diff --git a/core-java-collections/src/main/java/com/baeldung/java/list/WaysToIterate.java b/core-java-collections/src/main/java/com/baeldung/java/list/WaysToIterate.java
new file mode 100644
index 0000000000..3cce08eabb
--- /dev/null
+++ b/core-java-collections/src/main/java/com/baeldung/java/list/WaysToIterate.java
@@ -0,0 +1,67 @@
+package com.baeldung.java.list;
+
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.List;
+import java.util.ListIterator;
+
+/**
+ *  Demonstrates the different ways to loop over
+ *  the elements of a list.
+ */
+public class WaysToIterate {
+
+    List<String> countries = Arrays.asList("Germany", "Panama", "Australia");
+
+    /**
+     * Iterate over a list using a basic for loop
+     */
+    public void iterateWithForLoop() {
+        for (int i = 0; i < countries.size(); i++) {
+            System.out.println(countries.get(i));
+        }
+    }
+
+    /**
+     * Iterate over a list using the enhanced for loop
+     */
+    public void iterateWithEnhancedForLoop() {
+        for (String country : countries) {
+            System.out.println(country);
+        }
+    }
+
+    /**
+     * Iterate over a list using an Iterator
+     */
+    public void iterateWithIterator() {
+        Iterator<String> countriesIterator = countries.iterator();
+        while(countriesIterator.hasNext()) {
+            System.out.println(countriesIterator.next());
+        }
+    }
+
+    /**
+     * Iterate over a list using a ListIterator
+     */
+    public void iterateWithListIterator() {
+        ListIterator<String> listIterator = countries.listIterator();
+        while(listIterator.hasNext()) {
+            System.out.println(listIterator.next());
+        }
+    }
+
+    /**
+     * Iterate over a list using the Iterable.forEach() method
+     */
+    public void iterateWithForEach() {
+        countries.forEach(System.out::println);
+    }
+
+    /**
+     * Iterate over a list using the Stream.forEach() method
+     */
+    public void iterateWithStreamForEach() {
+        countries.stream().forEach((c) -> System.out.println(c));
+    }
+}
\ No newline at end of file
diff --git a/core-java-collections/src/test/java/com/baeldung/java/list/WaysToIterateUnitTest.java b/core-java-collections/src/test/java/com/baeldung/java/list/WaysToIterateUnitTest.java
new file mode 100644
index 0000000000..973c60b233
--- /dev/null
+++ b/core-java-collections/src/test/java/com/baeldung/java/list/WaysToIterateUnitTest.java
@@ -0,0 +1,71 @@
+package com.baeldung.java.list;
+
+import static org.junit.Assert.assertEquals;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.List;
+import java.util.ListIterator;
+
+import org.junit.Test;
+
+public class WaysToIterateUnitTest {
+
+    List<String> globalCountries = new ArrayList<String>();
+    List<String> europeanCountries = Arrays.asList("Germany", "Panama", "Australia");
+
+    @Test
+    public void whenIteratingUsingForLoop_thenReturnThreeAsSizeOfList() {
+        for (int i = 0; i < europeanCountries.size(); i++) {
+            globalCountries.add(europeanCountries.get(i));
+        }
+        assertEquals(globalCountries.size(), 3);
+        globalCountries.clear();
+    }
+
+    @Test
+    public void whenIteratingUsingEnhancedForLoop_thenReturnThreeAsSizeOfList() {
+        for (String country : europeanCountries) {
+            globalCountries.add(country);
+        }
+        assertEquals(globalCountries.size(), 3);
+        globalCountries.clear();
+    }
+
+    @Test
+    public void whenIteratingUsingIterator_thenReturnThreeAsSizeOfList() {
+        Iterator<String> countriesIterator = europeanCountries.iterator();
+        while (countriesIterator.hasNext()) {
+            globalCountries.add(countriesIterator.next());
+        }
+
+        assertEquals(globalCountries.size(), 3);
+        globalCountries.clear();
+    }
+
+    @Test
+    public void whenIteratingUsingListIterator_thenReturnThreeAsSizeOfList() {
+        ListIterator<String> countriesIterator = europeanCountries.listIterator();
+        while (countriesIterator.hasNext()) {
+            globalCountries.add(countriesIterator.next());
+        }
+
+        assertEquals(globalCountries.size(), 3);
+        globalCountries.clear();
+    }
+
+    @Test
+    public void whenIteratingUsingForEach_thenReturnThreeAsSizeOfList() {
+        europeanCountries.forEach(country -> globalCountries.add(country));
+        assertEquals(globalCountries.size(), 3);
+        globalCountries.clear();
+    }
+
+    @Test
+    public void whenIteratingUsingStreamForEach_thenReturnThreeAsSizeOfList() {
+        europeanCountries.stream().forEach((country) -> globalCountries.add(country));
+        assertEquals(globalCountries.size(), 3);
+        globalCountries.clear();
+    }
+}
\ No newline at end of file
diff --git a/core-java-concurrency/src/main/java/com/baeldung/concurrent/countdownlatch/CountdownLatchCountExample.java b/core-java-concurrency/src/main/java/com/baeldung/concurrent/countdownlatch/CountdownLatchCountExample.java
new file mode 100644
index 0000000000..08c7eeec03
--- /dev/null
+++ b/core-java-concurrency/src/main/java/com/baeldung/concurrent/countdownlatch/CountdownLatchCountExample.java
@@ -0,0 +1,33 @@
+package com.baeldung.concurrent.countdownlatch;
+
+import java.util.concurrent.CountDownLatch;
+
+public class CountdownLatchCountExample {
+
+    private int count;
+
+    public CountdownLatchCountExample(int count) {
+        this.count = count;
+    }
+
+    public boolean callTwiceInSameThread() {
+        CountDownLatch countDownLatch = new CountDownLatch(count);
+        Thread t = new Thread(() -> {
+            countDownLatch.countDown();
+            countDownLatch.countDown();
+        });
+        t.start();
+
+        try {
+            countDownLatch.await();
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+        return countDownLatch.getCount() == 0;
+    }
+
+    public static void main(String[] args) {
+        CountdownLatchCountExample ex = new CountdownLatchCountExample(2);
+        System.out.println("Is CountDown Completed : " + ex.callTwiceInSameThread());
+    }
+}
diff --git a/core-java-concurrency/src/main/java/com/baeldung/concurrent/countdownlatch/CountdownLatchResetExample.java b/core-java-concurrency/src/main/java/com/baeldung/concurrent/countdownlatch/CountdownLatchResetExample.java
new file mode 100644
index 0000000000..1828b7f91e
--- /dev/null
+++ b/core-java-concurrency/src/main/java/com/baeldung/concurrent/countdownlatch/CountdownLatchResetExample.java
@@ -0,0 +1,41 @@
+package com.baeldung.concurrent.countdownlatch;
+
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.atomic.AtomicInteger;
+
+public class CountdownLatchResetExample {
+
+    private int count;
+    private int threadCount;
+    private final AtomicInteger updateCount;
+
+    CountdownLatchResetExample(int count, int threadCount) {
+        updateCount = new AtomicInteger(0);
+        this.count = count;
+        this.threadCount = threadCount;
+    }
+
+    public int countWaits() {
+        CountDownLatch countDownLatch = new CountDownLatch(count);
+        ExecutorService es = Executors.newFixedThreadPool(threadCount);
+        for (int i = 0; i < threadCount; i++) {
+            es.execute(() -> {
+                long prevValue = countDownLatch.getCount();
+                countDownLatch.countDown();
+                if (countDownLatch.getCount() != prevValue) {
+                    updateCount.incrementAndGet();
+                }               
+            });
+        }
+        
+        es.shutdown();
+        return updateCount.get();
+    }
+
+    public static void main(String[] args) {
+        CountdownLatchResetExample ex = new CountdownLatchResetExample(5, 20);
+        System.out.println("Count : " + ex.countWaits());
+    }
+}
diff --git a/core-java-concurrency/src/main/java/com/baeldung/concurrent/cyclicbarrier/CyclicBarrierCompletionMethodExample.java b/core-java-concurrency/src/main/java/com/baeldung/concurrent/cyclicbarrier/CyclicBarrierCompletionMethodExample.java
new file mode 100644
index 0000000000..7c1299da62
--- /dev/null
+++ b/core-java-concurrency/src/main/java/com/baeldung/concurrent/cyclicbarrier/CyclicBarrierCompletionMethodExample.java
@@ -0,0 +1,45 @@
+package com.baeldung.concurrent.cyclicbarrier;
+
+import java.util.concurrent.BrokenBarrierException;
+import java.util.concurrent.CyclicBarrier;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.atomic.AtomicInteger;
+
+public class CyclicBarrierCompletionMethodExample {
+
+    private int count;
+    private int threadCount;
+    private final AtomicInteger updateCount;
+    
+    CyclicBarrierCompletionMethodExample(int count, int threadCount) {
+        updateCount = new AtomicInteger(0);
+        this.count = count;
+        this.threadCount = threadCount;
+    }
+
+    public int countTrips() {
+
+        CyclicBarrier cyclicBarrier = new CyclicBarrier(count, () -> {
+            updateCount.incrementAndGet();
+        });
+
+        ExecutorService es = Executors.newFixedThreadPool(threadCount);
+        for (int i = 0; i < threadCount; i++) {
+            es.execute(() -> {
+                try {
+                    cyclicBarrier.await();
+                } catch (InterruptedException | BrokenBarrierException e) {
+                    e.printStackTrace();
+                }
+            });
+        }
+        es.shutdown();
+        return updateCount.get();
+    }
+
+    public static void main(String[] args) {
+        CyclicBarrierCompletionMethodExample ex = new CyclicBarrierCompletionMethodExample(5, 20);
+        System.out.println("Count : " + ex.countTrips());
+    }
+}
diff --git a/core-java-concurrency/src/main/java/com/baeldung/concurrent/cyclicbarrier/CyclicBarrierCountExample.java b/core-java-concurrency/src/main/java/com/baeldung/concurrent/cyclicbarrier/CyclicBarrierCountExample.java
new file mode 100644
index 0000000000..9d637b428b
--- /dev/null
+++ b/core-java-concurrency/src/main/java/com/baeldung/concurrent/cyclicbarrier/CyclicBarrierCountExample.java
@@ -0,0 +1,32 @@
+package com.baeldung.concurrent.cyclicbarrier;
+
+import java.util.concurrent.BrokenBarrierException;
+import java.util.concurrent.CyclicBarrier;
+
+public class CyclicBarrierCountExample {
+
+    private int count;
+
+    public CyclicBarrierCountExample(int count) {
+        this.count = count;
+    }
+
+    public boolean callTwiceInSameThread() {
+        CyclicBarrier cyclicBarrier = new CyclicBarrier(count);
+        Thread t = new Thread(() -> {
+            try {
+                cyclicBarrier.await();
+                cyclicBarrier.await();
+            } catch (InterruptedException | BrokenBarrierException e) {
+                e.printStackTrace();
+            }
+        });
+        t.start();
+        return cyclicBarrier.isBroken();
+    }
+
+    public static void main(String[] args) {
+        CyclicBarrierCountExample ex = new CyclicBarrierCountExample(7);
+        System.out.println("Count : " + ex.callTwiceInSameThread());
+    }
+}
diff --git a/core-java-concurrency/src/main/java/com/baeldung/concurrent/cyclicbarrier/CyclicBarrierResetExample.java b/core-java-concurrency/src/main/java/com/baeldung/concurrent/cyclicbarrier/CyclicBarrierResetExample.java
new file mode 100644
index 0000000000..76b6198bc4
--- /dev/null
+++ b/core-java-concurrency/src/main/java/com/baeldung/concurrent/cyclicbarrier/CyclicBarrierResetExample.java
@@ -0,0 +1,46 @@
+package com.baeldung.concurrent.cyclicbarrier;
+
+import java.util.concurrent.BrokenBarrierException;
+import java.util.concurrent.CyclicBarrier;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.atomic.AtomicInteger;
+
+public class CyclicBarrierResetExample {
+
+    private int count;
+    private int threadCount;
+    private final AtomicInteger updateCount;
+
+    CyclicBarrierResetExample(int count, int threadCount) {
+        updateCount = new AtomicInteger(0);
+        this.count = count;
+        this.threadCount = threadCount;
+    }
+
+    public int countWaits() {
+
+        CyclicBarrier cyclicBarrier = new CyclicBarrier(count);
+
+        ExecutorService es = Executors.newFixedThreadPool(threadCount);
+        for (int i = 0; i < threadCount; i++) {
+            es.execute(() -> {
+                try {
+                    if (cyclicBarrier.getNumberWaiting() > 0) {
+                        updateCount.incrementAndGet();
+                    }   
+                    cyclicBarrier.await();
+                } catch (InterruptedException | BrokenBarrierException e) {
+                    e.printStackTrace();
+                }
+            });
+        }
+        es.shutdown();
+        return updateCount.get();
+    }
+
+    public static void main(String[] args) {
+        CyclicBarrierResetExample ex = new CyclicBarrierResetExample(7, 20);
+        System.out.println("Count : " + ex.countWaits());
+    }
+}
diff --git a/core-java-concurrency/src/test/java/com/baeldung/concurrent/countdownlatch/CountdownLatchCountExampleUnitTest.java b/core-java-concurrency/src/test/java/com/baeldung/concurrent/countdownlatch/CountdownLatchCountExampleUnitTest.java
new file mode 100644
index 0000000000..835efa53f2
--- /dev/null
+++ b/core-java-concurrency/src/test/java/com/baeldung/concurrent/countdownlatch/CountdownLatchCountExampleUnitTest.java
@@ -0,0 +1,15 @@
+package com.baeldung.concurrent.countdownlatch;
+
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Test;
+
+public class CountdownLatchCountExampleUnitTest {
+
+    @Test
+    public void whenCountDownLatch_completed() {
+        CountdownLatchCountExample ex = new CountdownLatchCountExample(2);
+        boolean isCompleted = ex.callTwiceInSameThread();
+        assertTrue(isCompleted);
+    }
+}
diff --git a/core-java-concurrency/src/test/java/com/baeldung/concurrent/countdownlatch/CountdownLatchResetExampleUnitTest.java b/core-java-concurrency/src/test/java/com/baeldung/concurrent/countdownlatch/CountdownLatchResetExampleUnitTest.java
new file mode 100644
index 0000000000..d2d43f6312
--- /dev/null
+++ b/core-java-concurrency/src/test/java/com/baeldung/concurrent/countdownlatch/CountdownLatchResetExampleUnitTest.java
@@ -0,0 +1,15 @@
+package com.baeldung.concurrent.countdownlatch;
+
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Test;
+
+public class CountdownLatchResetExampleUnitTest {
+    
+    @Test
+    public void whenCountDownLatch_noReset() {
+        CountdownLatchResetExample ex = new CountdownLatchResetExample(7,20);
+        int lineCount = ex.countWaits();
+        assertTrue(lineCount <= 7);
+    }
+}
diff --git a/core-java-concurrency/src/test/java/com/baeldung/concurrent/cyclicbarrier/CyclicBarrierCompletionMethodExampleUnitTest.java b/core-java-concurrency/src/test/java/com/baeldung/concurrent/cyclicbarrier/CyclicBarrierCompletionMethodExampleUnitTest.java
new file mode 100644
index 0000000000..310063c86c
--- /dev/null
+++ b/core-java-concurrency/src/test/java/com/baeldung/concurrent/cyclicbarrier/CyclicBarrierCompletionMethodExampleUnitTest.java
@@ -0,0 +1,15 @@
+package com.baeldung.concurrent.cyclicbarrier;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+public class CyclicBarrierCompletionMethodExampleUnitTest {
+    
+    @Test
+    public void whenCyclicBarrier_countTrips() {
+        CyclicBarrierCompletionMethodExample ex = new CyclicBarrierCompletionMethodExample(7,20);
+        int lineCount = ex.countTrips();
+        assertEquals(2, lineCount);
+    }
+}
diff --git a/core-java-concurrency/src/test/java/com/baeldung/concurrent/cyclicbarrier/CyclicBarrierCountExampleUnitTest.java b/core-java-concurrency/src/test/java/com/baeldung/concurrent/cyclicbarrier/CyclicBarrierCountExampleUnitTest.java
new file mode 100644
index 0000000000..9b7f3d9945
--- /dev/null
+++ b/core-java-concurrency/src/test/java/com/baeldung/concurrent/cyclicbarrier/CyclicBarrierCountExampleUnitTest.java
@@ -0,0 +1,15 @@
+package com.baeldung.concurrent.cyclicbarrier;
+
+import static org.junit.Assert.assertFalse;
+
+import org.junit.Test;
+
+public class CyclicBarrierCountExampleUnitTest {
+
+    @Test
+    public void whenCyclicBarrier_notCompleted() {
+        CyclicBarrierCountExample ex = new CyclicBarrierCountExample(2);
+        boolean isCompleted = ex.callTwiceInSameThread();
+        assertFalse(isCompleted);
+    }
+}
diff --git a/core-java-concurrency/src/test/java/com/baeldung/concurrent/cyclicbarrier/CyclicBarrierResetExampleUnitTest.java b/core-java-concurrency/src/test/java/com/baeldung/concurrent/cyclicbarrier/CyclicBarrierResetExampleUnitTest.java
new file mode 100644
index 0000000000..8d2b148f06
--- /dev/null
+++ b/core-java-concurrency/src/test/java/com/baeldung/concurrent/cyclicbarrier/CyclicBarrierResetExampleUnitTest.java
@@ -0,0 +1,15 @@
+package com.baeldung.concurrent.cyclicbarrier;
+
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Test;
+
+public class CyclicBarrierResetExampleUnitTest {
+    
+    @Test
+    public void whenCyclicBarrier_reset() {
+        CyclicBarrierResetExample ex = new CyclicBarrierResetExample(7,20);
+        int lineCount = ex.countWaits();
+        assertTrue(lineCount > 7);
+    }
+}
diff --git a/core-java-lang/pom.xml b/core-java-lang/pom.xml
index ace39de274..2f307859f1 100644
--- a/core-java-lang/pom.xml
+++ b/core-java-lang/pom.xml
@@ -66,6 +66,12 @@
             <artifactId>mail</artifactId>
             <version>${javax.mail.version}</version>
         </dependency>
+        <dependency>
+            <groupId>nl.jqno.equalsverifier</groupId>
+            <artifactId>equalsverifier</artifactId>
+            <version>${equalsverifier.version}</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <build>
@@ -424,6 +430,7 @@
         <maven-shade-plugin.version>3.1.1</maven-shade-plugin.version>
         <spring-boot-maven-plugin.version>2.0.3.RELEASE</spring-boot-maven-plugin.version>
         <exec-maven-plugin.version>1.6.0</exec-maven-plugin.version>
+        <equalsverifier.version>3.0.3</equalsverifier.version>
     </properties>
 
 </project>
diff --git a/core-java/src/main/java/com/baeldung/className/RetrievingClassName.java b/core-java-lang/src/main/java/com/baeldung/className/RetrievingClassName.java
similarity index 100%
rename from core-java/src/main/java/com/baeldung/className/RetrievingClassName.java
rename to core-java-lang/src/main/java/com/baeldung/className/RetrievingClassName.java
diff --git a/core-java-lang/src/main/java/com/baeldung/equalshashcode/Money.java b/core-java-lang/src/main/java/com/baeldung/equalshashcode/Money.java
new file mode 100644
index 0000000000..60c043545d
--- /dev/null
+++ b/core-java-lang/src/main/java/com/baeldung/equalshashcode/Money.java
@@ -0,0 +1,36 @@
+package com.baeldung.equalshashcode;
+
+class Money {
+
+    int amount;
+    String currencyCode;
+
+    Money(int amount, String currencyCode) {
+        this.amount = amount;
+        this.currencyCode = currencyCode;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (o == this)
+            return true;
+        if (!(o instanceof Money))
+            return false;
+        Money other = (Money)o;
+        boolean currencyCodeEquals = (this.currencyCode == null && other.currencyCode == null)
+          || (this.currencyCode != null && this.currencyCode.equals(other.currencyCode));
+        return this.amount == other.amount
+          && currencyCodeEquals;
+    }
+
+    @Override
+    public int hashCode() {
+        int result = 17;
+        result = 31 * result + amount;
+        if (currencyCode != null) {
+            result = 31 * result + currencyCode.hashCode();
+        }
+        return result;
+    }
+
+}
diff --git a/core-java-lang/src/main/java/com/baeldung/equalshashcode/Team.java b/core-java-lang/src/main/java/com/baeldung/equalshashcode/Team.java
new file mode 100644
index 0000000000..c2dee1de6b
--- /dev/null
+++ b/core-java-lang/src/main/java/com/baeldung/equalshashcode/Team.java
@@ -0,0 +1,39 @@
+package com.baeldung.equalshashcode;
+
+class Team {
+
+    final String city;
+    final String department;
+
+    Team(String city, String department) {
+        this.city = city;
+        this.department = department;
+    }
+
+    @Override
+    public final boolean equals(Object o) {
+        if (o == this)
+            return true;
+        if (!(o instanceof Team))
+            return false;
+        Team otherTeam = (Team)o;
+        boolean cityEquals = (this.city == null && otherTeam.city == null)
+          || this.city != null && this.city.equals(otherTeam.city);
+        boolean departmentEquals = (this.department == null && otherTeam.department == null)
+          || this.department != null && this.department.equals(otherTeam.department);
+        return cityEquals && departmentEquals;
+    }
+
+    @Override
+    public final int hashCode() {
+        int result = 17;
+        if (city != null) {
+            result = 31 * result + city.hashCode();
+        }
+        if (department != null) {
+            result = 31 * result + department.hashCode();
+        }
+        return result;
+    }
+
+}
diff --git a/core-java-lang/src/main/java/com/baeldung/equalshashcode/Voucher.java b/core-java-lang/src/main/java/com/baeldung/equalshashcode/Voucher.java
new file mode 100644
index 0000000000..19f46e0358
--- /dev/null
+++ b/core-java-lang/src/main/java/com/baeldung/equalshashcode/Voucher.java
@@ -0,0 +1,38 @@
+package com.baeldung.equalshashcode;
+
+class Voucher {
+
+    private Money value;
+    private String store;
+
+    Voucher(int amount, String currencyCode, String store) {
+        this.value = new Money(amount, currencyCode);
+        this.store = store;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (o == this)
+            return true;
+        if (!(o instanceof Voucher))
+            return false;
+        Voucher other = (Voucher)o;
+        boolean valueEquals = (this.value == null && other.value == null)
+          || (this.value != null && this.value.equals(other.value));
+        boolean storeEquals = (this.store == null && other.store == null)
+          || (this.store != null && this.store.equals(other.store));
+        return valueEquals && storeEquals;
+    }
+
+    @Override
+    public int hashCode() {
+        int result = 17;
+        if (this.value != null) {
+            result = 31 * result + value.hashCode();
+        }
+        if (this.store != null) {
+            result = 31 * result + store.hashCode();
+        }
+        return result;
+    }
+}
\ No newline at end of file
diff --git a/core-java-lang/src/main/java/com/baeldung/equalshashcode/WrongTeam.java b/core-java-lang/src/main/java/com/baeldung/equalshashcode/WrongTeam.java
new file mode 100644
index 0000000000..c4477aa790
--- /dev/null
+++ b/core-java-lang/src/main/java/com/baeldung/equalshashcode/WrongTeam.java
@@ -0,0 +1,30 @@
+package com.baeldung.equalshashcode;
+
+/* (non-Javadoc)
+* This class overrides equals, but it doesn't override hashCode.
+*
+* To see which problems this leads to:
+* TeamUnitTest.givenMapKeyWithoutHashCode_whenSearched_thenReturnsWrongValue
+*/
+class WrongTeam {
+
+    String city;
+    String department;
+
+    WrongTeam(String city, String department) {
+        this.city = city;
+        this.department = department;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (o == this)
+            return true;
+        if (!(o instanceof WrongTeam))
+            return false;
+        WrongTeam otherTeam = (WrongTeam)o;
+        return this.city == otherTeam.city
+          && this.department == otherTeam.department;
+    }
+
+}
diff --git a/core-java-lang/src/main/java/com/baeldung/equalshashcode/WrongVoucher.java b/core-java-lang/src/main/java/com/baeldung/equalshashcode/WrongVoucher.java
new file mode 100644
index 0000000000..97935bf8de
--- /dev/null
+++ b/core-java-lang/src/main/java/com/baeldung/equalshashcode/WrongVoucher.java
@@ -0,0 +1,47 @@
+package com.baeldung.equalshashcode;
+
+/* (non-Javadoc)
+* This class extends the Money class that has overridden the equals method and once again overrides the equals method.
+*
+* To see which problems this leads to:
+* MoneyUnitTest.givenMoneyAndVoucherInstances_whenEquals_thenReturnValuesArentSymmetric
+*/
+class WrongVoucher extends Money {
+
+    private String store;
+
+    WrongVoucher(int amount, String currencyCode, String store) {
+        super(amount, currencyCode);
+
+        this.store = store;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (o == this)
+            return true;
+        if (!(o instanceof WrongVoucher))
+            return false;
+        WrongVoucher other = (WrongVoucher)o;
+        boolean currencyCodeEquals = (this.currencyCode == null && other.currencyCode == null)
+          || (this.currencyCode != null && this.currencyCode.equals(other.currencyCode));
+        boolean storeEquals = (this.store == null && other.store == null)
+          || (this.store != null && this.store.equals(other.store));
+        return this.amount == other.amount
+          && currencyCodeEquals
+          && storeEquals;
+    }
+
+    @Override
+    public int hashCode() {
+        int result = 17;
+        result = 31 * result + amount;
+        if (this.currencyCode != null) {
+            result = 31 * result + currencyCode.hashCode();
+        }
+        if (this.store != null) {
+            result = 31 * result + store.hashCode();
+        }
+        return result;
+    }
+}
\ No newline at end of file
diff --git a/core-java/src/test/java/com/baeldung/className/RetrievingClassNameUnitTest.java b/core-java-lang/src/test/java/com/baeldung/className/RetrievingClassNameUnitTest.java
similarity index 100%
rename from core-java/src/test/java/com/baeldung/className/RetrievingClassNameUnitTest.java
rename to core-java-lang/src/test/java/com/baeldung/className/RetrievingClassNameUnitTest.java
diff --git a/core-java-lang/src/test/java/com/baeldung/equalshashcode/MoneyUnitTest.java b/core-java-lang/src/test/java/com/baeldung/equalshashcode/MoneyUnitTest.java
new file mode 100644
index 0000000000..60584fdb53
--- /dev/null
+++ b/core-java-lang/src/test/java/com/baeldung/equalshashcode/MoneyUnitTest.java
@@ -0,0 +1,27 @@
+package com.baeldung.equalshashcode;
+
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.assertFalse;
+
+import org.junit.Test;
+
+public class MoneyUnitTest {
+
+    @Test
+    public void givenMoneyInstancesWithSameAmountAndCurrency_whenEquals_thenReturnsTrue() {
+        Money income = new Money(55, "USD");
+        Money expenses = new Money(55, "USD");
+
+        assertTrue(income.equals(expenses));
+    }
+
+    @Test
+    public void givenMoneyAndVoucherInstances_whenEquals_thenReturnValuesArentSymmetric() {
+        Money cash = new Money(42, "USD");
+        WrongVoucher voucher = new WrongVoucher(42, "USD", "Amazon");
+
+        assertFalse(voucher.equals(cash));
+        assertTrue(cash.equals(voucher));
+    }
+
+}
diff --git a/core-java-lang/src/test/java/com/baeldung/equalshashcode/TeamUnitTest.java b/core-java-lang/src/test/java/com/baeldung/equalshashcode/TeamUnitTest.java
new file mode 100644
index 0000000000..a2de408796
--- /dev/null
+++ b/core-java-lang/src/test/java/com/baeldung/equalshashcode/TeamUnitTest.java
@@ -0,0 +1,46 @@
+package com.baeldung.equalshashcode;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.junit.Test;
+
+import nl.jqno.equalsverifier.EqualsVerifier;
+
+public class TeamUnitTest {
+
+    @Test
+    public void givenMapKeyWithHashCode_whenSearched_thenReturnsCorrectValue() {
+        Map<Team,String> leaders = new HashMap<>();
+        leaders.put(new Team("New York", "development"), "Anne");
+        leaders.put(new Team("Boston", "development"), "Brian");
+        leaders.put(new Team("Boston", "marketing"), "Charlie");
+
+        Team myTeam = new Team("New York", "development");
+        String myTeamleader = leaders.get(myTeam);
+
+        assertEquals("Anne", myTeamleader);
+    }
+
+    @Test
+    public void givenMapKeyWithoutHashCode_whenSearched_thenReturnsWrongValue() {
+        Map<WrongTeam,String> leaders = new HashMap<>();
+        leaders.put(new WrongTeam("New York", "development"), "Anne");
+        leaders.put(new WrongTeam("Boston", "development"), "Brian");
+        leaders.put(new WrongTeam("Boston", "marketing"), "Charlie");
+
+        WrongTeam myTeam = new WrongTeam("New York", "development");
+        String myTeamleader = leaders.get(myTeam);
+
+        assertFalse("Anne".equals(myTeamleader));
+    }
+
+    @Test
+    public void equalsContract() {
+        EqualsVerifier.forClass(Team.class).verify();
+    }
+
+}
diff --git a/core-java/src/main/java/com/baeldung/graph/Graph.java b/core-java/src/main/java/com/baeldung/graph/Graph.java
new file mode 100644
index 0000000000..43b5c0aa08
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/graph/Graph.java
@@ -0,0 +1,76 @@
+package com.baeldung.graph;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+public class Graph {
+    private Map<Vertex, List<Vertex>> adjVertices;
+
+    Graph() {
+        this.adjVertices = new HashMap<Vertex, List<Vertex>>();
+    }
+
+    void addVertex(String label) {
+        adjVertices.putIfAbsent(new Vertex(label), new ArrayList<>());
+    }
+
+    void removeVertex(String label) {
+        Vertex v = new Vertex(label);
+        adjVertices.values().stream().map(e -> e.remove(v)).collect(Collectors.toList());
+        adjVertices.remove(new Vertex(label));
+    }
+
+    void addEdge(String label1, String label2) {
+        Vertex v1 = new Vertex(label1);
+        Vertex v2 = new Vertex(label2);
+        adjVertices.get(v1).add(v2);
+        adjVertices.get(v2).add(v1);
+    }
+
+    void removeEdge(String label1, String label2) {
+        Vertex v1 = new Vertex(label1);
+        Vertex v2 = new Vertex(label2);
+        List<Vertex> eV1 = adjVertices.get(v1);
+        List<Vertex> eV2 = adjVertices.get(v2);
+        if (eV1 != null)
+            eV1.remove(v2);
+        if (eV2 != null)
+            eV2.remove(v1);
+    }
+
+    List<Vertex> getAdjVertices(String label) {
+        return adjVertices.get(new Vertex(label));
+    }
+    
+    String printGraph() {
+        StringBuffer sb = new StringBuffer();
+        for(Vertex v : adjVertices.keySet()) {
+            sb.append(v);
+            sb.append(adjVertices.get(v));
+        }
+        return sb.toString();
+    }
+
+    class Vertex {
+        String label;
+        Vertex(String label) {
+            this.label = label;
+        }
+        @Override
+        public boolean equals(Object obj) {
+            Vertex vertex = (Vertex) obj;
+            return vertex.label == label;
+        }
+        @Override
+        public int hashCode() {
+            return label.hashCode();
+        }
+        @Override
+        public String toString() {
+            return label;
+        }
+    }
+}
\ No newline at end of file
diff --git a/core-java/src/main/java/com/baeldung/graph/GraphTraversal.java b/core-java/src/main/java/com/baeldung/graph/GraphTraversal.java
new file mode 100644
index 0000000000..479e653a5c
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/graph/GraphTraversal.java
@@ -0,0 +1,44 @@
+package com.baeldung.graph;
+
+import java.util.LinkedHashSet;
+import java.util.LinkedList;
+import java.util.Queue;
+import java.util.Set;
+import java.util.Stack;
+
+import com.baeldung.graph.Graph.Vertex;
+
+public class GraphTraversal {
+    static Set<String> depthFirstTraversal(Graph graph, String root) {
+        Set<String> visited = new LinkedHashSet<String>();
+        Stack<String> stack = new Stack<String>();
+        stack.push(root);
+        while (!stack.isEmpty()) {
+            String vertex = stack.pop();
+            if (!visited.contains(vertex)) {
+                visited.add(vertex);
+                for (Vertex v : graph.getAdjVertices(vertex)) {              
+                    stack.push(v.label);
+                }
+            }
+        }
+        return visited;
+    }
+
+    static Set<String> breadthFirstTraversal(Graph graph, String root) {
+        Set<String> visited = new LinkedHashSet<String>();
+        Queue<String> queue = new LinkedList<String>();
+        queue.add(root);
+        visited.add(root);
+        while (!queue.isEmpty()) {
+            String vertex = queue.poll();
+            for (Vertex v : graph.getAdjVertices(vertex)) {
+                if (!visited.contains(v.label)) {
+                    visited.add(v.label);
+                    queue.add(v.label);
+                }
+            }
+        }
+        return visited;
+    }
+}
\ No newline at end of file
diff --git a/core-java/src/test/java/com/baeldung/graph/GraphTraversalUnitTest.java b/core-java/src/test/java/com/baeldung/graph/GraphTraversalUnitTest.java
new file mode 100644
index 0000000000..d955d56d95
--- /dev/null
+++ b/core-java/src/test/java/com/baeldung/graph/GraphTraversalUnitTest.java
@@ -0,0 +1,36 @@
+package com.baeldung.graph;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class GraphTraversalUnitTest {
+    @Test
+    public void givenAGraph_whenTraversingDepthFirst_thenExpectedResult() {
+        Graph graph = createGraph();
+        Assert.assertEquals("[Bob, Rob, Maria, Alice, Mark]", 
+            GraphTraversal.depthFirstTraversal(graph, "Bob").toString());
+    }
+    
+    @Test
+    public void givenAGraph_whenTraversingBreadthFirst_thenExpectedResult() {
+        Graph graph = createGraph();
+        Assert.assertEquals("[Bob, Alice, Rob, Mark, Maria]", 
+            GraphTraversal.breadthFirstTraversal(graph, "Bob").toString());
+    }
+    
+    Graph createGraph() {
+        Graph graph = new Graph();
+        graph.addVertex("Bob");
+        graph.addVertex("Alice");
+        graph.addVertex("Mark");
+        graph.addVertex("Rob");
+        graph.addVertex("Maria");
+        graph.addEdge("Bob", "Alice");
+        graph.addEdge("Bob", "Rob");
+        graph.addEdge("Alice", "Mark");
+        graph.addEdge("Rob", "Mark");
+        graph.addEdge("Alice", "Maria");
+        graph.addEdge("Rob", "Maria");
+        return graph;
+    }
+}
\ No newline at end of file
diff --git a/core-java/src/test/java/com/baeldung/regexp/optmization/OptimizedMatcherUnitTest.java b/core-java/src/test/java/com/baeldung/regexp/optmization/OptimizedMatcherManualTest.java
similarity index 98%
rename from core-java/src/test/java/com/baeldung/regexp/optmization/OptimizedMatcherUnitTest.java
rename to core-java/src/test/java/com/baeldung/regexp/optmization/OptimizedMatcherManualTest.java
index 2be6b6ad4b..f44968a5a7 100644
--- a/core-java/src/test/java/com/baeldung/regexp/optmization/OptimizedMatcherUnitTest.java
+++ b/core-java/src/test/java/com/baeldung/regexp/optmization/OptimizedMatcherManualTest.java
@@ -11,7 +11,7 @@ import java.util.regex.Pattern;
 
 import static org.junit.Assert.assertTrue;
 
-public class OptimizedMatcherUnitTest {
+public class OptimizedMatcherManualTest {
 
     private String action;
 
diff --git a/java-collections-conversions/src/test/java/org/baeldung/convertarraytostring/ArrayToStringUnitTest.java b/java-collections-conversions/src/test/java/org/baeldung/convertarraytostring/ArrayToStringUnitTest.java
new file mode 100644
index 0000000000..b563475997
--- /dev/null
+++ b/java-collections-conversions/src/test/java/org/baeldung/convertarraytostring/ArrayToStringUnitTest.java
@@ -0,0 +1,136 @@
+package org.baeldung.convertarraytostring;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import org.apache.commons.lang3.StringUtils;
+import org.junit.Test;
+
+import com.google.common.base.Joiner;
+import com.google.common.base.Splitter;
+
+import static org.hamcrest.CoreMatchers.instanceOf;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.assertEquals;
+
+public class ArrayToStringUnitTest {
+    
+    // convert with Java
+    
+    @Test
+    public void givenAStringArray_whenConvertBeforeJava8_thenReturnString() {
+
+        String[] strArray = { "Convert", "Array", "With", "Java" };
+        StringBuilder stringBuilder = new StringBuilder();
+        
+        for (int i = 0; i < strArray.length; i++) {
+            stringBuilder.append(strArray[i]);
+        }
+        String joinedString = stringBuilder.toString();
+        
+        assertThat(joinedString, instanceOf(String.class));
+        assertEquals("ConvertArrayWithJava", joinedString);
+    }
+
+    @Test
+    public void givenAString_whenConvertBeforeJava8_thenReturnStringArray() {
+
+        String input = "lorem ipsum dolor sit amet";
+        String[] strArray = input.split(" ");
+
+        assertThat(strArray, instanceOf(String[].class));
+        assertEquals(5, strArray.length);
+        
+        input = "loremipsum";
+        strArray = input.split("");
+        assertThat(strArray, instanceOf(String[].class));
+        assertEquals(10, strArray.length);        
+    }    
+    
+    @Test
+    public void givenAnIntArray_whenConvertBeforeJava8_thenReturnString() {
+
+        int[] strArray = { 1, 2, 3, 4, 5 };
+        StringBuilder stringBuilder = new StringBuilder();
+        
+        for (int i = 0; i < strArray.length; i++) {
+            stringBuilder.append(Integer.valueOf(strArray[i]));
+        }
+        String joinedString = stringBuilder.toString();
+        
+        assertThat(joinedString, instanceOf(String.class));
+        assertEquals("12345", joinedString);
+    }    
+    
+    // convert with Java Stream API
+    
+    @Test
+    public void givenAStringArray_whenConvertWithJavaStream_thenReturnString() {
+
+        String[] strArray = { "Convert", "With", "Java", "Streams" };
+        String joinedString = Arrays.stream(strArray)
+            .collect(Collectors.joining());
+        assertThat(joinedString, instanceOf(String.class));
+        assertEquals("ConvertWithJavaStreams", joinedString);
+        
+        joinedString = Arrays.stream(strArray)
+            .collect(Collectors.joining(","));
+        assertThat(joinedString, instanceOf(String.class));
+        assertEquals("Convert,With,Java,Streams", joinedString);
+    }    
+    
+    
+    // convert with Apache Commons
+
+    @Test
+    public void givenAStringArray_whenConvertWithApacheCommons_thenReturnString() {
+
+        String[] strArray = { "Convert", "With", "Apache", "Commons" };
+        String joinedString = StringUtils.join(strArray);
+
+        assertThat(joinedString, instanceOf(String.class));
+        assertEquals("ConvertWithApacheCommons", joinedString);
+    }
+    
+    @Test
+    public void givenAString_whenConvertWithApacheCommons_thenReturnStringArray() {
+
+        String input = "lorem ipsum dolor sit amet";
+        String[] strArray = StringUtils.split(input, " ");
+        
+        assertThat(strArray, instanceOf(String[].class));
+        assertEquals(5, strArray.length);
+    }  
+
+    
+    // convert with Guava
+
+    @Test
+    public void givenAStringArray_whenConvertWithGuava_thenReturnString() {
+
+        String[] strArray = { "Convert", "With", "Guava", null };
+        String joinedString = Joiner.on("")
+            .skipNulls()
+            .join(strArray);
+
+        assertThat(joinedString, instanceOf(String.class));
+        assertEquals("ConvertWithGuava", joinedString);
+    }
+    
+    
+    @Test
+    public void givenAString_whenConvertWithGuava_thenReturnStringArray() {
+
+        String input = "lorem ipsum dolor sit amet";
+                        
+        List<String> resultList = Splitter.on(' ')
+            .trimResults()
+            .omitEmptyStrings()
+            .splitToList(input);   
+        String[] strArray = resultList.toArray(new String[0]);
+        
+        assertThat(strArray, instanceOf(String[].class));
+        assertEquals(5, strArray.length);    
+    }  
+}
diff --git a/libraries-data/src/main/kafka-connect/01_Quick_Start/connect-file-sink.properties b/libraries-data/src/main/kafka-connect/01_Quick_Start/connect-file-sink.properties
new file mode 100644
index 0000000000..594ccc6e95
--- /dev/null
+++ b/libraries-data/src/main/kafka-connect/01_Quick_Start/connect-file-sink.properties
@@ -0,0 +1,20 @@
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+name=local-file-sink
+connector.class=FileStreamSink
+tasks.max=1
+file=test.sink.txt
+topics=connect-test
\ No newline at end of file
diff --git a/libraries-data/src/main/kafka-connect/01_Quick_Start/connect-file-source.properties b/libraries-data/src/main/kafka-connect/01_Quick_Start/connect-file-source.properties
new file mode 100644
index 0000000000..599cf4cb2a
--- /dev/null
+++ b/libraries-data/src/main/kafka-connect/01_Quick_Start/connect-file-source.properties
@@ -0,0 +1,20 @@
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+name=local-file-source
+connector.class=FileStreamSource
+tasks.max=1
+file=test.txt
+topic=connect-test
\ No newline at end of file
diff --git a/libraries-data/src/main/kafka-connect/01_Quick_Start/connect-standalone.properties b/libraries-data/src/main/kafka-connect/01_Quick_Start/connect-standalone.properties
new file mode 100644
index 0000000000..a2369fa144
--- /dev/null
+++ b/libraries-data/src/main/kafka-connect/01_Quick_Start/connect-standalone.properties
@@ -0,0 +1,44 @@
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# These are defaults. This file just demonstrates how to override some settings.
+bootstrap.servers=localhost:9092
+
+# The converters specify the format of data in Kafka and how to translate it into Connect data. Every Connect user will
+# need to configure these based on the format they want their data in when loaded from or stored into Kafka
+key.converter=org.apache.kafka.connect.json.JsonConverter
+value.converter=org.apache.kafka.connect.json.JsonConverter
+# Converter-specific settings can be passed in by prefixing the Converter's setting with the converter we want to apply
+# it to
+key.converter.schemas.enable=false
+value.converter.schemas.enable=false
+
+offset.storage.file.filename=/tmp/connect.offsets
+# Flush much faster than normal, which is useful for testing/debugging
+offset.flush.interval.ms=10000
+
+# Set to a list of filesystem paths separated by commas (,) to enable class loading isolation for plugins
+# (connectors, converters, transformations). The list should consist of top level directories that include 
+# any combination of: 
+# a) directories immediately containing jars with plugins and their dependencies
+# b) uber-jars with plugins and their dependencies
+# c) directories immediately containing the package directory structure of classes of plugins and their dependencies
+# Note: symlinks will be followed to discover dependencies or plugins.
+# Examples: 
+# plugin.path=/usr/local/share/java,/usr/local/share/kafka/plugins,/opt/connectors,
+# Replace the relative path below with an absolute path if you are planning to start Kafka Connect from within a
+# directory other than the home directory of Confluent Platform.
+plugin.path=C:\Software\confluent-5.0.0\share\java
+#plugin.path=./share/java
diff --git a/libraries-data/src/main/kafka-connect/02_Distributed/connect-distributed.properties b/libraries-data/src/main/kafka-connect/02_Distributed/connect-distributed.properties
new file mode 100644
index 0000000000..5b91baddbd
--- /dev/null
+++ b/libraries-data/src/main/kafka-connect/02_Distributed/connect-distributed.properties
@@ -0,0 +1,88 @@
+##
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+##
+
+# This file contains some of the configurations for the Kafka Connect distributed worker. This file is intended
+# to be used with the examples, and some settings may differ from those used in a production system, especially
+# the `bootstrap.servers` and those specifying replication factors.
+
+# A list of host/port pairs to use for establishing the initial connection to the Kafka cluster.
+bootstrap.servers=localhost:9092
+
+# unique name for the cluster, used in forming the Connect cluster group. Note that this must not conflict with consumer group IDs
+group.id=connect-cluster
+
+# The converters specify the format of data in Kafka and how to translate it into Connect data. Every Connect user will
+# need to configure these based on the format they want their data in when loaded from or stored into Kafka
+key.converter=org.apache.kafka.connect.json.JsonConverter
+value.converter=org.apache.kafka.connect.json.JsonConverter
+# Converter-specific settings can be passed in by prefixing the Converter's setting with the converter we want to apply
+# it to
+key.converter.schemas.enable=true
+value.converter.schemas.enable=true
+
+# Topic to use for storing offsets. This topic should have many partitions and be replicated and compacted.
+# Kafka Connect will attempt to create the topic automatically when needed, but you can always manually create
+# the topic before starting Kafka Connect if a specific topic configuration is needed.
+# Most users will want to use the built-in default replication factor of 3 or in some cases even specify a larger value.
+# Since this means there must be at least as many brokers as the maximum replication factor used, we'd like to be able
+# to run this example on a single-broker cluster and so here we instead set the replication factor to 1.
+offset.storage.topic=connect-offsets
+offset.storage.replication.factor=1
+#offset.storage.partitions=25
+
+# Topic to use for storing connector and task configurations; note that this should be a single partition, highly replicated,
+# and compacted topic. Kafka Connect will attempt to create the topic automatically when needed, but you can always manually create
+# the topic before starting Kafka Connect if a specific topic configuration is needed.
+# Most users will want to use the built-in default replication factor of 3 or in some cases even specify a larger value.
+# Since this means there must be at least as many brokers as the maximum replication factor used, we'd like to be able
+# to run this example on a single-broker cluster and so here we instead set the replication factor to 1.
+config.storage.topic=connect-configs
+config.storage.replication.factor=1
+
+# Topic to use for storing statuses. This topic can have multiple partitions and should be replicated and compacted.
+# Kafka Connect will attempt to create the topic automatically when needed, but you can always manually create
+# the topic before starting Kafka Connect if a specific topic configuration is needed.
+# Most users will want to use the built-in default replication factor of 3 or in some cases even specify a larger value.
+# Since this means there must be at least as many brokers as the maximum replication factor used, we'd like to be able
+# to run this example on a single-broker cluster and so here we instead set the replication factor to 1.
+status.storage.topic=connect-status
+status.storage.replication.factor=1
+#status.storage.partitions=5
+
+# Flush much faster than normal, which is useful for testing/debugging
+offset.flush.interval.ms=10000
+
+# These are provided to inform the user about the presence of the REST host and port configs 
+# Hostname & Port for the REST API to listen on. If this is set, it will bind to the interface used to listen to requests.
+#rest.host.name=
+#rest.port=8083
+
+# The Hostname & Port that will be given out to other workers to connect to i.e. URLs that are routable from other servers.
+#rest.advertised.host.name=
+#rest.advertised.port=
+
+# Set to a list of filesystem paths separated by commas (,) to enable class loading isolation for plugins
+# (connectors, converters, transformations). The list should consist of top level directories that include 
+# any combination of: 
+# a) directories immediately containing jars with plugins and their dependencies
+# b) uber-jars with plugins and their dependencies
+# c) directories immediately containing the package directory structure of classes of plugins and their dependencies
+# Examples: 
+# plugin.path=/usr/local/share/java,/usr/local/share/kafka/plugins,/opt/connectors,
+# Replace the relative path below with an absolute path if you are planning to start Kafka Connect from within a
+# directory other than the home directory of Confluent Platform.
+plugin.path=./share/java
diff --git a/libraries-data/src/main/kafka-connect/02_Distributed/connect-file-sink.json b/libraries-data/src/main/kafka-connect/02_Distributed/connect-file-sink.json
new file mode 100644
index 0000000000..8902ecce52
--- /dev/null
+++ b/libraries-data/src/main/kafka-connect/02_Distributed/connect-file-sink.json
@@ -0,0 +1,9 @@
+{
+    "name": "local-file-sink",
+    "config": {
+        "connector.class": "FileStreamSink",
+        "tasks.max": 1,
+        "file": "test-distributed.sink.txt",
+        "topics": "connect-distributed"
+    }
+}
diff --git a/libraries-data/src/main/kafka-connect/02_Distributed/connect-file-source.json b/libraries-data/src/main/kafka-connect/02_Distributed/connect-file-source.json
new file mode 100644
index 0000000000..77e949c91b
--- /dev/null
+++ b/libraries-data/src/main/kafka-connect/02_Distributed/connect-file-source.json
@@ -0,0 +1,9 @@
+{
+    "name": "local-file-source",
+    "config": {
+        "connector.class": "FileStreamSource",
+        "tasks.max": 1,
+        "file": "test-distributed.txt",
+        "topic": "connect-distributed"
+    }
+}
diff --git a/libraries-data/src/main/kafka-connect/03_Transform/connect-distributed.properties b/libraries-data/src/main/kafka-connect/03_Transform/connect-distributed.properties
new file mode 100644
index 0000000000..fa63be24b8
--- /dev/null
+++ b/libraries-data/src/main/kafka-connect/03_Transform/connect-distributed.properties
@@ -0,0 +1,88 @@
+##
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+##
+
+# This file contains some of the configurations for the Kafka Connect distributed worker. This file is intended
+# to be used with the examples, and some settings may differ from those used in a production system, especially
+# the `bootstrap.servers` and those specifying replication factors.
+
+# A list of host/port pairs to use for establishing the initial connection to the Kafka cluster.
+bootstrap.servers=localhost:9092
+
+# unique name for the cluster, used in forming the Connect cluster group. Note that this must not conflict with consumer group IDs
+group.id=connect-cluster
+
+# The converters specify the format of data in Kafka and how to translate it into Connect data. Every Connect user will
+# need to configure these based on the format they want their data in when loaded from or stored into Kafka
+key.converter=org.apache.kafka.connect.json.JsonConverter
+value.converter=org.apache.kafka.connect.json.JsonConverter
+# Converter-specific settings can be passed in by prefixing the Converter's setting with the converter we want to apply
+# it to
+key.converter.schemas.enable=false
+value.converter.schemas.enable=false
+
+# Topic to use for storing offsets. This topic should have many partitions and be replicated and compacted.
+# Kafka Connect will attempt to create the topic automatically when needed, but you can always manually create
+# the topic before starting Kafka Connect if a specific topic configuration is needed.
+# Most users will want to use the built-in default replication factor of 3 or in some cases even specify a larger value.
+# Since this means there must be at least as many brokers as the maximum replication factor used, we'd like to be able
+# to run this example on a single-broker cluster and so here we instead set the replication factor to 1.
+offset.storage.topic=connect-offsets
+offset.storage.replication.factor=1
+#offset.storage.partitions=25
+
+# Topic to use for storing connector and task configurations; note that this should be a single partition, highly replicated,
+# and compacted topic. Kafka Connect will attempt to create the topic automatically when needed, but you can always manually create
+# the topic before starting Kafka Connect if a specific topic configuration is needed.
+# Most users will want to use the built-in default replication factor of 3 or in some cases even specify a larger value.
+# Since this means there must be at least as many brokers as the maximum replication factor used, we'd like to be able
+# to run this example on a single-broker cluster and so here we instead set the replication factor to 1.
+config.storage.topic=connect-configs
+config.storage.replication.factor=1
+
+# Topic to use for storing statuses. This topic can have multiple partitions and should be replicated and compacted.
+# Kafka Connect will attempt to create the topic automatically when needed, but you can always manually create
+# the topic before starting Kafka Connect if a specific topic configuration is needed.
+# Most users will want to use the built-in default replication factor of 3 or in some cases even specify a larger value.
+# Since this means there must be at least as many brokers as the maximum replication factor used, we'd like to be able
+# to run this example on a single-broker cluster and so here we instead set the replication factor to 1.
+status.storage.topic=connect-status
+status.storage.replication.factor=1
+#status.storage.partitions=5
+
+# Flush much faster than normal, which is useful for testing/debugging
+offset.flush.interval.ms=10000
+
+# These are provided to inform the user about the presence of the REST host and port configs 
+# Hostname & Port for the REST API to listen on. If this is set, it will bind to the interface used to listen to requests.
+#rest.host.name=
+#rest.port=8083
+
+# The Hostname & Port that will be given out to other workers to connect to i.e. URLs that are routable from other servers.
+#rest.advertised.host.name=
+#rest.advertised.port=
+
+# Set to a list of filesystem paths separated by commas (,) to enable class loading isolation for plugins
+# (connectors, converters, transformations). The list should consist of top level directories that include 
+# any combination of: 
+# a) directories immediately containing jars with plugins and their dependencies
+# b) uber-jars with plugins and their dependencies
+# c) directories immediately containing the package directory structure of classes of plugins and their dependencies
+# Examples: 
+# plugin.path=/usr/local/share/java,/usr/local/share/kafka/plugins,/opt/connectors,
+# Replace the relative path below with an absolute path if you are planning to start Kafka Connect from within a
+# directory other than the home directory of Confluent Platform.
+plugin.path=./share/java
diff --git a/libraries-data/src/main/kafka-connect/03_Transform/connect-file-source-transform.json b/libraries-data/src/main/kafka-connect/03_Transform/connect-file-source-transform.json
new file mode 100644
index 0000000000..e5e21a0608
--- /dev/null
+++ b/libraries-data/src/main/kafka-connect/03_Transform/connect-file-source-transform.json
@@ -0,0 +1,15 @@
+{
+    "name": "local-file-source",
+    "config": {
+        "connector.class": "FileStreamSource",
+        "tasks.max": 1,
+        "file": "transformation.txt",
+        "topic": "connect-transformation",
+        "transforms": "MakeMap,InsertSource",
+        "transforms.MakeMap.type": "org.apache.kafka.connect.transforms.HoistField$Value",
+        "transforms.MakeMap.field": "line",
+        "transforms.InsertSource.type": "org.apache.kafka.connect.transforms.InsertField$Value",
+        "transforms.InsertSource.static.field": "data_source",
+        "transforms.InsertSource.static.value": "test-file-source"
+    }
+}
diff --git a/libraries-data/src/main/kafka-connect/04_Custom/connect-distributed.properties b/libraries-data/src/main/kafka-connect/04_Custom/connect-distributed.properties
new file mode 100644
index 0000000000..5b91baddbd
--- /dev/null
+++ b/libraries-data/src/main/kafka-connect/04_Custom/connect-distributed.properties
@@ -0,0 +1,88 @@
+##
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+##
+
+# This file contains some of the configurations for the Kafka Connect distributed worker. This file is intended
+# to be used with the examples, and some settings may differ from those used in a production system, especially
+# the `bootstrap.servers` and those specifying replication factors.
+
+# A list of host/port pairs to use for establishing the initial connection to the Kafka cluster.
+bootstrap.servers=localhost:9092
+
+# unique name for the cluster, used in forming the Connect cluster group. Note that this must not conflict with consumer group IDs
+group.id=connect-cluster
+
+# The converters specify the format of data in Kafka and how to translate it into Connect data. Every Connect user will
+# need to configure these based on the format they want their data in when loaded from or stored into Kafka
+key.converter=org.apache.kafka.connect.json.JsonConverter
+value.converter=org.apache.kafka.connect.json.JsonConverter
+# Converter-specific settings can be passed in by prefixing the Converter's setting with the converter we want to apply
+# it to
+key.converter.schemas.enable=true
+value.converter.schemas.enable=true
+
+# Topic to use for storing offsets. This topic should have many partitions and be replicated and compacted.
+# Kafka Connect will attempt to create the topic automatically when needed, but you can always manually create
+# the topic before starting Kafka Connect if a specific topic configuration is needed.
+# Most users will want to use the built-in default replication factor of 3 or in some cases even specify a larger value.
+# Since this means there must be at least as many brokers as the maximum replication factor used, we'd like to be able
+# to run this example on a single-broker cluster and so here we instead set the replication factor to 1.
+offset.storage.topic=connect-offsets
+offset.storage.replication.factor=1
+#offset.storage.partitions=25
+
+# Topic to use for storing connector and task configurations; note that this should be a single partition, highly replicated,
+# and compacted topic. Kafka Connect will attempt to create the topic automatically when needed, but you can always manually create
+# the topic before starting Kafka Connect if a specific topic configuration is needed.
+# Most users will want to use the built-in default replication factor of 3 or in some cases even specify a larger value.
+# Since this means there must be at least as many brokers as the maximum replication factor used, we'd like to be able
+# to run this example on a single-broker cluster and so here we instead set the replication factor to 1.
+config.storage.topic=connect-configs
+config.storage.replication.factor=1
+
+# Topic to use for storing statuses. This topic can have multiple partitions and should be replicated and compacted.
+# Kafka Connect will attempt to create the topic automatically when needed, but you can always manually create
+# the topic before starting Kafka Connect if a specific topic configuration is needed.
+# Most users will want to use the built-in default replication factor of 3 or in some cases even specify a larger value.
+# Since this means there must be at least as many brokers as the maximum replication factor used, we'd like to be able
+# to run this example on a single-broker cluster and so here we instead set the replication factor to 1.
+status.storage.topic=connect-status
+status.storage.replication.factor=1
+#status.storage.partitions=5
+
+# Flush much faster than normal, which is useful for testing/debugging
+offset.flush.interval.ms=10000
+
+# These are provided to inform the user about the presence of the REST host and port configs 
+# Hostname & Port for the REST API to listen on. If this is set, it will bind to the interface used to listen to requests.
+#rest.host.name=
+#rest.port=8083
+
+# The Hostname & Port that will be given out to other workers to connect to i.e. URLs that are routable from other servers.
+#rest.advertised.host.name=
+#rest.advertised.port=
+
+# Set to a list of filesystem paths separated by commas (,) to enable class loading isolation for plugins
+# (connectors, converters, transformations). The list should consist of top level directories that include 
+# any combination of: 
+# a) directories immediately containing jars with plugins and their dependencies
+# b) uber-jars with plugins and their dependencies
+# c) directories immediately containing the package directory structure of classes of plugins and their dependencies
+# Examples: 
+# plugin.path=/usr/local/share/java,/usr/local/share/kafka/plugins,/opt/connectors,
+# Replace the relative path below with an absolute path if you are planning to start Kafka Connect from within a
+# directory other than the home directory of Confluent Platform.
+plugin.path=./share/java
diff --git a/libraries-data/src/main/kafka-connect/04_Custom/connect-mongodb-sink.json b/libraries-data/src/main/kafka-connect/04_Custom/connect-mongodb-sink.json
new file mode 100644
index 0000000000..333768e4b7
--- /dev/null
+++ b/libraries-data/src/main/kafka-connect/04_Custom/connect-mongodb-sink.json
@@ -0,0 +1,22 @@
+{
+    "firstName": "John",
+    "lastName": "Smith",
+    "age": 25,
+    "address": {
+        "streetAddress": "21 2nd Street",
+        "city": "New York",
+        "state": "NY",
+        "postalCode": "10021"
+    },
+    "phoneNumber": [{
+            "type": "home",
+            "number": "212 555-1234"
+        }, {
+            "type": "fax",
+            "number": "646 555-4567"
+        }
+    ],
+    "gender": {
+        "type": "male"
+    }
+}
diff --git a/libraries-data/src/main/kafka-connect/04_Custom/connect-mqtt-source.json b/libraries-data/src/main/kafka-connect/04_Custom/connect-mqtt-source.json
new file mode 100644
index 0000000000..02d87c5ad7
--- /dev/null
+++ b/libraries-data/src/main/kafka-connect/04_Custom/connect-mqtt-source.json
@@ -0,0 +1,11 @@
+{
+    "name": "mqtt-source",
+    "config": {
+        "connector.class": "io.confluent.connect.mqtt.MqttSourceConnector",
+        "tasks.max": 1,
+        "mqtt.server.uri": "ws://broker.hivemq.com:8000/mqtt",
+        "mqtt.topics": "baeldung",
+        "kafka.topic": "connect-custom",
+        "value.converter": "org.apache.kafka.connect.converters.ByteArrayConverter"
+    }
+}
diff --git a/logging-modules/log4j/pom.xml b/logging-modules/log4j/pom.xml
index 1b27e03445..c5ce1d06ad 100644
--- a/logging-modules/log4j/pom.xml
+++ b/logging-modules/log4j/pom.xml
@@ -44,12 +44,6 @@
             <artifactId>disruptor</artifactId>
             <version>${disruptor.version}</version>
         </dependency>
-        <!-- Webflux for reactive logging example -->
-        <dependency>
-            <groupId>org.springframework.boot</groupId>
-            <artifactId>spring-boot-starter-webflux</artifactId>
-            <version>${spring-boot.version}</version>
-        </dependency>
     </dependencies>
 
     <properties>
@@ -57,7 +51,6 @@
         <log4j-api.version>2.7</log4j-api.version>
         <log4j-core.version>2.7</log4j-core.version>
         <disruptor.version>3.3.6</disruptor.version>
-        <spring-boot.version>2.1.0.RELEASE</spring-boot.version>
     </properties>
 
 </project>
\ No newline at end of file
diff --git a/persistence-modules/hibernate5/src/main/java/com/baeldung/hibernate/findall/FindAll.java b/persistence-modules/hibernate5/src/main/java/com/baeldung/hibernate/findall/FindAll.java
new file mode 100644
index 0000000000..cc0c234df0
--- /dev/null
+++ b/persistence-modules/hibernate5/src/main/java/com/baeldung/hibernate/findall/FindAll.java
@@ -0,0 +1,35 @@
+package com.baeldung.hibernate.findall;
+
+import java.util.List;
+
+import javax.persistence.TypedQuery;
+import javax.persistence.criteria.CriteriaBuilder;
+import javax.persistence.criteria.CriteriaQuery;
+import javax.persistence.criteria.Root;
+
+import org.hibernate.Session;
+
+import com.baeldung.hibernate.pojo.Student;
+
+public class FindAll {
+
+    private Session session;
+
+    public FindAll(Session session) {
+        super();
+        this.session = session;
+    }
+
+    public List<Student> findAllWithJpql() {
+        return session.createQuery("SELECT a FROM Student a", Student.class).getResultList();
+    }
+
+    public List<Student> findAllWithCriteriaQuery() {
+        CriteriaBuilder cb = session.getCriteriaBuilder();
+        CriteriaQuery<Student> cq = cb.createQuery(Student.class);
+        Root<Student> rootEntry = cq.from(Student.class);
+        CriteriaQuery<Student> all = cq.select(rootEntry);
+        TypedQuery<Student> allQuery = session.createQuery(all);
+        return allQuery.getResultList();
+    }
+}
diff --git a/persistence-modules/hibernate5/src/test/java/com/baeldung/hibernate/findall/FindAllUnitTest.java b/persistence-modules/hibernate5/src/test/java/com/baeldung/hibernate/findall/FindAllUnitTest.java
new file mode 100644
index 0000000000..8a1b9e9791
--- /dev/null
+++ b/persistence-modules/hibernate5/src/test/java/com/baeldung/hibernate/findall/FindAllUnitTest.java
@@ -0,0 +1,63 @@
+package com.baeldung.hibernate.findall;
+
+import static org.junit.Assert.assertEquals;
+
+import java.io.IOException;
+import java.util.List;
+
+import org.hibernate.Session;
+import org.hibernate.Transaction;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import com.baeldung.hibernate.HibernateUtil;
+import com.baeldung.hibernate.pojo.Student;
+
+public class FindAllUnitTest {
+
+    private Session session;
+    private Transaction transaction;
+    
+    private FindAll findAll;
+
+    @Before
+    public void setUp() throws IOException {
+
+        session = HibernateUtil.getSessionFactory().openSession();
+        transaction = session.beginTransaction();
+        findAll = new FindAll(session);
+
+        session.createNativeQuery("delete from Student").executeUpdate();
+
+        Student student1 = new Student();
+        session.persist(student1);
+
+        Student student2 = new Student();
+        session.persist(student2);
+
+        Student student3 = new Student();
+        session.persist(student3);
+
+        transaction.commit();
+        transaction = session.beginTransaction();
+    }
+
+    @After
+    public void tearDown() {
+        transaction.rollback();
+        session.close();
+    }
+
+    @Test
+    public void givenCriteriaQuery_WhenFindAll_ThenGetAllPersons() {
+        List<Student> list = findAll.findAllWithCriteriaQuery();
+        assertEquals(3, list.size());
+    }
+    
+    @Test
+    public void givenJpql_WhenFindAll_ThenGetAllPersons() {
+        List<Student> list = findAll.findAllWithJpql();
+        assertEquals(3, list.size());
+    }
+}
diff --git a/persistence-modules/spring-data-cassandra-reactive/pom.xml b/persistence-modules/spring-data-cassandra-reactive/pom.xml
new file mode 100644
index 0000000000..037b1fd3c1
--- /dev/null
+++ b/persistence-modules/spring-data-cassandra-reactive/pom.xml
@@ -0,0 +1,70 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>com.baeldung</groupId>
+    <artifactId>spring-data-cassandra-reactive</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <packaging>jar</packaging>
+
+    <name>spring-data-cassandra-reactive</name>
+    <description>Spring Data Cassandra reactive</description>
+
+    <parent>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-starter-parent</artifactId>
+        <version>2.1.0.RELEASE</version>
+        <relativePath/>
+    </parent>
+
+    <properties>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <project.reporting.outputEncoding>UTF-8
+        </project.reporting.outputEncoding>
+        <java.version>1.8</java.version>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.data</groupId>
+            <artifactId>spring-data-cassandra</artifactId>
+            <version>2.1.2.RELEASE</version>
+        </dependency>
+        <dependency>
+            <groupId>io.projectreactor</groupId>
+            <artifactId>reactor-core</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <optional>true</optional>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>io.projectreactor</groupId>
+            <artifactId>reactor-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+            </plugin>
+        </plugins>
+    </build>
+
+
+</project>
diff --git a/persistence-modules/spring-data-cassandra-reactive/src/main/java/com/baeldung/cassandra/reactive/SpringDataCassandraReactiveApplication.java b/persistence-modules/spring-data-cassandra-reactive/src/main/java/com/baeldung/cassandra/reactive/SpringDataCassandraReactiveApplication.java
new file mode 100644
index 0000000000..5f467042a3
--- /dev/null
+++ b/persistence-modules/spring-data-cassandra-reactive/src/main/java/com/baeldung/cassandra/reactive/SpringDataCassandraReactiveApplication.java
@@ -0,0 +1,12 @@
+package com.baeldung.cassandra.reactive;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class SpringDataCassandraReactiveApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(SpringDataCassandraReactiveApplication.class, args);
+    }
+}
diff --git a/persistence-modules/spring-data-cassandra-reactive/src/main/java/com/baeldung/cassandra/reactive/controller/EmployeeController.java b/persistence-modules/spring-data-cassandra-reactive/src/main/java/com/baeldung/cassandra/reactive/controller/EmployeeController.java
new file mode 100644
index 0000000000..e9de213e61
--- /dev/null
+++ b/persistence-modules/spring-data-cassandra-reactive/src/main/java/com/baeldung/cassandra/reactive/controller/EmployeeController.java
@@ -0,0 +1,49 @@
+package com.baeldung.cassandra.reactive.controller;
+
+import com.baeldung.cassandra.reactive.model.Employee;
+import com.baeldung.cassandra.reactive.service.EmployeeService;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+
+import javax.annotation.PostConstruct;
+import java.util.ArrayList;
+import java.util.List;
+
+@RestController
+@RequestMapping("employee")
+public class EmployeeController {
+
+    @Autowired
+    EmployeeService employeeService;
+
+    @PostConstruct
+    public void saveEmployees() {
+        List<Employee> employees = new ArrayList<>();
+        employees.add(new Employee(123, "John Doe", "Delaware", "jdoe@xyz.com", 31));
+        employees.add(new Employee(324, "Adam Smith", "North Carolina", "asmith@xyz.com", 43));
+        employees.add(new Employee(355, "Kevin Dunner", "Virginia", "kdunner@xyz.com", 24));
+        employees.add(new Employee(643, "Mike Lauren", "New York", "mlauren@xyz.com", 41));
+        employeeService.initializeEmployees(employees);
+    }
+
+    @GetMapping("/list")
+    public Flux<Employee> getAllEmployees() {
+        Flux<Employee> employees = employeeService.getAllEmployees();
+        return employees;
+    }
+
+    @GetMapping("/{id}")
+    public Mono<Employee> getEmployeeById(@PathVariable int id) {
+        return employeeService.getEmployeeById(id);
+    }
+
+    @GetMapping("/filterByAge/{age}")
+    public Flux<Employee> getEmployeesFilterByAge(@PathVariable int age) {
+        return employeeService.getEmployeesFilterByAge(age);
+    }
+}
diff --git a/persistence-modules/spring-data-cassandra-reactive/src/main/java/com/baeldung/cassandra/reactive/model/Employee.java b/persistence-modules/spring-data-cassandra-reactive/src/main/java/com/baeldung/cassandra/reactive/model/Employee.java
new file mode 100644
index 0000000000..a78f884778
--- /dev/null
+++ b/persistence-modules/spring-data-cassandra-reactive/src/main/java/com/baeldung/cassandra/reactive/model/Employee.java
@@ -0,0 +1,20 @@
+package com.baeldung.cassandra.reactive.model;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+import org.springframework.data.cassandra.core.mapping.PrimaryKey;
+import org.springframework.data.cassandra.core.mapping.Table;
+
+@Table
+@Data
+@AllArgsConstructor
+@NoArgsConstructor
+public class Employee {
+    @PrimaryKey
+    private int id;
+    private String name;
+    private String address;
+    private String email;
+    private int age;
+}
diff --git a/persistence-modules/spring-data-cassandra-reactive/src/main/java/com/baeldung/cassandra/reactive/repository/EmployeeRepository.java b/persistence-modules/spring-data-cassandra-reactive/src/main/java/com/baeldung/cassandra/reactive/repository/EmployeeRepository.java
new file mode 100644
index 0000000000..22dc2b4565
--- /dev/null
+++ b/persistence-modules/spring-data-cassandra-reactive/src/main/java/com/baeldung/cassandra/reactive/repository/EmployeeRepository.java
@@ -0,0 +1,11 @@
+package com.baeldung.cassandra.reactive.repository;
+
+import com.baeldung.cassandra.reactive.model.Employee;
+import org.springframework.data.cassandra.repository.AllowFiltering;
+import org.springframework.data.cassandra.repository.ReactiveCassandraRepository;
+import reactor.core.publisher.Flux;
+
+public interface EmployeeRepository extends ReactiveCassandraRepository<Employee, Integer> {
+    @AllowFiltering
+    Flux<Employee> findByAgeGreaterThan(int age);
+}
diff --git a/persistence-modules/spring-data-cassandra-reactive/src/main/java/com/baeldung/cassandra/reactive/service/EmployeeService.java b/persistence-modules/spring-data-cassandra-reactive/src/main/java/com/baeldung/cassandra/reactive/service/EmployeeService.java
new file mode 100644
index 0000000000..40c330937a
--- /dev/null
+++ b/persistence-modules/spring-data-cassandra-reactive/src/main/java/com/baeldung/cassandra/reactive/service/EmployeeService.java
@@ -0,0 +1,35 @@
+package com.baeldung.cassandra.reactive.service;
+
+import com.baeldung.cassandra.reactive.model.Employee;
+import com.baeldung.cassandra.reactive.repository.EmployeeRepository;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+
+import java.util.List;
+
+@Service
+public class EmployeeService {
+
+    @Autowired
+    EmployeeRepository employeeRepository;
+
+    public void initializeEmployees(List<Employee> employees) {
+        Flux<Employee> savedEmployees = employeeRepository.saveAll(employees);
+        savedEmployees.subscribe();
+    }
+
+    public Flux<Employee> getAllEmployees() {
+        Flux<Employee> employees =  employeeRepository.findAll();
+        return employees;
+    }
+
+    public Flux<Employee> getEmployeesFilterByAge(int age) {
+        return employeeRepository.findByAgeGreaterThan(age);
+    }
+
+    public Mono<Employee> getEmployeeById(int id) {
+        return employeeRepository.findById(id);
+    }
+}
diff --git a/persistence-modules/spring-data-cassandra-reactive/src/main/resources/application.properties b/persistence-modules/spring-data-cassandra-reactive/src/main/resources/application.properties
new file mode 100644
index 0000000000..7ed2f10131
--- /dev/null
+++ b/persistence-modules/spring-data-cassandra-reactive/src/main/resources/application.properties
@@ -0,0 +1,2 @@
+spring.data.cassandra.keyspace-name=practice
+spring.data.cassandra.port=9042
\ No newline at end of file
diff --git a/persistence-modules/spring-data-cassandra-reactive/src/test/java/com/baeldung/cassandra/reactive/ReactiveEmployeeRepositoryIntegrationTest.java b/persistence-modules/spring-data-cassandra-reactive/src/test/java/com/baeldung/cassandra/reactive/ReactiveEmployeeRepositoryIntegrationTest.java
new file mode 100644
index 0000000000..ad726fe969
--- /dev/null
+++ b/persistence-modules/spring-data-cassandra-reactive/src/test/java/com/baeldung/cassandra/reactive/ReactiveEmployeeRepositoryIntegrationTest.java
@@ -0,0 +1,55 @@
+package com.baeldung.cassandra.reactive;
+
+import com.baeldung.cassandra.reactive.model.Employee;
+import com.baeldung.cassandra.reactive.repository.EmployeeRepository;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.junit4.SpringRunner;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+import reactor.test.StepVerifier;
+
+
+@RunWith(SpringRunner.class)
+@SpringBootTest
+public class ReactiveEmployeeRepositoryIntegrationTest {
+
+	@Autowired
+	EmployeeRepository repository;
+
+	@Before
+	public void setUp() {
+
+		Flux<Employee> deleteAndInsert = repository.deleteAll() //
+				.thenMany(repository.saveAll(Flux.just(
+						new Employee(111, "John Doe", "Delaware", "jdoe@xyz.com", 31),
+						new Employee(222, "Adam Smith", "North Carolina", "asmith@xyz.com", 43),
+						new Employee(333, "Kevin Dunner", "Virginia", "kdunner@xyz.com", 24),
+						new Employee(444, "Mike Lauren", "New York", "mlauren@xyz.com", 41))));
+
+		StepVerifier.create(deleteAndInsert).expectNextCount(4).verifyComplete();
+	}
+
+	@Test
+	public void givenRecordsAreInserted_whenDbIsQueried_thenShouldIncludeNewRecords() {
+
+		Mono<Long> saveAndCount = repository.count()
+				.doOnNext(System.out::println)
+				.thenMany(repository.saveAll(Flux.just(new Employee(325, "Kim Jones", "Florida", "kjones@xyz.com", 42),
+						new Employee(654, "Tom Moody", "New Hampshire", "tmoody@xyz.com", 44))))
+				.last()
+				.flatMap(v -> repository.count())
+				.doOnNext(System.out::println);
+
+		StepVerifier.create(saveAndCount).expectNext(6L).verifyComplete();
+	}
+
+	@Test
+	public void givenAgeForFilter_whenDbIsQueried_thenShouldReturnFilteredRecords() {
+		StepVerifier.create(repository.findByAgeGreaterThan(35)).expectNextCount(2).verifyComplete();
+	}
+
+}
diff --git a/pom.xml b/pom.xml
index 70248b9993..8fa93373fc 100644
--- a/pom.xml
+++ b/pom.xml
@@ -377,6 +377,7 @@
 				<module>feign</module>
 				<module>flips</module>
 				<module>testing-modules/groovy-spock</module>
+				<module>testing-modules/load-testing-comparison</module>
 				<module>google-cloud</module>
 				<module>google-web-toolkit</module>
 				<module>gson</module>
@@ -636,7 +637,7 @@
                 <module>dubbo</module>
                 <module>persistence-modules/flyway</module>
                 <!-- <module>grpc</module> --><!-- protobuf-maven-plugin filecopy failure -->
-                <!-- <module>JGit</module> --><!-- Unit test failure -->
+                <module>JGit</module>
                 <module>jni</module>
                 <module>jooby</module>
                 <!-- <module>micronaut</module> --><!-- Not upgraded to java 9 -->
@@ -661,24 +662,13 @@
                 <module>sse-jaxrs</module>
                 <module>static-analysis</module>
                 <module>stripe</module>
-                <!-- <module>structurizr</module> --><!-- Artiifact not found -->
+                <module>structurizr</module>
                 <module>Twitter4J</module>
                 <module>wicket</module>
                 <module>xstream</module>
                 <module>cas/cas-secured-app</module>
                 <module>cas/cas-server</module>
-                <!-- <module>graphql/graphql-java</module> --><!-- Wrong parent -->
-                <!-- <module>guest/deep-jsf</module> --><!-- guest post on different site -->
-                <!-- <module>guest/junit5-example</module> --><!-- guest post on different site - Compilation failure -->
-                <!-- <module>guest/log4j2-example</module> --><!-- guest post on different site -->
-                <!-- <module>guest/logback-example</module> --><!-- guest post on different site -->
-                <!-- <module>guest/memory-leaks</module> --><!-- guest post on different site -->
-                <!-- <module>guest/remote-debugging</module> --><!-- guest post on different site -->
-                <!-- <module>guest/spring-boot-app</module> --><!-- guest post on different site -->
-                <!-- <module>guest/spring-mvc</module> --><!-- guest post on different site -->
-                <!-- <module>guest/spring-security</module> --><!-- guest post on different site -->
-                <!-- <module>guest/thread-pools</module> --><!-- guest post on different site -->
-                <!-- <module>guest/tomcat-app</module> --><!-- guest post on different site -->
+                <module>graphql/graphql-java</module>
                 <!-- <module>jenkins/hello-world</module> --> <!-- disabled in the default profile -->
                 <!-- <module>rule-engines/easy-rules</module> --><!-- Wrong Parent -->
                 <!-- <module>rule-engines/openl-tablets</module> --><!-- Wrong Parent -->
@@ -686,9 +676,6 @@
                 <module>spring-boot-custom-starter/greeter</module>
                 <module>persistence-modules/spring-boot-h2/spring-boot-h2-database</module>
                 <!--module>persistence-modules/spring-boot-h2/spring-boot-h2-remote-app</module-->
-                <!-- <module>guest\webservices\rest-client</module> --><!-- guest post on different site -->
-                <!-- <module>guest\webservices\rest-server</module> --><!-- guest post on different site -->
-                <!-- <module>guest\webservices\spring-rest-service</module> --><!-- guest post on different site -->
                 <module>flyway-cdi-extension</module>
                 
                 <module>spring-security-acl</module>
@@ -710,7 +697,7 @@
                 <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-react</module>
                 <module>spring-security-rest-basic-auth</module>
                 <module>spring-security-rest-custom</module>
                 <module>spring-security-rest</module>
@@ -733,8 +720,8 @@
                 <module>spring-rest-angular</module>
                 <module>spring-rest-full</module>
                 <module>spring-rest-query-language</module>
-                <!-- <module>spring-rest</module> --> <!-- temporarily disabled -->
-                <!-- <module>spring-rest-simple</module> --> <!-- temporarily disabled -->
+                <module>spring-rest</module>
+                <module>spring-rest-simple</module>
                 <module>spring-resttemplate</module>
 				<module>helidon</module>
             </modules>
@@ -1029,7 +1016,7 @@
                 
                 <module>jackson</module>
                 <module>java-strings</module>
-                <!--<module>core-java-9</module> --> <!-- Commented because we have still not upgraded to java 9 -->
+                <!--<module>core-java-9</module> --> <!-- we haven't upgraded to java 9 -->
                 <module>java-collections-conversions</module>
                 <module>java-collections-maps</module>
                 <module>java-streams</module>
@@ -1113,9 +1100,10 @@
                 <module>rabbitmq</module>
                 
                 <!-- very long running - temporarily disabled -->
-                <!-- 
+                <!--
+                
+                --> 
                 <module>persistence-modules/spring-data-mongodb</module>
-                -->
                 
             </modules>
 
@@ -1713,6 +1701,7 @@
                 <module>persistence-modules/spring-data-elasticsearch</module>
                 <module>core-java-concurrency</module>
 				<module>core-java-concurrency-collections</module>
+				<module>restx</module>
             </modules>
 
         </profile>
diff --git a/restx/data/credentials.json b/restx/data/credentials.json
new file mode 100644
index 0000000000..c1a4fcf531
--- /dev/null
+++ b/restx/data/credentials.json
@@ -0,0 +1,12 @@
+{
+    "//": "lines with // keys are just comments (we don't have real comments in json)",
+    "//": "this file stores password passed through md5+bcrypt hash",
+    "//": "you can use `restx hash md5+bcrypt {password}` shell command to get hashed passwords to put here",
+
+    "//": "to help startup with restx, there are comments with clear text passwords,",
+    "//": "which should obviously not be stored here.",
+    "user1": "$2a$10$iZluFUJShbjb1ue68bLrDuGCeJL9EMLHelVIf8u0SUbCseDOvKnoe",
+    "//": "user 1 password is 'user1-pwd'",
+    "user2": "$2a$10$oym3SYMFXf/9gGfDKKHO4eM1vWNqAZMsRZCL.BORCaP4yp5cdiCXu",
+    "//": "user 2 password is 'user2-pwd'"
+}
\ No newline at end of file
diff --git a/restx/data/users.json b/restx/data/users.json
new file mode 100644
index 0000000000..834e03c4b4
--- /dev/null
+++ b/restx/data/users.json
@@ -0,0 +1,4 @@
+[
+    {"name":"user1", "roles": ["hello"]},
+    {"name":"user2", "roles": []}
+]
\ No newline at end of file
diff --git a/restx/md.restx.json b/restx/md.restx.json
new file mode 100644
index 0000000000..c87244001c
--- /dev/null
+++ b/restx/md.restx.json
@@ -0,0 +1,38 @@
+{
+    "module": "restx-demo:restx-demo:0.1-SNAPSHOT",
+    "packaging": "war",
+
+    "properties": {
+        "java.version": "1.8",
+        "restx.version": "0.35-rc4"
+    },
+    "fragments": {
+        "maven": [
+            "classpath:///restx/build/fragments/maven/javadoc-apidoclet.xml"        ]
+    },
+    "dependencies": {
+        "compile": [
+            "io.restx:restx-core:${restx.version}",
+            "io.restx:restx-security-basic:${restx.version}",
+            "io.restx:restx-core-annotation-processor:${restx.version}",
+            "io.restx:restx-factory:${restx.version}",
+            "io.restx:restx-factory-admin:${restx.version}",
+            "io.restx:restx-validation:${restx.version}",
+            "io.restx:restx-monitor-codahale:${restx.version}",
+            "io.restx:restx-monitor-admin:${restx.version}",
+            "io.restx:restx-log-admin:${restx.version}",
+            "io.restx:restx-i18n-admin:${restx.version}",
+            "io.restx:restx-stats-admin:${restx.version}",
+            "io.restx:restx-servlet:${restx.version}",
+            "io.restx:restx-server-jetty8:${restx.version}!optional",
+            "io.restx:restx-apidocs:${restx.version}",
+            "io.restx:restx-specs-admin:${restx.version}",
+            "io.restx:restx-admin:${restx.version}",
+            "ch.qos.logback:logback-classic:1.0.13"
+        ],
+        "test": [
+            "io.restx:restx-specs-tests:${restx.version}",
+            "junit:junit:4.11"
+        ]
+    }
+}
diff --git a/restx/pom.xml b/restx/pom.xml
new file mode 100644
index 0000000000..c6233b968c
--- /dev/null
+++ b/restx/pom.xml
@@ -0,0 +1,155 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>restx</artifactId>
+    <version>0.1-SNAPSHOT</version>
+    <packaging>war</packaging>
+    <name>restx-demo</name>
+
+    <properties>
+        <maven.compiler.target>1.8</maven.compiler.target>
+        <maven.compiler.source>1.8</maven.compiler.source>
+        <restx.version>0.35-rc4</restx.version>
+    </properties>
+	
+	<parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>io.restx</groupId>
+            <artifactId>restx-core</artifactId>
+            <version>${restx.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>io.restx</groupId>
+            <artifactId>restx-security-basic</artifactId>
+            <version>${restx.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>io.restx</groupId>
+            <artifactId>restx-core-annotation-processor</artifactId>
+            <version>${restx.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>io.restx</groupId>
+            <artifactId>restx-factory</artifactId>
+            <version>${restx.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>io.restx</groupId>
+            <artifactId>restx-factory-admin</artifactId>
+            <version>${restx.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>io.restx</groupId>
+            <artifactId>restx-validation</artifactId>
+            <version>${restx.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>io.restx</groupId>
+            <artifactId>restx-monitor-codahale</artifactId>
+            <version>${restx.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>io.restx</groupId>
+            <artifactId>restx-monitor-admin</artifactId>
+            <version>${restx.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>io.restx</groupId>
+            <artifactId>restx-log-admin</artifactId>
+            <version>${restx.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>io.restx</groupId>
+            <artifactId>restx-i18n-admin</artifactId>
+            <version>${restx.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>io.restx</groupId>
+            <artifactId>restx-stats-admin</artifactId>
+            <version>${restx.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>io.restx</groupId>
+            <artifactId>restx-servlet</artifactId>
+            <version>${restx.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>io.restx</groupId>
+            <artifactId>restx-server-jetty8</artifactId>
+            <version>${restx.version}</version>
+            <optional>true</optional>
+        </dependency>
+        <dependency>
+            <groupId>io.restx</groupId>
+            <artifactId>restx-apidocs</artifactId>
+            <version>${restx.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>io.restx</groupId>
+            <artifactId>restx-specs-admin</artifactId>
+            <version>${restx.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>io.restx</groupId>
+            <artifactId>restx-admin</artifactId>
+            <version>${restx.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>ch.qos.logback</groupId>
+            <artifactId>logback-classic</artifactId>
+            <version>1.0.13</version>
+        </dependency>
+        <dependency>
+            <groupId>io.restx</groupId>
+            <artifactId>restx-specs-tests</artifactId>
+            <version>${restx.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>4.11</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-javadoc-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <id>attach-docs</id>
+                        <!--
+                            we generate javadoc before packaging the jar to let a chance to apidocs doclet
+                            to generate comments dictionary to be packaged inside the jar as a resource
+                            -->
+                        <phase>prepare-package</phase>
+                        <goals>
+                            <goal>jar</goal>
+                        </goals>
+                    </execution>
+                </executions>
+                <configuration>
+                    <source>${maven.compiler.source}</source>
+                    <doclet>restx.apidocs.doclet.ApidocsDoclet</doclet>
+                    <docletArtifact>
+                        <groupId>io.restx</groupId>
+                        <artifactId>restx-apidocs-doclet</artifactId>
+                        <version>${restx.version}</version>
+                    </docletArtifact>
+                    <additionalparam>-restx-target-dir ${project.basedir}/target/classes</additionalparam>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+</project>
diff --git a/restx/src/main/java/restx/demo/AppModule.java b/restx/src/main/java/restx/demo/AppModule.java
new file mode 100644
index 0000000000..26bc681481
--- /dev/null
+++ b/restx/src/main/java/restx/demo/AppModule.java
@@ -0,0 +1,74 @@
+package restx.demo;
+
+import restx.config.ConfigLoader;
+import restx.config.ConfigSupplier;
+import restx.factory.Provides;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.google.common.base.Charsets;
+import com.google.common.collect.ImmutableSet;
+import restx.security.*;
+import restx.factory.Module;
+import restx.factory.Provides;
+import javax.inject.Named;
+
+import java.nio.file.Paths;
+
+@Module
+public class AppModule {
+    @Provides
+    public SignatureKey signatureKey() {
+         return new SignatureKey("restx-demo -447494532235718370 restx-demo 801c9eaf-4116-48f2-906b-e979fba72757".getBytes(Charsets.UTF_8));
+    }
+
+    @Provides
+    @Named("restx.admin.password")
+    public String restxAdminPassword() {
+        return "4780";
+    }
+
+    @Provides
+    public ConfigSupplier appConfigSupplier(ConfigLoader configLoader) {
+        // Load settings.properties in restx.demo package as a set of config entries
+        return configLoader.fromResource("restx/demo/settings");
+    }
+
+    @Provides
+    public CredentialsStrategy credentialsStrategy() {
+        return new BCryptCredentialsStrategy();
+    }
+
+    @Provides
+    public BasicPrincipalAuthenticator basicPrincipalAuthenticator(
+            SecuritySettings securitySettings, CredentialsStrategy credentialsStrategy,
+            @Named("restx.admin.passwordHash") String defaultAdminPasswordHash, ObjectMapper mapper) {
+        return new StdBasicPrincipalAuthenticator(new StdUserService<>(
+                // use file based users repository.
+                // Developer's note: prefer another storage mechanism for your users if you need real user management
+                // and better perf
+                new FileBasedUserRepository<>(
+                        StdUser.class, // this is the class for the User objects, that you can get in your app code
+                        // with RestxSession.current().getPrincipal().get()
+                        // it can be a custom user class, it just need to be json deserializable
+                        mapper,
+
+                        // this is the default restx admin, useful to access the restx admin console.
+                        // if one user with restx-admin role is defined in the repository, this default user won't be
+                        // available anymore
+                        new StdUser("admin", ImmutableSet.<String>of("*")),
+
+                        // the path where users are stored
+                        Paths.get("data/users.json"),
+
+                        // the path where credentials are stored. isolating both is a good practice in terms of security
+                        // it is strongly recommended to follow this approach even if you use your own repository
+                        Paths.get("data/credentials.json"),
+
+                        // tells that we want to reload the files dynamically if they are touched.
+                        // this has a performance impact, if you know your users / credentials never change without a
+                        // restart you can disable this to get better perfs
+                        true),
+                credentialsStrategy, defaultAdminPasswordHash),
+                securitySettings);
+    }
+}
diff --git a/restx/src/main/java/restx/demo/AppServer.java b/restx/src/main/java/restx/demo/AppServer.java
new file mode 100644
index 0000000000..d66aadac68
--- /dev/null
+++ b/restx/src/main/java/restx/demo/AppServer.java
@@ -0,0 +1,32 @@
+package restx.demo;
+
+import com.google.common.base.Optional;
+import restx.server.WebServer;
+import restx.server.Jetty8WebServer;
+
+/**
+ * This class can be used to run the app.
+ *
+ * Alternatively, you can deploy the app as a war in a regular container like tomcat or jetty.
+ *
+ * Reading the port from system env PORT makes it compatible with heroku.
+ */
+public class AppServer {
+    public static final String WEB_INF_LOCATION = "src/main/webapp/WEB-INF/web.xml";
+    public static final String WEB_APP_LOCATION = "src/main/webapp";
+
+    public static void main(String[] args) throws Exception {
+        int port = Integer.valueOf(Optional.fromNullable(System.getenv("PORT")).or("8080"));
+        WebServer server = new Jetty8WebServer(WEB_INF_LOCATION, WEB_APP_LOCATION, port, "0.0.0.0");
+
+        /*
+         * load mode from system property if defined, or default to dev
+         * be careful with that setting, if you use this class to launch your server in production, make sure to launch
+         * it with -Drestx.mode=prod or change the default here
+         */
+        System.setProperty("restx.mode", System.getProperty("restx.mode", "dev"));
+        System.setProperty("restx.app.package", "restx.demo");
+
+        server.startAndAwait();
+    }
+}
diff --git a/restx/src/main/java/restx/demo/Roles.java b/restx/src/main/java/restx/demo/Roles.java
new file mode 100644
index 0000000000..1240da70d1
--- /dev/null
+++ b/restx/src/main/java/restx/demo/Roles.java
@@ -0,0 +1,10 @@
+package restx.demo;
+
+/**
+ * A list of roles for the application.
+ *
+ * We don't use an enum here because it must be used inside an annotation.
+ */
+public final class Roles {
+    public static final String HELLO_ROLE = "hello";
+}
diff --git a/restx/src/main/java/restx/demo/domain/Message.java b/restx/src/main/java/restx/demo/domain/Message.java
new file mode 100644
index 0000000000..733c00deff
--- /dev/null
+++ b/restx/src/main/java/restx/demo/domain/Message.java
@@ -0,0 +1,21 @@
+package restx.demo.domain;
+
+public class Message {
+    private String message;
+
+    public String getMessage() {
+        return message;
+    }
+
+    public Message setMessage(final String message) {
+        this.message = message;
+        return this;
+    }
+
+    @Override
+    public String toString() {
+        return "Message{" +
+                "message='" + message + '\'' +
+                '}';
+    }
+}
diff --git a/restx/src/main/java/restx/demo/rest/HelloResource.java b/restx/src/main/java/restx/demo/rest/HelloResource.java
new file mode 100644
index 0000000000..5cb2c2a5e6
--- /dev/null
+++ b/restx/src/main/java/restx/demo/rest/HelloResource.java
@@ -0,0 +1,62 @@
+package restx.demo.rest;
+
+import restx.demo.domain.Message;
+import restx.demo.Roles;
+import org.joda.time.DateTime;
+import restx.annotations.GET;
+import restx.annotations.POST;
+import restx.annotations.RestxResource;
+import restx.factory.Component;
+import restx.security.PermitAll;
+import restx.security.RolesAllowed;
+import restx.security.RestxSession;
+
+import javax.validation.constraints.NotNull;
+
+@Component @RestxResource
+public class HelloResource {
+
+    /**
+     * Say hello to currently logged in user.
+     *
+     * Authorized only for principals with Roles.HELLO_ROLE role.
+     *
+     * @return a Message to say hello
+     */
+    @GET("/message")
+    @RolesAllowed(Roles.HELLO_ROLE)
+    public Message sayHello() {
+        return new Message().setMessage(String.format(
+                "hello %s, it's %s",
+                RestxSession.current().getPrincipal().get().getName(),
+                DateTime.now().toString("HH:mm:ss")));
+    }
+
+    /**
+     * Say hello to anybody.
+     *
+     * Does not require authentication.
+     *
+     * @return a Message to say hello
+     */
+    @GET("/hello")
+    @PermitAll
+    public Message helloPublic(String who) {
+        return new Message().setMessage(String.format(
+                "hello %s, it's %s",
+                who, DateTime.now().toString("HH:mm:ss")));
+    }
+
+    public static class MyPOJO {
+        @NotNull
+        String value;
+        public String getValue(){ return value; }
+        public void setValue(String value){ this.value = value; }
+    }
+    @POST("/mypojo")
+    @PermitAll
+    public MyPOJO helloPojo(MyPOJO pojo){
+        pojo.setValue("hello "+pojo.getValue());
+        return pojo;
+    }
+}
diff --git a/restx/src/main/resources/logback.xml b/restx/src/main/resources/logback.xml
new file mode 100644
index 0000000000..524bca6b1f
--- /dev/null
+++ b/restx/src/main/resources/logback.xml
@@ -0,0 +1,94 @@
+<configuration>
+    <contextListener class="ch.qos.logback.classic.jul.LevelChangePropagator">
+        <resetJUL>true</resetJUL>
+    </contextListener>
+    <property name="LOGS_FOLDER" value="${logs.base:-logs}" />
+
+    <appender name="errorFile" class="ch.qos.logback.core.rolling.RollingFileAppender">
+        <File>${LOGS_FOLDER}/errors.log</File>
+        <filter class="ch.qos.logback.classic.filter.ThresholdFilter">
+            <level>ERROR</level>
+        </filter>
+        <encoder>
+            <pattern>%d [%-16thread] [%-10X{principal}] %-5level %logger{36} - %msg%n</pattern>
+        </encoder>
+        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
+            <fileNamePattern>${LOGS_FOLDER}/errors.%d.log</fileNamePattern>
+            <maxHistory>30</maxHistory>
+        </rollingPolicy>
+    </appender>
+
+    <if condition='p("restx.mode").equals("prod")'>
+        <then>
+            <!-- production mode -->
+            <appender name="appLog" class="ch.qos.logback.core.rolling.RollingFileAppender">
+                <File>${LOGS_FOLDER}/app.log</File>
+                <filter class="ch.qos.logback.classic.filter.ThresholdFilter">
+                    <level>INFO</level>
+                </filter>
+                <encoder>
+                    <pattern>%d [%-16thread] [%-10X{principal}] %-5level %logger{36} - %msg%n</pattern>
+                </encoder>
+                <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
+                    <fileNamePattern>${LOGS_FOLDER}/app.%d.log</fileNamePattern>
+                    <maxHistory>10</maxHistory>
+                </rollingPolicy>
+            </appender>
+            <appender name="debugFile" class="ch.qos.logback.core.rolling.RollingFileAppender">
+                <File>${LOGS_FOLDER}/debug.log</File>
+                <encoder>
+                    <pattern>%d [%-16thread] [%-10X{principal}] %-5level %logger{36} - %msg%n</pattern>
+                </encoder>
+                <rollingPolicy class="ch.qos.logback.core.rolling.FixedWindowRollingPolicy">
+                    <fileNamePattern>${LOGS_FOLDER}/debug.%i.log.zip</fileNamePattern>
+                    <minIndex>1</minIndex>
+                    <maxIndex>3</maxIndex>
+                </rollingPolicy>
+
+                <triggeringPolicy class="ch.qos.logback.core.rolling.SizeBasedTriggeringPolicy">
+                    <maxFileSize>50MB</maxFileSize>
+                </triggeringPolicy>
+            </appender>
+            <root level="INFO">
+                <appender-ref ref="debugFile" />
+                <appender-ref ref="appLog" />
+            </root>
+        </then>
+        <else>
+            <!-- not production mode -->
+            <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+                <encoder>
+                    <pattern>%d [%-16thread] [%-10X{principal}] %-5level %logger{36} - %msg%n</pattern>
+                </encoder>
+            </appender>
+            <appender name="appLog" class="ch.qos.logback.core.FileAppender">
+                <File>${LOGS_FOLDER}/app.log</File>
+                <encoder>
+                    <pattern>%d [%-16thread] [%-10X{principal}] %-5level %logger{36} - %msg%n</pattern>
+                </encoder>
+            </appender>
+
+            <root level="INFO">
+                <appender-ref ref="STDOUT" />
+                <appender-ref ref="appLog" />
+            </root>
+        </else>
+    </if>
+
+    <!-- clean up container logs -->
+    <logger name="org.eclipse.jetty.server.AbstractConnector" level="WARN" />
+    <logger name="org.eclipse.jetty.server.handler.ContextHandler" level="WARN" />
+    <logger name="org.eclipse.jetty.webapp.StandardDescriptorProcessor" level="WARN" />
+
+    <logger name="org.hibernate.validator.internal.engine.ConfigurationImpl" level="WARN" />
+    <logger name="org.reflections.Reflections" level="WARN" />
+
+    <logger name="restx.factory.Factory" level="WARN" />
+
+    <!-- app logs - set DEBUG level, in prod it will go to a dedicated file -->
+    <logger name="restx.demo" level="DEBUG" />
+
+    <root level="INFO">
+        <appender-ref ref="errorFile" />
+    </root>
+</configuration>
diff --git a/restx/src/main/resources/restx/demo/settings.properties b/restx/src/main/resources/restx/demo/settings.properties
new file mode 100644
index 0000000000..a03c2eea97
--- /dev/null
+++ b/restx/src/main/resources/restx/demo/settings.properties
@@ -0,0 +1 @@
+app.name=restx-demo
\ No newline at end of file
diff --git a/restx/src/main/webapp/WEB-INF/web.xml b/restx/src/main/webapp/WEB-INF/web.xml
new file mode 100644
index 0000000000..c651794526
--- /dev/null
+++ b/restx/src/main/webapp/WEB-INF/web.xml
@@ -0,0 +1,15 @@
+<web-app xmlns="http://java.sun.com/xml/ns/javaee"
+      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+      xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
+      version="3.0" metadata-complete="true">
+
+    <servlet>
+        <servlet-name>restx</servlet-name>
+        <servlet-class>restx.servlet.RestxMainRouterServlet</servlet-class>
+        <load-on-startup>1</load-on-startup>
+    </servlet>
+    <servlet-mapping>
+        <servlet-name>restx</servlet-name>
+        <url-pattern>/api/*</url-pattern>
+    </servlet-mapping>
+</web-app>
diff --git a/restx/src/test/java/restx/demo/rest/HelloResourceSpecUnitTest.java b/restx/src/test/java/restx/demo/rest/HelloResourceSpecUnitTest.java
new file mode 100644
index 0000000000..f67e4565b3
--- /dev/null
+++ b/restx/src/test/java/restx/demo/rest/HelloResourceSpecUnitTest.java
@@ -0,0 +1,23 @@
+package restx.demo.rest;
+
+import org.junit.runner.RunWith;
+
+import restx.tests.FindSpecsIn;
+import restx.tests.RestxSpecTestsRunner;
+
+@RunWith(RestxSpecTestsRunner.class)
+@FindSpecsIn("specs/hello")
+public class HelloResourceSpecUnitTest {
+
+    /**
+     * Useless, thanks to both @RunWith(RestxSpecTestsRunner.class) & @FindSpecsIn()
+     *
+     * @Rule
+     * public RestxSpecRule rule = new RestxSpecRule();
+     *
+     * @Test
+     * public void test_spec() throws Exception {
+     *     rule.runTest(specTestPath);
+     * }
+     */
+}
diff --git a/restx/src/test/resources/specs/hello/should_admin_say_hello.spec.yaml b/restx/src/test/resources/specs/hello/should_admin_say_hello.spec.yaml
new file mode 100644
index 0000000000..1b7b8f0f90
--- /dev/null
+++ b/restx/src/test/resources/specs/hello/should_admin_say_hello.spec.yaml
@@ -0,0 +1,10 @@
+title: should admin say hello
+given:
+  - time: 2013-08-28T01:18:00.822+02:00
+  - uuids: [ "e2b4430f-9541-4602-9a3a-413d17c56a6b" ]
+wts:
+  - when: |
+      GET message
+      $RestxSession: {"_expires":"2013-09-27T01:18:00.822+02:00","principal":"admin","sessionKey":"e2b4430f-9541-4602-9a3a-413d17c56a6b"}
+    then: |
+      {"message":"hello admin, it's 01:18:00"}
diff --git a/restx/src/test/resources/specs/hello/should_anyone_say_hello.spec.yaml b/restx/src/test/resources/specs/hello/should_anyone_say_hello.spec.yaml
new file mode 100644
index 0000000000..29b6faca34
--- /dev/null
+++ b/restx/src/test/resources/specs/hello/should_anyone_say_hello.spec.yaml
@@ -0,0 +1,8 @@
+title: should admin say hello
+given:
+  - time: 2013-08-28T01:18:00.822+02:00
+wts:
+  - when: |
+      GET hello?who=xavier
+    then: |
+      {"message":"hello xavier, it's 01:18:00"}
diff --git a/restx/src/test/resources/specs/hello/should_missing_value_triggers_validation_error.spec.yaml b/restx/src/test/resources/specs/hello/should_missing_value_triggers_validation_error.spec.yaml
new file mode 100644
index 0000000000..d0c6323caf
--- /dev/null
+++ b/restx/src/test/resources/specs/hello/should_missing_value_triggers_validation_error.spec.yaml
@@ -0,0 +1,17 @@
+title: should missing post value triggers a validation error
+given:
+  - time: 2013-08-28T01:18:00.822+02:00
+  - uuids: [ "e2b4430f-9541-4602-9a3a-413d17c56a6b" ]
+wts:
+  - when: |
+      POST mypojo
+      $RestxSession: {"_expires":"2013-09-27T01:18:00.822+02:00","principal":"user1","sessionKey":"e2b4430f-9541-4602-9a3a-413d17c56a6b"}
+      {}
+    then: |
+      400
+  - when: |
+      POST mypojo
+      $RestxSession: {"_expires":"2013-09-27T01:18:00.822+02:00","principal":"user1","sessionKey":"e2b4430f-9541-4602-9a3a-413d17c56a6b"}
+      {"value":"world"}
+    then: |
+      {"value":"hello world"}
diff --git a/restx/src/test/resources/specs/hello/should_user1_say_hello.spec.yaml b/restx/src/test/resources/specs/hello/should_user1_say_hello.spec.yaml
new file mode 100644
index 0000000000..791a3a2776
--- /dev/null
+++ b/restx/src/test/resources/specs/hello/should_user1_say_hello.spec.yaml
@@ -0,0 +1,10 @@
+title: should user1 say hello
+given:
+  - time: 2013-08-28T01:18:00.822+02:00
+  - uuids: [ "e2b4430f-9541-4602-9a3a-413d17c56a6b" ]
+wts:
+  - when: |
+      GET message
+      $RestxSession: {"_expires":"2013-09-27T01:18:00.822+02:00","principal":"user1","sessionKey":"e2b4430f-9541-4602-9a3a-413d17c56a6b"}
+    then: |
+      {"message":"hello user1, it's 01:18:00"}
diff --git a/restx/src/test/resources/specs/hello/should_user2_not_say_hello.spec.yaml b/restx/src/test/resources/specs/hello/should_user2_not_say_hello.spec.yaml
new file mode 100644
index 0000000000..ead5af8d0c
--- /dev/null
+++ b/restx/src/test/resources/specs/hello/should_user2_not_say_hello.spec.yaml
@@ -0,0 +1,10 @@
+title: should user2 not say hello
+given:
+  - time: 2013-08-28T01:19:44.770+02:00
+  - uuids: [ "56f71fcc-42d3-422f-9458-8ad37fc4a0b5" ]
+wts:
+  - when: |
+      GET message
+      $RestxSession: {"_expires":"2013-09-27T01:19:44.770+02:00","principal":"user2","sessionKey":"56f71fcc-42d3-422f-9458-8ad37fc4a0b5"}
+    then: |
+      403
diff --git a/spring-5-reactive/src/main/java/com/baeldung/debugging/consumer/ConsumerSSEApplication.java b/spring-5-reactive/src/main/java/com/baeldung/debugging/consumer/ConsumerSSEApplication.java
new file mode 100644
index 0000000000..55db3d7392
--- /dev/null
+++ b/spring-5-reactive/src/main/java/com/baeldung/debugging/consumer/ConsumerSSEApplication.java
@@ -0,0 +1,33 @@
+package com.baeldung.debugging.consumer;
+
+import java.util.Collections;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.autoconfigure.mongo.MongoReactiveAutoConfiguration;
+import org.springframework.context.annotation.Bean;
+import org.springframework.scheduling.annotation.EnableScheduling;
+import org.springframework.security.config.web.server.ServerHttpSecurity;
+import org.springframework.security.web.server.SecurityWebFilterChain;
+
+import reactor.core.publisher.Hooks;
+
+@SpringBootApplication(exclude = MongoReactiveAutoConfiguration.class)
+@EnableScheduling
+public class ConsumerSSEApplication {
+
+    public static void main(String[] args) {
+        Hooks.onOperatorDebug();
+        SpringApplication app = new SpringApplication(ConsumerSSEApplication.class);
+        app.setDefaultProperties(Collections.singletonMap("server.port", "8082"));
+        app.run(args);
+    }
+
+    @Bean
+    public SecurityWebFilterChain springSecurityFilterChain(ServerHttpSecurity http) {
+        http.authorizeExchange()
+            .anyExchange()
+            .permitAll();
+        return http.build();
+    }
+}
diff --git a/spring-5-reactive/src/main/java/com/baeldung/debugging/consumer/chronjobs/ChronJobs.java b/spring-5-reactive/src/main/java/com/baeldung/debugging/consumer/chronjobs/ChronJobs.java
new file mode 100644
index 0000000000..09cbc34a6f
--- /dev/null
+++ b/spring-5-reactive/src/main/java/com/baeldung/debugging/consumer/chronjobs/ChronJobs.java
@@ -0,0 +1,122 @@
+package com.baeldung.debugging.consumer.chronjobs;
+
+import java.time.Duration;
+import java.util.concurrent.ThreadLocalRandom;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.MediaType;
+import org.springframework.scheduling.annotation.Scheduled;
+import org.springframework.stereotype.Component;
+import org.springframework.web.reactive.function.client.WebClient;
+
+import com.baeldung.debugging.consumer.model.Foo;
+import com.baeldung.debugging.consumer.model.FooDto;
+import com.baeldung.debugging.consumer.service.FooService;
+
+import reactor.core.publisher.Flux;
+
+@Component
+public class ChronJobs {
+
+    private static Logger logger = LoggerFactory.getLogger(ChronJobs.class);
+    private WebClient client = WebClient.create("http://localhost:8081");
+
+    @Autowired
+    private FooService service;
+
+    @Scheduled(fixedRate = 10000)
+    public void consumeInfiniteFlux() {
+        Flux<Foo> fluxFoo = client.get()
+            .uri("/functional-reactive/periodic-foo")
+            .accept(MediaType.TEXT_EVENT_STREAM)
+            .retrieve()
+            .bodyToFlux(FooDto.class)
+            .delayElements(Duration.ofMillis(100))
+            .map(dto -> {
+                logger.debug("process 1 with dto id {} name{}", dto.getId(), dto.getName());
+                return new Foo(dto);
+            });
+        Integer random = ThreadLocalRandom.current()
+            .nextInt(0, 3);
+        switch (random) {
+        case 0:
+            logger.info("process 1 with approach 1");
+            service.processFoo(fluxFoo);
+            break;
+        case 1:
+            logger.info("process 1 with approach 1 EH");
+            service.processUsingApproachOneWithErrorHandling(fluxFoo);
+            break;
+        default:
+            logger.info("process 1 with approach 2");
+            service.processFooInAnotherScenario(fluxFoo);
+            break;
+
+        }
+    }
+
+    @Scheduled(fixedRate = 20000)
+    public void consumeFiniteFlux2() {
+        Flux<Foo> fluxFoo = client.get()
+            .uri("/functional-reactive/periodic-foo-2")
+            .accept(MediaType.TEXT_EVENT_STREAM)
+            .retrieve()
+            .bodyToFlux(FooDto.class)
+            .delayElements(Duration.ofMillis(100))
+            .map(dto -> {
+                logger.debug("process 2 with dto id {} name{}", dto.getId(), dto.getName());
+                return new Foo(dto);
+            });
+        Integer random = ThreadLocalRandom.current()
+            .nextInt(0, 3);
+        switch (random) {
+        case 0:
+            logger.info("process 2 with approach 1");
+            service.processFoo(fluxFoo);
+            break;
+        case 1:
+            logger.info("process 2 with approach 1 EH");
+            service.processUsingApproachOneWithErrorHandling(fluxFoo);
+            break;
+        default:
+            logger.info("process 2 with approach 2");
+            service.processFooInAnotherScenario(fluxFoo);
+            break;
+
+        }
+    }
+
+    @Scheduled(fixedRate = 20000)
+    public void consumeFiniteFlux3() {
+        Flux<Foo> fluxFoo = client.get()
+            .uri("/functional-reactive/periodic-foo-2")
+            .accept(MediaType.TEXT_EVENT_STREAM)
+            .retrieve()
+            .bodyToFlux(FooDto.class)
+            .delayElements(Duration.ofMillis(100))
+            .map(dto -> {
+                logger.debug("process 3 with dto id {} name{}", dto.getId(), dto.getName());
+                return new Foo(dto);
+            });
+        logger.info("process 3 with approach 3");
+        service.processUsingApproachThree(fluxFoo);
+    }
+
+    @Scheduled(fixedRate = 20000)
+    public void consumeFiniteFluxWithCheckpoint4() {
+        Flux<Foo> fluxFoo = client.get()
+            .uri("/functional-reactive/periodic-foo-2")
+            .accept(MediaType.TEXT_EVENT_STREAM)
+            .retrieve()
+            .bodyToFlux(FooDto.class)
+            .delayElements(Duration.ofMillis(100))
+            .map(dto -> {
+                logger.debug("process 4 with dto id {} name{}", dto.getId(), dto.getName());
+                return new Foo(dto);
+            });
+        logger.info("process 4 with approach 4");
+        service.processUsingApproachFourWithCheckpoint(fluxFoo);
+    }
+}
diff --git a/spring-5-reactive/src/main/java/com/baeldung/debugging/consumer/controllers/ReactiveConfigsToggleRestController.java b/spring-5-reactive/src/main/java/com/baeldung/debugging/consumer/controllers/ReactiveConfigsToggleRestController.java
new file mode 100644
index 0000000000..3dcdc6c7c0
--- /dev/null
+++ b/spring-5-reactive/src/main/java/com/baeldung/debugging/consumer/controllers/ReactiveConfigsToggleRestController.java
@@ -0,0 +1,23 @@
+package com.baeldung.debugging.consumer.controllers;
+
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import reactor.core.publisher.Hooks;
+
+@RestController
+public class ReactiveConfigsToggleRestController {
+
+    @GetMapping("/debug-hook-on")
+    public String setReactiveDebugOn() {
+        Hooks.onOperatorDebug();
+        return "DEBUG HOOK ON";
+    }
+
+    @GetMapping("/debug-hook-off")
+    public String setReactiveDebugOff() {
+        Hooks.resetOnOperatorDebug();
+        return "DEBUG HOOK OFF";
+    }
+
+}
diff --git a/spring-5-reactive/src/main/java/com/baeldung/debugging/consumer/model/Foo.java b/spring-5-reactive/src/main/java/com/baeldung/debugging/consumer/model/Foo.java
new file mode 100644
index 0000000000..e101457b84
--- /dev/null
+++ b/spring-5-reactive/src/main/java/com/baeldung/debugging/consumer/model/Foo.java
@@ -0,0 +1,26 @@
+package com.baeldung.debugging.consumer.model;
+
+import java.util.concurrent.ThreadLocalRandom;
+
+import org.springframework.data.annotation.Id;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+
+@Data
+@AllArgsConstructor
+public class Foo {
+
+    @Id
+    private Integer id;
+    private String formattedName;
+    private Integer quantity;
+
+    public Foo(FooDto dto) {
+        this.id = (ThreadLocalRandom.current()
+            .nextInt(0, 100) == 0) ? null : dto.getId();
+        this.formattedName = dto.getName();
+        this.quantity = ThreadLocalRandom.current()
+            .nextInt(0, 10);
+    }
+}
diff --git a/spring-5-reactive/src/main/java/com/baeldung/debugging/consumer/model/FooDto.java b/spring-5-reactive/src/main/java/com/baeldung/debugging/consumer/model/FooDto.java
new file mode 100644
index 0000000000..50508fd216
--- /dev/null
+++ b/spring-5-reactive/src/main/java/com/baeldung/debugging/consumer/model/FooDto.java
@@ -0,0 +1,12 @@
+package com.baeldung.debugging.consumer.model;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+
+@Data
+@AllArgsConstructor
+public class FooDto {
+
+    private Integer id;
+    private String name;
+}
diff --git a/spring-5-reactive/src/main/java/com/baeldung/debugging/consumer/service/FooNameHelper.java b/spring-5-reactive/src/main/java/com/baeldung/debugging/consumer/service/FooNameHelper.java
new file mode 100644
index 0000000000..772b360437
--- /dev/null
+++ b/spring-5-reactive/src/main/java/com/baeldung/debugging/consumer/service/FooNameHelper.java
@@ -0,0 +1,45 @@
+package com.baeldung.debugging.consumer.service;
+
+import java.util.concurrent.ThreadLocalRandom;
+
+import com.baeldung.debugging.consumer.model.Foo;
+
+import reactor.core.publisher.Flux;
+
+public class FooNameHelper {
+
+    public static Flux<Foo> concatAndSubstringFooName(Flux<Foo> flux) {
+        flux = concatFooName(flux);
+        flux = substringFooName(flux);
+        return flux;
+    }
+
+    public static Flux<Foo> concatFooName(Flux<Foo> flux) {
+        flux = flux.map(foo -> {
+            String processedName = null;
+            Integer random = ThreadLocalRandom.current()
+                .nextInt(0, 80);
+            processedName = (random != 0) ? foo.getFormattedName() : foo.getFormattedName() + "-bael";
+            foo.setFormattedName(processedName);
+            return foo;
+        });
+        return flux;
+    }
+
+    public static Flux<Foo> substringFooName(Flux<Foo> flux) {
+        return flux.map(foo -> {
+            String processedName;
+            Integer random = ThreadLocalRandom.current()
+                .nextInt(0, 100);
+
+            processedName = (random == 0) ? foo.getFormattedName()
+                .substring(10, 15)
+                : foo.getFormattedName()
+                    .substring(0, 5);
+
+            foo.setFormattedName(processedName);
+            return foo;
+        });
+    }
+
+}
diff --git a/spring-5-reactive/src/main/java/com/baeldung/debugging/consumer/service/FooQuantityHelper.java b/spring-5-reactive/src/main/java/com/baeldung/debugging/consumer/service/FooQuantityHelper.java
new file mode 100644
index 0000000000..615239313d
--- /dev/null
+++ b/spring-5-reactive/src/main/java/com/baeldung/debugging/consumer/service/FooQuantityHelper.java
@@ -0,0 +1,31 @@
+package com.baeldung.debugging.consumer.service;
+
+import java.util.concurrent.ThreadLocalRandom;
+
+import com.baeldung.debugging.consumer.model.Foo;
+
+import reactor.core.publisher.Flux;
+
+public class FooQuantityHelper {
+
+    public static Flux<Foo> processFooReducingQuantity(Flux<Foo> flux) {
+        flux = flux.map(foo -> {
+            Integer result;
+            Integer random = ThreadLocalRandom.current()
+                .nextInt(0, 90);
+            result = (random == 0) ? result = 0 : foo.getQuantity() + 2;
+            foo.setQuantity(result);
+            return foo;
+        });
+        return divideFooQuantity(flux);
+    }
+
+    public static Flux<Foo> divideFooQuantity(Flux<Foo> flux) {
+        return flux.map(foo -> {
+            Integer result = Math.round(5 / foo.getQuantity());
+            foo.setQuantity(result);
+            return foo;
+        });
+    }
+
+}
diff --git a/spring-5-reactive/src/main/java/com/baeldung/debugging/consumer/service/FooReporter.java b/spring-5-reactive/src/main/java/com/baeldung/debugging/consumer/service/FooReporter.java
new file mode 100644
index 0000000000..f53cd238e0
--- /dev/null
+++ b/spring-5-reactive/src/main/java/com/baeldung/debugging/consumer/service/FooReporter.java
@@ -0,0 +1,26 @@
+package com.baeldung.debugging.consumer.service;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.baeldung.debugging.consumer.model.Foo;
+
+import reactor.core.publisher.Flux;
+
+public class FooReporter {
+
+    private static Logger logger = LoggerFactory.getLogger(FooReporter.class);
+
+    public static Flux<Foo> reportResult(Flux<Foo> input, String approach) {
+        return input.map(foo -> {
+            if (foo.getId() == null)
+                throw new IllegalArgumentException("Null id is not valid!");
+            logger.info("Reporting for approach {}: Foo with id '{}' name '{}' and quantity '{}'", approach, foo.getId(), foo.getFormattedName(), foo.getQuantity());
+            return foo;
+        });
+    }
+
+    public static Flux<Foo> reportResult(Flux<Foo> input) {
+        return reportResult(input, "default");
+    }
+}
diff --git a/spring-5-reactive/src/main/java/com/baeldung/debugging/consumer/service/FooService.java b/spring-5-reactive/src/main/java/com/baeldung/debugging/consumer/service/FooService.java
new file mode 100644
index 0000000000..937e445ef5
--- /dev/null
+++ b/spring-5-reactive/src/main/java/com/baeldung/debugging/consumer/service/FooService.java
@@ -0,0 +1,91 @@
+package com.baeldung.debugging.consumer.service;
+
+import static com.baeldung.debugging.consumer.service.FooNameHelper.concatAndSubstringFooName;
+import static com.baeldung.debugging.consumer.service.FooNameHelper.substringFooName;
+import static com.baeldung.debugging.consumer.service.FooQuantityHelper.divideFooQuantity;
+import static com.baeldung.debugging.consumer.service.FooQuantityHelper.processFooReducingQuantity;
+import static com.baeldung.debugging.consumer.service.FooReporter.reportResult;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Component;
+
+import com.baeldung.debugging.consumer.model.Foo;
+
+import reactor.core.publisher.Flux;
+
+@Component
+public class FooService {
+
+    private static Logger logger = LoggerFactory.getLogger(FooService.class);
+
+    public void processFoo(Flux<Foo> flux) {
+        flux = FooNameHelper.concatFooName(flux);
+        flux = FooNameHelper.substringFooName(flux);
+        flux = flux.log();
+        flux = FooReporter.reportResult(flux);
+        flux = flux.doOnError(error -> {
+            logger.error("The following error happened on processFoo method!", error);
+        });
+        flux.subscribe();
+    }
+
+    public void processFooInAnotherScenario(Flux<Foo> flux) {
+        flux = FooNameHelper.substringFooName(flux);
+        flux = FooQuantityHelper.divideFooQuantity(flux);
+        flux.subscribe();
+    }
+
+    public void processUsingApproachOneWithErrorHandling(Flux<Foo> flux) {
+        logger.info("starting approach one w error handling!");
+        flux = concatAndSubstringFooName(flux);
+        flux = concatAndSubstringFooName(flux);
+        flux = substringFooName(flux);
+        flux = processFooReducingQuantity(flux);
+        flux = processFooReducingQuantity(flux);
+        flux = processFooReducingQuantity(flux);
+        flux = reportResult(flux, "ONE w/ EH");
+        flux = flux.doOnError(error -> {
+            logger.error("Approach 1 with Error Handling failed!", error);
+        });
+        flux.subscribe();
+    }
+
+    public void processUsingApproachThree(Flux<Foo> flux) {
+        logger.info("starting approach three!");
+        flux = concatAndSubstringFooName(flux);
+        flux = reportResult(flux, "THREE");
+        flux = flux.doOnError(error -> {
+            logger.error("Approach 3 failed!", error);
+        });
+        flux.subscribe();
+    }
+
+    public void processUsingApproachFourWithCheckpoint(Flux<Foo> flux) {
+        logger.info("starting approach four!");
+        flux = concatAndSubstringFooName(flux);
+        flux = flux.checkpoint("CHECKPOINT 1");
+        flux = concatAndSubstringFooName(flux);
+        flux = divideFooQuantity(flux);
+        flux = flux.checkpoint("CHECKPOINT 2", true);
+        flux = reportResult(flux, "FOUR");
+        flux = concatAndSubstringFooName(flux).doOnError(error -> {
+            logger.error("Approach 4 failed!", error);
+        });
+        flux.subscribe();
+    }
+
+    public void processUsingApproachFourWithInitialCheckpoint(Flux<Foo> flux) {
+        logger.info("starting approach four!");
+        flux = concatAndSubstringFooName(flux);
+        flux = flux.checkpoint("CHECKPOINT 1", true);
+        flux = concatAndSubstringFooName(flux);
+        flux = divideFooQuantity(flux);
+        flux = reportResult(flux, "FOUR");
+        flux = flux.doOnError(error -> {
+            logger.error("Approach 4-2 failed!", error);
+        });
+        flux.subscribe();
+    }
+
+}
diff --git a/spring-5-reactive/src/main/java/com/baeldung/debugging/server/ServerSSEApplication.java b/spring-5-reactive/src/main/java/com/baeldung/debugging/server/ServerSSEApplication.java
new file mode 100644
index 0000000000..6b24ee39f0
--- /dev/null
+++ b/spring-5-reactive/src/main/java/com/baeldung/debugging/server/ServerSSEApplication.java
@@ -0,0 +1,29 @@
+package com.baeldung.debugging.server;
+
+import java.util.Collections;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.Bean;
+import org.springframework.security.config.web.server.ServerHttpSecurity;
+import org.springframework.security.web.server.SecurityWebFilterChain;
+import org.springframework.web.reactive.config.EnableWebFlux;
+
+@EnableWebFlux
+@SpringBootApplication
+public class ServerSSEApplication {
+    
+    public static void main(String[] args) {
+        SpringApplication app = new SpringApplication(ServerSSEApplication.class);
+        app.setDefaultProperties(Collections.singletonMap("server.port", "8081"));
+        app.run(args);
+    }
+    
+    @Bean
+    public SecurityWebFilterChain springSecurityFilterChain(ServerHttpSecurity http) {
+        http.authorizeExchange()
+            .anyExchange()
+            .permitAll();
+        return http.build();
+    }
+}
diff --git a/spring-5-reactive/src/main/java/com/baeldung/debugging/server/handlers/ServerHandler.java b/spring-5-reactive/src/main/java/com/baeldung/debugging/server/handlers/ServerHandler.java
new file mode 100644
index 0000000000..759cd9b01d
--- /dev/null
+++ b/spring-5-reactive/src/main/java/com/baeldung/debugging/server/handlers/ServerHandler.java
@@ -0,0 +1,47 @@
+package com.baeldung.debugging.server.handlers;
+
+import java.time.Duration;
+import java.util.concurrent.ThreadLocalRandom;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.http.MediaType;
+import org.springframework.stereotype.Component;
+import org.springframework.web.reactive.function.server.ServerRequest;
+import org.springframework.web.reactive.function.server.ServerResponse;
+
+import com.baeldung.debugging.server.model.Foo;
+
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+
+@Component
+public class ServerHandler {
+
+    private static Logger logger = LoggerFactory.getLogger(ServerHandler.class);
+
+    public Mono<ServerResponse> useHandler(final ServerRequest request) {
+        // there are chances that something goes wrong here...
+        return ServerResponse.ok()
+            .contentType(MediaType.TEXT_EVENT_STREAM)
+            .body(Flux.interval(Duration.ofSeconds(1))
+                .map(sequence -> {
+                    logger.info("retrieving Foo. Sequence: {}", sequence);
+                    if (ThreadLocalRandom.current()
+                        .nextInt(0, 50) == 1) {
+                        throw new RuntimeException("There was an error retrieving the Foo!");
+                    }
+                    return new Foo(sequence, "name" + sequence);
+
+                }), Foo.class);
+    }
+
+    public Mono<ServerResponse> useHandlerFinite(final ServerRequest request) {
+        return ServerResponse.ok()
+            .contentType(MediaType.TEXT_EVENT_STREAM)
+            .body(Flux.range(0, 50)
+                .map(sequence -> {
+                    return new Foo(new Long(sequence), "theFooNameNumber" + sequence);
+                }), Foo.class);
+    }
+}
diff --git a/spring-5-reactive/src/main/java/com/baeldung/debugging/server/model/Foo.java b/spring-5-reactive/src/main/java/com/baeldung/debugging/server/model/Foo.java
new file mode 100644
index 0000000000..a60e468e7f
--- /dev/null
+++ b/spring-5-reactive/src/main/java/com/baeldung/debugging/server/model/Foo.java
@@ -0,0 +1,16 @@
+package com.baeldung.debugging.server.model;
+
+import org.springframework.data.annotation.Id;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+
+@Data
+@AllArgsConstructor
+public class Foo {
+
+    @Id
+    private Long id;
+    private String name;
+
+}
diff --git a/spring-5-reactive/src/main/java/com/baeldung/debugging/server/routers/ServerRouter.java b/spring-5-reactive/src/main/java/com/baeldung/debugging/server/routers/ServerRouter.java
new file mode 100644
index 0000000000..6378b2213d
--- /dev/null
+++ b/spring-5-reactive/src/main/java/com/baeldung/debugging/server/routers/ServerRouter.java
@@ -0,0 +1,22 @@
+package com.baeldung.debugging.server.routers;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.reactive.function.server.RequestPredicates;
+import org.springframework.web.reactive.function.server.RouterFunction;
+import org.springframework.web.reactive.function.server.RouterFunctions;
+import org.springframework.web.reactive.function.server.ServerResponse;
+
+import com.baeldung.debugging.server.handlers.ServerHandler;
+
+@Configuration
+public class ServerRouter {
+
+	@Bean
+	public RouterFunction<ServerResponse> responseRoute(@Autowired ServerHandler handler) {
+		return RouterFunctions.route(RequestPredicates.GET("/functional-reactive/periodic-foo"), handler::useHandler)
+				.andRoute(RequestPredicates.GET("/functional-reactive/periodic-foo-2"), handler::useHandlerFinite);
+	}
+
+}
diff --git a/logging-modules/log4j/src/main/java/com/baeldung/webFluxLogging/WebFluxLoggingExample.java b/spring-5-reactive/src/main/java/com/baeldung/webflux/logging/WebFluxLoggingExample.java
similarity index 91%
rename from logging-modules/log4j/src/main/java/com/baeldung/webFluxLogging/WebFluxLoggingExample.java
rename to spring-5-reactive/src/main/java/com/baeldung/webflux/logging/WebFluxLoggingExample.java
index f429fd57f3..c4881b2296 100644
--- a/logging-modules/log4j/src/main/java/com/baeldung/webFluxLogging/WebFluxLoggingExample.java
+++ b/spring-5-reactive/src/main/java/com/baeldung/webflux/logging/WebFluxLoggingExample.java
@@ -1,4 +1,4 @@
-package com.baeldung.webFluxLogging;
+package com.baeldung.webflux.logging;
 
 import reactor.core.publisher.Flux;
 
diff --git a/spring-5-reactive/src/main/resources/application.properties b/spring-5-reactive/src/main/resources/application.properties
index 92f3116f84..4b49e8e8a2 100644
--- a/spring-5-reactive/src/main/resources/application.properties
+++ b/spring-5-reactive/src/main/resources/application.properties
@@ -1,2 +1 @@
-logging.level.root=INFO
-
+logging.level.root=INFO
\ No newline at end of file
diff --git a/spring-5-reactive/src/test/java/com/baeldung/debugging/consumer/ConsumerFooServiceIntegrationTest.java b/spring-5-reactive/src/test/java/com/baeldung/debugging/consumer/ConsumerFooServiceIntegrationTest.java
new file mode 100644
index 0000000000..b7ed031ec7
--- /dev/null
+++ b/spring-5-reactive/src/test/java/com/baeldung/debugging/consumer/ConsumerFooServiceIntegrationTest.java
@@ -0,0 +1,65 @@
+package com.baeldung.debugging.consumer;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Optional;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import com.baeldung.debugging.consumer.model.Foo;
+import com.baeldung.debugging.consumer.service.FooService;
+import com.baeldung.debugging.consumer.utils.ListAppender;
+
+import ch.qos.logback.classic.spi.ILoggingEvent;
+import ch.qos.logback.classic.spi.IThrowableProxy;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Hooks;
+
+public class ConsumerFooServiceIntegrationTest {
+
+    FooService service = new FooService();
+
+    @BeforeEach
+    public void clearLogList() {
+        Hooks.onOperatorDebug();
+        ListAppender.clearEventList();
+    }
+
+    @Test
+    public void givenFooWithNullId_whenProcessFoo_thenLogsWithDebugTrace() {
+        Foo one = new Foo(1, "nameverylong", 8);
+        Foo two = new Foo(null, "nameverylong", 4);
+        Flux<Foo> flux = Flux.just(one, two);
+
+        service.processFoo(flux);
+
+        Collection<String> allLoggedEntries = ListAppender.getEvents()
+            .stream()
+            .map(ILoggingEvent::getFormattedMessage)
+            .collect(Collectors.toList());
+
+        Collection<String> allSuppressedEntries = ListAppender.getEvents()
+            .stream()
+            .map(ILoggingEvent::getThrowableProxy)
+            .flatMap(t -> {
+                return Optional.ofNullable(t)
+                    .map(IThrowableProxy::getSuppressed)
+                    .map(Arrays::stream)
+                    .orElse(Stream.empty());
+            })
+            .map(IThrowableProxy::getMessage)
+            .collect(Collectors.toList());
+        assertThat(allLoggedEntries).anyMatch(entry -> entry.contains("The following error happened on processFoo method!"))
+            .anyMatch(entry -> entry.contains("| onSubscribe"))
+            .anyMatch(entry -> entry.contains("| cancel()"));
+
+        assertThat(allSuppressedEntries).anyMatch(entry -> entry.contains("Assembly trace from producer"))
+            .anyMatch(entry -> entry.contains("Error has been observed by the following operator(s)"));
+    }
+
+}
diff --git a/spring-5-reactive/src/test/java/com/baeldung/debugging/consumer/ConsumerFooServiceLiveTest.java b/spring-5-reactive/src/test/java/com/baeldung/debugging/consumer/ConsumerFooServiceLiveTest.java
new file mode 100644
index 0000000000..af9bdfbc9b
--- /dev/null
+++ b/spring-5-reactive/src/test/java/com/baeldung/debugging/consumer/ConsumerFooServiceLiveTest.java
@@ -0,0 +1,49 @@
+package com.baeldung.debugging.consumer;
+
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+import org.springframework.test.web.reactive.server.WebTestClient;
+import org.springframework.test.web.reactive.server.WebTestClient.ResponseSpec;
+
+import com.baeldung.debugging.consumer.service.FooService;
+
+public class ConsumerFooServiceLiveTest {
+
+    FooService service = new FooService();
+
+    private static final String BASE_URL = "http://localhost:8082";
+    private static final String DEBUG_HOOK_ON = BASE_URL + "/debug-hook-on";
+    private static final String DEBUG_HOOK_OFF = BASE_URL + "/debug-hook-off";
+
+    private static WebTestClient client;
+
+    @BeforeAll
+    public static void setup() {
+        client = WebTestClient.bindToServer()
+            .baseUrl(BASE_URL)
+            .build();
+    }
+
+    @Test
+    public void whenRequestingDebugHookOn_thenObtainExpectedMessage() {
+        ResponseSpec response = client.get()
+            .uri(DEBUG_HOOK_ON)
+            .exchange();
+        response.expectStatus()
+            .isOk()
+            .expectBody(String.class)
+            .isEqualTo("DEBUG HOOK ON");
+    }
+
+    @Test
+    public void whenRequestingDebugHookOff_thenObtainExpectedMessage() {
+        ResponseSpec response = client.get()
+            .uri(DEBUG_HOOK_OFF)
+            .exchange();
+        response.expectStatus()
+            .isOk()
+            .expectBody(String.class)
+            .isEqualTo("DEBUG HOOK OFF");
+    }
+
+}
diff --git a/spring-5-reactive/src/test/java/com/baeldung/debugging/consumer/utils/ListAppender.java b/spring-5-reactive/src/test/java/com/baeldung/debugging/consumer/utils/ListAppender.java
new file mode 100644
index 0000000000..c8c1c110bb
--- /dev/null
+++ b/spring-5-reactive/src/test/java/com/baeldung/debugging/consumer/utils/ListAppender.java
@@ -0,0 +1,25 @@
+package com.baeldung.debugging.consumer.utils;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import ch.qos.logback.classic.spi.ILoggingEvent;
+import ch.qos.logback.core.AppenderBase;
+
+public class ListAppender extends AppenderBase<ILoggingEvent> {
+
+    static private List<ILoggingEvent> events = new ArrayList<>();
+
+    @Override
+    protected void append(ILoggingEvent eventObject) {
+        events.add(eventObject);
+    }
+
+    public static List<ILoggingEvent> getEvents() {
+        return events;
+    }
+
+    public static void clearEventList() {
+        events.clear();
+    }
+}
diff --git a/spring-5-reactive/src/test/resources/logback-test.xml b/spring-5-reactive/src/test/resources/logback-test.xml
new file mode 100644
index 0000000000..514029e402
--- /dev/null
+++ b/spring-5-reactive/src/test/resources/logback-test.xml
@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+	<include
+		resource="org/springframework/boot/logging/logback/base.xml" />
+	<appender name="LISTAPPENDER"
+		class="com.baeldung.debugging.consumer.utils.ListAppender">
+	</appender>
+	<logger
+		name="com.baeldung.debugging.consumer.service.FooService">
+		<appender-ref ref="LISTAPPENDER" />
+	</logger>
+	<root level="info">
+		<appender-ref ref="CONSOLE" />
+		<appender-ref ref="LISTAPPENDER" />
+	</root>
+</configuration>  
\ No newline at end of file
diff --git a/spring-5-security-oauth/pom.xml b/spring-5-security-oauth/pom.xml
index f200052adf..59150a153f 100644
--- a/spring-5-security-oauth/pom.xml
+++ b/spring-5-security-oauth/pom.xml
@@ -31,7 +31,7 @@
         </dependency>
         <dependency>
             <groupId>org.thymeleaf.extras</groupId>
-            <artifactId>thymeleaf-extras-springsecurity4</artifactId>
+            <artifactId>thymeleaf-extras-springsecurity5</artifactId>
         </dependency>
 
         <!-- oauth2 -->
@@ -66,7 +66,8 @@
     </dependencies>
 	
     <properties>
-        <oauth-auto.version>2.0.1.RELEASE</oauth-auto.version>
+        <spring-boot.version>2.1.0.RELEASE</spring-boot.version>
+        <oauth-auto.version>2.1.0.RELEASE</oauth-auto.version>
         <start-class>com.baeldung.oauth2.SpringOAuthApplication</start-class>
     </properties>
 
diff --git a/spring-5-security-oauth/src/main/java/com/baeldung/oauth2/CustomAuthorizationRequestResolver.java b/spring-5-security-oauth/src/main/java/com/baeldung/oauth2/CustomAuthorizationRequestResolver.java
new file mode 100644
index 0000000000..025064423d
--- /dev/null
+++ b/spring-5-security-oauth/src/main/java/com/baeldung/oauth2/CustomAuthorizationRequestResolver.java
@@ -0,0 +1,50 @@
+package com.baeldung.oauth2;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import javax.servlet.http.HttpServletRequest;
+
+import org.springframework.security.oauth2.client.registration.ClientRegistrationRepository;
+import org.springframework.security.oauth2.client.web.DefaultOAuth2AuthorizationRequestResolver;
+import org.springframework.security.oauth2.client.web.OAuth2AuthorizationRequestResolver;
+import org.springframework.security.oauth2.core.endpoint.OAuth2AuthorizationRequest;
+
+public class CustomAuthorizationRequestResolver implements OAuth2AuthorizationRequestResolver {
+    
+    private OAuth2AuthorizationRequestResolver defaultResolver;
+
+    public CustomAuthorizationRequestResolver(ClientRegistrationRepository repo, String authorizationRequestBaseUri){
+        defaultResolver = new DefaultOAuth2AuthorizationRequestResolver(repo, authorizationRequestBaseUri);
+    }
+
+    @Override
+    public OAuth2AuthorizationRequest resolve(HttpServletRequest request) {
+        OAuth2AuthorizationRequest req = defaultResolver.resolve(request);
+        if(req != null){
+            req = customizeAuthorizationRequest(req);
+        }
+        return req;
+    }
+
+    @Override
+    public OAuth2AuthorizationRequest resolve(HttpServletRequest request, String clientRegistrationId) {
+        OAuth2AuthorizationRequest req = defaultResolver.resolve(request, clientRegistrationId);
+        if(req != null){
+            req = customizeAuthorizationRequest(req);
+        }
+        return req;
+    }
+
+    private OAuth2AuthorizationRequest customizeAuthorizationRequest(OAuth2AuthorizationRequest req) {
+        Map<String,Object> extraParams = new HashMap<String,Object>();
+        extraParams.putAll(req.getAdditionalParameters()); //VIP note
+        extraParams.put("test", "extra");
+        System.out.println("here =====================");
+        return OAuth2AuthorizationRequest.from(req).additionalParameters(extraParams).build();
+    }
+
+    private OAuth2AuthorizationRequest customizeAuthorizationRequest1(OAuth2AuthorizationRequest req) {
+        return OAuth2AuthorizationRequest.from(req).state("xyz").build();
+    }
+}
diff --git a/spring-5-security-oauth/src/main/java/com/baeldung/oauth2/CustomRequestEntityConverter.java b/spring-5-security-oauth/src/main/java/com/baeldung/oauth2/CustomRequestEntityConverter.java
new file mode 100644
index 0000000000..8884065769
--- /dev/null
+++ b/spring-5-security-oauth/src/main/java/com/baeldung/oauth2/CustomRequestEntityConverter.java
@@ -0,0 +1,26 @@
+package com.baeldung.oauth2;
+
+import org.springframework.core.convert.converter.Converter;
+import org.springframework.http.RequestEntity;
+import org.springframework.security.oauth2.client.endpoint.OAuth2AuthorizationCodeGrantRequest;
+import org.springframework.security.oauth2.client.endpoint.OAuth2AuthorizationCodeGrantRequestEntityConverter;
+import org.springframework.util.MultiValueMap;
+
+public class CustomRequestEntityConverter implements Converter<OAuth2AuthorizationCodeGrantRequest, RequestEntity<?>> {
+
+    private OAuth2AuthorizationCodeGrantRequestEntityConverter defaultConverter;
+    
+    public CustomRequestEntityConverter() {
+        defaultConverter = new OAuth2AuthorizationCodeGrantRequestEntityConverter();
+    }
+    
+    @Override
+    public RequestEntity<?> convert(OAuth2AuthorizationCodeGrantRequest req) {
+        RequestEntity<?> entity = defaultConverter.convert(req);
+        MultiValueMap<String, String> params = (MultiValueMap<String,String>) entity.getBody();
+        params.add("test2", "extra2");
+        System.out.println(params.entrySet());
+        return new RequestEntity<>(params, entity.getHeaders(), entity.getMethod(), entity.getUrl());
+    }
+
+}
diff --git a/spring-5-security-oauth/src/main/java/com/baeldung/oauth2/CustomTokenResponseConverter.java b/spring-5-security-oauth/src/main/java/com/baeldung/oauth2/CustomTokenResponseConverter.java
new file mode 100644
index 0000000000..741f44871a
--- /dev/null
+++ b/spring-5-security-oauth/src/main/java/com/baeldung/oauth2/CustomTokenResponseConverter.java
@@ -0,0 +1,67 @@
+package com.baeldung.oauth2;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.Set;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import org.springframework.core.convert.converter.Converter;
+import org.springframework.security.oauth2.core.OAuth2AccessToken;
+import org.springframework.security.oauth2.core.endpoint.OAuth2AccessTokenResponse;
+import org.springframework.security.oauth2.core.endpoint.OAuth2ParameterNames;
+import org.springframework.util.StringUtils;
+
+public class CustomTokenResponseConverter implements Converter<Map<String, String>, OAuth2AccessTokenResponse> {
+    private static final Set<String> TOKEN_RESPONSE_PARAMETER_NAMES = Stream.of(
+        OAuth2ParameterNames.ACCESS_TOKEN, 
+        OAuth2ParameterNames.TOKEN_TYPE, 
+        OAuth2ParameterNames.EXPIRES_IN, 
+        OAuth2ParameterNames.REFRESH_TOKEN, 
+        OAuth2ParameterNames.SCOPE) .collect(Collectors.toSet());
+
+    @Override
+    public OAuth2AccessTokenResponse convert(Map<String, String> tokenResponseParameters) {
+        String accessToken = tokenResponseParameters.get(OAuth2ParameterNames.ACCESS_TOKEN);
+
+        OAuth2AccessToken.TokenType accessTokenType = null;
+        if (OAuth2AccessToken.TokenType.BEARER.getValue()
+            .equalsIgnoreCase(tokenResponseParameters.get(OAuth2ParameterNames.TOKEN_TYPE))) {
+            accessTokenType = OAuth2AccessToken.TokenType.BEARER;
+        }
+
+        long expiresIn = 0;
+        if (tokenResponseParameters.containsKey(OAuth2ParameterNames.EXPIRES_IN)) {
+            try {
+                expiresIn = Long.valueOf(tokenResponseParameters.get(OAuth2ParameterNames.EXPIRES_IN));
+            } catch (NumberFormatException ex) {
+            }
+        }
+
+        Set<String> scopes = Collections.emptySet();
+        if (tokenResponseParameters.containsKey(OAuth2ParameterNames.SCOPE)) {
+            String scope = tokenResponseParameters.get(OAuth2ParameterNames.SCOPE);
+            scopes = Arrays.stream(StringUtils.delimitedListToStringArray(scope, " "))
+                .collect(Collectors.toSet());
+        }
+
+        String refreshToken = tokenResponseParameters.get(OAuth2ParameterNames.REFRESH_TOKEN);
+
+        Map<String, Object> additionalParameters = new LinkedHashMap<>();
+        tokenResponseParameters.entrySet()
+            .stream()
+            .filter(e -> !TOKEN_RESPONSE_PARAMETER_NAMES.contains(e.getKey()))
+            .forEach(e -> additionalParameters.put(e.getKey(), e.getValue()));
+
+        return OAuth2AccessTokenResponse.withToken(accessToken)
+            .tokenType(accessTokenType)
+            .expiresIn(expiresIn)
+            .scopes(scopes)
+            .refreshToken(refreshToken)
+            .additionalParameters(additionalParameters)
+            .build();
+    }
+
+}
diff --git a/spring-5-security-oauth/src/main/java/com/baeldung/oauth2/SecurityConfig.java b/spring-5-security-oauth/src/main/java/com/baeldung/oauth2/SecurityConfig.java
index b45f325767..cf27b01a75 100644
--- a/spring-5-security-oauth/src/main/java/com/baeldung/oauth2/SecurityConfig.java
+++ b/spring-5-security-oauth/src/main/java/com/baeldung/oauth2/SecurityConfig.java
@@ -9,18 +9,22 @@ import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.PropertySource;
 import org.springframework.core.env.Environment;
+import org.springframework.http.converter.FormHttpMessageConverter;
 import org.springframework.security.config.annotation.web.builders.HttpSecurity;
 import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
 import org.springframework.security.config.oauth2.client.CommonOAuth2Provider;
-import org.springframework.security.oauth2.client.endpoint.NimbusAuthorizationCodeTokenResponseClient;
+import org.springframework.security.oauth2.client.endpoint.DefaultAuthorizationCodeTokenResponseClient;
 import org.springframework.security.oauth2.client.endpoint.OAuth2AccessTokenResponseClient;
 import org.springframework.security.oauth2.client.endpoint.OAuth2AuthorizationCodeGrantRequest;
+import org.springframework.security.oauth2.client.http.OAuth2ErrorResponseErrorHandler;
 import org.springframework.security.oauth2.client.registration.ClientRegistration;
 import org.springframework.security.oauth2.client.registration.ClientRegistrationRepository;
 import org.springframework.security.oauth2.client.registration.InMemoryClientRegistrationRepository;
 import org.springframework.security.oauth2.client.web.AuthorizationRequestRepository;
 import org.springframework.security.oauth2.client.web.HttpSessionOAuth2AuthorizationRequestRepository;
 import org.springframework.security.oauth2.core.endpoint.OAuth2AuthorizationRequest;
+import org.springframework.security.oauth2.core.http.converter.OAuth2AccessTokenResponseHttpMessageConverter;
+import org.springframework.web.client.RestTemplate;
 
 @Configuration
 @PropertySource("application-oauth2.properties")
@@ -37,6 +41,8 @@ public class SecurityConfig extends WebSecurityConfigurerAdapter {
             .oauth2Login()
             .loginPage("/oauth_login")
             .authorizationEndpoint()
+                        .authorizationRequestResolver( new CustomAuthorizationRequestResolver(clientRegistrationRepository(),"/oauth2/authorize-client"))
+
             .baseUri("/oauth2/authorize-client")
             .authorizationRequestRepository(authorizationRequestRepository())
             .and()
@@ -54,7 +60,15 @@ public class SecurityConfig extends WebSecurityConfigurerAdapter {
 
     @Bean
     public OAuth2AccessTokenResponseClient<OAuth2AuthorizationCodeGrantRequest> accessTokenResponseClient() {
-        return new NimbusAuthorizationCodeTokenResponseClient();
+        DefaultAuthorizationCodeTokenResponseClient accessTokenResponseClient = new DefaultAuthorizationCodeTokenResponseClient();
+        accessTokenResponseClient.setRequestEntityConverter(new CustomRequestEntityConverter());
+        
+        OAuth2AccessTokenResponseHttpMessageConverter tokenResponseHttpMessageConverter = new OAuth2AccessTokenResponseHttpMessageConverter();
+        tokenResponseHttpMessageConverter.setTokenResponseConverter(new CustomTokenResponseConverter());
+        RestTemplate restTemplate = new RestTemplate(Arrays.asList(new FormHttpMessageConverter(), tokenResponseHttpMessageConverter));
+        restTemplate.setErrorHandler(new OAuth2ErrorResponseErrorHandler());
+        accessTokenResponseClient.setRestOperations(restTemplate);
+        return accessTokenResponseClient;
     }
 
     
diff --git a/spring-boot-autoconfiguration/src/main/resources/META-INF/spring.factories b/spring-boot-autoconfiguration/src/main/resources/META-INF/spring.factories
index 5f55544eff..11c775fc6c 100644
--- a/spring-boot-autoconfiguration/src/main/resources/META-INF/spring.factories
+++ b/spring-boot-autoconfiguration/src/main/resources/META-INF/spring.factories
@@ -1,3 +1 @@
-org.springframework.boot.diagnostics.FailureAnalyzer=com.baeldung.failureanalyzer.MyBeanNotOfRequiredTypeFailureAnalyzer
-
-org.springframework.boot.autoconfigure.EnableAutoConfiguration=com.baeldung.autoconfiguration.MySQLAutoconfiguration
\ No newline at end of file
+org.springframework.boot.autoconfigure.EnableAutoConfiguration=com.baeldung.autoconfiguration.MySQLAutoconfiguration
diff --git a/spring-boot/src/main/java/com/baeldung/mongodb/Application.java b/spring-boot/src/main/java/com/baeldung/mongodb/Application.java
index 092ce3352b..c0a9ad59a7 100644
--- a/spring-boot/src/main/java/com/baeldung/mongodb/Application.java
+++ b/spring-boot/src/main/java/com/baeldung/mongodb/Application.java
@@ -1,11 +1,19 @@
 package com.baeldung.mongodb;
 
+import com.baeldung.mongodb.daos.UserRepository;
+import com.baeldung.mongodb.models.User;
+import org.springframework.boot.CommandLineRunner;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.Bean;
+
+import java.util.List;
 
 @SpringBootApplication
 public class Application {
+
     public static void main(String[] args) {
         SpringApplication.run(Application.class, args);
     }
+
 }
diff --git a/spring-boot/src/main/java/com/baeldung/mongodb/daos/UserRepository.java b/spring-boot/src/main/java/com/baeldung/mongodb/daos/UserRepository.java
new file mode 100755
index 0000000000..7f58fdd1c8
--- /dev/null
+++ b/spring-boot/src/main/java/com/baeldung/mongodb/daos/UserRepository.java
@@ -0,0 +1,10 @@
+package com.baeldung.mongodb.daos;
+
+
+import com.baeldung.mongodb.models.User;
+import org.springframework.data.mongodb.repository.MongoRepository;
+
+
+public interface UserRepository extends MongoRepository<User, Long> {
+
+}
diff --git a/spring-boot/src/main/java/com/baeldung/mongodb/events/UserModelListener.java b/spring-boot/src/main/java/com/baeldung/mongodb/events/UserModelListener.java
new file mode 100644
index 0000000000..24b53f3d2d
--- /dev/null
+++ b/spring-boot/src/main/java/com/baeldung/mongodb/events/UserModelListener.java
@@ -0,0 +1,28 @@
+package com.baeldung.mongodb.events;
+
+
+import com.baeldung.mongodb.models.User;
+import com.baeldung.mongodb.services.SequenceGeneratorService;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.data.mongodb.core.mapping.event.AbstractMongoEventListener;
+import org.springframework.data.mongodb.core.mapping.event.BeforeConvertEvent;
+import org.springframework.stereotype.Component;
+
+
+@Component
+public class UserModelListener extends AbstractMongoEventListener<User> {
+
+    private SequenceGeneratorService sequenceGenerator;
+
+    @Autowired
+    public UserModelListener(SequenceGeneratorService sequenceGenerator) {
+        this.sequenceGenerator = sequenceGenerator;
+    }
+
+    @Override
+    public void onBeforeConvert(BeforeConvertEvent<User> event) {
+        event.getSource().setId(sequenceGenerator.generateSequence(User.SEQUENCE_NAME));
+    }
+
+
+}
diff --git a/spring-boot/src/main/java/com/baeldung/mongodb/models/DatabaseSequence.java b/spring-boot/src/main/java/com/baeldung/mongodb/models/DatabaseSequence.java
new file mode 100755
index 0000000000..c2c04f7ee6
--- /dev/null
+++ b/spring-boot/src/main/java/com/baeldung/mongodb/models/DatabaseSequence.java
@@ -0,0 +1,32 @@
+package com.baeldung.mongodb.models;
+
+import org.springframework.data.annotation.Id;
+import org.springframework.data.mongodb.core.mapping.Document;
+
+
+@Document(collection = "database_sequences")
+public class DatabaseSequence {
+
+    @Id
+    private String id;
+
+    private long seq;
+
+    public DatabaseSequence() {}
+
+    public String getId() {
+        return id;
+    }
+
+    public void setId(String id) {
+        this.id = id;
+    }
+
+    public long getSeq() {
+        return seq;
+    }
+
+    public void setSeq(long seq) {
+        this.seq = seq;
+    }
+}
diff --git a/spring-boot/src/main/java/com/baeldung/mongodb/models/User.java b/spring-boot/src/main/java/com/baeldung/mongodb/models/User.java
new file mode 100755
index 0000000000..1f08074313
--- /dev/null
+++ b/spring-boot/src/main/java/com/baeldung/mongodb/models/User.java
@@ -0,0 +1,73 @@
+package com.baeldung.mongodb.models;
+
+import org.springframework.data.annotation.Id;
+import org.springframework.data.annotation.Transient;
+import org.springframework.data.mongodb.core.mapping.Document;
+
+
+@Document(collection = "users")
+public class User {
+
+    @Transient
+    public static final String SEQUENCE_NAME = "users_sequence";
+
+    @Id
+    private long id;
+
+    private String firstName;
+
+    private String lastName;
+
+    private String email;
+
+    public User() { }
+
+    public User(String firstName, String lastName, String email) {
+        this.firstName = firstName;
+        this.lastName = lastName;
+        this.email = email;
+    }
+
+    public long getId() {
+        return id;
+    }
+
+    public void setId(long id) {
+        this.id = id;
+    }
+
+    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 String getEmail() {
+        return email;
+    }
+
+    public void setEmail(String email) {
+        this.email = email;
+    }
+    
+
+    @Override
+    public String toString() {
+        return "User{" +
+                "id=" + id +
+                ", firstName='" + firstName + '\'' +
+                ", lastName='" + lastName + '\'' +
+                ", email='" + email + '\'' +
+                '}';
+    }
+}
diff --git a/spring-boot/src/main/java/com/baeldung/mongodb/services/SequenceGeneratorService.java b/spring-boot/src/main/java/com/baeldung/mongodb/services/SequenceGeneratorService.java
new file mode 100755
index 0000000000..52ece27d63
--- /dev/null
+++ b/spring-boot/src/main/java/com/baeldung/mongodb/services/SequenceGeneratorService.java
@@ -0,0 +1,35 @@
+package com.baeldung.mongodb.services;
+
+import com.baeldung.mongodb.models.DatabaseSequence;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.data.mongodb.core.MongoOperations;
+import org.springframework.data.mongodb.core.query.Update;
+import org.springframework.stereotype.Service;
+
+import java.util.Objects;
+
+import static org.springframework.data.mongodb.core.FindAndModifyOptions.options;
+import static org.springframework.data.mongodb.core.query.Criteria.where;
+import static org.springframework.data.mongodb.core.query.Query.query;
+
+
+@Service
+public class SequenceGeneratorService {
+
+
+    private MongoOperations mongoOperations;
+
+    @Autowired
+    public SequenceGeneratorService(MongoOperations mongoOperations) {
+        this.mongoOperations = mongoOperations;
+    }
+
+    public long generateSequence(String seqName) {
+
+        DatabaseSequence counter = mongoOperations.findAndModify(query(where("_id").is(seqName)),
+                new Update().inc("seq",1), options().returnNew(true).upsert(true),
+                DatabaseSequence.class);
+        return !Objects.isNull(counter) ? counter.getSeq() : 1;
+
+    }
+}
diff --git a/spring-boot/src/test/java/com/baeldung/mongodb/MongoDbAutoGeneratedFieldIntegrationTest.java b/spring-boot/src/test/java/com/baeldung/mongodb/MongoDbAutoGeneratedFieldIntegrationTest.java
new file mode 100644
index 0000000000..3430bca69a
--- /dev/null
+++ b/spring-boot/src/test/java/com/baeldung/mongodb/MongoDbAutoGeneratedFieldIntegrationTest.java
@@ -0,0 +1,36 @@
+package com.baeldung.mongodb;
+
+import com.baeldung.mongodb.daos.UserRepository;
+import com.baeldung.mongodb.models.User;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.test.context.junit4.SpringRunner;
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.util.List;
+
+
+@RunWith(SpringRunner.class)
+public class MongoDbAutoGeneratedFieldIntegrationTest {
+
+    @Autowired
+    private UserRepository userRepository;
+
+    @Test
+    public void contextLoads() {}
+
+    @Test
+    public void givenUserObject_whenSave_thenCreateNewUser() {
+
+        User user = new User();
+        user.setFirstName("John");
+        user.setLastName("Doe");
+        user.setEmail("john.doe@example.com");
+        userRepository.save(user);
+
+        assertThat(userRepository.findAll().size()).isGreaterThan(0);
+    }
+
+
+}