(Object o) {
-        if (this == o)
-            return true;
-        if (o == null || getClass() != o.getClass())
-            return false;
-        Tuple tuple = (Tuple) o;
-        return type == tuple.type && author.equals(tuple.author);
-    }
-
-    @Override
-    public int hashCode() {
-        return Objects.hash(type, author);
-    }
-
-    @Override
-    public String toString() {
-        return "Tuple{" + "type=" + type + ", author='" + author + '\'' + '}';
-    }
-}

core-java-modules/core-java-8/src/test/java/com/baeldung/java_8_features/groupingby/Java8GroupingByCollectorUnitTest.java

@@ -1,215 +0,0 @@
-package com.baeldung.java_8_features.groupingby;
-
-import static java.util.Comparator.comparingInt;
-import static java.util.stream.Collectors.averagingInt;
-import static java.util.stream.Collectors.counting;
-import static java.util.stream.Collectors.groupingBy;
-import static java.util.stream.Collectors.groupingByConcurrent;
-import static java.util.stream.Collectors.joining;
-import static java.util.stream.Collectors.mapping;
-import static java.util.stream.Collectors.maxBy;
-import static java.util.stream.Collectors.summarizingInt;
-import static java.util.stream.Collectors.summingInt;
-import static java.util.stream.Collectors.toList;
-import static java.util.stream.Collectors.toSet;
-import static org.assertj.core.api.Assertions.assertThat;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNull;
-import static org.junit.Assert.assertTrue;
-
-import java.util.Arrays;
-import java.util.EnumMap;
-import java.util.IntSummaryStatistics;
-import java.util.List;
-import java.util.Map;
-import java.util.Optional;
-import java.util.Set;
-import java.util.concurrent.ConcurrentMap;
-
-import org.junit.Test;
-
-public class Java8GroupingByCollectorUnitTest {
-
-    private static final List<BlogPost> posts = Arrays.asList(new BlogPost("News item 1", "Author 1", BlogPostType.NEWS, 15), new BlogPost("Tech review 1", "Author 2", BlogPostType.REVIEW, 5),
-        new BlogPost("Programming guide", "Author 1", BlogPostType.GUIDE, 20), new BlogPost("News item 2", "Author 2", BlogPostType.NEWS, 35), new BlogPost("Tech review 2", "Author 1", BlogPostType.REVIEW, 15));
-
-    @Test
-    public void givenAListOfPosts_whenGroupedByType_thenGetAMapBetweenTypeAndPosts() {
-        Map<BlogPostType, List<BlogPost>> postsPerType = posts.stream()
-            .collect(groupingBy(BlogPost::getType));
-
-        assertEquals(2, postsPerType.get(BlogPostType.NEWS)
-            .size());
-        assertEquals(1, postsPerType.get(BlogPostType.GUIDE)
-            .size());
-        assertEquals(2, postsPerType.get(BlogPostType.REVIEW)
-            .size());
-    }
-
-    @Test
-    public void givenAListOfPosts_whenGroupedByTypeAndTheirTitlesAreJoinedInAString_thenGetAMapBetweenTypeAndCsvTitles() {
-        Map<BlogPostType, String> postsPerType = posts.stream()
-            .collect(groupingBy(BlogPost::getType, mapping(BlogPost::getTitle, joining(", ", "Post titles: [", "]"))));
-
-        assertEquals("Post titles: [News item 1, News item 2]", postsPerType.get(BlogPostType.NEWS));
-        assertEquals("Post titles: [Programming guide]", postsPerType.get(BlogPostType.GUIDE));
-        assertEquals("Post titles: [Tech review 1, Tech review 2]", postsPerType.get(BlogPostType.REVIEW));
-    }
-
-    @Test
-    public void givenAListOfPosts_whenGroupedByTypeAndSumTheLikes_thenGetAMapBetweenTypeAndPostLikes() {
-        Map<BlogPostType, Integer> likesPerType = posts.stream()
-            .collect(groupingBy(BlogPost::getType, summingInt(BlogPost::getLikes)));
-
-        assertEquals(50, likesPerType.get(BlogPostType.NEWS)
-            .intValue());
-        assertEquals(20, likesPerType.get(BlogPostType.REVIEW)
-            .intValue());
-        assertEquals(20, likesPerType.get(BlogPostType.GUIDE)
-            .intValue());
-    }
-
-    @Test
-    public void givenAListOfPosts_whenGroupedByTypeInAnEnumMap_thenGetAnEnumMapBetweenTypeAndPosts() {
-        EnumMap<BlogPostType, List<BlogPost>> postsPerType = posts.stream()
-            .collect(groupingBy(BlogPost::getType, () -> new EnumMap<>(BlogPostType.class), toList()));
-
-        assertEquals(2, postsPerType.get(BlogPostType.NEWS)
-            .size());
-        assertEquals(1, postsPerType.get(BlogPostType.GUIDE)
-            .size());
-        assertEquals(2, postsPerType.get(BlogPostType.REVIEW)
-            .size());
-    }
-
-    @Test
-    public void givenAListOfPosts_whenGroupedByTypeInSets_thenGetAMapBetweenTypesAndSetsOfPosts() {
-        Map<BlogPostType, Set<BlogPost>> postsPerType = posts.stream()
-            .collect(groupingBy(BlogPost::getType, toSet()));
-
-        assertEquals(2, postsPerType.get(BlogPostType.NEWS)
-            .size());
-        assertEquals(1, postsPerType.get(BlogPostType.GUIDE)
-            .size());
-        assertEquals(2, postsPerType.get(BlogPostType.REVIEW)
-            .size());
-    }
-
-    @Test
-    public void givenAListOfPosts_whenGroupedByTypeConcurrently_thenGetAMapBetweenTypeAndPosts() {
-        ConcurrentMap<BlogPostType, List<BlogPost>> postsPerType = posts.parallelStream()
-            .collect(groupingByConcurrent(BlogPost::getType));
-
-        assertEquals(2, postsPerType.get(BlogPostType.NEWS)
-            .size());
-        assertEquals(1, postsPerType.get(BlogPostType.GUIDE)
-            .size());
-        assertEquals(2, postsPerType.get(BlogPostType.REVIEW)
-            .size());
-    }
-
-    @Test
-    public void givenAListOfPosts_whenGroupedByTypeAndAveragingLikes_thenGetAMapBetweenTypeAndAverageNumberOfLikes() {
-        Map<BlogPostType, Double> averageLikesPerType = posts.stream()
-            .collect(groupingBy(BlogPost::getType, averagingInt(BlogPost::getLikes)));
-
-        assertEquals(25, averageLikesPerType.get(BlogPostType.NEWS)
-            .intValue());
-        assertEquals(20, averageLikesPerType.get(BlogPostType.GUIDE)
-            .intValue());
-        assertEquals(10, averageLikesPerType.get(BlogPostType.REVIEW)
-            .intValue());
-    }
-
-    @Test
-    public void givenAListOfPosts_whenGroupedByTypeAndCounted_thenGetAMapBetweenTypeAndNumberOfPosts() {
-        Map<BlogPostType, Long> numberOfPostsPerType = posts.stream()
-            .collect(groupingBy(BlogPost::getType, counting()));
-
-        assertEquals(2, numberOfPostsPerType.get(BlogPostType.NEWS)
-            .intValue());
-        assertEquals(1, numberOfPostsPerType.get(BlogPostType.GUIDE)
-            .intValue());
-        assertEquals(2, numberOfPostsPerType.get(BlogPostType.REVIEW)
-            .intValue());
-    }
-
-    @Test
-    public void givenAListOfPosts_whenGroupedByTypeAndMaxingLikes_thenGetAMapBetweenTypeAndMaximumNumberOfLikes() {
-        Map<BlogPostType, Optional<BlogPost>> maxLikesPerPostType = posts.stream()
-            .collect(groupingBy(BlogPost::getType, maxBy(comparingInt(BlogPost::getLikes))));
-
-        assertTrue(maxLikesPerPostType.get(BlogPostType.NEWS)
-            .isPresent());
-        assertEquals(35, maxLikesPerPostType.get(BlogPostType.NEWS)
-            .get()
-            .getLikes());
-
-        assertTrue(maxLikesPerPostType.get(BlogPostType.GUIDE)
-            .isPresent());
-        assertEquals(20, maxLikesPerPostType.get(BlogPostType.GUIDE)
-            .get()
-            .getLikes());
-
-        assertTrue(maxLikesPerPostType.get(BlogPostType.REVIEW)
-            .isPresent());
-        assertEquals(15, maxLikesPerPostType.get(BlogPostType.REVIEW)
-            .get()
-            .getLikes());
-    }
-
-    @Test
-    public void givenAListOfPosts_whenGroupedByAuthorAndThenByType_thenGetAMapBetweenAuthorAndMapsBetweenTypeAndBlogPosts() {
-        Map<String, Map<BlogPostType, List<BlogPost>>> map = posts.stream()
-            .collect(groupingBy(BlogPost::getAuthor, groupingBy(BlogPost::getType)));
-
-        assertEquals(1, map.get("Author 1")
-            .get(BlogPostType.NEWS)
-            .size());
-        assertEquals(1, map.get("Author 1")
-            .get(BlogPostType.GUIDE)
-            .size());
-        assertEquals(1, map.get("Author 1")
-            .get(BlogPostType.REVIEW)
-            .size());
-
-        assertEquals(1, map.get("Author 2")
-            .get(BlogPostType.NEWS)
-            .size());
-        assertEquals(1, map.get("Author 2")
-            .get(BlogPostType.REVIEW)
-            .size());
-        assertNull(map.get("Author 2")
-            .get(BlogPostType.GUIDE));
-    }
-
-    @Test
-    public void givenAListOfPosts_whenGroupedByTypeAndSummarizingLikes_thenGetAMapBetweenTypeAndSummary() {
-        Map<BlogPostType, IntSummaryStatistics> likeStatisticsPerType = posts.stream()
-            .collect(groupingBy(BlogPost::getType, summarizingInt(BlogPost::getLikes)));
-
-        IntSummaryStatistics newsLikeStatistics = likeStatisticsPerType.get(BlogPostType.NEWS);
-
-        assertEquals(2, newsLikeStatistics.getCount());
-        assertEquals(50, newsLikeStatistics.getSum());
-        assertEquals(25.0, newsLikeStatistics.getAverage(), 0.001);
-        assertEquals(35, newsLikeStatistics.getMax());
-        assertEquals(15, newsLikeStatistics.getMin());
-    }
-
-    @Test
-    public void givenAListOfPosts_whenGroupedByComplexMapKeyType_thenGetAMapBetweenTupleAndList() {
-        Map<Tuple, List<BlogPost>> postsPerTypeAndAuthor = posts.stream()
-            .collect(groupingBy(post -> new Tuple(post.getType(), post.getAuthor())));
-
-        List<BlogPost> result = postsPerTypeAndAuthor.get(new Tuple(BlogPostType.GUIDE, "Author 1"));
-
-        assertThat(result.size()).isEqualTo(1);
-
-        BlogPost blogPost = result.get(0);
-
-        assertThat(blogPost.getTitle()).isEqualTo("Programming guide");
-        assertThat(blogPost.getType()).isEqualTo(BlogPostType.GUIDE);
-        assertThat(blogPost.getAuthor()).isEqualTo("Author 1");
-    }
-}

core-java-modules/core-java-9-new-features/README.md

@@ -6,7 +6,6 @@ This module contains articles about core Java features that have been introduced
 
 - [New Features in Java 9](https://www.baeldung.com/new-java-9)
 - [Java 9 Variable Handles Demystified](http://www.baeldung.com/java-variable-handles)
-- [Exploring the New HTTP Client in Java 9 and 11](http://www.baeldung.com/java-9-http-client)
 - [Multi-Release Jar Files](https://www.baeldung.com/java-multi-release-jar)
 - [Ahead of Time Compilation (AoT)](https://www.baeldung.com/ahead-of-time-compilation)
 - [Introduction to Java 9 StackWalking API](https://www.baeldung.com/java-9-stackwalking-api)

core-java-modules/core-java-9-new-features/src/modules/com.baeldung.httpclient/com/baeldung/httpclient/HttpClientExample.java

@@ -1,84 +0,0 @@
-/*
- * To change this license header, choose License Headers in Project Properties.
- * To change this template file, choose Tools | Templates
- * and open the template in the editor.
- */
-package com.baeldung.httpclient;
-
-import java.io.File;
-import java.io.IOException;
-import java.net.URI;
-import java.net.URISyntaxException;
-import java.nio.file.Paths;
-import java.util.Arrays;
-import java.util.List;
-import java.util.concurrent.CompletableFuture;
-import java.util.stream.Collectors;
-import jdk.incubator.http.HttpClient;
-import jdk.incubator.http.HttpRequest;
-import jdk.incubator.http.HttpRequest.BodyProcessor;
-import jdk.incubator.http.HttpResponse;
-import jdk.incubator.http.HttpResponse.BodyHandler;
-
-/**
- *
- * @author pkaria
- */
-public class HttpClientExample {
-    
-    public static void main(String[] args) throws Exception {
-        httpGetRequest();
-        httpPostRequest();
-        asynchronousRequest();
-        asynchronousMultipleRequests();
-    }
-
-    public static void httpGetRequest() throws URISyntaxException, IOException, InterruptedException {
-        HttpClient client = HttpClient.newHttpClient();
-        URI httpURI = new URI("http://jsonplaceholder.typicode.com/posts/1");
-        HttpRequest request = HttpRequest.newBuilder(httpURI).GET()
-          .headers("Accept-Enconding", "gzip, deflate").build();
-        HttpResponse<String> response = client.send(request, HttpResponse.BodyHandler.asString());
-        String responseBody = response.body();
-        int responseStatusCode = response.statusCode();
-        System.out.println(responseBody);
-    }
-
-    public static void httpPostRequest() throws URISyntaxException, IOException, InterruptedException {
-        HttpClient client = HttpClient
-                .newBuilder()
-                .build();
-        HttpRequest request = HttpRequest
-                .newBuilder(new URI("http://jsonplaceholder.typicode.com/posts"))
-                .POST(BodyProcessor.fromString("Sample Post Request"))
-                .build();
-        HttpResponse<String> response
-                = client.send(request, HttpResponse.BodyHandler.asString());
-        String responseBody = response.body();
-        System.out.println(responseBody);
-    }
-
-    public static void asynchronousRequest() throws URISyntaxException {
-        HttpClient client = HttpClient.newHttpClient();
-        URI httpURI = new URI("http://jsonplaceholder.typicode.com/posts/1");
-        HttpRequest request = HttpRequest.newBuilder(httpURI).GET().build();
-        CompletableFuture<HttpResponse<String>> futureResponse = client.sendAsync(request,
-                HttpResponse.BodyHandler.asString());
-    }
-
-    public static void asynchronousMultipleRequests() throws URISyntaxException {
-        List<URI> targets = Arrays.asList(new URI("http://jsonplaceholder.typicode.com/posts/1"), new URI("http://jsonplaceholder.typicode.com/posts/2"));
-        HttpClient client = HttpClient.newHttpClient();
-        List<CompletableFuture<File>> futures = targets
-                .stream()
-                .map(target -> client
-                .sendAsync(
-                        HttpRequest.newBuilder(target)
-                                .GET()
-                                .build(),
-                        BodyHandler.asFile(Paths.get("base", target.getPath())))
-                .thenApply(response -> response.body())
-                .thenApply(path -> path.toFile()))
-                .collect(Collectors.toList());
-    }
-}

core-java-modules/core-java-9-new-features/src/modules/com.baeldung.httpclient/module-info.java

@@ -1,3 +0,0 @@
-module com.baeldung.httpclient {   
-	requires jdk.incubator.httpclient;
-}

core-java-modules/core-java-9-new-features/src/test/java/com/baeldung/java9/httpclient/HttpClientIntegrationTest.java

@@ -1,218 +0,0 @@
-package com.baeldung.java9.httpclient;
-
-import jdk.incubator.http.HttpClient;
-import jdk.incubator.http.HttpRequest;
-import jdk.incubator.http.HttpResponse;
-import org.junit.Test;
-
-import java.io.IOException;
-import java.net.*;
-import java.util.Arrays;
-import java.util.List;
-import java.util.concurrent.CompletableFuture;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Executors;
-import java.util.stream.Collectors;
-
-import static org.hamcrest.CoreMatchers.containsString;
-import static org.hamcrest.CoreMatchers.equalTo;
-import static org.hamcrest.collection.IsEmptyCollection.empty;
-import static org.hamcrest.core.IsNot.not;
-import static org.junit.Assert.assertThat;
-
-/**
- * Created by adam.
- */
-public class HttpClientIntegrationTest {
-
-    @Test
-    public void shouldReturnSampleDataContentWhenConnectViaSystemProxy() throws IOException, InterruptedException, URISyntaxException {
-        HttpRequest request = HttpRequest.newBuilder()
-            .uri(new URI("https://postman-echo.com/post"))
-            .headers("Content-Type", "text/plain;charset=UTF-8")
-            .POST(HttpRequest.BodyProcessor.fromString("Sample body"))
-            .build();
-
-        HttpResponse<String> response = HttpClient.newBuilder()
-            .proxy(ProxySelector.getDefault())
-            .build()
-            .send(request, HttpResponse.BodyHandler.asString());
-
-        assertThat(response.statusCode(), equalTo(HttpURLConnection.HTTP_OK));
-        assertThat(response.body(), containsString("Sample body"));
-    }
-
-    @Test
-    public void shouldNotFollowRedirectWhenSetToDefaultNever() throws IOException, InterruptedException, URISyntaxException {
-        HttpRequest request = HttpRequest.newBuilder()
-            .uri(new URI("http://stackoverflow.com"))
-            .version(HttpClient.Version.HTTP_1_1)
-            .GET()
-            .build();
-        HttpResponse<String> response = HttpClient.newBuilder()
-            .build()
-            .send(request, HttpResponse.BodyHandler.asString());
-
-        assertThat(response.statusCode(), equalTo(HttpURLConnection.HTTP_MOVED_PERM));
-        assertThat(response.body(), containsString(""));
-    }
-
-    @Test
-    public void shouldFollowRedirectWhenSetToAlways() throws IOException, InterruptedException, URISyntaxException {
-        HttpRequest request = HttpRequest.newBuilder()
-            .uri(new URI("http://stackoverflow.com"))
-            .version(HttpClient.Version.HTTP_1_1)
-            .GET()
-            .build();
-        HttpResponse<String> response = HttpClient.newBuilder()
-            .followRedirects(HttpClient.Redirect.ALWAYS)
-            .build()
-            .send(request, HttpResponse.BodyHandler.asString());
-
-        assertThat(response.statusCode(), equalTo(HttpURLConnection.HTTP_OK));
-        assertThat(response.finalRequest()
-            .uri()
-            .toString(), equalTo("https://stackoverflow.com/"));
-    }
-
-    @Test
-    public void shouldReturnOKStatusForAuthenticatedAccess() throws URISyntaxException, IOException, InterruptedException {
-        HttpRequest request = HttpRequest.newBuilder()
-            .uri(new URI("https://postman-echo.com/basic-auth"))
-            .GET()
-            .build();
-        HttpResponse<String> response = HttpClient.newBuilder()
-            .authenticator(new Authenticator() {
-                @Override
-                protected PasswordAuthentication getPasswordAuthentication() {
-                    return new PasswordAuthentication("postman", "password".toCharArray());
-                }
-            })
-            .build()
-            .send(request, HttpResponse.BodyHandler.asString());
-
-        assertThat(response.statusCode(), equalTo(HttpURLConnection.HTTP_OK));
-    }
-
-    @Test
-    public void shouldSendRequestAsync() throws URISyntaxException, InterruptedException, ExecutionException {
-        HttpRequest request = HttpRequest.newBuilder()
-            .uri(new URI("https://postman-echo.com/post"))
-            .headers("Content-Type", "text/plain;charset=UTF-8")
-            .POST(HttpRequest.BodyProcessor.fromString("Sample body"))
-            .build();
-        CompletableFuture<HttpResponse<String>> response = HttpClient.newBuilder()
-            .build()
-            .sendAsync(request, HttpResponse.BodyHandler.asString());
-
-        assertThat(response.get()
-            .statusCode(), equalTo(HttpURLConnection.HTTP_OK));
-    }
-
-    @Test
-    public void shouldUseJustTwoThreadWhenProcessingSendAsyncRequest() throws URISyntaxException, InterruptedException, ExecutionException {
-        HttpRequest request = HttpRequest.newBuilder()
-            .uri(new URI("https://postman-echo.com/get"))
-            .GET()
-            .build();
-
-        ExecutorService executorService = Executors.newFixedThreadPool(2);
-
-        CompletableFuture<HttpResponse<String>> response1 = HttpClient.newBuilder()
-            .executor(executorService)
-            .build()
-            .sendAsync(request, HttpResponse.BodyHandler.asString());
-
-        CompletableFuture<HttpResponse<String>> response2 = HttpClient.newBuilder()
-            .executor(executorService)
-            .build()
-            .sendAsync(request, HttpResponse.BodyHandler.asString());
-
-        CompletableFuture<HttpResponse<String>> response3 = HttpClient.newBuilder()
-            .executor(executorService)
-            .build()
-            .sendAsync(request, HttpResponse.BodyHandler.asString());
-
-        CompletableFuture.allOf(response1, response2, response3)
-            .join();
-
-        assertThat(response1.get()
-            .statusCode(), equalTo(HttpURLConnection.HTTP_OK));
-        assertThat(response2.get()
-            .statusCode(), equalTo(HttpURLConnection.HTTP_OK));
-        assertThat(response3.get()
-            .statusCode(), equalTo(HttpURLConnection.HTTP_OK));
-    }
-
-    @Test
-    public void shouldNotStoreCookieWhenPolicyAcceptNone() throws URISyntaxException, IOException, InterruptedException {
-        HttpRequest request = HttpRequest.newBuilder()
-            .uri(new URI("https://postman-echo.com/get"))
-            .GET()
-            .build();
-
-        HttpClient httpClient = HttpClient.newBuilder()
-            .cookieManager(new CookieManager(null, CookiePolicy.ACCEPT_NONE))
-            .build();
-
-        httpClient.send(request, HttpResponse.BodyHandler.asString());
-
-        assertThat(httpClient.cookieManager()
-            .get()
-            .getCookieStore()
-            .getCookies(), empty());
-    }
-
-    @Test
-    public void shouldStoreCookieWhenPolicyAcceptAll() throws URISyntaxException, IOException, InterruptedException {
-        HttpRequest request = HttpRequest.newBuilder()
-            .uri(new URI("https://postman-echo.com/get"))
-            .GET()
-            .build();
-
-        HttpClient httpClient = HttpClient.newBuilder()
-            .cookieManager(new CookieManager(null, CookiePolicy.ACCEPT_ALL))
-            .build();
-
-        httpClient.send(request, HttpResponse.BodyHandler.asString());
-
-        assertThat(httpClient.cookieManager()
-            .get()
-            .getCookieStore()
-            .getCookies(), not(empty()));
-    }
-
-    @Test
-    public void shouldProcessMultipleRequestViaStream() throws URISyntaxException, ExecutionException, InterruptedException {
-        List<URI> targets = Arrays.asList(new URI("https://postman-echo.com/get?foo1=bar1"), new URI("https://postman-echo.com/get?foo2=bar2"));
-
-        HttpClient client = HttpClient.newHttpClient();
-
-        List<CompletableFuture<String>> futures = targets.stream()
-            .map(target -> client.sendAsync(HttpRequest.newBuilder(target)
-                .GET()
-                .build(), HttpResponse.BodyHandler.asString())
-                .thenApply(response -> response.body()))
-            .collect(Collectors.toList());
-
-        CompletableFuture.allOf(futures.toArray(new CompletableFuture[0]))
-            .join();
-
-        if (futures.get(0)
-            .get()
-            .contains("foo1")) {
-            assertThat(futures.get(0)
-                .get(), containsString("bar1"));
-            assertThat(futures.get(1)
-                .get(), containsString("bar2"));
-        } else {
-            assertThat(futures.get(1)
-                .get(), containsString("bar2"));
-            assertThat(futures.get(1)
-                .get(), containsString("bar1"));
-        }
-
-    }
-
-}

core-java-modules/core-java-9-new-features/src/test/java/com/baeldung/java9/httpclient/HttpRequestIntegrationTest.java

@@ -1,171 +0,0 @@
-package com.baeldung.java9.httpclient;
-
-import jdk.incubator.http.HttpClient;
-import jdk.incubator.http.HttpRequest;
-import jdk.incubator.http.HttpResponse;
-import org.junit.Test;
-
-import java.io.ByteArrayInputStream;
-import java.io.IOException;
-import java.net.HttpURLConnection;
-import java.net.URI;
-import java.net.URISyntaxException;
-import java.nio.file.Paths;
-import java.security.NoSuchAlgorithmException;
-import java.time.Duration;
-
-import static java.time.temporal.ChronoUnit.SECONDS;
-import static org.hamcrest.CoreMatchers.containsString;
-import static org.hamcrest.CoreMatchers.equalTo;
-import static org.junit.Assert.assertThat;
-
-/**
- * Created by adam.
- */
-public class HttpRequestIntegrationTest {
-
-    @Test
-    public void shouldReturnStatusOKWhenSendGetRequest() throws IOException, InterruptedException, URISyntaxException {
-        HttpRequest request = HttpRequest.newBuilder()
-            .uri(new URI("https://postman-echo.com/get"))
-            .GET()
-            .build();
-
-        HttpResponse<String> response = HttpClient.newHttpClient()
-            .send(request, HttpResponse.BodyHandler.asString());
-
-        assertThat(response.statusCode(), equalTo(HttpURLConnection.HTTP_OK));
-    }
-
-    @Test
-    public void shouldUseHttp2WhenWebsiteUsesHttp2() throws IOException, InterruptedException, URISyntaxException {
-        HttpRequest request = HttpRequest.newBuilder()
-            .uri(new URI("https://stackoverflow.com"))
-            .version(HttpClient.Version.HTTP_2)
-            .GET()
-            .build();
-        HttpResponse<String> response = HttpClient.newHttpClient()
-            .send(request, HttpResponse.BodyHandler.asString());
-
-        assertThat(response.statusCode(), equalTo(HttpURLConnection.HTTP_OK));
-        assertThat(response.version(), equalTo(HttpClient.Version.HTTP_2));
-    }
-
-    @Test
-    public void shouldFallbackToHttp1_1WhenWebsiteDoesNotUseHttp2() throws IOException, InterruptedException, URISyntaxException, NoSuchAlgorithmException {
-        HttpRequest request = HttpRequest.newBuilder()
-            .uri(new URI("https://postman-echo.com/get"))
-            .version(HttpClient.Version.HTTP_2)
-            .GET()
-            .build();
-
-        HttpResponse<String> response = HttpClient.newHttpClient()
-            .send(request, HttpResponse.BodyHandler.asString());
-
-        assertThat(response.version(), equalTo(HttpClient.Version.HTTP_1_1));
-    }
-
-    @Test
-    public void shouldReturnStatusOKWhenSendGetRequestWithDummyHeaders() throws IOException, InterruptedException, URISyntaxException {
-        HttpRequest request = HttpRequest.newBuilder()
-            .uri(new URI("https://postman-echo.com/get"))
-            .headers("key1", "value1", "key2", "value2")
-            .GET()
-            .build();
-
-        HttpResponse<String> response = HttpClient.newHttpClient()
-            .send(request, HttpResponse.BodyHandler.asString());
-
-        assertThat(response.statusCode(), equalTo(HttpURLConnection.HTTP_OK));
-    }
-
-    @Test
-    public void shouldReturnStatusOKWhenSendGetRequestTimeoutSet() throws IOException, InterruptedException, URISyntaxException {
-        HttpRequest request = HttpRequest.newBuilder()
-            .uri(new URI("https://postman-echo.com/get"))
-            .timeout(Duration.of(10, SECONDS))
-            .GET()
-            .build();
-
-        HttpResponse<String> response = HttpClient.newHttpClient()
-            .send(request, HttpResponse.BodyHandler.asString());
-
-        assertThat(response.statusCode(), equalTo(HttpURLConnection.HTTP_OK));
-    }
-
-    @Test
-    public void shouldReturnNoContentWhenPostWithNoBody() throws IOException, InterruptedException, URISyntaxException {
-        HttpRequest request = HttpRequest.newBuilder()
-            .uri(new URI("https://postman-echo.com/post"))
-            .POST(HttpRequest.noBody())
-            .build();
-
-        HttpResponse<String> response = HttpClient.newHttpClient()
-            .send(request, HttpResponse.BodyHandler.asString());
-
-        assertThat(response.statusCode(), equalTo(HttpURLConnection.HTTP_OK));
-    }
-
-    @Test
-    public void shouldReturnSampleDataContentWhenPostWithBodyText() throws IOException, InterruptedException, URISyntaxException {
-        HttpRequest request = HttpRequest.newBuilder()
-            .uri(new URI("https://postman-echo.com/post"))
-            .headers("Content-Type", "text/plain;charset=UTF-8")
-            .POST(HttpRequest.BodyProcessor.fromString("Sample request body"))
-            .build();
-
-        HttpResponse<String> response = HttpClient.newHttpClient()
-            .send(request, HttpResponse.BodyHandler.asString());
-
-        assertThat(response.statusCode(), equalTo(HttpURLConnection.HTTP_OK));
-        assertThat(response.body(), containsString("Sample request body"));
-    }
-
-    @Test
-    public void shouldReturnSampleDataContentWhenPostWithInputStream() throws IOException, InterruptedException, URISyntaxException {
-        byte[] sampleData = "Sample request body".getBytes();
-        HttpRequest request = HttpRequest.newBuilder()
-            .uri(new URI("https://postman-echo.com/post"))
-            .headers("Content-Type", "text/plain;charset=UTF-8")
-            .POST(HttpRequest.BodyProcessor.fromInputStream(() -> new ByteArrayInputStream(sampleData)))
-            .build();
-
-        HttpResponse<String> response = HttpClient.newHttpClient()
-            .send(request, HttpResponse.BodyHandler.asString());
-
-        assertThat(response.statusCode(), equalTo(HttpURLConnection.HTTP_OK));
-        assertThat(response.body(), containsString("Sample request body"));
-    }
-
-    @Test
-    public void shouldReturnSampleDataContentWhenPostWithByteArrayProcessorStream() throws IOException, InterruptedException, URISyntaxException {
-        byte[] sampleData = "Sample request body".getBytes();
-        HttpRequest request = HttpRequest.newBuilder()
-            .uri(new URI("https://postman-echo.com/post"))
-            .headers("Content-Type", "text/plain;charset=UTF-8")
-            .POST(HttpRequest.BodyProcessor.fromByteArray(sampleData))
-            .build();
-
-        HttpResponse<String> response = HttpClient.newHttpClient()
-            .send(request, HttpResponse.BodyHandler.asString());
-
-        assertThat(response.statusCode(), equalTo(HttpURLConnection.HTTP_OK));
-        assertThat(response.body(), containsString("Sample request body"));
-    }
-
-    @Test
-    public void shouldReturnSampleDataContentWhenPostWithFileProcessorStream() throws IOException, InterruptedException, URISyntaxException {
-        HttpRequest request = HttpRequest.newBuilder()
-            .uri(new URI("https://postman-echo.com/post"))
-            .headers("Content-Type", "text/plain;charset=UTF-8")
-            .POST(HttpRequest.BodyProcessor.fromFile(Paths.get("src/test/resources/sample.txt")))
-            .build();
-
-        HttpResponse<String> response = HttpClient.newHttpClient()
-            .send(request, HttpResponse.BodyHandler.asString());
-
-        assertThat(response.statusCode(), equalTo(HttpURLConnection.HTTP_OK));
-        assertThat(response.body(), containsString("Sample file content"));
-    }
-
-}

core-java-modules/core-java-9-new-features/src/test/java/com/baeldung/java9/httpclient/HttpResponseIntegrationTest.java

@@ -1,55 +0,0 @@
-package com.baeldung.java9.httpclient;
-
-import jdk.incubator.http.HttpClient;
-import jdk.incubator.http.HttpRequest;
-import jdk.incubator.http.HttpResponse;
-import org.junit.Test;
-
-import java.io.IOException;
-import java.net.HttpURLConnection;
-import java.net.URI;
-import java.net.URISyntaxException;
-
-import static org.hamcrest.CoreMatchers.equalTo;
-import static org.hamcrest.Matchers.isEmptyString;
-import static org.hamcrest.core.IsNot.not;
-import static org.junit.Assert.assertThat;
-
-/**
- * Created by adam.
- */
-public class HttpResponseIntegrationTest {
-
-    @Test
-    public void shouldReturnStatusOKWhenSendGetRequest() throws IOException, InterruptedException, URISyntaxException {
-        HttpRequest request = HttpRequest.newBuilder()
-            .uri(new URI("https://postman-echo.com/get"))
-            .GET()
-            .build();
-
-        HttpResponse<String> response = HttpClient.newHttpClient()
-            .send(request, HttpResponse.BodyHandler.asString());
-
-        assertThat(response.statusCode(), equalTo(HttpURLConnection.HTTP_OK));
-        assertThat(response.body(), not(isEmptyString()));
-    }
-
-    @Test
-    public void shouldResponseURIDifferentThanRequestUIRWhenRedirect() throws IOException, InterruptedException, URISyntaxException {
-        HttpRequest request = HttpRequest.newBuilder()
-            .uri(new URI("http://stackoverflow.com"))
-            .version(HttpClient.Version.HTTP_1_1)
-            .GET()
-            .build();
-        HttpResponse<String> response = HttpClient.newBuilder()
-            .followRedirects(HttpClient.Redirect.ALWAYS)
-            .build()
-            .send(request, HttpResponse.BodyHandler.asString());
-
-        assertThat(request.uri()
-            .toString(), equalTo("http://stackoverflow.com"));
-        assertThat(response.uri()
-            .toString(), equalTo("https://stackoverflow.com/"));
-    }
-
-}

core-java-modules/core-java-annotations/pom.xml

@@ -1,7 +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">
+         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>core-java-annotations</artifactId>
     <version>0.1.0-SNAPSHOT</version>
@@ -12,9 +12,21 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
+    <dependencies>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${assertj-core.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <properties>
+        <assertj-core.version>3.10.0</assertj-core.version>
+    </properties>
+
     <build>
         <finalName>core-java-annotations</finalName>
         <resources>

core-java-modules/core-java-annotations/src/main/java/com/baeldung/readannotations/ClassWithAnnotations.java

@@ -0,0 +1,9 @@
+package com.baeldung.readannotations;
+
+public class ClassWithAnnotations {
+
+    @FirstAnnotation
+    @SecondAnnotation
+    @ThirdAnnotation
+    private String classMember;
+}

core-java-modules/core-java-annotations/src/main/java/com/baeldung/readannotations/FirstAnnotation.java

@@ -0,0 +1,8 @@
+package com.baeldung.readannotations;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+@Retention(RetentionPolicy.RUNTIME)
+public @interface FirstAnnotation {
+}

core-java-modules/core-java-annotations/src/main/java/com/baeldung/readannotations/SecondAnnotation.java

@@ -0,0 +1,8 @@
+package com.baeldung.readannotations;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+@Retention(RetentionPolicy.RUNTIME)
+public @interface SecondAnnotation {
+}

core-java-modules/core-java-annotations/src/main/java/com/baeldung/readannotations/ThirdAnnotation.java

@@ -0,0 +1,8 @@
+package com.baeldung.readannotations;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+@Retention(RetentionPolicy.SOURCE)
+public @interface ThirdAnnotation {
+}

core-java-modules/core-java-annotations/src/test/java/com/baeldung/readannotations/ClassWithAnnotationsUnitTest.java

@@ -0,0 +1,34 @@
+package com.baeldung.readannotations;
+
+import org.junit.Test;
+
+import java.lang.annotation.Annotation;
+import java.lang.reflect.Field;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class ClassWithAnnotationsUnitTest {
+
+    @Test
+    public void whenCallingGetDeclaredAnnotations_thenOnlyRuntimeAnnotationsAreAvailable() throws NoSuchFieldException {
+        Field classMemberField = ClassWithAnnotations.class.getDeclaredField("classMember");
+        Annotation[] annotations = classMemberField.getDeclaredAnnotations();
+        assertThat(annotations).hasSize(2);
+    }
+
+    @Test
+    public void whenCallingIsAnnotationPresent_thenOnlyRuntimeAnnotationsAreAvailable() throws NoSuchFieldException {
+        Field classMemberField = ClassWithAnnotations.class.getDeclaredField("classMember");
+        assertThat(classMemberField.isAnnotationPresent(FirstAnnotation.class)).isTrue();
+        assertThat(classMemberField.isAnnotationPresent(SecondAnnotation.class)).isTrue();
+        assertThat(classMemberField.isAnnotationPresent(ThirdAnnotation.class)).isFalse();
+    }
+
+    @Test
+    public void whenCallingGetDeclaredAnnotationsOrGetAnnotations_thenSameAnnotationsAreReturned() throws NoSuchFieldException {
+        Field classMemberField = ClassWithAnnotations.class.getDeclaredField("classMember");
+        Annotation[] declaredAnnotations = classMemberField.getDeclaredAnnotations();
+        Annotation[] annotations = classMemberField.getAnnotations();
+        assertThat(declaredAnnotations).containsExactly(annotations);
+    }
+}

core-java-modules/core-java-arrays-sorting/pom.xml

@@ -11,7 +11,6 @@
         <artifactId>core-java-modules</artifactId>
         <groupId>com.baeldung.core-java-modules</groupId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-char/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-collections-2/pom.xml

@@ -11,7 +11,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-collections-3/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-collections-4/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../pom.xml</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-collections-array-list/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-collections-list-2/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-collections-list-3/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-collections-list/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-collections-maps-2/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-collections-maps-3/README.md

@@ -8,5 +8,5 @@ This module contains articles about Map data structures in Java.
 - [The Map.computeIfAbsent() Method](https://www.baeldung.com/java-map-computeifabsent)
 - [Collections.synchronizedMap vs. ConcurrentHashMap](https://www.baeldung.com/java-synchronizedmap-vs-concurrenthashmap)
 - [Java HashMap Load Factor](https://www.baeldung.com/java-hashmap-load-factor)
-- [Converting java.util.Properties to HashMap](https://www.baeldung.com/java-convert-properties-to-hashmap)
+- [Converting Java Properties to HashMap](https://www.baeldung.com/java-convert-properties-to-hashmap)
 - More articles: [[<-- prev]](/core-java-modules/core-java-collections-maps-2)

core-java-modules/core-java-collections-maps-3/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-collections-maps-3/src/main/java/com/baeldung/map/hashmap/entryremoval/RemoveEntryApplication.java

@@ -0,0 +1,74 @@
+package com.baeldung.map.hashmap.entryremoval;
+
+import java.util.ConcurrentModificationException;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.Map.Entry;
+import java.util.concurrent.ConcurrentHashMap;
+
+public class RemoveEntryApplication {
+
+    public static void main(String[] args) {
+
+        HashMap<String, String> foodItemTypeMap = new HashMap<>();
+        foodItemTypeMap.put("Apple", "Fruit");
+        foodItemTypeMap.put("Grape", "Fruit");
+        foodItemTypeMap.put("Mango", "Fruit");
+        foodItemTypeMap.put("Carrot", "Vegetable");
+        foodItemTypeMap.put("Potato", "Vegetable");
+        foodItemTypeMap.put("Spinach", "Vegetable");
+        // Current Map Status: {Potato=Vegetable, Apple=Fruit, Carrot=Vegetable, Grape=Fruit, Mango=Fruit, Spinach=Vegetable}
+
+        foodItemTypeMap.remove("Apple");
+        // Current Map Status: {Potato=Vegetable, Carrot=Vegetable, Grape=Fruit, Mango=Fruit, Spinach=Vegetable}
+
+        foodItemTypeMap.remove("Grape", "Vegetable");
+        // Current Map Status: {Potato=Vegetable, Carrot=Vegetable, Grape=Fruit, Mango=Fruit, Spinach=Vegetable}
+
+        try {
+            for (Entry<String, String> item : foodItemTypeMap.entrySet()) {
+                if (item.getKey()
+                    .equals("Potato")) {
+                    foodItemTypeMap.remove(item.getKey());
+                }
+            }
+        } catch (ConcurrentModificationException e) {
+            System.out.println("Exception occured while updating map: " + e.toString());
+        }
+
+        foodItemTypeMap.entrySet()
+            .removeIf(entry -> entry.getKey()
+                .equals("Grape"));
+        // Current Map Status: {Carrot=Vegetable, Mango=Fruit, Spinach=Vegetable}
+
+        Iterator<Entry<String, String>> iterator = foodItemTypeMap.entrySet()
+            .iterator();
+        while (iterator.hasNext()) {
+            if (iterator.next()
+                .getKey()
+                .equals("Carrot"))
+                iterator.remove();
+        }
+        // Current Map Status: {Mango=Fruit, Spinach=Vegetable}
+
+        // Use ConcurrentHashMap
+        ConcurrentHashMap<String, String> foodItemTypeConcMap = new ConcurrentHashMap<>();
+        foodItemTypeConcMap.put("Apple", "Fruit");
+        foodItemTypeConcMap.put("Grape", "Fruit");
+        foodItemTypeConcMap.put("Mango", "Fruit");
+        foodItemTypeConcMap.put("Carrot", "Vegetable");
+        foodItemTypeConcMap.put("Potato", "Vegetable");
+        foodItemTypeConcMap.put("Spinach", "Vegetable");
+
+        for (Entry<String, String> item : foodItemTypeConcMap.entrySet()) {
+            if (item.getKey() != null && item.getKey()
+                .equals("Potato")) {
+                foodItemTypeConcMap.remove(item.getKey());
+            }
+        }
+
+        // foodItemTypeConcMap : {Apple=Fruit, Carrot=Vegetable, Grape=Fruit, Mango=Fruit, Spinach=Vegetable}
+
+    }
+
+}

core-java-modules/core-java-collections-maps-4/README.md

@@ -0,0 +1,6 @@
+## Java Collections Cookbooks and Examples
+
+This module contains articles about Map data structures in Java.
+
+### Relevant Articles: 
+- [Using a Custom Class as a Key in a Java HashMap](https://www.baeldung.com/java-custom-class-map-key)

core-java-modules/core-java-collections-maps-4/pom.xml

@@ -0,0 +1,34 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>core-java-collections-maps-4</artifactId>
+    <version>0.1.0-SNAPSHOT</version>
+    <name>core-java-collections-maps-4</name>
+    <packaging>jar</packaging>
+
+    <parent>
+        <groupId>com.baeldung.core-java-modules</groupId>
+        <artifactId>core-java-modules</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../pom.xml</relativePath>
+    </parent>
+
+    <build>
+        <pluginManagement>
+            <plugins>
+                <plugin>
+                    <groupId>org.apache.maven.plugins</groupId>
+                    <artifactId>maven-surefire-plugin</artifactId>
+                    <version>3.0.0-M5</version>
+                    <configuration>
+                        <!-- those tests are not made for CI purposes, but for manual testing -->
+                        <groups>!performance</groups>
+                    </configuration>
+                </plugin>
+            </plugins>
+        </pluginManagement>
+    </build>
+
+</project>

core-java-modules/core-java-collections-maps-4/src/main/java/com/baeldung/maps/CoordinateKey.java

@@ -0,0 +1,39 @@
+package com.baeldung.maps;
+
+import java.util.Objects;
+
+public class CoordinateKey {
+
+    private final int x;
+    private final int y;
+    private final int hashCode;
+
+    public CoordinateKey(int x, int y) {
+        this.x = x;
+        this.y = y;
+        this.hashCode = Objects.hash(x, y);
+    }
+
+    public int getX() {
+        return x;
+    }
+
+    public int getY() {
+        return y;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o)
+            return true;
+        if (o == null || getClass() != o.getClass())
+            return false;
+        CoordinateKey that = (CoordinateKey) o;
+        return x == that.x && y == that.y;
+    }
+
+    @Override
+    public int hashCode() {
+        return this.hashCode;
+    }
+}

core-java-modules/core-java-collections-maps-4/src/main/java/com/baeldung/maps/CoordinateMutableKey.java

@@ -0,0 +1,45 @@
+package com.baeldung.maps;
+
+import java.util.Objects;
+
+public class CoordinateMutableKey {
+
+    private int x;
+    private int y;
+
+    public CoordinateMutableKey(int x, int y) {
+        this.x = x;
+        this.y = y;
+    }
+
+    public int getX() {
+        return x;
+    }
+
+    public void setX(int x) {
+        this.x = x;
+    }
+
+    public int getY() {
+        return y;
+    }
+
+    public void setY(int y) {
+        this.y = y;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o)
+            return true;
+        if (o == null || getClass() != o.getClass())
+            return false;
+        CoordinateMutableKey that = (CoordinateMutableKey) o;
+        return x == that.x && y == that.y;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(x, y);
+    }
+}

core-java-modules/core-java-collections-maps-4/src/main/java/com/baeldung/maps/CoordinateSlowKey.java

@@ -0,0 +1,13 @@
+package com.baeldung.maps;
+
+public class CoordinateSlowKey extends CoordinateKey {
+
+    public CoordinateSlowKey(int x, int y) {
+        super(x, y);
+    }
+
+    @Override
+    public int hashCode() {
+        return 1;
+    }
+}

core-java-modules/core-java-collections-maps-4/src/test/java/com/baeldung/maps/CoordinateKeyUnitTest.java

@@ -0,0 +1,80 @@
+package com.baeldung.maps;
+
+import org.junit.jupiter.api.Tag;
+import org.junit.jupiter.api.Test;
+
+import java.awt.*;
+import java.util.HashMap;
+import java.util.Map;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+
+public class CoordinateKeyUnitTest {
+
+    private Map<CoordinateKey, Color> pixels = new HashMap<>();
+
+    @Test
+    void testOptimalKey() {
+        // setup
+        CoordinateKey coord = new CoordinateKey(1, 2);
+        pixels.put(coord, Color.CYAN);
+        // read out color correctly
+        assertEquals(Color.CYAN, pixels.get(coord));
+    }
+
+    @Test
+    void testSlowKey() {
+        // setup
+        CoordinateKey coord = new CoordinateSlowKey(1, 2);
+        pixels.put(coord, Color.CYAN);
+        // read out color correctly
+        assertEquals(Color.CYAN, pixels.get(coord));
+    }
+
+    // Performance Test Parameters - change here
+    private static final int MAX_X = 100;
+    private static final int MAX_Y = 100;
+    private static final int COUNT_OF_QUERIES = 1000;
+    private static final int QUERY_X = 1;
+    private static final int QUERY_Y = 1;
+
+    @Tag("performance")
+    @Test
+    void testKeyPerformance() {
+        // generate some sample keys and values
+        for (int x = 0; x < MAX_X; x++) {
+            for (int y = 0; y < MAX_Y; y++) {
+                pixels.put(new CoordinateKey(x, y), new Color(x % 255, y % 255, (x + y) % 255));
+            }
+        }
+        // read out multiple times and measure time
+        CoordinateKey coord = new CoordinateKey(QUERY_X, QUERY_Y);
+        long t1 = System.currentTimeMillis();
+        for (int i = 0; i < COUNT_OF_QUERIES; i++) {
+            assertNotNull(pixels.get(coord));
+        }
+        long t2 = System.currentTimeMillis();
+        System.out.printf("Optimal key performance: %d ms%n", t2 - t1);
+    }
+
+    @Tag("performance")
+    @Test
+    void testSlowKeyPerformance() {
+        // generate some sample keys and values
+        for (int x = 0; x < MAX_X; x++) {
+            for (int y = 0; y < MAX_Y; y++) {
+                pixels.put(new CoordinateSlowKey(x, y), new Color(x % 255, y % 255, (x + y) % 255));
+            }
+        }
+        // read out multiple times and measure time
+        CoordinateKey coord = new CoordinateSlowKey(QUERY_X, QUERY_Y);
+        long t1 = System.currentTimeMillis();
+        for (int i = 0; i < COUNT_OF_QUERIES; i++) {
+            assertNotNull(pixels.get(coord));
+        }
+        long t2 = System.currentTimeMillis();
+        System.out.printf("Slow key performance: %d ms%n", t2 - t1);
+    }
+
+}

core-java-modules/core-java-collections-maps-4/src/test/java/com/baeldung/maps/CoordinateMutableKeyUnitTest.java

@@ -0,0 +1,27 @@
+package com.baeldung.maps;
+
+import org.junit.jupiter.api.Test;
+
+import java.awt.*;
+import java.util.HashMap;
+import java.util.Map;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
+
+public class CoordinateMutableKeyUnitTest {
+
+    @Test
+    void testKeyMutable() {
+        // setup
+        Map<CoordinateMutableKey, Color> pixels = new HashMap<>();
+        CoordinateMutableKey coord = new CoordinateMutableKey(1, 2);
+        pixels.put(coord, Color.CYAN);
+        // read out color correctly
+        assertEquals(Color.CYAN, pixels.get(coord));
+        // change key's hashcode should result in null value
+        coord.setX(10);
+        assertNull(pixels.get(coord));
+    }
+
+}

core-java-modules/core-java-collections-maps/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-collections/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-concurrency-2/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-concurrency-advanced-2/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-concurrency-advanced-3/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-concurrency-advanced-4/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-concurrency-advanced/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-concurrency-basic-2/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <build>

core-java-modules/core-java-concurrency-basic/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-concurrency-collections-2/pom.xml

@@ -11,7 +11,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-concurrency-collections/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

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

@@ -3,6 +3,6 @@
 ### Relevant Articles:
 
 - [Read and Write User Input in Java](http://www.baeldung.com/java-console-input-output)
-- [Formatting with printf() in Java](https://www.baeldung.com/java-printstream-printf)
+- [Formatting Output with printf() in Java](https://www.baeldung.com/java-printstream-printf)
 - [ASCII Art in Java](http://www.baeldung.com/ascii-art-in-java)
 - [System.console() vs. System.out](https://www.baeldung.com/java-system-console-vs-system-out)

core-java-modules/core-java-console/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <build>

core-java-modules/core-java-date-operations-2/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-exceptions-2/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-exceptions-3/pom.xml

@@ -13,7 +13,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-exceptions/pom.xml

@@ -13,7 +13,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-function/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-functional/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
 </project>

core-java-modules/core-java-io-2/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-io-3/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-io-4/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-io-apis/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-io-conversions/README.md

@@ -13,4 +13,5 @@ This module contains articles about core Java input/output(IO) conversions.
 - [Java – Write a Reader to File](https://www.baeldung.com/java-write-reader-to-file)
 - [Java – Reader to Byte Array](https://www.baeldung.com/java-convert-reader-to-byte-array)
 - [Java – Reader to InputStream](https://www.baeldung.com/java-convert-reader-to-inputstream)
+- [Java String to InputStream](https://www.baeldung.com/convert-string-to-input-stream)
 - More articles: [[next -->]](/core-java-modules/core-java-io-conversions-2)

core-java-modules/core-java-io-conversions/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-io/src/main/resources/logback.xml

@@ -9,6 +9,7 @@
 
     <logger name="org.springframework" level="WARN" />
     <logger name="org.springframework.transaction" level="WARN" />
+    <logger name="net.sf.jmimemagic" level="WARN" />
 
     <!-- in order to debug some marshalling issues, this needs to be TRACE -->
     <logger name="org.springframework.web.servlet.mvc" level="WARN" />

core-java-modules/core-java-jar/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>
@@ -76,6 +75,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-dependency-plugin</artifactId>
+                <version>${maven-dependency-plugin.version}</version>
                 <executions>
                     <execution>
                         <id>copy-dependencies</id>
@@ -106,6 +106,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-assembly-plugin</artifactId>
+                <version>${maven-assembly-plugin.version}</version>
                 <executions>
                     <execution>
                         <phase>package</phase>
@@ -383,6 +384,8 @@
         <maven-jar-plugin.version>3.0.2</maven-jar-plugin.version>
         <onejar-maven-plugin.version>1.4.4</onejar-maven-plugin.version>
         <maven-shade-plugin.version>3.1.1</maven-shade-plugin.version>
+        <maven-assembly-plugin.version>3.3.0</maven-assembly-plugin.version>
+        <maven-dependency-plugin.version>3.2.0</maven-dependency-plugin.version>
         <spring-boot-maven-plugin.version>2.0.3.RELEASE</spring-boot-maven-plugin.version>
         <source.version>1.8</source.version>
         <target.version>1.8</target.version>

core-java-modules/core-java-jndi/src/test/java/com/baeldung/jndi/JndiUnitTest.java

@@ -1,5 +1,6 @@
 package com.baeldung.jndi;
 
+import org.junit.jupiter.api.AfterAll;
 import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
 import org.springframework.jdbc.datasource.DriverManagerDataSource;
@@ -56,5 +57,11 @@ class JndiUnitTest {
         assertNotNull(ds);
         assertNotNull(ds.getConnection());
     }
+    
+    @AfterAll
+    static void tearDown() throws Exception {
+       ctx.close();
+    }
+
 
 }

core-java-modules/core-java-jndi/src/test/java/com/baeldung/jndi/exceptions/JndiExceptionsUnitTest.java

@@ -6,7 +6,6 @@ import javax.naming.InitialContext;
 import javax.naming.NameNotFoundException;
 import javax.naming.NoInitialContextException;
 
-import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.MethodOrderer;
 import org.junit.jupiter.api.Order;
 import org.junit.jupiter.api.Test;
@@ -16,14 +15,17 @@ import org.springframework.mock.jndi.SimpleNamingContextBuilder;
 
 @TestMethodOrder(MethodOrderer.OrderAnnotation.class)
 public class JndiExceptionsUnitTest {
+    
+    InitialContext ctx;
 
     @Test
     @Order(1)
     void givenNoContext_whenLookupObject_thenThrowNoInitialContext() {
         assertThrows(NoInitialContextException.class, () -> {
             JndiTemplate jndiTemplate = new JndiTemplate();
-            InitialContext ctx = (InitialContext) jndiTemplate.getContext();
+            ctx = (InitialContext) jndiTemplate.getContext();
             ctx.lookup("java:comp/env/jdbc/datasource");
+            ctx.close();
         }).printStackTrace();
     }
 
@@ -35,8 +37,9 @@ public class JndiExceptionsUnitTest {
             builder.activate();
 
             JndiTemplate jndiTemplate = new JndiTemplate();
-            InitialContext ctx = (InitialContext) jndiTemplate.getContext();
+            ctx = (InitialContext) jndiTemplate.getContext();
             ctx.lookup("badJndiName");
+            ctx.close();
         }).printStackTrace();
     }
 

core-java-modules/core-java-jvm-2/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-lambdas/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-lang-2/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

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

@@ -2,7 +2,7 @@
 
 This module contains articles about core features in the Java language
 
-- [Class.isInstance vs Class.isAssignableFrom](https://www.baeldung.com/java-isinstance-isassignablefrom)
+- [Class.isInstance vs Class.isAssignableFrom and instanceof](https://www.baeldung.com/java-isinstance-isassignablefrom)
 - [Converting a Java String Into a Boolean](https://www.baeldung.com/java-string-to-boolean)
 - [When are Static Variables Initialized in Java?](https://www.baeldung.com/java-static-variables-initialization)
 - [Checking if a Class Exists in Java](https://www.baeldung.com/java-check-class-exists)

core-java-modules/core-java-lang-3/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-lang-3/src/test/java/com/baeldung/isinstancevsisassignablefrom/IsInstanceIsAssignableFromUnitTest.java

@@ -6,57 +6,80 @@ import static org.junit.Assert.assertTrue;
 import org.junit.Test;
 
 public class IsInstanceIsAssignableFromUnitTest {
-    
+
     @Test
-    public void whenUsingIsInstanceProperly_desiredResultsHappen() {
+    public void whenUsingInstanceOfProperly_thenDesiredResultsHappen() {
+        Shape shape = new Triangle();
+        Triangle triangle = new Triangle();
+        IsoscelesTriangle isoscelesTriangle = new IsoscelesTriangle();
+        Shape nonspecificShape = null;
+
+        assertTrue(shape instanceof Shape);
+        assertTrue(triangle instanceof Shape);
+        assertTrue(isoscelesTriangle instanceof Shape);
+        assertFalse(nonspecificShape instanceof Shape);
+
+        assertTrue(shape instanceof Triangle);
+        assertTrue(triangle instanceof Triangle);
+        assertTrue(isoscelesTriangle instanceof Triangle);
+        assertFalse(nonspecificShape instanceof Triangle);
+
+        assertFalse(shape instanceof IsoscelesTriangle);
+        assertFalse(triangle instanceof IsoscelesTriangle);
+        assertTrue(isoscelesTriangle instanceof IsoscelesTriangle);
+        assertFalse(nonspecificShape instanceof IsoscelesTriangle);
+    }
+
+    @Test
+    public void whenUsingIsInstanceProperly_thenDesiredResultsHappen() {
         Shape shape = new Triangle();
         Triangle triangle = new Triangle();
         IsoscelesTriangle isoscelesTriangle = new IsoscelesTriangle();
         Triangle isoscelesTriangle2 = new IsoscelesTriangle();
         Shape nonspecificShape = null;
-        
+
         assertTrue(Shape.class.isInstance(shape));
         assertTrue(Shape.class.isInstance(triangle));
         assertTrue(Shape.class.isInstance(isoscelesTriangle));
         assertTrue(Shape.class.isInstance(isoscelesTriangle2));
         assertFalse(Shape.class.isInstance(nonspecificShape));
-        
+
         assertTrue(Triangle.class.isInstance(shape));
         assertTrue(Triangle.class.isInstance(triangle));
         assertTrue(Triangle.class.isInstance(isoscelesTriangle));
         assertTrue(Triangle.class.isInstance(isoscelesTriangle2));
-        
+
         assertFalse(IsoscelesTriangle.class.isInstance(shape));
         assertFalse(IsoscelesTriangle.class.isInstance(triangle));
         assertTrue(IsoscelesTriangle.class.isInstance(isoscelesTriangle));
-        assertTrue(IsoscelesTriangle.class.isInstance(isoscelesTriangle2));        
+        assertTrue(IsoscelesTriangle.class.isInstance(isoscelesTriangle2));
     }
-    
+
     @Test
-    public void whenUsingIsAssignableFromProperly_desiredResultsHappen() {
+    public void whenUsingIsAssignableFromProperly_thenDesiredResultsHappen() {
         Shape shape = new Triangle();
         Triangle triangle = new Triangle();
         IsoscelesTriangle isoscelesTriangle = new IsoscelesTriangle();
         Triangle isoscelesTriangle2 = new IsoscelesTriangle();
-        
+
         assertFalse(shape.getClass().isAssignableFrom(Shape.class));
         assertTrue(shape.getClass().isAssignableFrom(shape.getClass()));
         assertTrue(shape.getClass().isAssignableFrom(triangle.getClass()));
         assertTrue(shape.getClass().isAssignableFrom(isoscelesTriangle.getClass()));
         assertTrue(shape.getClass().isAssignableFrom(isoscelesTriangle2.getClass()));
-        
+
         assertFalse(triangle.getClass().isAssignableFrom(Shape.class));
         assertTrue(triangle.getClass().isAssignableFrom(shape.getClass()));
         assertTrue(triangle.getClass().isAssignableFrom(triangle.getClass()));
         assertTrue(triangle.getClass().isAssignableFrom(isoscelesTriangle.getClass()));
         assertTrue(triangle.getClass().isAssignableFrom(isoscelesTriangle2.getClass()));
-        
+
         assertFalse(isoscelesTriangle.getClass().isAssignableFrom(Shape.class));
         assertFalse(isoscelesTriangle.getClass().isAssignableFrom(shape.getClass()));
         assertFalse(isoscelesTriangle.getClass().isAssignableFrom(triangle.getClass()));
         assertTrue(isoscelesTriangle.getClass().isAssignableFrom(isoscelesTriangle.getClass()));
         assertTrue(isoscelesTriangle.getClass().isAssignableFrom(isoscelesTriangle2.getClass()));
-        
+
         assertFalse(isoscelesTriangle2.getClass().isAssignableFrom(Shape.class));
         assertFalse(isoscelesTriangle2.getClass().isAssignableFrom(shape.getClass()));
         assertFalse(isoscelesTriangle2.getClass().isAssignableFrom(triangle.getClass()));
@@ -64,4 +87,31 @@ public class IsInstanceIsAssignableFromUnitTest {
         assertTrue(isoscelesTriangle2.getClass().isAssignableFrom(isoscelesTriangle2.getClass()));
     }
 
+    @Test(expected = NullPointerException.class)
+    public void whenUsingNull_thenDesiredResultsHappen() {
+        assertFalse(null instanceof Shape);
+        assertFalse(Shape.class.isInstance(null));
+        assertFalse(Shape.class.isAssignableFrom(null)); // NullPointerException
+    }
+
+    @Test
+    public void whenUsingPrimitiveType_thenDesiredResultsHappen() {
+        //assertFalse(10 instanceof int); // illegal
+        assertFalse(int.class.isInstance(10));
+        assertTrue(Integer.class.isInstance(10));
+        assertTrue(int.class.isAssignableFrom(int.class));
+        assertFalse(float.class.isAssignableFrom(int.class));
+    }
+
+    @Test
+    public void whenUsingClassInstanceVariable_thenDesiredResultsHappen() {
+        Shape shape = new Triangle();
+        Triangle triangle = new Triangle();
+        Class<?> clazz = shape.getClass();
+
+        //assertFalse(triangle instanceof clazz); // illegal
+        assertTrue(clazz.isInstance(triangle));
+        assertTrue(clazz.isAssignableFrom(triangle.getClass()));
+    }
+
 }

core-java-modules/core-java-lang-4/README.md

@@ -8,3 +8,4 @@ This module contains articles about core features in the Java language
 - [Java Objects.hash() vs Objects.hashCode()](https://www.baeldung.com/java-objects-hash-vs-objects-hashcode)
 - [Referencing a Method in Javadoc Comments](https://www.baeldung.com/java-method-in-javadoc)
 - [Tiered Compilation in JVM](https://www.baeldung.com/jvm-tiered-compilation)
+- [Fixing the “Declared package does not match the expected package” Error](https://www.baeldung.com/java-declared-expected-package-error)

core-java-modules/core-java-lang-4/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-lang-math-2/pom.xml

@@ -11,7 +11,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-lang-math-3/pom.xml

@@ -11,7 +11,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-lang-math/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/core-java-lang-operators-2/pom.xml

@@ -12,7 +12,6 @@
         <groupId>com.baeldung.core-java-modules</groupId>
         <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../</relativePath>
     </parent>
 
     <dependencies>