Merge pull request #5 from eugenp/master

Merge
2018-08-04 17:04:51 +05:30 · 2018-08-04 17:04:51 +05:30 · c1d6c92857
parent d0d9402822 2cc5ec5711
commit c1d6c92857
245 changed files with 17207 additions and 449 deletions
--- a/.gitignore
+++ b/.gitignore
@ -56,4 +56,9 @@ core-java-io/hard_link.txt
 core-java-io/target_link.txt
 core-java/src/main/java/com/baeldung/manifest/MANIFEST.MF
 ethereum/logs/
-jmeter/src/main/resources/*-JMeter.csv
+jmeter/src/main/resources/*-JMeter.csv
+
+**/node_modules/
+**/dist
+**/tmp
+**/out-tsc
--- a/core-java-8/README.md
+++ b/core-java-8/README.md
@ -56,3 +56,4 @@
 - [Generalized Target-Type Inference in Java](http://www.baeldung.com/java-generalized-target-type-inference)
 - [Image to Base64 String Conversion](http://www.baeldung.com/java-base64-image-string)
 - [Calculate Age in Java](http://www.baeldung.com/java-get-age)
+- [Add Hours To a Date In Java](http://www.baeldung.com/java-add-hours-date)
--- a/core-java-8/src/main/java/com/baeldung/nullsafecollectionstreams/NullSafeCollectionStreamsUsingCommonsEmptyIfNull.java
+++ b/core-java-8/src/main/java/com/baeldung/nullsafecollectionstreams/NullSafeCollectionStreamsUsingCommonsEmptyIfNull.java
@ -0,0 +1,19 @@
+package com.baeldung.nullsafecollectionstreams;
+
+import java.util.Collection;
+import java.util.stream.Stream;
+import static org.apache.commons.collections4.CollectionUtils.emptyIfNull;
+
+public class NullSafeCollectionStreamsUsingCommonsEmptyIfNull {
+
+    /**
+    * This method shows how to make a null safe stream from a collection through the use of 
+    * emptyIfNull() method from Apache Commons CollectionUtils library
+    * 
+     * @param collection The collection that is to be converted into a stream
+     * @return The stream that has been created from the collection or an empty stream if the collection is null
+    */
+    public Stream<String> collectionAsStream(Collection<String> collection) {
+        return emptyIfNull(collection).stream();
+    }
+}
--- a/core-java-8/src/main/java/com/baeldung/nullsafecollectionstreams/NullSafeCollectionStreamsUsingJava8OptionalContainer.java
+++ b/core-java-8/src/main/java/com/baeldung/nullsafecollectionstreams/NullSafeCollectionStreamsUsingJava8OptionalContainer.java
@ -0,0 +1,21 @@
+package com.baeldung.nullsafecollectionstreams;
+
+import java.util.Collection;
+import java.util.Optional;
+import java.util.stream.Stream;
+
+public class NullSafeCollectionStreamsUsingJava8OptionalContainer {
+
+    /**
+    * This method shows how to make a null safe stream from a collection  through the use of 
+    * Java SE 8’s Optional Container
+    * 
+     * @param collection The collection that is to be converted into a stream
+     * @return The stream that has been created from the collection or an empty stream if the collection is null
+    */
+    public Stream<String> collectionAsStream(Collection<String> collection) {
+        return Optional.ofNullable(collection)
+            .map(Collection::stream)
+            .orElseGet(Stream::empty);
+    }
+}
--- a/core-java-8/src/main/java/com/baeldung/nullsafecollectionstreams/NullSafeCollectionStreamsUsingNullDereferenceCheck.java
+++ b/core-java-8/src/main/java/com/baeldung/nullsafecollectionstreams/NullSafeCollectionStreamsUsingNullDereferenceCheck.java
@ -0,0 +1,20 @@
+package com.baeldung.nullsafecollectionstreams;
+
+import java.util.Collection;
+import java.util.stream.Stream;
+
+public class NullSafeCollectionStreamsUsingNullDereferenceCheck {
+    
+    /**
+    * This method shows how to make a null safe stream from a collection through the use of a check 
+    * to prevent null dereferences
+    * 
+    * @param collection The collection that is to be converted into a stream
+    * @return The stream that has been created from the collection or an empty stream if the collection is null
+    */
+    public Stream<String> collectionAsStream(Collection<String> collection) {
+        return collection == null ? Stream.empty() : collection.stream();
+    }    
+
+
+}
--- a/core-java-8/src/test/java/com/baeldung/nullsafecollectionstreams/NullSafeCollectionStreamsUsingCommonsEmptyIfNullUnitTest.java
+++ b/core-java-8/src/test/java/com/baeldung/nullsafecollectionstreams/NullSafeCollectionStreamsUsingCommonsEmptyIfNullUnitTest.java
@ -0,0 +1,41 @@
+package com.baeldung.nullsafecollectionstreams;
+
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.stream.Stream;
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+
+public class NullSafeCollectionStreamsUsingCommonsEmptyIfNullUnitTest {
+
+    private final NullSafeCollectionStreamsUsingCommonsEmptyIfNull instance = 
+            new NullSafeCollectionStreamsUsingCommonsEmptyIfNull();
+
+    @Test
+    public void whenCollectionIsNull_thenExpectAnEmptyStream() {
+        Collection<String> collection = null;
+        Stream<String> expResult = Stream.empty();
+        Stream<String> result = instance.collectionAsStream(collection);
+        assertStreamEquals(expResult, result);
+
+    }
+
+    @Test
+    public void whenCollectionHasElements_thenExpectAStreamOfExactlyTheSameElements() {
+
+        Collection<String> collection = Arrays.asList("a", "b", "c");
+        Stream<String> expResult = Arrays.stream(new String[] { "a", "b", "c" });
+        Stream<String> result = instance.collectionAsStream(collection);
+        assertStreamEquals(expResult, result);
+    }
+
+    private static void assertStreamEquals(Stream<?> s1, Stream<?> s2) {
+        Iterator<?> iter1 = s1.iterator(), iter2 = s2.iterator();
+        while (iter1.hasNext() && iter2.hasNext())
+            assertEquals(iter1.next(), iter2.next());
+        assert !iter1.hasNext() && !iter2.hasNext();
+    }
+    
+}
--- a/core-java-8/src/test/java/com/baeldung/nullsafecollectionstreams/NullSafeCollectionStreamsUsingJava8OptionalContainerUnitTest.java
+++ b/core-java-8/src/test/java/com/baeldung/nullsafecollectionstreams/NullSafeCollectionStreamsUsingJava8OptionalContainerUnitTest.java
@ -0,0 +1,53 @@
+/*
+ * 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.nullsafecollectionstreams;
+
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.stream.Stream;
+import org.junit.After;
+import org.junit.AfterClass;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+/**
+ *
+ * @author Kwaje Anthony <kwajeanthony@gmail.com>
+ */
+public class NullSafeCollectionStreamsUsingJava8OptionalContainerUnitTest {
+    
+    private final NullSafeCollectionStreamsUsingJava8OptionalContainer instance = 
+            new NullSafeCollectionStreamsUsingJava8OptionalContainer();
+
+    @Test
+    public void whenCollectionIsNull_thenExpectAnEmptyStream() {
+        Collection<String> collection = null;
+        Stream<String> expResult = Stream.empty();
+        Stream<String> result = instance.collectionAsStream(collection);
+        assertStreamEquals(expResult, result);
+
+    }
+
+    @Test
+    public void whenCollectionHasElements_thenExpectAStreamOfExactlyTheSameElements() {
+
+        Collection<String> collection = Arrays.asList("a", "b", "c");
+        Stream<String> expResult = Arrays.stream(new String[] { "a", "b", "c" });
+        Stream<String> result = instance.collectionAsStream(collection);
+        assertStreamEquals(expResult, result);
+    }
+
+    private static void assertStreamEquals(Stream<?> s1, Stream<?> s2) {
+        Iterator<?> iter1 = s1.iterator(), iter2 = s2.iterator();
+        while (iter1.hasNext() && iter2.hasNext())
+            assertEquals(iter1.next(), iter2.next());
+        assert !iter1.hasNext() && !iter2.hasNext();
+    }
+    
+}
--- a/core-java-8/src/test/java/com/baeldung/nullsafecollectionstreams/NullSafeCollectionStreamsUsingNullDereferenceCheckUnitTest.java
+++ b/core-java-8/src/test/java/com/baeldung/nullsafecollectionstreams/NullSafeCollectionStreamsUsingNullDereferenceCheckUnitTest.java
@ -0,0 +1,45 @@
+
+package com.baeldung.nullsafecollectionstreams;
+
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.stream.Stream;
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+/**
+ *
+ * @author Kwaje Anthony <kwajeanthony@gmail.com>
+ */
+public class NullSafeCollectionStreamsUsingNullDereferenceCheckUnitTest {
+
+    private final NullSafeCollectionStreamsUsingNullDereferenceCheck instance = 
+            new NullSafeCollectionStreamsUsingNullDereferenceCheck();
+
+    @Test
+    public void whenCollectionIsNull_thenExpectAnEmptyStream() {
+        Collection<String> collection = null;
+        Stream<String> expResult = Stream.empty();
+        Stream<String> result = instance.collectionAsStream(collection);
+        assertStreamEquals(expResult, result);
+
+    }
+
+    @Test
+    public void whenCollectionHasElements_thenExpectAStreamOfExactlyTheSameElements() {
+
+        Collection<String> collection = Arrays.asList("a", "b", "c");
+        Stream<String> expResult = Arrays.stream(new String[] { "a", "b", "c" });
+        Stream<String> result = instance.collectionAsStream(collection);
+        assertStreamEquals(expResult, result);
+    }
+
+    private static void assertStreamEquals(Stream<?> s1, Stream<?> s2) {
+        Iterator<?> iter1 = s1.iterator(), iter2 = s2.iterator();
+        while (iter1.hasNext() && iter2.hasNext())
+            assertEquals(iter1.next(), iter2.next());
+        assert !iter1.hasNext() && !iter2.hasNext();
+    }
+
+}
--- a/core-java-collections/pom.xml
+++ b/core-java-collections/pom.xml
@ -36,11 +36,6 @@
            <artifactId>commons-lang3</artifactId>
            <version>${commons-lang3.version}</version>
        </dependency>
-        <dependency>
-            <groupId>org.eclipse.collections</groupId>
-            <artifactId>eclipse-collections-api</artifactId>
-            <version>${eclipse.collections.version}</version>
-        </dependency>
        <dependency>
            <groupId>org.eclipse.collections</groupId>
            <artifactId>eclipse-collections</artifactId>
--- a/core-java-collections/src/main/java/com/baeldung/list/list/listoflist/Pen.java
+++ b/core-java-collections/src/main/java/com/baeldung/list/list/listoflist/Pen.java
--- a/core-java-collections/src/main/java/com/baeldung/list/list/listoflist/Pencil.java
+++ b/core-java-collections/src/main/java/com/baeldung/list/list/listoflist/Pencil.java
--- a/core-java-collections/src/main/java/com/baeldung/list/list/listoflist/Rubber.java
+++ b/core-java-collections/src/main/java/com/baeldung/list/list/listoflist/Rubber.java
--- a/core-java-collections/src/main/java/com/baeldung/list/list/listoflist/Stationery.java
+++ b/core-java-collections/src/main/java/com/baeldung/list/list/listoflist/Stationery.java
--- a/core-java-collections/src/main/java/com/baeldung/list/removeall/RemoveAll.java
+++ b/core-java-collections/src/main/java/com/baeldung/list/removeall/RemoveAll.java
@ -0,0 +1,111 @@
+package com.baeldung.list.removeall;
+
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Objects;
+import java.util.stream.Collectors;
+
+public class RemoveAll {
+
+    static void removeWithWhileLoopPrimitiveElement(List<Integer> list, int element) {
+        while (list.contains(element)) {
+            list.remove(element);
+        }
+    }
+
+    static void removeWithWhileLoopNonPrimitiveElement(List<Integer> list, Integer element) {
+        while (list.contains(element)) {
+            list.remove(element);
+        }
+    }
+
+    static void removeWithWhileLoopStoringFirstOccurrenceIndex(List<Integer> list, Integer element) {
+        int index;
+        while ((index = list.indexOf(element)) >= 0) {
+            list.remove(index);
+        }
+    }
+
+    static void removeWithCallingRemoveUntilModifies(List<Integer> list, Integer element) {
+        while (list.remove(element))
+            ;
+    }
+
+    static void removeWithStandardForLoopUsingIndex(List<Integer> list, int element) {
+        for (int i = 0; i < list.size(); i++) {
+            if (Objects.equals(element, list.get(i))) {
+                list.remove(i);
+            }
+        }
+    }
+
+    static void removeWithForLoopDecrementOnRemove(List<Integer> list, int element) {
+        for (int i = 0; i < list.size(); i++) {
+            if (Objects.equals(element, list.get(i))) {
+                list.remove(i);
+                i--;
+            }
+        }
+    }
+
+    static void removeWithForLoopIncrementIfRemains(List<Integer> list, int element) {
+        for (int i = 0; i < list.size();) {
+            if (Objects.equals(element, list.get(i))) {
+                list.remove(i);
+            } else {
+                i++;
+            }
+        }
+    }
+
+    static void removeWithForEachLoop(List<Integer> list, int element) {
+        for (Integer number : list) {
+            if (Objects.equals(number, element)) {
+                list.remove(number);
+            }
+        }
+    }
+
+    static void removeWithIterator(List<Integer> list, int element) {
+        for (Iterator<Integer> i = list.iterator(); i.hasNext();) {
+            Integer number = i.next();
+            if (Objects.equals(number, element)) {
+                i.remove();
+            }
+        }
+    }
+
+    static List<Integer> removeWithCollectingAndReturningRemainingElements(List<Integer> list, int element) {
+        List<Integer> remainingElements = new ArrayList<>();
+        for (Integer number : list) {
+            if (!Objects.equals(number, element)) {
+                remainingElements.add(number);
+            }
+        }
+        return remainingElements;
+    }
+
+    static void removeWithCollectingRemainingElementsAndAddingToOriginalList(List<Integer> list, int element) {
+        List<Integer> remainingElements = new ArrayList<>();
+        for (Integer number : list) {
+            if (!Objects.equals(number, element)) {
+                remainingElements.add(number);
+            }
+        }
+
+        list.clear();
+        list.addAll(remainingElements);
+    }
+
+    static List<Integer> removeWithStreamFilter(List<Integer> list, Integer element) {
+        return list.stream()
+            .filter(e -> !Objects.equals(e, element))
+            .collect(Collectors.toList());
+    }
+
+    static void removeWithRemoveIf(List<Integer> list, Integer element) {
+        list.removeIf(n -> Objects.equals(n, element));
+    }
+
+}
--- a/core-java-collections/src/main/java/com/baeldung/thread_safe_lifo/DequeBasedSynchronizedStack.java
+++ b/core-java-collections/src/main/java/com/baeldung/thread_safe_lifo/DequeBasedSynchronizedStack.java
@ -0,0 +1,36 @@
+package com.baeldung.thread_safe_lifo;
+
+import java.util.ArrayDeque;
+
+/**
+ * Deque Based Stack implementation.
+ */
+public class DequeBasedSynchronizedStack<T> {
+
+    // Internal Deque which gets decorated for synchronization.
+    private ArrayDeque<T> dequeStore = new ArrayDeque<>();
+
+    public DequeBasedSynchronizedStack(int initialCapacity) {
+        this.dequeStore = new ArrayDeque<>(initialCapacity);
+    }
+
+    public DequeBasedSynchronizedStack() {
+
+    }
+
+    public synchronized T pop() {
+        return this.dequeStore.pop();
+    }
+
+    public synchronized void push(T element) {
+        this.dequeStore.push(element);
+    }
+
+    public synchronized T peek() {
+        return this.dequeStore.peek();
+    }
+
+    public synchronized int size() {
+        return this.dequeStore.size();
+    }
+}
--- a/core-java-collections/src/test/java/com/baeldung/list/removeall/RemoveAllUnitTest.java
+++ b/core-java-collections/src/test/java/com/baeldung/list/removeall/RemoveAllUnitTest.java
@ -0,0 +1,210 @@
+package com.baeldung.list.removeall;
+
+import static com.baeldung.list.removeall.RemoveAll.removeWithCallingRemoveUntilModifies;
+import static com.baeldung.list.removeall.RemoveAll.removeWithCollectingAndReturningRemainingElements;
+import static com.baeldung.list.removeall.RemoveAll.removeWithCollectingRemainingElementsAndAddingToOriginalList;
+import static com.baeldung.list.removeall.RemoveAll.removeWithForEachLoop;
+import static com.baeldung.list.removeall.RemoveAll.removeWithForLoopDecrementOnRemove;
+import static com.baeldung.list.removeall.RemoveAll.removeWithForLoopIncrementIfRemains;
+import static com.baeldung.list.removeall.RemoveAll.removeWithIterator;
+import static com.baeldung.list.removeall.RemoveAll.removeWithRemoveIf;
+import static com.baeldung.list.removeall.RemoveAll.removeWithStandardForLoopUsingIndex;
+import static com.baeldung.list.removeall.RemoveAll.removeWithStreamFilter;
+import static com.baeldung.list.removeall.RemoveAll.removeWithWhileLoopNonPrimitiveElement;
+import static com.baeldung.list.removeall.RemoveAll.removeWithWhileLoopPrimitiveElement;
+import static com.baeldung.list.removeall.RemoveAll.removeWithWhileLoopStoringFirstOccurrenceIndex;
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.ConcurrentModificationException;
+import java.util.List;
+
+import org.junit.Test;
+
+public class RemoveAllUnitTest {
+
+	private List<Integer> list(Integer... elements) {
+		return new ArrayList<>(Arrays.asList(elements));
+	}
+
+	@Test
+	public void givenAList_whenRemovingElementsWithWhileLoopUsingPrimitiveElement_thenTheResultCorrect() {
+		// given
+		List<Integer> list = list(1, 2, 3);
+		int valueToRemove = 1;
+
+		// when
+		assertThatThrownBy(() -> removeWithWhileLoopPrimitiveElement(list, valueToRemove))
+				.isInstanceOf(IndexOutOfBoundsException.class);
+	}
+
+	@Test
+	public void givenAList_whenRemovingElementsWithWhileLoopUsingNonPrimitiveElement_thenTheResultCorrect() {
+		// given
+		List<Integer> list = list(1, 2, 3);
+		int valueToRemove = 1;
+
+		// when
+		removeWithWhileLoopNonPrimitiveElement(list, valueToRemove);
+
+		// then
+		assertThat(list).isEqualTo(list(2, 3));
+	}
+
+	@Test
+	public void givenAList_whenRemovingElementsWithWhileLoopStoringFirstOccurrenceIndex_thenTheResultCorrect() {
+		// given
+		List<Integer> list = list(1, 2, 3);
+		int valueToRemove = 1;
+
+		// when
+		removeWithWhileLoopStoringFirstOccurrenceIndex(list, valueToRemove);
+
+		// then
+		assertThat(list).isEqualTo(list(2, 3));
+	}
+
+	@Test
+	public void givenAList_whenRemovingElementsWithCallingRemoveUntilModifies_thenTheResultIsCorrect() {
+		// given
+		List<Integer> list = list(1, 1, 2, 3);
+		int valueToRemove = 1;
+
+		// when
+		removeWithCallingRemoveUntilModifies(list, valueToRemove);
+
+		// then
+		assertThat(list).isEqualTo(list(2, 3));
+	}
+
+	@Test
+	public void givenAListWithoutDuplication_whenRemovingElementsWithStandardForLoopUsingIndex_thenTheResultIsCorrect() {
+		// given
+		List<Integer> list = list(1, 2, 3);
+		int valueToRemove = 1;
+
+		// when
+		removeWithStandardForLoopUsingIndex(list, valueToRemove);
+
+		// then
+		assertThat(list).isEqualTo(list(2, 3));
+	}
+
+	@Test
+	public void givenAListWithAdjacentElements_whenRemovingElementsWithStandardForLoop_thenTheResultIsInCorrect() {
+		// given
+		List<Integer> list = list(1, 1, 2, 3);
+		int valueToRemove = 1;
+
+		// when
+		removeWithStandardForLoopUsingIndex(list, valueToRemove);
+
+		// then
+		assertThat(list).isEqualTo(list(1, 2, 3));
+	}
+
+	@Test
+	public void givenAListWithAdjacentElements_whenRemovingElementsWithForLoopAndDecrementOnRemove_thenTheResultIsCorrect() {
+		// given
+		List<Integer> list = list(1, 1, 2, 3);
+		int valueToRemove = 1;
+
+		// when
+		removeWithForLoopDecrementOnRemove(list, valueToRemove);
+
+		// then
+		assertThat(list).isEqualTo(list(2, 3));
+	}
+
+	@Test
+	public void givenAListWithAdjacentElements_whenRemovingElementsWithForLoopAndIncrementIfRemains_thenTheResultIsCorrect() {
+		// given
+		List<Integer> list = list(1, 1, 2, 3);
+		int valueToRemove = 1;
+
+		// when
+		removeWithForLoopIncrementIfRemains(list, valueToRemove);
+
+		// then
+		assertThat(list).isEqualTo(list(2, 3));
+	}
+
+	@Test
+	public void givenAList_whenRemovingElementsWithForEachLoop_thenExceptionIsThrown() {
+		// given
+		List<Integer> list = list(1, 1, 2, 3);
+		int valueToRemove = 1;
+
+		// when
+		assertThatThrownBy(() -> removeWithForEachLoop(list, valueToRemove))
+				.isInstanceOf(ConcurrentModificationException.class);
+	}
+
+	@Test
+	public void givenAList_whenRemovingElementsWithIterator_thenTheResultIsCorrect() {
+		// given
+		List<Integer> list = list(1, 1, 2, 3);
+		int valueToRemove = 1;
+
+		// when
+		removeWithIterator(list, valueToRemove);
+
+		// then
+		assertThat(list).isEqualTo(list(2, 3));
+	}
+
+	@Test
+	public void givenAList_whenRemovingElementsWithCollectingAndReturningRemainingElements_thenTheResultIsCorrect() {
+		// given
+		List<Integer> list = list(1, 1, 2, 3);
+		int valueToRemove = 1;
+
+		// when
+		List<Integer> result = removeWithCollectingAndReturningRemainingElements(list, valueToRemove);
+
+		// then
+		assertThat(result).isEqualTo(list(2, 3));
+	}
+
+	@Test
+	public void givenAList_whenRemovingElementsWithCollectingRemainingAndAddingToOriginalList_thenTheResultIsCorrect() {
+		// given
+		List<Integer> list = list(1, 1, 2, 3);
+		int valueToRemove = 1;
+
+		// when
+		removeWithCollectingRemainingElementsAndAddingToOriginalList(list, valueToRemove);
+
+		// then
+		assertThat(list).isEqualTo(list(2, 3));
+	}
+
+	@Test
+	public void givenAList_whenRemovingElementsWithStreamFilter_thenTheResultIsCorrect() {
+		// given
+		List<Integer> list = list(1, 1, 2, 3);
+		int valueToRemove = 1;
+
+		// when
+		List<Integer> result = removeWithStreamFilter(list, valueToRemove);
+
+		// then
+		assertThat(result).isEqualTo(list(2, 3));
+	}
+
+	@Test
+	public void givenAList_whenRemovingElementsWithCallingRemoveIf_thenTheResultIsCorrect() {
+		// given
+		List<Integer> list = list(1, 1, 2, 3);
+		int valueToRemove = 1;
+
+		// when
+		removeWithRemoveIf(list, valueToRemove);
+
+		// then
+		assertThat(list).isEqualTo(list(2, 3));
+	}
+
+}
--- a/core-java-collections/src/test/java/com/baeldung/stack_tests/MultithreadingCorrectnessStackUnitTest.java
+++ b/core-java-collections/src/test/java/com/baeldung/stack_tests/MultithreadingCorrectnessStackUnitTest.java
@ -0,0 +1,101 @@
+package com.baeldung.stack_tests;
+
+import com.baeldung.thread_safe_lifo.DequeBasedSynchronizedStack;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.util.ArrayDeque;
+import java.util.concurrent.ConcurrentLinkedDeque;
+
+import static java.util.stream.IntStream.range;
+
+/**
+ * Correctness tests for Stack in multi threaded environment.
+ */
+public class MultithreadingCorrectnessStackUnitTest {
+
+    @Test
+    public void givenSynchronizedDeque_whenExecutedParallel_thenWorkRight() {
+
+        DequeBasedSynchronizedStack<Integer> deque = new DequeBasedSynchronizedStack<>();
+
+        // Serial execution of push on ConcurrentLinkedQueue will always result in correct execution.
+        range(1, 10000).forEach(value -> deque.push(value));
+
+        int sum = 0;
+        while(deque.peek() != null) {
+            sum += deque.pop();
+        }
+
+        Assert.assertEquals(49995000, sum);
+
+        // Parallel execution of push on ConcurrentLinkedQueue will always result in correct execution.
+        range(1, 10000).parallel().forEach(value -> deque.push(value));
+
+        sum = 0;
+        while(deque.peek() != null) {
+            sum += deque.pop();
+        }
+
+        Assert.assertEquals(49995000, sum);
+    }
+
+    @Test
+    public void givenConcurrentLinkedQueue_whenExecutedParallel_thenWorkRight() {
+
+        ConcurrentLinkedDeque<Integer> deque = new ConcurrentLinkedDeque<>();
+
+        // Serial execution of push on ConcurrentLinkedQueue will always result in correct execution.
+        range(1, 10000).forEach(value -> deque.push(value));
+
+        int sum = 0;
+        while(deque.peek() != null) {
+            sum += deque.pop();
+        }
+
+        Assert.assertEquals(49995000, sum);
+
+        // Parallel execution of push on ConcurrentLinkedQueue will always result in correct execution.
+        range(1, 10000).parallel().forEach(value -> deque.push(value));
+
+        sum = 0;
+        while(deque.peek() != null) {
+            sum += deque.pop();
+        }
+
+        Assert.assertEquals(49995000, sum);
+    }
+
+    @Test
+    public void givenArrayDeque_whenExecutedParallel_thenShouldFail() {
+
+        ArrayDeque<Integer> deque = new ArrayDeque<>();
+
+        // Serial execution of push on ArrayDeque will always result in correct execution.
+        range(1, 10000).forEach(value -> deque.push(value));
+
+        int sum = 0;
+        while(deque.peek() != null) {
+            sum += deque.pop();
+        }
+
+        Assert.assertEquals(49995000, sum);
+
+        // Parallel execution of push on ArrayDeque will not result in correct execution.
+        range(1, 10000).parallel().forEach(value -> deque.push(value));
+
+        sum = 0;
+        while(deque.peek() != null) {
+            sum += deque.pop();
+        }
+
+        // This shouldn't happen.
+        if(sum == 49995000) {
+            System.out.println("Something wrong in the environment, Please try some big value and check");
+            // To safe-guard build without test failures.
+            return;
+        }
+
+        Assert.assertNotEquals(49995000, sum);
+    }
+}
--- a/core-java-collections/src/test/java/com/baeldung/stack_tests/StackUnitTest.java
+++ b/core-java-collections/src/test/java/com/baeldung/stack_tests/StackUnitTest.java
@ -0,0 +1,63 @@
+package com.baeldung.stack_tests;
+
+import com.baeldung.thread_safe_lifo.DequeBasedSynchronizedStack;
+import com.google.common.collect.Streams;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.util.ArrayDeque;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Stack;
+import java.util.concurrent.ConcurrentLinkedDeque;
+import java.util.stream.Stream;
+
+import static java.util.stream.IntStream.range;
+
+/**
+ * These tests are to understand the Stack implementation in Java Collections.
+ */
+public class StackUnitTest {
+
+    @Test
+    public void givenStack_whenPushPopPeek_thenWorkRight() {
+        Stack<String> namesStack = new Stack<>();
+
+        namesStack.push("Bill Gates");
+        namesStack.push("Elon Musk");
+
+        Assert.assertEquals("Elon Musk", namesStack.peek());
+        Assert.assertEquals("Elon Musk", namesStack.pop());
+        Assert.assertEquals("Bill Gates", namesStack.pop());
+
+        Assert.assertEquals(0, namesStack.size());
+    }
+
+    @Test
+    public void givenSynchronizedDeque_whenPushPopPeek_thenWorkRight() {
+        DequeBasedSynchronizedStack<String> namesStack = new DequeBasedSynchronizedStack<>();
+
+        namesStack.push("Bill Gates");
+        namesStack.push("Elon Musk");
+
+        Assert.assertEquals("Elon Musk", namesStack.peek());
+        Assert.assertEquals("Elon Musk", namesStack.pop());
+        Assert.assertEquals("Bill Gates", namesStack.pop());
+
+        Assert.assertEquals(0, namesStack.size());
+    }
+
+    @Test
+    public void givenConcurrentLinkedDeque_whenPushPopPeek_thenWorkRight() {
+        ConcurrentLinkedDeque<String> namesStack = new ConcurrentLinkedDeque<>();
+
+        namesStack.push("Bill Gates");
+        namesStack.push("Elon Musk");
+
+        Assert.assertEquals("Elon Musk", namesStack.peek());
+        Assert.assertEquals("Elon Musk", namesStack.pop());
+        Assert.assertEquals("Bill Gates", namesStack.pop());
+
+        Assert.assertEquals(0, namesStack.size());
+    }
+}
--- a/core-java-io/src/test/java/com/baeldung/file/FilenameFilterManualTest.java
+++ b/core-java-io/src/test/java/com/baeldung/file/FilenameFilterManualTest.java
@ -0,0 +1,48 @@
+package com.baeldung.file;
+
+import java.io.File;
+import java.io.FilenameFilter;
+import java.util.Arrays;
+import java.util.List;
+import java.util.function.Predicate;
+import java.util.stream.Collectors;
+
+import org.junit.Assert;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+public class FilenameFilterManualTest {
+
+    private static File directory;
+
+    @BeforeClass
+    public static void setupClass() {
+        directory = new File(FilenameFilterManualTest.class.getClassLoader()
+            .getResource("testFolder")
+            .getFile());
+    }
+
+    @Test
+    public void whenFilteringFilesEndingWithJson_thenEqualExpectedFiles() {
+        FilenameFilter filter = (dir, name) -> name.endsWith(".json");
+
+        String[] expectedFiles = { "people.json", "students.json" };
+        String[] actualFiles = directory.list(filter);
+
+        Assert.assertArrayEquals(expectedFiles, actualFiles);
+    }
+
+    @Test
+    public void whenFilteringFilesEndingWithXml_thenEqualExpectedFiles() {
+        Predicate<String> predicate = (name) -> name.endsWith(".xml");
+
+        String[] expectedFiles = { "teachers.xml", "workers.xml" };
+        List<String> files = Arrays.stream(directory.list())
+            .filter(predicate)
+            .collect(Collectors.toList());
+        String[] actualFiles = files.toArray(new String[files.size()]);
+
+        Assert.assertArrayEquals(expectedFiles, actualFiles);
+    }
+
+}
--- a/core-java-io/src/test/resources/testFolder/people.json
+++ b/core-java-io/src/test/resources/testFolder/people.json
@ -0,0 +1 @@
+{}
--- a/core-java-io/src/test/resources/testFolder/students.json
+++ b/core-java-io/src/test/resources/testFolder/students.json
@ -0,0 +1 @@
+{}
--- a/core-java-io/src/test/resources/testFolder/teachers.xml
+++ b/core-java-io/src/test/resources/testFolder/teachers.xml
@ -0,0 +1 @@
+<xml></xml>
--- a/core-java-io/src/test/resources/testFolder/workers.xml
+++ b/core-java-io/src/test/resources/testFolder/workers.xml
@ -0,0 +1 @@
+<xml></xml>
--- a/core-java/src/main/java/com/baeldung/exceptionhandling/Exceptions.java
+++ b/core-java/src/main/java/com/baeldung/exceptionhandling/Exceptions.java
@ -0,0 +1,212 @@
+package com.baeldung.exceptionhandling;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.List;
+import java.util.Scanner;
+import java.util.logging.Logger;
+import java.util.stream.Collectors;
+
+public class Exceptions {
+
+    private final static Logger logger = Logger.getLogger("ExceptionLogging");
+
+    public static List<Player> getPlayers() throws IOException {
+        Path path = Paths.get("players.dat");
+        List<String> players = Files.readAllLines(path);
+
+        return players.stream()
+          .map(Player::new)
+          .collect(Collectors.toList());
+    }
+
+    public List<Player> loadAllPlayers(String playersFile) throws IOException{
+        try {
+            throw new IOException();
+        } catch(IOException ex) {
+            throw new IllegalStateException();
+        }
+    }
+
+    public int getPlayerScoreThrows(String playerFile) throws FileNotFoundException {		 
+        Scanner contents = new Scanner(new File(playerFile));
+        return Integer.parseInt(contents.nextLine());
+    }
+
+    public int getPlayerScoreTryCatch(String playerFile) {
+        try {
+            Scanner contents = new Scanner(new File(playerFile));
+            return Integer.parseInt(contents.nextLine());
+        } catch (FileNotFoundException noFile) {
+            throw new IllegalArgumentException("File not found");
+        }
+    }
+
+    public int getPlayerScoreTryCatchRecovery(String playerFile) {
+        try {
+            Scanner contents = new Scanner(new File(playerFile));
+            return Integer.parseInt(contents.nextLine());
+        } catch ( FileNotFoundException noFile ) {
+            logger.warning("File not found, resetting score.");
+            return 0;
+        }
+    }
+
+    public int getPlayerScoreFinally(String playerFile) throws FileNotFoundException {
+        Scanner contents = null;
+        try {
+            contents = new Scanner(new File(playerFile));
+            return Integer.parseInt(contents.nextLine());
+        } finally {
+            if (contents != null) {
+                contents.close();
+            }
+        }
+    }
+
+    public int getPlayerScoreTryWithResources(String playerFile) {
+        try (Scanner contents = new Scanner(new File(playerFile))) {
+            return Integer.parseInt(contents.nextLine());
+        } catch (FileNotFoundException e ) {
+            logger.warning("File not found, resetting score.");
+            return 0;
+        }
+    }
+
+    public int getPlayerScoreMultipleCatchBlocks(String playerFile) {
+        try (Scanner contents = new Scanner(new File(playerFile))) {
+            return Integer.parseInt(contents.nextLine());
+        } catch (IOException e) {
+            logger.warning("Player file wouldn't load!");
+            return 0;
+        } catch (NumberFormatException e) {
+            logger.warning("Player file was corrupted!");
+            return 0;
+        }
+    }
+
+    public int getPlayerScoreMultipleCatchBlocksAlternative(String playerFile) {
+        try (Scanner contents = new Scanner(new File(playerFile)) ) {
+            return Integer.parseInt(contents.nextLine());
+        } catch (FileNotFoundException e) {
+            logger.warning("Player file not found!");
+            return 0;
+        } catch (IOException e) {
+            logger.warning("Player file wouldn't load!");
+            return 0;
+        } catch (NumberFormatException e) {
+            logger.warning("Player file was corrupted!");
+            return 0;
+        }
+    }
+
+    public int getPlayerScoreUnionCatchBlocks(String playerFile) {
+        try (Scanner contents = new Scanner(new File(playerFile))) {
+            return Integer.parseInt(contents.nextLine());
+        } catch (IOException | NumberFormatException e) {
+            logger.warning("Failed to load score!");
+            return 0;
+        }
+    }
+
+    public List<Player> loadAllPlayersThrowingChecked(String playersFile) throws TimeoutException {
+        boolean tooLong = true;
+
+        while (!tooLong) {
+            // ... potentially long operation
+        }
+            throw new TimeoutException("This operation took too long");
+    }
+
+    public List<Player> loadAllPlayersThrowingUnchecked(String playersFile) throws TimeoutException {
+        if(!isFilenameValid(playersFile)) {
+            throw new IllegalArgumentException("Filename isn't valid!");
+        }
+        return null;
+
+        // ...
+    }
+
+    public List<Player> loadAllPlayersWrapping(String playersFile) throws IOException {
+        try { 
+            throw new IOException();
+        } catch (IOException io) { 		
+            throw io;
+        }
+    }
+
+    public List<Player> loadAllPlayersRethrowing(String playersFile) throws PlayerLoadException {
+        try { 
+            throw new IOException();
+        } catch (IOException io) { 		
+            throw new PlayerLoadException(io);
+        }
+    }
+
+    public List<Player> loadAllPlayersThrowable(String playersFile) {
+        try {
+            throw new NullPointerException();
+        } catch ( Throwable t ) {
+            throw t;
+        }
+    }
+
+    class FewerExceptions extends Exceptions {
+        @Override
+        public List<Player> loadAllPlayers(String playersFile) {  //can't add "throws MyCheckedException 
+            return null;
+            // overridden
+        }
+    }
+
+    public void throwAsGotoAntiPattern() {
+        try {
+            // bunch of code
+            throw new MyException();
+            // second bunch of code
+        } catch ( MyException e ) {
+            // third bunch of code
+        }
+    }
+
+    public int getPlayerScoreSwallowingExceptionAntiPattern(String playerFile) {
+        try {
+        // ...
+        } catch (Exception e) {} // <== catch and swallow
+            return 0;
+    }
+
+    public int getPlayerScoreSwallowingExceptionAntiPatternAlternative(String playerFile) {
+        try {
+            // ...
+        } catch (Exception e) {
+             e.printStackTrace();
+        }
+      return 0;
+    }
+
+    public int getPlayerScoreSwallowingExceptionAntiPatternAlternative2(String playerFile) throws PlayerScoreException {
+        try {
+            throw new IOException();
+        } catch (IOException e) {
+            throw new PlayerScoreException(e);
+        }
+    }
+
+    public int getPlayerScoreReturnInFinallyAntiPattern(String playerFile) {
+        int score = 0;
+        try {
+            throw new IOException();
+        } finally {
+            return score; // <== the IOException is dropped
+        }
+    }
+
+    private boolean isFilenameValid(String name) {
+        return false;
+    }
+}
--- a/core-java/src/main/java/com/baeldung/exceptionhandling/MyException.java
+++ b/core-java/src/main/java/com/baeldung/exceptionhandling/MyException.java
@ -0,0 +1,5 @@
+package com.baeldung.exceptionhandling;
+
+public class MyException extends Throwable {
+
+}
--- a/core-java/src/main/java/com/baeldung/exceptionhandling/Player.java
+++ b/core-java/src/main/java/com/baeldung/exceptionhandling/Player.java
@ -0,0 +1,12 @@
+package com.baeldung.exceptionhandling;
+
+public class Player {
+
+    public int id;
+    public String name;
+
+    public Player(String name) {
+        this.name = name;
+    }
+
+}
--- a/core-java/src/main/java/com/baeldung/exceptionhandling/PlayerLoadException.java
+++ b/core-java/src/main/java/com/baeldung/exceptionhandling/PlayerLoadException.java
@ -0,0 +1,11 @@
+package com.baeldung.exceptionhandling;
+
+import java.io.IOException;
+
+public class PlayerLoadException extends Exception {
+
+    public PlayerLoadException(IOException io) {
+        super(io);
+    }
+
+}
--- a/core-java/src/main/java/com/baeldung/exceptionhandling/PlayerScoreException.java
+++ b/core-java/src/main/java/com/baeldung/exceptionhandling/PlayerScoreException.java
@ -0,0 +1,8 @@
+package com.baeldung.exceptionhandling;
+
+public class PlayerScoreException extends Exception {
+
+    public PlayerScoreException(Exception e) {
+        super(e);
+    }
+}
--- a/core-java/src/main/java/com/baeldung/exceptionhandling/TimeoutException.java
+++ b/core-java/src/main/java/com/baeldung/exceptionhandling/TimeoutException.java
@ -0,0 +1,8 @@
+package com.baeldung.exceptionhandling;
+
+public class TimeoutException extends Exception {
+
+    public TimeoutException(String message) {
+        super(message);
+    }
+}
--- a/core-java/src/main/java/com/baeldung/objectsize/InstrumentationAgent.java
+++ b/core-java/src/main/java/com/baeldung/objectsize/InstrumentationAgent.java
@ -0,0 +1,18 @@
+package com.baeldung.objectsize;
+
+import java.lang.instrument.Instrumentation;
+
+public class InstrumentationAgent {
+    private static volatile Instrumentation globalInstrumentation;
+
+    public static void premain(final String agentArgs, final Instrumentation inst) {
+        globalInstrumentation = inst;
+    }
+
+    public static long getObjectSize(final Object object) {
+        if (globalInstrumentation == null) {
+            throw new IllegalStateException("Agent not initialized.");
+        }
+        return globalInstrumentation.getObjectSize(object);
+    }
+}
--- a/core-java/src/main/java/com/baeldung/objectsize/InstrumentationExample.java
+++ b/core-java/src/main/java/com/baeldung/objectsize/InstrumentationExample.java
@ -0,0 +1,59 @@
+package com.baeldung.objectsize;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class InstrumentationExample {
+
+    public static void printObjectSize(Object object) {
+        System.out.println("Object type: " + object.getClass() + ", size: " + InstrumentationAgent.getObjectSize(object) + " bytes");
+    }
+
+    public static void main(String[] arguments) {
+        String emptyString = "";
+        String string = "Estimating Object Size Using Instrumentation";
+        String[] stringArray = { emptyString, string, "com.baeldung" };
+        String[] anotherStringArray = new String[100];
+        List<String> stringList = new ArrayList<>();
+        StringBuilder stringBuilder = new StringBuilder(100);
+        int maxIntPrimitive = Integer.MAX_VALUE;
+        int minIntPrimitive = Integer.MIN_VALUE;
+        Integer maxInteger = Integer.MAX_VALUE;
+        Integer minInteger = Integer.MIN_VALUE;
+        long zeroLong = 0L;
+        double zeroDouble = 0.0;
+        boolean falseBoolean = false;
+        Object object = new Object();
+
+        class EmptyClass {
+        }
+        EmptyClass emptyClass = new EmptyClass();
+
+        class StringClass {
+            public String s;
+        }
+        StringClass stringClass = new StringClass();
+
+        printObjectSize(emptyString);
+        printObjectSize(string);
+        printObjectSize(stringArray);
+        printObjectSize(anotherStringArray);
+        printObjectSize(stringList);
+        printObjectSize(stringBuilder);
+        printObjectSize(maxIntPrimitive);
+        printObjectSize(minIntPrimitive);
+        printObjectSize(maxInteger);
+        printObjectSize(minInteger);
+        printObjectSize(zeroLong);
+        printObjectSize(zeroDouble);
+        printObjectSize(falseBoolean);
+        printObjectSize(Day.TUESDAY);
+        printObjectSize(object);
+        printObjectSize(emptyClass);
+        printObjectSize(stringClass);
+    }
+
+    public enum Day {
+        MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY, SUNDAY
+    }
+}
--- a/core-java/src/main/java/com/baeldung/objectsize/MANIFEST.MF
+++ b/core-java/src/main/java/com/baeldung/objectsize/MANIFEST.MF
@ -0,0 +1 @@
+Premain-class: com.baeldung.objectsize.InstrumentationAgent
--- a/core-java/src/test/java/com/baeldung/array/RemoveFirstElementUnitTest.java
+++ b/core-java/src/test/java/com/baeldung/array/RemoveFirstElementUnitTest.java
@ -0,0 +1,42 @@
+package com.baeldung.array;
+
+import org.junit.Test;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.LinkedList;
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class RemoveFirstElementUnitTest {
+
+    @Test
+    public void givenStringArray_whenRemovingFirstElement_thenArrayIsSmallerAndElementRemoved() {
+        String[] stringArray = {"foo", "bar", "baz"};
+
+        String[] modifiedArray = Arrays.copyOfRange(stringArray, 1, stringArray.length);
+
+        assertThat(modifiedArray.length).isEqualTo(2);
+        assertThat(modifiedArray[0]).isEqualTo("bar");
+    }
+
+    @Test
+    public void givenArrayList_whenRemovingFirstElement_thenListSmallerAndElementRemoved() {
+        List<String> stringList = new ArrayList<>(Arrays.asList("foo", "bar", "baz"));
+        stringList.remove(0);
+
+        assertThat(stringList.size()).isEqualTo(2);
+        assertThat(stringList.get(0)).isEqualTo("bar");
+    }
+
+    @Test
+    public void givenLinkedList_whenRemovingFirstElement_thenListSmallerAndElementRemoved() {
+        List<String> stringList = new LinkedList<>(Arrays.asList("foo", "bar", "baz"));
+        stringList.remove(0);
+
+        assertThat(stringList.size()).isEqualTo(2);
+        assertThat(stringList.get(0)).isEqualTo("bar");
+    }
+
+}
--- a/core-java/src/test/java/com/baeldung/exceptionhandling/ExceptionsUnitTest.java
+++ b/core-java/src/test/java/com/baeldung/exceptionhandling/ExceptionsUnitTest.java
@ -0,0 +1,86 @@
+package com.baeldung.exceptionhandling;
+
+import org.junit.Test;
+
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.nio.file.NoSuchFileException;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+public class ExceptionsUnitTest {
+
+    Exceptions exceptions = new Exceptions();
+
+    @Test
+    public void getPlayers() {
+        assertThatThrownBy(() -> exceptions.getPlayers())
+            .isInstanceOf(NoSuchFileException.class);
+    }
+
+    @Test
+    public void loadAllPlayers() {
+        assertThatThrownBy(() -> exceptions.loadAllPlayers(""))
+            .isInstanceOf(IOException.class);
+    }
+
+    @Test
+    public void getPlayerScoreThrows() {
+        assertThatThrownBy(() -> exceptions.getPlayerScoreThrows(""))
+            .isInstanceOf(FileNotFoundException.class);
+    }
+    
+    @Test
+    public void getPlayerScoreTryCatch() {
+        assertThatThrownBy(() -> exceptions.getPlayerScoreTryCatch(""))
+            .isInstanceOf(IllegalArgumentException.class);
+    }
+    
+    @Test
+    public void getPlayerScoreFinally() {
+        assertThatThrownBy(() -> exceptions.getPlayerScoreFinally(""))
+            .isInstanceOf(FileNotFoundException.class);
+    }
+    
+    @Test
+    public void loadAllPlayersThrowingChecked() {
+        assertThatThrownBy(() -> exceptions.loadAllPlayersThrowingChecked(""))
+            .isInstanceOf(TimeoutException.class);
+    }
+    
+    @Test
+    public void loadAllPlayersThrowingUnchecked() {
+        assertThatThrownBy(() -> exceptions.loadAllPlayersThrowingUnchecked(""))
+            .isInstanceOf(IllegalArgumentException.class);
+    }
+    
+    @Test
+    public void loadAllPlayersWrapping() {
+        assertThatThrownBy(() -> exceptions.loadAllPlayersWrapping(""))
+            .isInstanceOf(IOException.class);
+    }
+    
+    @Test
+    public void loadAllPlayersRethrowing() {
+        assertThatThrownBy(() -> exceptions.loadAllPlayersRethrowing(""))
+            .isInstanceOf(PlayerLoadException.class);
+    }
+    
+    @Test
+    public void loadAllPlayersThrowable() {
+        assertThatThrownBy(() -> exceptions.loadAllPlayersThrowable(""))
+            .isInstanceOf(NullPointerException.class);
+    }
+    
+    @Test
+    public void throwAsGotoAntiPattern() {
+        assertThatThrownBy(() -> exceptions.throwAsGotoAntiPattern())
+            .isInstanceOf(MyException.class);
+    }
+    
+    @Test
+    public void getPlayerScoreSwallowingExceptionAntiPatternAlternative2() {
+        assertThatThrownBy(() -> exceptions.getPlayerScoreSwallowingExceptionAntiPatternAlternative2(""))
+            .isInstanceOf(PlayerScoreException.class);
+    }
+}
--- a/core-java/src/test/java/com/baeldung/java/listInitialization/ListInitializationUnitTest.java
+++ b/core-java/src/test/java/com/baeldung/java/listInitialization/ListInitializationUnitTest.java
@ -0,0 +1,73 @@
+package com.baeldung.java.listInitialization;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import lombok.extern.java.Log;
+
+import org.junit.Assert;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+
+@Log
+public class ListInitializationUnitTest {
+
+    @Rule
+    public ExpectedException exception = ExpectedException.none();
+
+    @Test
+    public void givenAnonymousInnerClass_thenInitialiseList() {
+        List<String> cities = new ArrayList() {
+            // Inside declaration of the subclass
+
+            // You can have multiple initializer block
+            {
+                log.info("Inside the first initializer block.");
+            }
+
+            {
+                log.info("Inside the second initializer block.");
+                add("New York");
+                add("Rio");
+                add("Tokyo");
+            }
+        };
+
+        Assert.assertTrue(cities.contains("New York"));
+    }
+
+    @Test
+    public void givenArraysAsList_thenInitialiseList() {
+        List<String> list = Arrays.asList("foo", "bar");
+
+        Assert.assertTrue(list.contains("foo"));
+    }
+
+    @Test
+    public void givenArraysAsList_whenAdd_thenUnsupportedException() {
+        List<String> list = Arrays.asList("foo", "bar");
+
+        exception.expect(UnsupportedOperationException.class);
+        list.add("baz");
+    }
+
+    @Test
+    public void givenArrayAsList_whenCreated_thenShareReference() {
+        String[] array = { "foo", "bar" };
+        List<String> list = Arrays.asList(array);
+        array[0] = "baz";
+        Assert.assertEquals("baz", list.get(0));
+    }
+
+    @Test
+    public void givenStream_thenInitializeList() {
+        List<String> list = Stream.of("foo", "bar")
+            .collect(Collectors.toList());
+
+        Assert.assertTrue(list.contains("foo"));
+    }
+}
--- a/core-kotlin/README.md
+++ b/core-kotlin/README.md
@ -36,3 +36,4 @@
 - [Working with Enums in Kotlin](http://www.baeldung.com/kotlin-enum)
 - [Create a Java and Kotlin Project with Maven](http://www.baeldung.com/kotlin-maven-java-project)
 - [Reflection with Kotlin](http://www.baeldung.com/kotlin-reflection)
+- [Get a Random Number in Kotlin](http://www.baeldung.com/kotlin-random-number)
--- a/core-kotlin/src/main/kotlin/com/baeldung/builder/FoodOrder.kt
+++ b/core-kotlin/src/main/kotlin/com/baeldung/builder/FoodOrder.kt
@ -0,0 +1,39 @@
+package com.baeldung.builder
+
+class FoodOrder private constructor(builder: FoodOrder.Builder) {
+
+    val bread: String?
+    val condiments: String?
+    val meat: String?
+    val fish: String?
+
+    init {
+        this.bread = builder.bread
+        this.condiments = builder.condiments
+        this.meat = builder.meat
+        this.fish = builder.fish
+    }
+
+    class Builder {
+
+        var bread: String? = null
+            private set
+        var condiments: String? = null
+            private set
+        var meat: String? = null
+            private set
+        var fish: String? = null
+            private set
+
+        fun bread(bread: String) = apply { this.bread = bread }
+
+        fun condiments(condiments: String) = apply { this.condiments = condiments }
+
+        fun meat(meat: String) = apply { this.meat = meat }
+
+        fun fish(fish: String) = apply { this.fish = fish }
+
+        fun build() = FoodOrder(this)
+
+    }
+}
--- a/core-kotlin/src/main/kotlin/com/baeldung/builder/FoodOrderApply.kt
+++ b/core-kotlin/src/main/kotlin/com/baeldung/builder/FoodOrderApply.kt
@ -0,0 +1,8 @@
+package com.baeldung.builder
+
+class FoodOrderApply {
+    var bread: String? = null
+    var condiments: String? = null
+    var meat: String? = null
+    var fish: String? = null
+}
--- a/core-kotlin/src/main/kotlin/com/baeldung/builder/FoodOrderNamed.kt
+++ b/core-kotlin/src/main/kotlin/com/baeldung/builder/FoodOrderNamed.kt
@ -0,0 +1,7 @@
+package com.baeldung.builder
+
+data class FoodOrderNamed(
+        val bread: String? = null,
+        val condiments: String? = null,
+        val meat: String? = null,
+        val fish: String? = null)
--- a/core-kotlin/src/test/kotlin/com/baeldung/builder/BuilderPatternUnitTest.kt
+++ b/core-kotlin/src/test/kotlin/com/baeldung/builder/BuilderPatternUnitTest.kt
@ -0,0 +1,139 @@
+package com.baeldung.builder
+
+import org.junit.jupiter.api.Assertions
+import org.junit.jupiter.api.Test
+
+internal class BuilderPatternUnitTest {
+
+    @Test
+    fun whenBuildingFoodOrderSettingValues_thenFieldsNotNull() {
+
+        val foodOrder = FoodOrder.Builder()
+                .bread("white bread")
+                .meat("bacon")
+                .fish("salmon")
+                .condiments("olive oil")
+                .build()
+
+        Assertions.assertNotNull(foodOrder.bread)
+        Assertions.assertNotNull(foodOrder.meat)
+        Assertions.assertNotNull(foodOrder.condiments)
+        Assertions.assertNotNull(foodOrder.fish)
+    }
+
+    @Test
+    fun whenBuildingFoodOrderSettingValues_thenFieldsContainsValues() {
+
+        val foodOrder = FoodOrder.Builder()
+                .bread("white bread")
+                .meat("bacon")
+                .fish("salmon")
+                .condiments("olive oil")
+                .build()
+
+        Assertions.assertEquals("white bread", foodOrder.bread)
+        Assertions.assertEquals("bacon", foodOrder.meat)
+        Assertions.assertEquals("olive oil", foodOrder.condiments)
+        Assertions.assertEquals("salmon", foodOrder.fish)
+    }
+
+    @Test
+    fun whenBuildingFoodOrderWithoutSettingValues_thenFieldsNull() {
+
+        val foodOrder = FoodOrder.Builder()
+                .build()
+
+        Assertions.assertNull(foodOrder.bread)
+        Assertions.assertNull(foodOrder.meat)
+        Assertions.assertNull(foodOrder.condiments)
+        Assertions.assertNull(foodOrder.fish)
+    }
+
+
+    @Test
+    fun whenBuildingFoodOrderNamedSettingValues_thenFieldsNotNull() {
+
+        val foodOrder = FoodOrderNamed(
+                meat = "bacon",
+                fish = "salmon",
+                condiments = "olive oil",
+                bread = "white bread"
+        )
+
+        Assertions.assertNotNull(foodOrder.bread)
+        Assertions.assertNotNull(foodOrder.meat)
+        Assertions.assertNotNull(foodOrder.condiments)
+        Assertions.assertNotNull(foodOrder.fish)
+    }
+
+    @Test
+    fun whenBuildingFoodOrderNamedSettingValues_thenFieldsContainsValues() {
+
+        val foodOrder = FoodOrderNamed(
+                meat = "bacon",
+                fish = "salmon",
+                condiments = "olive oil",
+                bread = "white bread"
+        )
+
+        Assertions.assertEquals("white bread", foodOrder.bread)
+        Assertions.assertEquals("bacon", foodOrder.meat)
+        Assertions.assertEquals("olive oil", foodOrder.condiments)
+        Assertions.assertEquals("salmon", foodOrder.fish)
+    }
+
+    @Test
+    fun whenBuildingFoodOrderNamedWithoutSettingValues_thenFieldsNull() {
+
+        val foodOrder = FoodOrderNamed()
+
+        Assertions.assertNull(foodOrder.bread)
+        Assertions.assertNull(foodOrder.meat)
+        Assertions.assertNull(foodOrder.condiments)
+        Assertions.assertNull(foodOrder.fish)
+    }
+
+    @Test
+    fun whenBuildingFoodOrderApplySettingValues_thenFieldsNotNull() {
+
+        val foodOrder = FoodOrderApply().apply {
+            meat = "bacon"
+            fish = "salmon"
+            condiments = "olive oil"
+            bread = "white bread"
+        }
+
+        Assertions.assertNotNull(foodOrder.bread)
+        Assertions.assertNotNull(foodOrder.meat)
+        Assertions.assertNotNull(foodOrder.condiments)
+        Assertions.assertNotNull(foodOrder.fish)
+    }
+
+    @Test
+    fun whenBuildingFoodOrderApplySettingValues_thenFieldsContainsValues() {
+
+        val foodOrder = FoodOrderApply().apply {
+            meat = "bacon"
+            fish = "salmon"
+            condiments = "olive oil"
+            bread = "white bread"
+        }
+
+        Assertions.assertEquals("white bread", foodOrder.bread)
+        Assertions.assertEquals("bacon", foodOrder.meat)
+        Assertions.assertEquals("olive oil", foodOrder.condiments)
+        Assertions.assertEquals("salmon", foodOrder.fish)
+    }
+
+    @Test
+    fun whenBuildingFoodOrderApplyWithoutSettingValues_thenFieldsNull() {
+
+        val foodOrder = FoodOrderApply()
+
+        Assertions.assertNull(foodOrder.bread)
+        Assertions.assertNull(foodOrder.meat)
+        Assertions.assertNull(foodOrder.condiments)
+        Assertions.assertNull(foodOrder.fish)
+    }
+
+}
--- a/jmh/README.md
+++ b/jmh/README.md
@ -1,3 +1,4 @@
 ## Relevant articles:

 - [Microbenchmarking with Java](http://www.baeldung.com/java-microbenchmark-harness)
+
--- a/libraries-server/.gitignore
+++ b/libraries-server/.gitignore
@ -0,0 +1,9 @@
+*.class
+
+# Folders #
+/gensrc
+/target
+
+# Packaged files #
+*.jar
+/bin/
--- a/libraries-server/pom.xml
+++ b/libraries-server/pom.xml
@ -1,23 +1,19 @@
 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
-    <groupId>org.baeldung</groupId>
-    <artifactId>mqtt</artifactId>
+    <groupId>com.baeldung</groupId>
+    <artifactId>libraries-server</artifactId>
    <version>0.0.1-SNAPSHOT</version>
-
-    <parent>
+     <parent>
        <groupId>com.baeldung</groupId>
        <artifactId>parent-modules</artifactId>
        <version>1.0.0-SNAPSHOT</version>
    </parent>
-
-    <dependencies>
+     <dependencies>
        <dependency>
            <groupId>org.eclipse.paho</groupId>
            <artifactId>org.eclipse.paho.client.mqttv3</artifactId>
            <version>1.2.0</version>
        </dependency>	
    </dependencies>
-
-
-</project>
+ </project>
--- a/libraries-server/src/main/java/com/baeldung/mqtt/EngineTemperatureSensor.java
+++ b/libraries-server/src/main/java/com/baeldung/mqtt/EngineTemperatureSensor.java
--- a/libraries-server/src/test/java/com/baeldung/mqtt/EngineTemperatureSensorLiveTest.java
+++ b/libraries-server/src/test/java/com/baeldung/mqtt/EngineTemperatureSensorLiveTest.java
--- a/libraries/.gitignore
+++ b/libraries/.gitignore
@ -6,3 +6,4 @@

 # Packaged files #
 *.jar
+/bin/
--- a/libraries/pom.xml
+++ b/libraries/pom.xml
@ -772,6 +772,12 @@
            <scope>test</scope>
        </dependency>

+        <dependency>
+            <groupId>org.yaml</groupId>
+            <artifactId>snakeyaml</artifactId>
+            <version>${snakeyaml.version}</version>            
+        </dependency>       
+
    </dependencies>

    <repositories>
@ -909,6 +915,7 @@
    </build>

    <properties>
+        <snakeyaml.version>1.21</snakeyaml.version>
        <googleclient.version>1.23.0</googleclient.version>
        <crdt.version>0.1.0</crdt.version>
        <multiverse.version>0.7.0</multiverse.version>
@ -1019,4 +1026,4 @@
        <maven-jar-plugin.version>3.0.2</maven-jar-plugin.version>
    </properties>

-</project>
+</project>
--- a/libraries/src/main/java/com/baeldung/snakeyaml/Address.java
+++ b/libraries/src/main/java/com/baeldung/snakeyaml/Address.java
@ -0,0 +1,41 @@
+package com.baeldung.snakeyaml;
+
+public class Address {
+    private String line;
+    private String city;
+    private String state;
+    private Integer zip;
+
+    public String getLine() {
+        return line;
+    }
+
+    public void setLine(String line) {
+        this.line = line;
+    }
+
+    public String getCity() {
+        return city;
+    }
+
+    public void setCity(String city) {
+        this.city = city;
+    }
+
+    public String getState() {
+        return state;
+    }
+
+    public void setState(String state) {
+        this.state = state;
+    }
+
+    public Integer getZip() {
+        return zip;
+    }
+
+    public void setZip(Integer zip) {
+        this.zip = zip;
+    }
+
+}
--- a/libraries/src/main/java/com/baeldung/snakeyaml/Contact.java
+++ b/libraries/src/main/java/com/baeldung/snakeyaml/Contact.java
@ -0,0 +1,26 @@
+package com.baeldung.snakeyaml;
+
+public class Contact {
+
+    private String type;
+
+    private int number;
+
+
+    public String getType() {
+        return type;
+    }
+
+    public void setType(String type) {
+        this.type = type;
+    }
+
+    public int getNumber() {
+        return number;
+    }
+
+    public void setNumber(int number) {
+        this.number = number;
+    }
+
+}
--- a/libraries/src/main/java/com/baeldung/snakeyaml/Customer.java
+++ b/libraries/src/main/java/com/baeldung/snakeyaml/Customer.java
@ -0,0 +1,53 @@
+package com.baeldung.snakeyaml;
+
+import java.util.List;
+
+public class Customer {
+
+    private String firstName;
+    private String lastName;
+    private int age;
+    private List<Contact> contactDetails;
+    private Address homeAddress;
+
+    public String getFirstName() {
+        return firstName;
+    }
+
+    public void setFirstName(String firstName) {
+        this.firstName = firstName;
+    }
+
+    public String getLastName() {
+        return lastName;
+    }
+
+    public void setLastName(String lastName) {
+        this.lastName = lastName;
+    }
+
+    public int getAge() {
+        return age;
+    }
+
+    public void setAge(int age) {
+        this.age = age;
+    }
+
+    public List<Contact> getContactDetails() {
+        return contactDetails;
+    }
+
+    public void setContactDetails(List<Contact> contactDetails) {
+        this.contactDetails = contactDetails;
+    }
+
+    public Address getHomeAddress() {
+        return homeAddress;
+    }
+
+    public void setHomeAddress(Address homeAddress) {
+        this.homeAddress = homeAddress;
+    }    
+
+}
--- a/libraries/src/test/java/com/baeldung/snakeyaml/JavaToYAMLSerializationUnitTest.java
+++ b/libraries/src/test/java/com/baeldung/snakeyaml/JavaToYAMLSerializationUnitTest.java
@ -0,0 +1,54 @@
+package com.baeldung.snakeyaml;
+
+import static org.junit.Assert.assertEquals;
+
+import java.io.StringWriter;
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+import org.junit.Test;
+import org.yaml.snakeyaml.Yaml;
+import org.yaml.snakeyaml.nodes.Tag;
+
+import com.baeldung.snakeyaml.Customer;
+
+public class JavaToYAMLSerializationUnitTest {
+
+    @Test
+    public void whenDumpMap_thenGenerateCorrectYAML() {
+        Map<String, Object> data = new LinkedHashMap<String, Object>();
+        data.put("name", "Silenthand Olleander");
+        data.put("race", "Human");
+        data.put("traits", new String[] { "ONE_HAND", "ONE_EYE" });
+        Yaml yaml = new Yaml();
+        StringWriter writer = new StringWriter();
+        yaml.dump(data, writer);
+        String expectedYaml = "name: Silenthand Olleander\nrace: Human\ntraits: [ONE_HAND, ONE_EYE]\n";
+        assertEquals(expectedYaml, writer.toString());
+    }
+
+    @Test
+    public void whenDumpACustomType_thenGenerateCorrectYAML() {
+        Customer customer = new Customer();
+        customer.setAge(45);
+        customer.setFirstName("Greg");
+        customer.setLastName("McDowell");
+        Yaml yaml = new Yaml();
+        StringWriter writer = new StringWriter();
+        yaml.dump(customer, writer);        
+        String expectedYaml = "!!com.baeldung.snakeyaml.Customer {age: 45, contactDetails: null, firstName: Greg,\n  homeAddress: null, lastName: McDowell}\n";
+        assertEquals(expectedYaml, writer.toString());
+    }
+
+    @Test
+    public void whenDumpAsCustomType_thenGenerateCorrectYAML() {
+        Customer customer = new Customer();
+        customer.setAge(45);
+        customer.setFirstName("Greg");
+        customer.setLastName("McDowell");
+        Yaml yaml = new Yaml();
+        String expectedYaml = "{age: 45, contactDetails: null, firstName: Greg, homeAddress: null, lastName: McDowell}\n";
+        assertEquals(expectedYaml, yaml.dumpAs(customer, Tag.MAP, null));
+    }
+
+}
--- a/libraries/src/test/java/com/baeldung/snakeyaml/YAMLToJavaDeserialisationUnitTest.java
+++ b/libraries/src/test/java/com/baeldung/snakeyaml/YAMLToJavaDeserialisationUnitTest.java
@ -0,0 +1,131 @@
+package com.baeldung.snakeyaml;
+
+import org.junit.Test;
+import org.yaml.snakeyaml.TypeDescription;
+import org.yaml.snakeyaml.Yaml;
+import org.yaml.snakeyaml.constructor.Constructor;
+
+import java.io.InputStream;
+import java.util.Date;
+import java.util.Map;
+
+import static org.junit.Assert.*;
+
+public class YAMLToJavaDeserialisationUnitTest {
+
+    @Test
+    public void whenLoadYAMLDocument_thenLoadCorrectMap() {
+        Yaml yaml = new Yaml();
+        InputStream inputStream = this.getClass()
+            .getClassLoader()
+            .getResourceAsStream("yaml/customer.yaml");
+        Map<String, Object> obj = yaml.load(inputStream);
+        assertEquals("John", obj.get("firstName"));
+        assertEquals("Doe", obj.get("lastName"));
+        assertEquals(20, obj.get("age"));
+    }
+
+    @Test
+    public void whenLoadYAMLDocumentWithTopLevelClass_thenLoadCorrectJavaObject() {
+        Yaml yaml = new Yaml(new Constructor(Customer.class));
+        InputStream inputStream = this.getClass()
+            .getClassLoader()
+            .getResourceAsStream("yaml/customer.yaml");
+        Customer customer = yaml.load(inputStream);
+        assertEquals("John", customer.getFirstName());
+        assertEquals("Doe", customer.getLastName());
+        assertEquals(20, customer.getAge());
+    }
+
+    @Test
+    public void whenLoadYAMLDocumentWithAssumedClass_thenLoadCorrectJavaObject() {
+        Yaml yaml = new Yaml();
+        InputStream inputStream = this.getClass()
+            .getClassLoader()
+            .getResourceAsStream("yaml/customer_with_type.yaml");
+        Customer customer = yaml.load(inputStream);
+        assertEquals("John", customer.getFirstName());
+        assertEquals("Doe", customer.getLastName());
+        assertEquals(20, customer.getAge());
+    }
+
+    @Test
+    public void whenLoadYAML_thenLoadCorrectImplicitTypes() {
+        Yaml yaml = new Yaml();
+        Map<Object, Object> document = yaml.load("3.0: 2018-07-22");
+        assertNotNull(document);
+        assertEquals(1, document.size());
+        assertTrue(document.containsKey(3.0d));
+        assertTrue(document.get(3.0d) instanceof Date);
+    }
+
+    @Test
+    public void whenLoadYAMLDocumentWithTopLevelClass_thenLoadCorrectJavaObjectWithNestedObjects() {
+        Yaml yaml = new Yaml(new Constructor(Customer.class));
+        InputStream inputStream = this.getClass()
+            .getClassLoader()
+            .getResourceAsStream("yaml/customer_with_contact_details_and_address.yaml");
+        Customer customer = yaml.load(inputStream);
+        assertNotNull(customer);
+        assertEquals("John", customer.getFirstName());
+        assertEquals("Doe", customer.getLastName());
+        assertEquals(31, customer.getAge());
+        assertNotNull(customer.getContactDetails());
+        assertEquals(2, customer.getContactDetails().size());
+        assertEquals("mobile", customer.getContactDetails()
+            .get(0)
+            .getType());
+        assertEquals(123456789,customer.getContactDetails()
+            .get(0)
+            .getNumber());
+        assertEquals("landline", customer.getContactDetails()
+            .get(1)
+            .getType());
+        assertEquals(456786868, customer.getContactDetails()
+            .get(1)
+            .getNumber());
+        assertNotNull(customer.getHomeAddress());
+        assertEquals("Xyz, DEF Street", customer.getHomeAddress()
+            .getLine());
+    }
+
+    @Test
+    public void whenLoadYAMLDocumentWithTypeDescription_thenLoadCorrectJavaObjectWithCorrectGenericType() {
+        Constructor constructor = new Constructor(Customer.class);
+        TypeDescription customTypeDescription = new TypeDescription(Customer.class);
+        customTypeDescription.addPropertyParameters("contactDetails", Contact.class);
+        constructor.addTypeDescription(customTypeDescription);
+        Yaml yaml = new Yaml(constructor);
+        InputStream inputStream = this.getClass()
+            .getClassLoader()
+            .getResourceAsStream("yaml/customer_with_contact_details.yaml");
+        Customer customer = yaml.load(inputStream);
+        assertNotNull(customer);
+        assertEquals("John", customer.getFirstName());
+        assertEquals("Doe", customer.getLastName());
+        assertEquals(31, customer.getAge());
+        assertNotNull(customer.getContactDetails());
+        assertEquals(2, customer.getContactDetails().size());
+        assertEquals("mobile", customer.getContactDetails()
+            .get(0)
+            .getType());
+        assertEquals("landline", customer.getContactDetails()
+            .get(1)
+            .getType());
+    }
+
+    @Test
+    public void whenLoadMultipleYAMLDocuments_thenLoadCorrectJavaObjects() {
+        Yaml yaml = new Yaml(new Constructor(Customer.class));
+        InputStream inputStream = this.getClass()
+            .getClassLoader()
+            .getResourceAsStream("yaml/customers.yaml");
+        int count = 0;
+        for (Object object : yaml.loadAll(inputStream)) {
+            count++;
+            assertTrue(object instanceof Customer);
+        }
+        assertEquals(2, count);
+    }
+
+}
--- a/libraries/src/test/resources/yaml/customer.yaml
+++ b/libraries/src/test/resources/yaml/customer.yaml
@ -0,0 +1,3 @@
+firstName: "John"
+lastName: "Doe"
+age: 20
--- a/libraries/src/test/resources/yaml/customer_with_contact_details.yaml
+++ b/libraries/src/test/resources/yaml/customer_with_contact_details.yaml
@ -0,0 +1,7 @@
+firstName: "John"
+lastName: "Doe"
+age: 31
+contactDetails:
+   - { type: "mobile", number: 123456789}
+   - { type: "landline", number: 456786868}
+   
--- a/libraries/src/test/resources/yaml/customer_with_contact_details_and_address.yaml
+++ b/libraries/src/test/resources/yaml/customer_with_contact_details_and_address.yaml
@ -0,0 +1,13 @@
+firstName: "John"
+lastName: "Doe"
+age: 31
+contactDetails:
+   - type: "mobile"
+     number: 123456789
+   - type: "landline"
+     number: 456786868
+homeAddress:
+   line: "Xyz, DEF Street"
+   city: "City Y"
+   state: "State Y"
+   zip: 345657
--- a/libraries/src/test/resources/yaml/customer_with_contact_details_and_tags.yaml
+++ b/libraries/src/test/resources/yaml/customer_with_contact_details_and_tags.yaml
@ -0,0 +1,6 @@
+firstName: "John"
+lastName: "Doe"
+age: 31
+contactDetails:
+   - !contact { type: "mobile", number: 123456789}
+   - !contact { type: "landline", number: 456786868}
--- a/libraries/src/test/resources/yaml/customer_with_type.yaml
+++ b/libraries/src/test/resources/yaml/customer_with_type.yaml
@ -0,0 +1,4 @@
+!!com.baeldung.snakeyaml.Customer
+firstName: "John"
+lastName: "Doe"
+age: 20
--- a/libraries/src/test/resources/yaml/customers.yaml
+++ b/libraries/src/test/resources/yaml/customers.yaml
@ -0,0 +1,8 @@
+---
+firstName: "John"
+lastName: "Doe"
+age: 20
+---
+firstName: "Jack"
+lastName: "Jones"
+age: 25
--- a/logging-modules/log4j/src/main/java/com/baeldung/slf4j/SLF4JLogExceptions.java
+++ b/logging-modules/log4j/src/main/java/com/baeldung/slf4j/SLF4JLogExceptions.java
@ -0,0 +1,16 @@
+package com.baeldung.slf4j;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class SLF4JLogExceptions {
+
+    public static void main(String[] args) {
+        Logger logger = LoggerFactory.getLogger(SLF4JLogExceptions.class);
+
+        logger.error("An exception occurred!");
+        logger.error("An exception occurred!", new Exception("Custom exception"));
+        logger.error("{}, {}! An exception occurred!", "Hello", "World", new Exception("Custom exception"));
+    }
+
+}
--- a/mqtt/README.md
+++ b/mqtt/README.md
@ -1,4 +0,0 @@
-### Relevant Articles: 
-================================
-
- [MQTT Client in Java](http://www.baeldung.com/mqtt-client)
--- a/persistence-modules/java-jpa/README.md
+++ b/persistence-modules/java-jpa/README.md
@ -0,0 +1,3 @@
+# Relevant Articles
+
+* [A Guide to SqlResultSetMapping](http://www.baeldung.com/jpa-sql-resultset-mapping)
--- a/pom.xml
+++ b/pom.xml
@ -197,7 +197,7 @@
 		</extensions>
 		<pluginManagement>
 			<plugins>
-				<!--This plugin's configuration is used to store Eclipse m2e settings 
+				<!--This plugin's configuration is used to store Eclipse m2e settings
 					only. It has no influence on the Maven build itself. -->
 				<plugin>
 					<groupId>org.eclipse.m2e</groupId>
@ -368,6 +368,7 @@
 				<module>jws</module>
 				<module>libraries</module>
 				<module>libraries-data</module>
+				<module>libraries-server</module>
 				<module>linkrest</module>
 				<module>logging-modules/log-mdc</module>
 				<module>logging-modules/log4j</module>
@ -551,6 +552,8 @@
 				<module>spring-reactive-kotlin</module>
 				<module>jnosql</module>
 				<module>testing-modules/junit-abstract</module>
+				<module>sse-jaxrs</module>
+				<module>spring-boot-angular-ecommerce</module>
 			</modules>

 		</profile>
@ -599,35 +602,35 @@

 				<!-- <module>core-java-9</module> --> <!-- Commented because we have still not upgraded to java 9 -->

-				<!-- <module>asm</module> <module>atomix</module> <module>apache-cayenne</module> 
-					<module>aws</module> <module>aws-lambda</module> <module>akka-streams</module> 
-					<module>algorithms</module> <module>annotations</module> <module>apache-cxf</module> 
-					<module>apache-fop</module> <module>apache-poi</module> <module>apache-tika</module> 
-					<module>apache-thrift</module> <module>apache-curator</module> <module>apache-zookeeper</module> 
-					<module>apache-opennlp</module> <module>autovalue</module> <module>axon</module> 
-					<module>azure</module> <module>bootique</module> <module>cdi</module> <module>core-java</module> 
-					<module>core-java-collections</module> <module>core-java-io</module> <module>core-java-8</module> 
-					<module>core-kotlin</module> <module>core-groovy</module> <module>core-java-concurrency</module> 
-					<module>couchbase</module> <module>deltaspike</module> <module>dozer</module> 
-					<module>ethereum</module> <module>ejb</module> <module>feign</module> <module>flips</module> 
-					<module>geotools</module> <module>testing-modules/groovy-spock</module> <module>testing-modules/gatling</module> 
-					<module>google-cloud</module> <module>google-web-toolkit</module> <module>gson</module> 
-					<module>guava</module> <module>guava-modules/guava-18</module> <module>guava-modules/guava-19</module> 
-					<module>guava-modules/guava-21</module> <module>guice</module> <module>disruptor</module> 
-					<module>spring-static-resources</module> <module>hazelcast</module> <module>hbase</module> 
-					<module>hibernate5</module> <module>httpclient</module> <module>hystrix</module> 
-					<module>image-processing</module> <module>immutables</module> <module>influxdb</module> 
-					<module>jackson</module> <module>persistence-modules/java-cassandra</module> 
-					<module>vavr</module> <module>java-lite</module> <module>java-numbers</module> 
-					<module>java-rmi</module> <module>java-vavr-stream</module> <module>javax-servlets</module> 
-					<module>javaxval</module> <module>jaxb</module> <module>javafx</module> <module>jgroups</module> 
-					<module>jee-7</module> <module>jhipster/jhipster-monolithic</module> <module>jjwt</module> 
-					<module>jpa-storedprocedure</module> <module>jsf</module> <module>json-path</module> 
-					<module>json</module> <module>jsoup</module> <module>testing-modules/junit-5</module> 
-					<module>jws</module> <module>libraries-data</module> <module>linkrest</module> 
-					<module>logging-modules/log-mdc</module> <module>logging-modules/log4j</module> 
-					<module>logging-modules/log4j2</module> <module>logging-modules/logback</module> 
-					<module>lombok</module> <module>mapstruct</module> <module>metrics</module> 
+				<!-- <module>asm</module> <module>atomix</module> <module>apache-cayenne</module>
+					<module>aws</module> <module>aws-lambda</module> <module>akka-streams</module>
+					<module>algorithms</module> <module>annotations</module> <module>apache-cxf</module>
+					<module>apache-fop</module> <module>apache-poi</module> <module>apache-tika</module>
+					<module>apache-thrift</module> <module>apache-curator</module> <module>apache-zookeeper</module>
+					<module>apache-opennlp</module> <module>autovalue</module> <module>axon</module>
+					<module>azure</module> <module>bootique</module> <module>cdi</module> <module>core-java</module>
+					<module>core-java-collections</module> <module>core-java-io</module> <module>core-java-8</module>
+					<module>core-kotlin</module> <module>core-groovy</module> <module>core-java-concurrency</module>
+					<module>couchbase</module> <module>deltaspike</module> <module>dozer</module>
+					<module>ethereum</module> <module>ejb</module> <module>feign</module> <module>flips</module>
+					<module>geotools</module> <module>testing-modules/groovy-spock</module> <module>testing-modules/gatling</module>
+					<module>google-cloud</module> <module>google-web-toolkit</module> <module>gson</module>
+					<module>guava</module> <module>guava-modules/guava-18</module> <module>guava-modules/guava-19</module>
+					<module>guava-modules/guava-21</module> <module>guice</module> <module>disruptor</module>
+					<module>spring-static-resources</module> <module>hazelcast</module> <module>hbase</module>
+					<module>hibernate5</module> <module>httpclient</module> <module>hystrix</module>
+					<module>image-processing</module> <module>immutables</module> <module>influxdb</module>
+					<module>jackson</module> <module>persistence-modules/java-cassandra</module>
+					<module>vavr</module> <module>java-lite</module> <module>java-numbers</module>
+					<module>java-rmi</module> <module>java-vavr-stream</module> <module>javax-servlets</module>
+					<module>javaxval</module> <module>jaxb</module> <module>javafx</module> <module>jgroups</module>
+					<module>jee-7</module> <module>jhipster/jhipster-monolithic</module> <module>jjwt</module>
+					<module>jpa-storedprocedure</module> <module>jsf</module> <module>json-path</module>
+					<module>json</module> <module>jsoup</module> <module>testing-modules/junit-5</module>
+					<module>jws</module> <module>libraries-data</module> <module>linkrest</module>
+					<module>logging-modules/log-mdc</module> <module>logging-modules/log4j</module>
+					<module>logging-modules/log4j2</module> <module>logging-modules/logback</module>
+					<module>lombok</module> <module>mapstruct</module> <module>metrics</module>
 					<module>maven</module> <module>mesos-marathon</module> <module>msf4j</module> -->

 				<!-- group 1 - OK, 27min, 7911Kb log, 8 failusres -->
@ -670,8 +673,8 @@
 				<module>spring-amqp-simple</module>
 				<module>spring-apache-camel</module>
 				<module>spring-batch</module>
-				<module>testing-modules/junit-abstract</module>
-
+				<module>testing-modules/junit-abstract</module>				
+				<module>jmh</module>

 				<!-- group 2 - Pass, 11-16 min, 42 test failures, 4,020 KB -->

@ -750,37 +753,37 @@

 				<!-- group 4 -->

-				<!-- <module>spring-security-acl</module> <module>spring-security-cache-control</module> 
-					<module>spring-security-client/spring-security-jsp-authentication</module> 
-					<module>spring-security-client/spring-security-jsp-authorize</module> <module>spring-security-client/spring-security-jsp-config</module> 
-					<module>spring-security-client/spring-security-mvc</module> <module>spring-security-client/spring-security-thymeleaf-authentication</module> 
-					<module>spring-security-client/spring-security-thymeleaf-authorize</module> 
-					<module>spring-security-client/spring-security-thymeleaf-config</module> 
-					<module>spring-security-core</module> <module>spring-security-mvc-boot</module> 
-					<module>spring-security-mvc-custom</module> <module>spring-security-mvc-digest-auth</module> 
-					<module>spring-security-mvc-ldap</module> <module>spring-security-mvc-login</module> 
-					<module>spring-security-mvc-persisted-remember-me</module> <module>spring-security-mvc-session</module> 
-					<module>spring-security-mvc-socket</module> <module>spring-security-openid</module> 
-					<module>spring-security-react</module> <module>spring-security-rest-basic-auth</module> 
-					<module>spring-security-rest-custom</module> <module>spring-security-rest</module> 
-					<module>spring-security-sso</module> <module>spring-security-x509</module> 
-					<module>spring-session</module> <module>spring-sleuth</module> <module>spring-social-login</module> 
-					<module>spring-spel</module> <module>spring-state-machine</module> <module>spring-thymeleaf</module> 
-					<module>spring-userservice</module> <module>spring-zuul</module> <module>spring-reactor</module> 
-					<module>spring-vertx</module> <module>spring-jinq</module> <module>spring-rest-embedded-tomcat</module> 
-					<module>testing-modules/testing</module> <module>testing-modules/testng</module> 
-					<module>video-tutorials</module> <module>xml</module> <module>xmlunit-2</module> 
-					<module>struts-2</module> <module>apache-velocity</module> <module>apache-solrj</module> 
-					<module>rabbitmq</module> <module>vertx</module> <module>persistence-modules/spring-data-gemfire</module> 
-					<module>mybatis</module> <module>spring-drools</module> <module>drools</module> 
-					<module>persistence-modules/liquibase</module> <module>spring-boot-property-exp</module> 
-					<module>testing-modules/mockserver</module> <module>testing-modules/test-containers</module> 
-					<module>undertow</module> <module>vertx-and-rxjava</module> <module>saas</module> 
-					<module>deeplearning4j</module> <module>lucene</module> <module>vraptor</module> 
-					<module>persistence-modules/java-cockroachdb</module> <module>spring-security-thymeleaf</module> 
-					<module>persistence-modules/java-jdbi</module> <module>jersey</module> <module>java-spi</module> 
-					<module>performance-tests</module> <module>twilio</module> <module>spring-boot-ctx-fluent</module> 
-					<module>java-ee-8-security-api</module> <module>spring-webflux-amqp</module> 
+				<!-- <module>spring-security-acl</module> <module>spring-security-cache-control</module>
+					<module>spring-security-client/spring-security-jsp-authentication</module>
+					<module>spring-security-client/spring-security-jsp-authorize</module> <module>spring-security-client/spring-security-jsp-config</module>
+					<module>spring-security-client/spring-security-mvc</module> <module>spring-security-client/spring-security-thymeleaf-authentication</module>
+					<module>spring-security-client/spring-security-thymeleaf-authorize</module>
+					<module>spring-security-client/spring-security-thymeleaf-config</module>
+					<module>spring-security-core</module> <module>spring-security-mvc-boot</module>
+					<module>spring-security-mvc-custom</module> <module>spring-security-mvc-digest-auth</module>
+					<module>spring-security-mvc-ldap</module> <module>spring-security-mvc-login</module>
+					<module>spring-security-mvc-persisted-remember-me</module> <module>spring-security-mvc-session</module>
+					<module>spring-security-mvc-socket</module> <module>spring-security-openid</module>
+					<module>spring-security-react</module> <module>spring-security-rest-basic-auth</module>
+					<module>spring-security-rest-custom</module> <module>spring-security-rest</module>
+					<module>spring-security-sso</module> <module>spring-security-x509</module>
+					<module>spring-session</module> <module>spring-sleuth</module> <module>spring-social-login</module>
+					<module>spring-spel</module> <module>spring-state-machine</module> <module>spring-thymeleaf</module>
+					<module>spring-userservice</module> <module>spring-zuul</module> <module>spring-reactor</module>
+					<module>spring-vertx</module> <module>spring-jinq</module> <module>spring-rest-embedded-tomcat</module>
+					<module>testing-modules/testing</module> <module>testing-modules/testng</module>
+					<module>video-tutorials</module> <module>xml</module> <module>xmlunit-2</module>
+					<module>struts-2</module> <module>apache-velocity</module> <module>apache-solrj</module>
+					<module>rabbitmq</module> <module>vertx</module> <module>persistence-modules/spring-data-gemfire</module>
+					<module>mybatis</module> <module>spring-drools</module> <module>drools</module>
+					<module>persistence-modules/liquibase</module> <module>spring-boot-property-exp</module>
+					<module>testing-modules/mockserver</module> <module>testing-modules/test-containers</module>
+					<module>undertow</module> <module>vertx-and-rxjava</module> <module>saas</module>
+					<module>deeplearning4j</module> <module>lucene</module> <module>vraptor</module>
+					<module>persistence-modules/java-cockroachdb</module> <module>spring-security-thymeleaf</module>
+					<module>persistence-modules/java-jdbi</module> <module>jersey</module> <module>java-spi</module>
+					<module>performance-tests</module> <module>twilio</module> <module>spring-boot-ctx-fluent</module>
+					<module>java-ee-8-security-api</module> <module>spring-webflux-amqp</module>
 					<module>antlr</module> <module>maven-archetype</module> <module>apache-meecrowave</module> -->

 				<!-- group 4 - OK, 12 min, 3,961 KB log, 12 failed tests -->
@ -793,7 +796,7 @@

 		<profile>
 			<id>integration-lite</id>
-			
+
 			<build>
 				<plugins>
 					<plugin>
@ -832,7 +835,7 @@
 				<module>parent-spring-4</module>
 				<module>parent-spring-5</module>
 				<module>parent-java</module>
-				
+
 				<module>asm</module>
 				<module>atomix</module>
 				<module>apache-cayenne</module>
@ -859,7 +862,7 @@
 				<module>core-java-io</module>
 				<module>core-java-8</module>
 				<module>core-groovy</module>
-				
+
 				<module>couchbase</module>
 				<module>deltaspike</module>
 				<module>dozer</module>
@ -1077,15 +1080,15 @@
 				<module>maven-archetype</module>
 				<module>apache-meecrowave</module>
 				<module>testing-modules/junit-abstract</module>
-                
+
                <module>spring-hibernate4</module>
                <module>xml</module>
                <module>vertx</module>
                <module>metrics</module>
                <module>httpclient</module>
-                
+
                <!-- problematic -->
-                <!-- 
+                <!--
                <module>ejb</module>
                <module>persistence-modules/java-cassandra</module>
                <module>persistence-modules/spring-data-cassandra</module>
@ -1095,9 +1098,9 @@

                <module>jmeter</module>
 				-->
-                
+
 				<!-- heavy -->
-				<!-- 
+				<!--
 				<module>libraries</module>
 				<module>geotools</module>
 				<module>jhipster/jhipster-monolithic</module>
@ -1111,7 +1114,7 @@
                <module>spring-security-mvc-custom</module>
                <module>core-java-concurrency</module>
 				-->
-                
+
                <!-- 30:32 min -->
 			</modules>

@ -1119,7 +1122,7 @@

        <profile>
            <id>integration-heavy</id>
-            
+
            <build>
                <plugins>
                    <plugin>
@ -1158,7 +1161,7 @@
                <module>parent-spring-4</module>
                <module>parent-spring-5</module>
                <module>parent-java</module>
-                
+
                <module>libraries</module>
                <module>geotools</module>
                <module>jhipster/jhipster-monolithic</module>
@ -1236,4 +1239,4 @@
 		<!-- <maven-pmd-plugin.version>3.9.0</maven-pmd-plugin.version> -->
 		<maven-pmd-plugin.version>3.8</maven-pmd-plugin.version>
 	</properties>
-</project>
+</project>
--- a/spring-5-mvc/README.md
+++ b/spring-5-mvc/README.md
@ -1,2 +1,3 @@
 ### Relevant Articles:
 - [Spring Boot and Kotlin](http://www.baeldung.com/spring-boot-kotlin)
+- [Spring MVC Streaming and SSE Request Processing](http://www.baeldung.com/spring-mvc-sse-streams)
--- a/spring-5-mvc/src/main/java/com/baeldung/web/ResponseBodyEmitterController.java
+++ b/spring-5-mvc/src/main/java/com/baeldung/web/ResponseBodyEmitterController.java
@ -13,11 +13,11 @@ import org.springframework.web.servlet.mvc.method.annotation.ResponseBodyEmitter

@Controller
 public class ResponseBodyEmitterController {
+    private ExecutorService nonBlockingService = Executors.newSingleThreadExecutor();

    @GetMapping(Constants.API_RBE)
    public ResponseEntity<ResponseBodyEmitter> handleRbe() {
        ResponseBodyEmitter emitter = new ResponseBodyEmitter();
-        ExecutorService nonBlockingService = Executors.newSingleThreadExecutor();

            nonBlockingService.execute(() -> {
                try {
--- a/spring-5-mvc/src/main/java/com/baeldung/web/SseEmitterController.java
+++ b/spring-5-mvc/src/main/java/com/baeldung/web/SseEmitterController.java
@ -10,12 +10,12 @@ import org.springframework.web.servlet.mvc.method.annotation.SseEmitter;

@Controller
 public class SseEmitterController {
+    private ExecutorService nonBlockingService = Executors.newCachedThreadPool();

    @GetMapping(Constants.API_SSE)
    public SseEmitter handleSse() {
        SseEmitter emitter = new SseEmitter();

-        ExecutorService nonBlockingService = Executors.newSingleThreadExecutor();
        nonBlockingService.execute(() -> {
            try {
                emitter.send(Constants.API_SSE_MSG + " @ " + new Date());
@ -29,4 +29,4 @@ public class SseEmitterController {
        return emitter;
    }

-}
+}
--- a/spring-5-reactive/src/main/java/com/baeldung/functional/FormHandler.java
+++ b/spring-5-reactive/src/main/java/com/baeldung/functional/FormHandler.java
@ -34,8 +34,7 @@ public class FormHandler {

    private AtomicLong extractData(List<DataBuffer> dataBuffers) {
        AtomicLong atomicLong = new AtomicLong(0);
-        dataBuffers.forEach(d -> atomicLong.addAndGet(d.asByteBuffer()
-            .array().length));
+        dataBuffers.forEach(d -> atomicLong.addAndGet(d.readableByteCount()));
        return atomicLong;
    }
 }
--- a/spring-5-reactive/src/main/java/com/baeldung/functional/FunctionalWebApplication.java
+++ b/spring-5-reactive/src/main/java/com/baeldung/functional/FunctionalWebApplication.java
@ -13,6 +13,7 @@ import java.util.List;
 import java.util.concurrent.CopyOnWriteArrayList;

 import org.apache.catalina.Context;
+import org.apache.catalina.Wrapper;
 import org.apache.catalina.startup.Tomcat;
 import org.springframework.boot.web.embedded.tomcat.TomcatWebServer;
 import org.springframework.boot.web.server.WebServer;
@ -61,7 +62,8 @@ public class FunctionalWebApplication {
        tomcat.setPort(9090);
        Context rootContext = tomcat.addContext("", System.getProperty("java.io.tmpdir"));
        ServletHttpHandlerAdapter servlet = new ServletHttpHandlerAdapter(httpHandler);
-        Tomcat.addServlet(rootContext, "httpHandlerServlet", servlet);
+        Wrapper servletWrapper = Tomcat.addServlet(rootContext, "httpHandlerServlet", servlet);
+        servletWrapper.setAsyncSupported(true);
        rootContext.addServletMappingDecoded("/", "httpHandlerServlet");

        TomcatWebServer server = new TomcatWebServer(tomcat);
--- a/spring-5-reactive/src/main/java/com/baeldung/reactive/SpringSecurity5Application.java
+++ b/spring-5-reactive/src/main/java/com/baeldung/reactive/SpringSecurity5Application.java
@ -11,7 +11,7 @@ import org.springframework.web.server.adapter.WebHttpHandlerBuilder;
 import reactor.ipc.netty.NettyContext;
 import reactor.ipc.netty.http.server.HttpServer;

-@ComponentScan(basePackages = {"com.baeldung.security"})
+@ComponentScan(basePackages = {"com.baeldung.reactive.security"})
@EnableWebFlux
 public class SpringSecurity5Application {

--- a/spring-5-reactive/src/main/java/com/baeldung/reactive/cors/global/controllers/FurtherCorsConfigsController.java
+++ b/spring-5-reactive/src/main/java/com/baeldung/reactive/cors/global/controllers/FurtherCorsConfigsController.java
@ -8,7 +8,7 @@ import org.springframework.web.bind.annotation.RestController;

 import reactor.core.publisher.Mono;

-@RestController
+@RestController("FurtherCorsConfigsController-cors-on-global-config-and-more")
@RequestMapping("/cors-on-global-config-and-more")
 public class FurtherCorsConfigsController {

--- a/spring-5-reactive/src/main/java/com/baeldung/reactive/cors/global/controllers/RegularRestController.java
+++ b/spring-5-reactive/src/main/java/com/baeldung/reactive/cors/global/controllers/RegularRestController.java
@ -7,7 +7,7 @@ import org.springframework.web.bind.annotation.RestController;

 import reactor.core.publisher.Mono;

-@RestController
+@RestController("RegularRestController-cors-on-global-config")
@RequestMapping("/cors-on-global-config")
 public class RegularRestController {

--- a/spring-5-reactive/src/main/java/com/baeldung/reactive/security/SecurityConfig.java
+++ b/spring-5-reactive/src/main/java/com/baeldung/reactive/security/SecurityConfig.java
@ -19,7 +19,7 @@ public class SecurityConfig {
    @Bean
    public SecurityWebFilterChain securitygWebFilterChain(ServerHttpSecurity http) {
        return http.authorizeExchange()
-            .pathMatchers("/admin")
+            .pathMatchers("/", "/admin")
            .hasAuthority("ROLE_ADMIN")
            .matchers(EndpointRequest.to(FeaturesEndpoint.class))
            .permitAll()
--- a/spring-5-reactive/src/main/java/com/baeldung/reactive/urlmatch/ExploreSpring5URLPatternUsingRouterFunctions.java
+++ b/spring-5-reactive/src/main/java/com/baeldung/reactive/urlmatch/ExploreSpring5URLPatternUsingRouterFunctions.java
@ -7,6 +7,7 @@ import static org.springframework.web.reactive.function.server.RouterFunctions.t
 import static org.springframework.web.reactive.function.server.ServerResponse.ok;

 import org.apache.catalina.Context;
+import org.apache.catalina.Wrapper;
 import org.apache.catalina.startup.Tomcat;
 import org.springframework.boot.web.embedded.tomcat.TomcatWebServer;
 import org.springframework.boot.web.server.WebServer;
@ -41,7 +42,8 @@ public class ExploreSpring5URLPatternUsingRouterFunctions {
        tomcat.setPort(9090);
        Context rootContext = tomcat.addContext("", System.getProperty("java.io.tmpdir"));
        ServletHttpHandlerAdapter servlet = new ServletHttpHandlerAdapter(httpHandler);
-        Tomcat.addServlet(rootContext, "httpHandlerServlet", servlet);
+        Wrapper servletWrapper = Tomcat.addServlet(rootContext, "httpHandlerServlet", servlet);
+        servletWrapper.setAsyncSupported(true);
        rootContext.addServletMappingDecoded("/", "httpHandlerServlet");

        TomcatWebServer server = new TomcatWebServer(tomcat);
--- a/spring-5-reactive/src/main/java/com/baeldung/reactive/webflux/EmployeeCreationEvent.java
+++ b/spring-5-reactive/src/main/java/com/baeldung/reactive/webflux/EmployeeCreationEvent.java
@ -4,8 +4,12 @@ import lombok.AllArgsConstructor;
 import lombok.Data;

@Data
-@AllArgsConstructor
 public class EmployeeCreationEvent {
    private String employeeId;
    private String creationTime;
+    public EmployeeCreationEvent(String employeeId, String creationTime) {
+        super();
+        this.employeeId = employeeId;
+        this.creationTime = creationTime;
+    }
 }
--- a/spring-5-reactive/src/main/java/com/baeldung/reactive/webflux/EmployeeWebSocketHandler.java
+++ b/spring-5-reactive/src/main/java/com/baeldung/reactive/webflux/EmployeeWebSocketHandler.java
@ -15,7 +15,7 @@ import com.fasterxml.jackson.databind.ObjectMapper;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;

-@Component
+@Component("EmployeeWebSocketHandler")
 public class EmployeeWebSocketHandler implements WebSocketHandler {

    ObjectMapper om = new ObjectMapper();
--- a/spring-5-reactive/src/main/java/com/baeldung/websocket/ReactiveWebSocketConfiguration.java
+++ b/spring-5-reactive/src/main/java/com/baeldung/websocket/ReactiveWebSocketConfiguration.java
@ -1,19 +1,22 @@
 package com.baeldung.websocket;

+import java.util.HashMap;
+import java.util.Map;
+
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Qualifier;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.web.reactive.HandlerMapping;
 import org.springframework.web.reactive.handler.SimpleUrlHandlerMapping;
 import org.springframework.web.reactive.socket.WebSocketHandler;
 import org.springframework.web.reactive.socket.server.support.WebSocketHandlerAdapter;
-import java.util.HashMap;
-import java.util.Map;

@Configuration
 public class ReactiveWebSocketConfiguration {

    @Autowired
+    @Qualifier("ReactiveWebSocketHandler")
    private WebSocketHandler webSocketHandler;

    @Bean
--- a/spring-5-reactive/src/main/java/com/baeldung/websocket/ReactiveWebSocketHandler.java
+++ b/spring-5-reactive/src/main/java/com/baeldung/websocket/ReactiveWebSocketHandler.java
@ -14,7 +14,7 @@ import java.time.Duration;
 import static java.time.LocalDateTime.now;
 import static java.util.UUID.randomUUID;

-@Component
+@Component("ReactiveWebSocketHandler")
 public class ReactiveWebSocketHandler implements WebSocketHandler {

    private static final ObjectMapper json = new ObjectMapper();
--- a/spring-5-reactive/src/test/java/com/baeldung/functional/FunctionalWebApplicationIntegrationTest.java
+++ b/spring-5-reactive/src/test/java/com/baeldung/functional/FunctionalWebApplicationIntegrationTest.java
@ -1,5 +1,8 @@
 package com.baeldung.functional;

+import static org.springframework.web.reactive.function.BodyInserters.fromObject;
+import static org.springframework.web.reactive.function.BodyInserters.fromResource;
+
 import org.junit.AfterClass;
 import org.junit.BeforeClass;
 import org.junit.Test;
@ -12,9 +15,6 @@ import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.util.MultiValueMap;
 import org.springframework.web.reactive.function.BodyInserters;

-import static org.springframework.web.reactive.function.BodyInserters.fromObject;
-import static org.springframework.web.reactive.function.BodyInserters.fromResource;
-
 public class FunctionalWebApplicationIntegrationTest {

    private static WebTestClient client;
--- a/spring-5-reactive/src/test/java/com/baeldung/reactive/urlmatch/ExploreSpring5URLPatternUsingRouterFunctionsIntegrationTest.java
+++ b/spring-5-reactive/src/test/java/com/baeldung/reactive/urlmatch/ExploreSpring5URLPatternUsingRouterFunctionsIntegrationTest.java
@ -6,8 +6,6 @@ import org.junit.Test;
 import org.springframework.boot.web.server.WebServer;
 import org.springframework.test.web.reactive.server.WebTestClient;

-import com.baeldung.reactive.urlmatch.ExploreSpring5URLPatternUsingRouterFunctions;
-
 public class ExploreSpring5URLPatternUsingRouterFunctionsIntegrationTest {

    private static WebTestClient client;
--- a/spring-5-reactive/src/test/java/com/baeldung/web/client/WebTestClientIntegrationTest.java
+++ b/spring-5-reactive/src/test/java/com/baeldung/web/client/WebTestClientIntegrationTest.java
@ -53,7 +53,7 @@ public class WebTestClientIntegrationTest {
            .uri("/resource")
            .exchange()
            .expectStatus()
-            .is3xxRedirection()
+            .isOk()
            .expectBody();
    }

--- a/spring-5-reactive/src/test/resources/baeldung-weekly.png
+++ b/spring-5-reactive/src/test/resources/baeldung-weekly.png
--- a/spring-5-security/src/main/java/com/baeldung/oauth2extractors/ExtractorsApplication.java
+++ b/spring-5-security/src/main/java/com/baeldung/oauth2extractors/ExtractorsApplication.java
@ -1,7 +1,9 @@
 package com.baeldung.oauth2extractors;

+import org.apache.logging.log4j.util.Strings;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.core.env.AbstractEnvironment;
 import org.springframework.stereotype.Controller;
 import org.springframework.web.bind.annotation.RequestMapping;

@ -9,6 +11,13 @@ import org.springframework.web.bind.annotation.RequestMapping;
@Controller
 public class ExtractorsApplication {
    public static void main(String[] args) {
+        if (Strings.isEmpty(System.getProperty(AbstractEnvironment.ACTIVE_PROFILES_PROPERTY_NAME))) {
+            /*System.setProperty(AbstractEnvironment.ACTIVE_PROFILES_PROPERTY_NAME,
+                    "oauth2-extractors-baeldung");*/
+            System.setProperty(AbstractEnvironment.ACTIVE_PROFILES_PROPERTY_NAME,
+                    "oauth2-extractors-github");
+        }
+
        SpringApplication.run(ExtractorsApplication.class, args);
    }

--- a/spring-5-security/src/main/java/com/baeldung/oauth2extractors/configuration/SecurityConfig.java
+++ b/spring-5-security/src/main/java/com/baeldung/oauth2extractors/configuration/SecurityConfig.java
@ -1,18 +1,19 @@
 package com.baeldung.oauth2extractors.configuration;

-import com.baeldung.oauth2extractors.extractor.CustomAuthoritiesExtractor;
-import com.baeldung.oauth2extractors.extractor.CustomPrincipalExtractor;
+import com.baeldung.oauth2extractors.extractor.custom.BaeldungAuthoritiesExtractor;
+import com.baeldung.oauth2extractors.extractor.custom.BaeldungPrincipalExtractor;
+import com.baeldung.oauth2extractors.extractor.github.GithubAuthoritiesExtractor;
+import com.baeldung.oauth2extractors.extractor.github.GithubPrincipalExtractor;
 import org.springframework.boot.autoconfigure.security.oauth2.client.EnableOAuth2Sso;
 import org.springframework.boot.autoconfigure.security.oauth2.resource.AuthoritiesExtractor;
 import org.springframework.boot.autoconfigure.security.oauth2.resource.PrincipalExtractor;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
-import org.springframework.context.annotation.PropertySource;
+import org.springframework.context.annotation.Profile;
 import org.springframework.security.config.annotation.web.builders.HttpSecurity;
 import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;

@Configuration
-@PropertySource("application-oauth2-extractors.properties")
@EnableOAuth2Sso
 public class SecurityConfig extends WebSecurityConfigurerAdapter {

@ -29,12 +30,26 @@ public class SecurityConfig extends WebSecurityConfigurerAdapter {
    }

    @Bean
-    public PrincipalExtractor principalExtractor() {
-        return new CustomPrincipalExtractor();
+    @Profile("oauth2-extractors-baeldung")
+    public PrincipalExtractor baeldungPrincipalExtractor() {
+        return new BaeldungPrincipalExtractor();
    }

    @Bean
-    public AuthoritiesExtractor authoritiesExtractor() {
-        return new CustomAuthoritiesExtractor();
+    @Profile("oauth2-extractors-baeldung")
+    public AuthoritiesExtractor baeldungAuthoritiesExtractor() {
+        return new BaeldungAuthoritiesExtractor();
+    }
+
+    @Bean
+    @Profile("oauth2-extractors-github")
+    public PrincipalExtractor githubPrincipalExtractor() {
+        return new GithubPrincipalExtractor();
+    }
+
+    @Bean
+    @Profile("oauth2-extractors-github")
+    public AuthoritiesExtractor githubAuthoritiesExtractor() {
+        return new GithubAuthoritiesExtractor();
    }
 }
--- a/spring-5-security/src/main/java/com/baeldung/oauth2extractors/extractor/custom/BaeldungAuthoritiesExtractor.java
+++ b/spring-5-security/src/main/java/com/baeldung/oauth2extractors/extractor/custom/BaeldungAuthoritiesExtractor.java
@ -0,0 +1,29 @@
+package com.baeldung.oauth2extractors.extractor.custom;
+
+import org.springframework.boot.autoconfigure.security.oauth2.resource.AuthoritiesExtractor;
+import org.springframework.security.core.GrantedAuthority;
+import org.springframework.security.core.authority.AuthorityUtils;
+
+import java.util.ArrayList;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+
+public class BaeldungAuthoritiesExtractor implements AuthoritiesExtractor {
+
+    @Override
+    public List<GrantedAuthority> extractAuthorities(Map<String, Object> map) {
+        return AuthorityUtils
+                .commaSeparatedStringToAuthorityList(asAuthorities(map));
+    }
+
+    private String asAuthorities(Map<String, Object> map) {
+        List<String> authorities = new ArrayList<>();
+        authorities.add("BAELDUNG_USER");
+        List<LinkedHashMap<String, String>> authz = (List<LinkedHashMap<String, String>>) map.get("authorities");
+        for (LinkedHashMap<String, String> entry : authz) {
+            authorities.add(entry.get("authority"));
+        }
+        return String.join(",", authorities);
+    }
+}
--- a/spring-5-security/src/main/java/com/baeldung/oauth2extractors/extractor/custom/BaeldungPrincipalExtractor.java
+++ b/spring-5-security/src/main/java/com/baeldung/oauth2extractors/extractor/custom/BaeldungPrincipalExtractor.java
@ -0,0 +1,13 @@
+package com.baeldung.oauth2extractors.extractor.custom;
+
+import org.springframework.boot.autoconfigure.security.oauth2.resource.PrincipalExtractor;
+
+import java.util.Map;
+
+public class BaeldungPrincipalExtractor implements PrincipalExtractor {
+
+    @Override
+    public Object extractPrincipal(Map<String, Object> map) {
+        return map.get("name");
+    }
+}
--- a/spring-5-security/src/main/java/com/baeldung/oauth2extractors/extractor/github/GithubAuthoritiesExtractor.java
+++ b/spring-5-security/src/main/java/com/baeldung/oauth2extractors/extractor/github/GithubAuthoritiesExtractor.java
@ -1,4 +1,4 @@
-package com.baeldung.oauth2extractors.extractor;
+package com.baeldung.oauth2extractors.extractor.github;

 import org.springframework.boot.autoconfigure.security.oauth2.resource.AuthoritiesExtractor;
 import org.springframework.security.core.GrantedAuthority;
@ -9,7 +9,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.Objects;

-public class CustomAuthoritiesExtractor implements AuthoritiesExtractor {
+public class GithubAuthoritiesExtractor implements AuthoritiesExtractor {
    private List<GrantedAuthority> GITHUB_FREE_AUTHORITIES = AuthorityUtils
            .commaSeparatedStringToAuthorityList("GITHUB_USER,GITHUB_USER_FREE");
    private List<GrantedAuthority> GITHUB_SUBSCRIBED_AUTHORITIES = AuthorityUtils
--- a/spring-5-security/src/main/java/com/baeldung/oauth2extractors/extractor/github/GithubPrincipalExtractor.java
+++ b/spring-5-security/src/main/java/com/baeldung/oauth2extractors/extractor/github/GithubPrincipalExtractor.java
@ -1,10 +1,10 @@
-package com.baeldung.oauth2extractors.extractor;
+package com.baeldung.oauth2extractors.extractor.github;

 import org.springframework.boot.autoconfigure.security.oauth2.resource.PrincipalExtractor;

 import java.util.Map;

-public class CustomPrincipalExtractor implements PrincipalExtractor {
+public class GithubPrincipalExtractor implements PrincipalExtractor {

    @Override
    public Object extractPrincipal(Map<String, Object> map) {
--- a/spring-5-security/src/main/resources/application-oauth2-extractors-baeldung.properties
+++ b/spring-5-security/src/main/resources/application-oauth2-extractors-baeldung.properties
@ -0,0 +1,6 @@
+server.port=8082
+security.oauth2.client.client-id=SampleClientId
+security.oauth2.client.client-secret=secret
+security.oauth2.client.access-token-uri=http://localhost:8081/auth/oauth/token
+security.oauth2.client.user-authorization-uri=http://localhost:8081/auth/oauth/authorize
+security.oauth2.resource.user-info-uri=http://localhost:8081/auth/user/me
--- a/spring-5-security/src/main/resources/application-oauth2-extractors-github.properties
+++ b/spring-5-security/src/main/resources/application-oauth2-extractors-github.properties
@ -1,3 +1,4 @@
+server.port=8082
 security.oauth2.client.client-id=89a7c4facbb3434d599d
 security.oauth2.client.client-secret=9b3b08e4a340bd20e866787e4645b54f73d74b6a
 security.oauth2.client.access-token-uri=https://github.com/login/oauth/access_token
--- a/spring-5-security/src/test/java/com/baeldung/oauth2extractors/ExtractorsUnitTest.java
+++ b/spring-5-security/src/test/java/com/baeldung/oauth2extractors/ExtractorsUnitTest.java
@ -6,6 +6,7 @@ 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.ActiveProfiles;
 import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.junit4.SpringRunner;
 import org.springframework.test.web.servlet.MockMvc;
@ -21,6 +22,7 @@ import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.
@RunWith(SpringRunner.class)
@SpringBootTest(classes = ExtractorsApplication.class, webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
@ContextConfiguration(classes = {SecurityConfig.class})
+@ActiveProfiles("oauth2-extractors-github")
 public class ExtractorsUnitTest {

    @Autowired
--- a/spring-boot-angular-ecommerce/README.md
+++ b/spring-boot-angular-ecommerce/README.md
@ -0,0 +1,2 @@
+### Relevant Articles:
+- [A Simple E-Commerce Implementation with Spring]()
--- a/spring-boot-angular-ecommerce/pom.xml
+++ b/spring-boot-angular-ecommerce/pom.xml
@ -0,0 +1,84 @@
+<?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>spring-boot-angular-ecommerce</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <packaging>jar</packaging>
+
+    <name>spring-boot-angular-ecommerce</name>
+    <description>Spring Boot Angular E-commerce Appliciation</description>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <dependencyManagement>
+        <dependencies>
+            <dependency>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-dependencies</artifactId>
+                <version>${spring.boot.version}</version>
+                <type>pom</type>
+                <scope>import</scope>
+            </dependency>
+        </dependencies>
+    </dependencyManagement>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-data-jpa</artifactId>
+            <version>${spring.boot.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+            <version>${spring.boot.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-devtools</artifactId>
+            <version>${spring.boot.version}</version>
+            <scope>runtime</scope>
+        </dependency>
+        <dependency>
+            <groupId>com.h2database</groupId>
+            <artifactId>h2</artifactId>
+            <version>1.4.197</version>
+            <scope>runtime</scope>
+        </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.datatype</groupId>
+            <artifactId>jackson-datatype-jsr310</artifactId>
+            <version>2.9.6</version>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <version>${spring.boot.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+                <version>${spring-boot-maven-plugin.version}</version>
+            </plugin>
+        </plugins>
+    </build>
+
+    <properties>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
+        <java.version>1.8</java.version>
+        <spring.boot.version>2.0.3.RELEASE</spring.boot.version>
+        <spring-boot-maven-plugin.version>2.0.4.RELEASE</spring-boot-maven-plugin.version>
+    </properties>
+</project>
--- a/spring-boot-angular-ecommerce/src/main/frontend/.editorconfig
+++ b/spring-boot-angular-ecommerce/src/main/frontend/.editorconfig
@ -0,0 +1,13 @@
+# Editor configuration, see http://editorconfig.org
+root = true
+
+[*]
+charset = utf-8
+indent_style = space
+indent_size = 4
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[*.md]
+max_line_length = off
+trim_trailing_whitespace = false
--- a/spring-boot-angular-ecommerce/src/main/frontend/README.md
+++ b/spring-boot-angular-ecommerce/src/main/frontend/README.md
@ -0,0 +1,27 @@
+# Frontend
+
+This project was generated with [Angular CLI](https://github.com/angular/angular-cli) version 6.0.8.
+
+## Development server
+
+Run `ng serve` for a dev server. Navigate to `http://localhost:4200/`. The app will automatically reload if you change any of the source files.
+
+## Code scaffolding
+
+Run `ng generate component component-name` to generate a new component. You can also use `ng generate directive|pipe|service|class|guard|interface|enum|module`.
+
+## Build
+
+Run `ng build` to build the project. The build artifacts will be stored in the `dist/` directory. Use the `--prod` flag for a production build.
+
+## Running unit tests
+
+Run `ng test` to execute the unit tests via [Karma](https://karma-runner.github.io).
+
+## Running end-to-end tests
+
+Run `ng e2e` to execute the end-to-end tests via [Protractor](http://www.protractortest.org/).
+
+## Further help
+
+To get more help on the Angular CLI use `ng help` or go check out the [Angular CLI README](https://github.com/angular/angular-cli/blob/master/README.md).
--- a/spring-boot-angular-ecommerce/src/main/frontend/angular.json
+++ b/spring-boot-angular-ecommerce/src/main/frontend/angular.json
@ -0,0 +1,128 @@
+{
+  "$schema": "./node_modules/@angular/cli/lib/config/schema.json",
+  "version": 1,
+  "newProjectRoot": "projects",
+  "projects": {
+    "frontend": {
+      "root": "",
+      "sourceRoot": "src",
+      "projectType": "application",
+      "prefix": "app",
+      "schematics": {},
+      "architect": {
+        "build": {
+          "builder": "@angular-devkit/build-angular:browser",
+          "options": {
+            "outputPath": "dist/frontend",
+            "index": "src/index.html",
+            "main": "src/main.ts",
+            "polyfills": "src/polyfills.ts",
+            "tsConfig": "src/tsconfig.app.json",
+            "assets": [
+              "src/favicon.ico",
+              "src/assets"
+            ],
+            "styles": [
+              "node_modules/bootstrap/dist/css/bootstrap.min.css",
+              "src/styles.css"
+            ],
+            "scripts": []
+          },
+          "configurations": {
+            "production": {
+              "fileReplacements": [
+                {
+                  "replace": "src/environments/environment.ts",
+                  "with": "src/environments/environment.prod.ts"
+                }
+              ],
+              "optimization": true,
+              "outputHashing": "all",
+              "sourceMap": false,
+              "extractCss": true,
+              "namedChunks": false,
+              "aot": true,
+              "extractLicenses": true,
+              "vendorChunk": false,
+              "buildOptimizer": true
+            }
+          }
+        },
+        "serve": {
+          "builder": "@angular-devkit/build-angular:dev-server",
+          "options": {
+            "browserTarget": "frontend:build"
+          },
+          "configurations": {
+            "production": {
+              "browserTarget": "frontend:build:production"
+            }
+          }
+        },
+        "extract-i18n": {
+          "builder": "@angular-devkit/build-angular:extract-i18n",
+          "options": {
+            "browserTarget": "frontend:build"
+          }
+        },
+        "test": {
+          "builder": "@angular-devkit/build-angular:karma",
+          "options": {
+            "main": "src/test.ts",
+            "polyfills": "src/polyfills.ts",
+            "tsConfig": "src/tsconfig.spec.json",
+            "karmaConfig": "src/karma.conf.js",
+            "styles": [
+              "src/styles.css"
+            ],
+            "scripts": [],
+            "assets": [
+              "src/favicon.ico",
+              "src/assets"
+            ]
+          }
+        },
+        "lint": {
+          "builder": "@angular-devkit/build-angular:tslint",
+          "options": {
+            "tsConfig": [
+              "src/tsconfig.app.json",
+              "src/tsconfig.spec.json"
+            ],
+            "exclude": [
+              "**/node_modules/**"
+            ]
+          }
+        }
+      }
+    },
+    "frontend-e2e": {
+      "root": "e2e/",
+      "projectType": "application",
+      "architect": {
+        "e2e": {
+          "builder": "@angular-devkit/build-angular:protractor",
+          "options": {
+            "protractorConfig": "e2e/protractor.conf.js",
+            "devServerTarget": "frontend:serve"
+          },
+          "configurations": {
+            "production": {
+              "devServerTarget": "frontend:serve:production"
+            }
+          }
+        },
+        "lint": {
+          "builder": "@angular-devkit/build-angular:tslint",
+          "options": {
+            "tsConfig": "e2e/tsconfig.e2e.json",
+            "exclude": [
+              "**/node_modules/**"
+            ]
+          }
+        }
+      }
+    }
+  },
+  "defaultProject": "frontend"
+}
--- a/spring-boot-angular-ecommerce/src/main/frontend/e2e/protractor.conf.js
+++ b/spring-boot-angular-ecommerce/src/main/frontend/e2e/protractor.conf.js
@ -0,0 +1,28 @@
+// Protractor configuration file, see link for more information
+// https://github.com/angular/protractor/blob/master/lib/config.ts
+
+const { SpecReporter } = require('jasmine-spec-reporter');
+
+exports.config = {
+  allScriptsTimeout: 11000,
+  specs: [
+    './src/**/*.e2e-spec.ts'
+  ],
+  capabilities: {
+    'browserName': 'chrome'
+  },
+  directConnect: true,
+  baseUrl: 'http://localhost:4200/',
+  framework: 'jasmine',
+  jasmineNodeOpts: {
+    showColors: true,
+    defaultTimeoutInterval: 30000,
+    print: function() {}
+  },
+  onPrepare() {
+    require('ts-node').register({
+      project: require('path').join(__dirname, './tsconfig.e2e.json')
+    });
+    jasmine.getEnv().addReporter(new SpecReporter({ spec: { displayStacktrace: true } }));
+  }
+};
--- a/spring-boot-angular-ecommerce/src/main/frontend/e2e/src/app.e2e-spec.ts
+++ b/spring-boot-angular-ecommerce/src/main/frontend/e2e/src/app.e2e-spec.ts
@ -0,0 +1,14 @@
+import { AppPage } from './app.po';
+
+describe('workspace-project App', () => {
+  let page: AppPage;
+
+  beforeEach(() => {
+    page = new AppPage();
+  });
+
+  it('should display welcome message', () => {
+    page.navigateTo();
+    expect(page.getParagraphText()).toEqual('Welcome to frontend!');
+  });
+});
--- a/spring-boot-angular-ecommerce/src/main/frontend/e2e/src/app.po.ts
+++ b/spring-boot-angular-ecommerce/src/main/frontend/e2e/src/app.po.ts
@ -0,0 +1,11 @@
+import { browser, by, element } from 'protractor';
+
+export class AppPage {
+  navigateTo() {
+    return browser.get('/');
+  }
+
+  getParagraphText() {
+    return element(by.css('app-root h1')).getText();
+  }
+}
--- a/spring-boot-angular-ecommerce/src/main/frontend/e2e/tsconfig.e2e.json
+++ b/spring-boot-angular-ecommerce/src/main/frontend/e2e/tsconfig.e2e.json
@ -0,0 +1,13 @@
+{
+  "extends": "../tsconfig.json",
+  "compilerOptions": {
+    "outDir": "../out-tsc/app",
+    "module": "commonjs",
+    "target": "es5",
+    "types": [
+      "jasmine",
+      "jasminewd2",
+      "node"
+    ]
+  }
+}
--- a/spring-boot-angular-ecommerce/src/main/frontend/package-lock.json
+++ b/spring-boot-angular-ecommerce/src/main/frontend/package-lock.json
--- a/spring-boot-angular-ecommerce/src/main/frontend/package.json
+++ b/spring-boot-angular-ecommerce/src/main/frontend/package.json
@ -0,0 +1,49 @@
+{
+  "name": "frontend",
+  "version": "0.0.0",
+  "scripts": {
+    "ng": "ng",
+    "start": "ng serve --proxy-config proxy-conf.json",
+    "build": "ng build",
+    "test": "ng test",
+    "lint": "ng lint",
+    "e2e": "ng e2e"
+  },
+  "private": true,
+  "dependencies": {
+    "@angular/animations": "^6.0.3",
+    "@angular/common": "^6.0.3",
+    "@angular/compiler": "^6.0.3",
+    "@angular/core": "^6.0.3",
+    "@angular/forms": "^6.0.3",
+    "@angular/http": "^6.0.3",
+    "@angular/platform-browser": "^6.0.3",
+    "@angular/platform-browser-dynamic": "^6.0.3",
+    "@angular/router": "^6.0.3",
+    "bootstrap": "^4.1.2",
+    "core-js": "^2.5.4",
+    "rxjs": "^6.0.0",
+    "zone.js": "^0.8.26"
+  },
+  "devDependencies": {
+    "@angular/compiler-cli": "^6.0.3",
+    "@angular-devkit/build-angular": "~0.6.8",
+    "typescript": "~2.7.2",
+    "@angular/cli": "~6.0.8",
+    "@angular/language-service": "^6.0.3",
+    "@types/jasmine": "~2.8.6",
+    "@types/jasminewd2": "~2.0.3",
+    "@types/node": "~8.9.4",
+    "codelyzer": "~4.2.1",
+    "jasmine-core": "~2.99.1",
+    "jasmine-spec-reporter": "~4.2.1",
+    "karma": "~1.7.1",
+    "karma-chrome-launcher": "~2.2.0",
+    "karma-coverage-istanbul-reporter": "~2.0.0",
+    "karma-jasmine": "~1.1.1",
+    "karma-jasmine-html-reporter": "^0.2.2",
+    "protractor": "~5.3.0",
+    "ts-node": "~5.0.1",
+    "tslint": "~5.9.1"
+  }
+}
--- a/Show More
+++ b/Show More
				`@ -0,0 +1 @@`
				`Premain-class: com.baeldung.objectsize.InstrumentationAgent`