Merge pull request #12 from eugenp/master

update

akka-http/pom.xml

@@ -1,47 +1,46 @@
-<?xml version="1.0"?>
+<?xml version="1.0" encoding="UTF-8"?>
-<project
+<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
-	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+         xmlns="http://maven.apache.org/POM/4.0.0"
-	xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
-	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>akka-http</artifactId>
+    <name>akka-http</name>
 
-	<modelVersion>4.0.0</modelVersion>
+    <parent>
-	<artifactId>akka-http</artifactId>
+        <groupId>com.baeldung</groupId>
-	<name>akka-http</name>
+        <artifactId>parent-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
 
-	<parent>
+    <dependencies>
-		<artifactId>parent-modules</artifactId>
+        <dependency>
-		<groupId>com.baeldung</groupId>
+            <groupId>com.typesafe.akka</groupId>
-		<version>1.0.0-SNAPSHOT</version>
+            <artifactId>akka-http_2.12</artifactId>
-	</parent>
+            <version>${akka.http.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.typesafe.akka</groupId>
+            <artifactId>akka-stream_2.12</artifactId>
+            <version>${akka.stream.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.typesafe.akka</groupId>
+            <artifactId>akka-http-jackson_2.12</artifactId>
+            <version>${akka.http.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.typesafe.akka</groupId>
+            <artifactId>akka-http-testkit_2.12</artifactId>
+            <version>${akka.http.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
 
-	<dependencies>
+    <properties>
-		<dependency>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-			<groupId>com.typesafe.akka</groupId>
+        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
-			<artifactId>akka-http_2.12</artifactId>
+        <akka.http.version>10.0.11</akka.http.version>
-			<version>${akka.http.version}</version>
+        <akka.stream.version>2.5.11</akka.stream.version>
-		</dependency>
+    </properties>
-		<dependency>
-			<groupId>com.typesafe.akka</groupId>
-			<artifactId>akka-stream_2.12</artifactId>
-			<version>${akka.stream.version}</version>
-		</dependency>
-		<dependency>
-			<groupId>com.typesafe.akka</groupId>
-			<artifactId>akka-http-jackson_2.12</artifactId>
-			<version>${akka.http.version}</version>
-		</dependency>
-		<dependency>
-			<groupId>com.typesafe.akka</groupId>
-			<artifactId>akka-http-testkit_2.12</artifactId>
-			<version>${akka.http.version}</version>
-			<scope>test</scope>
-		</dependency>
-	</dependencies>
 
-	<properties>
-		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
-		<akka.http.version>10.0.11</akka.http.version>
-		<akka.stream.version>2.5.11</akka.stream.version>
-	</properties>
 </project>

akka-streams/pom.xml

@@ -1,13 +1,13 @@
 <?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">
+         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>akka-streams</artifactId>
     <name>akka-streams</name>
 
     <parent>
-        <artifactId>parent-modules</artifactId>
         <groupId>com.baeldung</groupId>
+        <artifactId>parent-modules</artifactId>
         <version>1.0.0-SNAPSHOT</version>
     </parent>
 

algorithms-genetic/pom.xml

@@ -1,10 +1,11 @@
+<?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">
+         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>algorithms-genetic</artifactId>
     <version>0.0.1-SNAPSHOT</version>
     <name>algorithms-genetic</name>
-    
+
     <parent>
         <groupId>com.baeldung</groupId>
         <artifactId>parent-modules</artifactId>
@@ -60,5 +61,4 @@
         <commons-codec.version>1.11</commons-codec.version>
     </properties>
 
-    
 </project>

algorithms-miscellaneous-1/pom.xml

@@ -1,10 +1,11 @@
+<?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">
+         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>algorithms-miscellaneous-1</artifactId>
     <version>0.0.1-SNAPSHOT</version>
     <name>algorithms-miscellaneous-1</name>
-    
+
     <parent>
         <groupId>com.baeldung</groupId>
         <artifactId>parent-modules</artifactId>
@@ -43,7 +44,7 @@
             <groupId>com.github.dpaukov</groupId>
             <artifactId>combinatoricslib3</artifactId>
             <version>${combinatoricslib3.version}</version>
-         </dependency>
+        </dependency>
     </dependencies>
 
     <build>

algorithms-miscellaneous-2/pom.xml

@@ -1,5 +1,6 @@
+<?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">
+         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>algorithms-miscellaneous-2</artifactId>
     <version>0.0.1-SNAPSHOT</version>
@@ -34,9 +35,9 @@
             <version>${org.jgrapht.core.version}</version>
         </dependency>
         <dependency>
-        	<groupId>org.jgrapht</groupId>
+            <groupId>org.jgrapht</groupId>
-        	<artifactId>jgrapht-ext</artifactId>
+            <artifactId>jgrapht-ext</artifactId>
-        	<version>${org.jgrapht.ext.version}</version>
+            <version>${org.jgrapht.ext.version}</version>
         </dependency>
         <dependency>
             <groupId>pl.allegro.finance</groupId>

algorithms-miscellaneous-3/pom.xml

@@ -1,3 +1,4 @@
+<?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>
@@ -91,4 +92,5 @@
         <jmh-core.version>1.19</jmh-core.version>
         <jmh-generator.version>1.19</jmh-generator.version>
     </properties>
+
 </project>

algorithms-miscellaneous-4/pom.xml

@@ -1,10 +1,11 @@
+<?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">
+         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>algorithms-miscellaneous-4</artifactId>
     <version>0.0.1-SNAPSHOT</version>
     <name>algorithms-miscellaneous-4</name>
-    
+
     <parent>
         <groupId>com.baeldung</groupId>
         <artifactId>parent-modules</artifactId>

algorithms-miscellaneous-5/pom.xml

@@ -1,5 +1,6 @@
+<?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">
+         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>algorithms-miscellaneous-5</artifactId>
     <version>0.0.1-SNAPSHOT</version>

algorithms-miscellaneous-5/src/main/java/com/baeldung/algorithms/maximumsubarray/BruteForceAlgorithm.java

@@ -0,0 +1,35 @@
+package com.baeldung.algorithms.maximumsubarray;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class BruteForceAlgorithm {
+
+    private Logger logger = LoggerFactory.getLogger(BruteForceAlgorithm.class.getName());
+
+    public int maxSubArray(int[] arr) {
+
+        int size = arr.length;
+        int maximumSubArraySum = Integer.MIN_VALUE;
+        int start = 0;
+        int end = 0;
+
+        for (int left = 0; left < size; left++) {
+
+            int runningWindowSum = 0;
+
+            for (int right = left; right < size; right++) {
+                runningWindowSum += arr[right];
+
+                if (runningWindowSum > maximumSubArraySum) {
+                    maximumSubArraySum = runningWindowSum;
+                    start = left;
+                    end = right;
+                }
+            }
+        }
+        logger.info("Found Maximum Subarray between {} and {}", start, end);
+        return maximumSubArraySum;
+    }
+
+}

algorithms-miscellaneous-5/src/main/java/com/baeldung/algorithms/maximumsubarray/KadaneAlgorithm.java

@@ -0,0 +1,34 @@
+package com.baeldung.algorithms.maximumsubarray;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class KadaneAlgorithm {
+
+    private Logger logger = LoggerFactory.getLogger(BruteForceAlgorithm.class.getName());
+
+    public int maxSubArraySum(int[] arr) {
+
+        int size = arr.length;
+        int start = 0;
+        int end = 0;
+
+        int maxSoFar = 0, maxEndingHere = 0;
+
+        for (int i = 0; i < size; i++) {
+
+            if (arr[i] > maxEndingHere + arr[i]) {
+                start = i;
+                maxEndingHere = arr[i];
+            } else
+                maxEndingHere = maxEndingHere + arr[i];
+
+            if (maxSoFar < maxEndingHere) {
+                maxSoFar = maxEndingHere;
+                end = i;
+            }
+        }
+        logger.info("Found Maximum Subarray between {} and {}", start, end);
+        return maxSoFar;
+    }
+}

algorithms-miscellaneous-5/src/main/java/com/baeldung/algorithms/prim/Edge.java

@@ -0,0 +1,36 @@
+package com.baeldung.algorithms.prim;
+
+public class Edge {
+
+    private int weight;
+    private boolean isIncluded = false;
+    private boolean isPrinted = false;
+
+    public Edge(int weight) {
+        this.weight = weight;
+    }
+
+    public int getWeight() {
+        return weight;
+    }
+
+    public void setWeight(int weight) {
+        this.weight = weight;
+    }
+
+    public boolean isIncluded() {
+        return isIncluded;
+    }
+
+    public void setIncluded(boolean included) {
+        isIncluded = included;
+    }
+
+    public boolean isPrinted() {
+        return isPrinted;
+    }
+
+    public void setPrinted(boolean printed) {
+        isPrinted = printed;
+    }
+}

algorithms-miscellaneous-5/src/main/java/com/baeldung/algorithms/prim/Prim.java

@@ -0,0 +1,73 @@
+package com.baeldung.algorithms.prim;
+
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+
+import org.apache.commons.math3.util.Pair;
+
+public class Prim {
+
+    private List<Vertex> graph;
+
+    public Prim(List<Vertex> graph){
+        this.graph = graph;
+    }
+
+    public void run(){
+        if (graph.size() > 0){
+            graph.get(0).setVisited(true);
+        }
+        while (isDisconnected()){
+            Edge nextMinimum = new Edge(Integer.MAX_VALUE);
+            Vertex nextVertex = graph.get(0);
+            for (Vertex vertex : graph){
+                if (vertex.isVisited()){
+                    Pair<Vertex, Edge> candidate = vertex.nextMinimum();
+                    if (candidate.getValue().getWeight() < nextMinimum.getWeight()){
+                        nextMinimum = candidate.getValue();
+                        nextVertex = candidate.getKey();
+                    }
+                }
+            }
+            nextMinimum.setIncluded(true);
+            nextVertex.setVisited(true);
+        }
+    }
+
+    private boolean isDisconnected(){
+        for (Vertex vertex : graph){
+            if (!vertex.isVisited()){
+                return true;
+            }
+        }
+        return false;
+    }
+
+    public String originalGraphToString(){
+        StringBuilder sb = new StringBuilder();
+        for (Vertex vertex : graph){
+            sb.append(vertex.originalToString());
+        }
+        return sb.toString();
+    }
+
+    public void resetPrintHistory(){
+        for (Vertex vertex : graph){
+            Iterator<Map.Entry<Vertex,Edge>> it = vertex.getEdges().entrySet().iterator();
+            while (it.hasNext()) {
+                Map.Entry<Vertex,Edge> pair = it.next();
+                pair.getValue().setPrinted(false);
+            }
+        }
+    }
+
+    public String minimumSpanningTreeToString(){
+        StringBuilder sb = new StringBuilder();
+        for (Vertex vertex : graph){
+            sb.append(vertex.includedToString());
+        }
+        return sb.toString();
+    }
+
+}

algorithms-miscellaneous-5/src/main/java/com/baeldung/algorithms/prim/Vertex.java

@@ -0,0 +1,106 @@
+package com.baeldung.algorithms.prim;
+
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.Map;
+
+import org.apache.commons.math3.util.Pair;
+
+public class Vertex {
+
+    private String label = null;
+    private Map<Vertex, Edge> edges = new HashMap<>();
+    private boolean isVisited = false;
+
+    public Vertex(String label){
+        this.label = label;
+    }
+
+    public String getLabel() {
+        return label;
+    }
+
+    public void setLabel(String label) {
+        this.label = label;
+    }
+
+    public Map<Vertex, Edge> getEdges() {
+        return edges;
+    }
+
+    public void addEdge(Vertex vertex, Edge edge){
+        if (this.edges.containsKey(vertex)){
+            if (edge.getWeight() < this.edges.get(vertex).getWeight()){
+                this.edges.replace(vertex, edge);
+            }
+        } else {
+            this.edges.put(vertex, edge);
+        }
+    }
+
+    public boolean isVisited() {
+        return isVisited;
+    }
+
+    public void setVisited(boolean visited) {
+        isVisited = visited;
+    }
+
+    public Pair<Vertex, Edge> nextMinimum(){
+        Edge nextMinimum = new Edge(Integer.MAX_VALUE);
+        Vertex nextVertex = this;
+        Iterator<Map.Entry<Vertex,Edge>> it = edges.entrySet().iterator();
+        while (it.hasNext()) {
+            Map.Entry<Vertex,Edge> pair = it.next();
+            if (!pair.getKey().isVisited()){
+                if (!pair.getValue().isIncluded()) {
+                    if (pair.getValue().getWeight() < nextMinimum.getWeight()) {
+                        nextMinimum = pair.getValue();
+                        nextVertex = pair.getKey();
+                    }
+                }
+            }
+        }
+        return new Pair<>(nextVertex, nextMinimum);
+    }
+
+    public String originalToString(){
+        StringBuilder sb = new StringBuilder();
+        Iterator<Map.Entry<Vertex,Edge>> it = edges.entrySet().iterator();
+        while (it.hasNext()) {
+            Map.Entry<Vertex,Edge> pair = it.next();
+            if (!pair.getValue().isPrinted()) {
+                sb.append(getLabel());
+                sb.append(" --- ");
+                sb.append(pair.getValue().getWeight());
+                sb.append(" --- ");
+                sb.append(pair.getKey().getLabel());
+                sb.append("\n");
+                pair.getValue().setPrinted(true);
+            }
+        }
+        return sb.toString();
+    }
+
+    public String includedToString(){
+        StringBuilder sb = new StringBuilder();
+        if (isVisited()) {
+            Iterator<Map.Entry<Vertex,Edge>> it = edges.entrySet().iterator();
+            while (it.hasNext()) {
+                Map.Entry<Vertex,Edge> pair = it.next();
+                if (pair.getValue().isIncluded()) {
+                    if (!pair.getValue().isPrinted()) {
+                        sb.append(getLabel());
+                        sb.append(" --- ");
+                        sb.append(pair.getValue().getWeight());
+                        sb.append(" --- ");
+                        sb.append(pair.getKey().getLabel());
+                        sb.append("\n");
+                        pair.getValue().setPrinted(true);
+                    }
+                }
+            }
+        }
+        return sb.toString();
+    }
+}

algorithms-miscellaneous-5/src/test/java/com/baeldung/algorithms/maximumsubarray/BruteForceAlgorithmUnitTest.java

@@ -0,0 +1,19 @@
+package com.baeldung.algorithms.maximumsubarray;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class BruteForceAlgorithmUnitTest {
+
+    @Test
+    void givenArrayWithNegativeNumberWhenMaximumSubarrayThenReturns6() {
+        //given
+        int[] arr = new int[]{-3, 1, -8, 4, -1, 2, 1, -5, 5};
+        //when
+        BruteForceAlgorithm algorithm = new BruteForceAlgorithm();
+        int maximumSum = algorithm.maxSubArray(arr);
+        //then
+        assertEquals(6, maximumSum);
+    }
+}

algorithms-miscellaneous-5/src/test/java/com/baeldung/algorithms/maximumsubarray/KadaneAlgorithmUnitTest.java

@@ -0,0 +1,19 @@
+package com.baeldung.algorithms.maximumsubarray;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class KadaneAlgorithmUnitTest {
+
+    @Test
+    void givenArrayWithNegativeNumberWhenMaximumSubarrayThenReturns6() {
+        //given
+        int[] arr = new int[]{-3, 1, -8, 4, -1, 2, 1, -5, 5};
+        //when
+        KadaneAlgorithm algorithm = new KadaneAlgorithm();
+        int maxSum = algorithm.maxSubArraySum(arr);
+        //then
+        assertEquals(6, maxSum);
+    }
+}

algorithms-miscellaneous-5/src/test/java/com/baeldung/algorithms/prim/PrimUnitTest.java

@@ -0,0 +1,54 @@
+package com.baeldung.algorithms.prim;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.junit.Test;
+
+public class PrimUnitTest {
+
+    @Test
+    public void givenAGraph_whenPrimRuns_thenPrintMST() {
+        Prim prim = new Prim(createGraph());
+        System.out.println(prim.originalGraphToString());
+        System.out.println("----------------");
+        prim.run();
+        System.out.println();
+        prim.resetPrintHistory();
+        System.out.println(prim.minimumSpanningTreeToString());
+    }
+
+    public static List<Vertex> createGraph() {
+        List<Vertex> graph = new ArrayList<>();
+        Vertex a = new Vertex("A");
+        Vertex b = new Vertex("B");
+        Vertex c = new Vertex("C");
+        Vertex d = new Vertex("D");
+        Vertex e = new Vertex("E");
+        Edge ab = new Edge(2);
+        a.addEdge(b, ab);
+        b.addEdge(a, ab);
+        Edge ac = new Edge(3);
+        a.addEdge(c, ac);
+        c.addEdge(a, ac);
+        Edge bc = new Edge(2);
+        b.addEdge(c, bc);
+        c.addEdge(b, bc);
+        Edge be = new Edge(5);
+        b.addEdge(e, be);
+        e.addEdge(b, be);
+        Edge cd = new Edge(1);
+        c.addEdge(d, cd);
+        d.addEdge(c, cd);
+        Edge ce = new Edge(1);
+        c.addEdge(e, ce);
+        e.addEdge(c, ce);
+        graph.add(a);
+        graph.add(b);
+        graph.add(c);
+        graph.add(d);
+        graph.add(e);
+        return graph;
+    }
+
+}

algorithms-searching/pom.xml

@@ -1,5 +1,6 @@
+<?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">
+         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>algorithms-searching</artifactId>
     <version>0.0.1-SNAPSHOT</version>

algorithms-sorting/pom.xml

@@ -1,5 +1,6 @@
+<?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">
+         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>algorithms-sorting</artifactId>
     <version>0.0.1-SNAPSHOT</version>

animal-sniffer-mvn-plugin/pom.xml

@@ -1,5 +1,6 @@
+<?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/maven-v4_0_0.xsd">
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>animal-sniffer-mvn-plugin</artifactId>
     <version>1.0-SNAPSHOT</version>
@@ -43,4 +44,5 @@
         <animal-sniffer-maven-plugin.version>1.16</animal-sniffer-maven-plugin.version>
         <org.codehaus.mojo.signature.java16.version>1.0</org.codehaus.mojo.signature.java16.version>
     </properties>
+    
 </project>

annotations/annotation-processing/pom.xml

@@ -1,10 +1,10 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://maven.apache.org/POM/4.0.0"
-    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+         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>annotation-processing</artifactId>
     <name>annotation-processing</name>
-    
+
     <parent>
         <groupId>com.baeldung</groupId>
         <version>1.0.0-SNAPSHOT</version>

annotations/annotation-user/pom.xml

@@ -1,13 +1,13 @@
 <?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">
+         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>annotation-user</artifactId>
     <name>annotation-user</name>
 
     <parent>
-        <artifactId>annotations</artifactId>
         <groupId>com.baeldung</groupId>
+        <artifactId>annotations</artifactId>
         <version>1.0.0-SNAPSHOT</version>
         <relativePath>../</relativePath>
     </parent>

annotations/pom.xml

@@ -1,14 +1,14 @@
 <?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">
+         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>annotations</artifactId>
     <name>annotations</name>
     <packaging>pom</packaging>
-    
+
     <parent>
-        <artifactId>parent-modules</artifactId>
         <groupId>com.baeldung</groupId>
+        <artifactId>parent-modules</artifactId>
         <version>1.0.0-SNAPSHOT</version>
     </parent>
 

antlr/pom.xml

@@ -1,5 +1,6 @@
+<?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/maven-v4_0_0.xsd">
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>antlr</artifactId>
     <name>antlr</name>
@@ -52,9 +53,10 @@
             </plugin>
         </plugins>
     </build>
-    	
+
     <properties>
         <antlr.version>4.7.1</antlr.version>
         <mojo.version>3.0.0</mojo.version>
     </properties>
+    
 </project>

apache-avro/pom.xml

@@ -5,7 +5,7 @@
     <modelVersion>4.0.0</modelVersion>
     <artifactId>apache-avro</artifactId>
     <version>0.0.1-SNAPSHOT</version>
-	<name>apache-avro</name>
+    <name>apache-avro</name>
 
     <parent>
         <groupId>com.baeldung</groupId>
@@ -67,5 +67,5 @@
         <avro.version>1.8.2</avro.version>
         <slf4j.version>1.7.25</slf4j.version>
     </properties>
-	
+
 </project>

apache-bval/pom.xml

@@ -1,11 +1,11 @@
+<?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">
+         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>apache-bval</groupId>
     <artifactId>apache-bval</artifactId>
     <version>0.0.1-SNAPSHOT</version>
     <name>apache-bval</name>
-    
+
     <parent>
         <groupId>com.baeldung</groupId>
         <artifactId>parent-modules</artifactId>

apache-curator/pom.xml

@@ -1,9 +1,10 @@
+<?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">
+         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>apache-curator</artifactId>
     <version>0.0.1-SNAPSHOT</version>
-	<name>apache-curator</name>
+    <name>apache-curator</name>
     <packaging>jar</packaging>
 
     <parent>

apache-cxf/cxf-aegis/README.md

@@ -0,0 +1,3 @@
+### Relevant Articles
+
+- [Introduction to Apache CXF Aegis Data Binding](https://www.baeldung.com/aegis-data-binding-in-apache-cxf)

apache-cxf/cxf-aegis/pom.xml

@@ -1,9 +1,10 @@
+<?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/maven-v4_0_0.xsd">
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>cxf-aegis</artifactId>
-	<name>cxf-aegis</name>
+    <name>cxf-aegis</name>
-	
+
     <parent>
         <groupId>com.baeldung</groupId>
         <artifactId>apache-cxf</artifactId>

apache-cxf/cxf-introduction/pom.xml

@@ -1,11 +1,10 @@
 <?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/maven-v4_0_0.xsd">
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>cxf-introduction</artifactId>
-	<name>cxf-introduction</name>
+    <name>cxf-introduction</name>
-	
+
     <parent>
         <groupId>com.baeldung</groupId>
         <artifactId>apache-cxf</artifactId>

apache-cxf/cxf-jaxrs-implementation/pom.xml

@@ -1,11 +1,10 @@
 <?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/maven-v4_0_0.xsd">
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>cxf-jaxrs-implementation</artifactId>
-	<name>cxf-jaxrs-implementation</name>
+    <name>cxf-jaxrs-implementation</name>
-	
+
     <parent>
         <groupId>com.baeldung</groupId>
         <artifactId>apache-cxf</artifactId>

apache-cxf/cxf-spring/README.md

@@ -0,0 +1,3 @@
+### Relevant Articles:
+
+- [A Guide to Apache CXF with Spring](https://www.baeldung.com/apache-cxf-with-spring)

apache-cxf/cxf-spring/pom.xml

@@ -1,9 +1,10 @@
+<?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/maven-v4_0_0.xsd">
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>cxf-spring</artifactId>
+    <name>cxf-spring</name>
     <packaging>war</packaging>
-	<name>cxf-spring</name>
 
     <parent>
         <groupId>com.baeldung</groupId>
@@ -98,7 +99,6 @@
                 </plugins>
             </build>
         </profile>
-
     </profiles>
 
     <properties>

apache-cxf/pom.xml

@@ -1,3 +1,4 @@
+<?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>

apache-cxf/sse-jaxrs/pom.xml

@@ -16,6 +16,6 @@
     <modules>
         <module>sse-jaxrs-server</module>
         <module>sse-jaxrs-client</module>
-   </modules>
+    </modules>
 
 </project>

apache-cxf/sse-jaxrs/sse-jaxrs-client/pom.xml

@@ -5,7 +5,7 @@
     <modelVersion>4.0.0</modelVersion>
     <artifactId>sse-jaxrs-client</artifactId>
     <name>sse-jaxrs-client</name>
-    
+
     <parent>
         <groupId>com.baeldung</groupId>
         <artifactId>sse-jaxrs</artifactId>

apache-fop/pom.xml

@@ -1,5 +1,6 @@
+<?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">
+         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>apache-fop</artifactId>
     <version>0.1-SNAPSHOT</version>

apache-geode/pom.xml

@@ -6,7 +6,7 @@
     <artifactId>apache-geode</artifactId>
     <version>1.0-SNAPSHOT</version>
     <name>apache-geode</name>
-    
+
     <parent>
         <groupId>com.baeldung</groupId>
         <artifactId>parent-modules</artifactId>
@@ -20,8 +20,9 @@
             <version>${geode.core}</version>
         </dependency>
     </dependencies>
-	
+
     <properties>
         <geode.core>1.6.0</geode.core>
     </properties>
+
 </project>

apache-meecrowave/pom.xml

@@ -1,11 +1,12 @@
+<?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">
+         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>apache-meecrowave</artifactId>
     <version>0.0.1</version>
     <name>apache-meecrowave</name>
     <description>A sample REST API application with Meecrowave</description>
-    
+
     <parent>
         <groupId>com.baeldung</groupId>
         <artifactId>parent-modules</artifactId>
@@ -38,7 +39,7 @@
             <scope>test</scope>
         </dependency>
     </dependencies>
-	
+
     <build>
         <plugins>
             <plugin>
@@ -48,14 +49,15 @@
             </plugin>
         </plugins>
     </build>
-	
+
     <properties>
         <maven.compiler.source>1.8</maven.compiler.source>
         <maven.compiler.target>1.8</maven.compiler.target>
-		<meecrowave-junit.version>1.2.0</meecrowave-junit.version>
+        <meecrowave-junit.version>1.2.0</meecrowave-junit.version>
-		<okhttp.version>3.10.0</okhttp.version>
+        <okhttp.version>3.10.0</okhttp.version>
-		<meecrowave-jpa.version>1.2.1</meecrowave-jpa.version>
+        <meecrowave-jpa.version>1.2.1</meecrowave-jpa.version>
-		<meecrowave-core.version>1.2.1</meecrowave-core.version>
+        <meecrowave-core.version>1.2.1</meecrowave-core.version>
-		<meecrowave-maven-plugin.version>1.2.1</meecrowave-maven-plugin.version>
+        <meecrowave-maven-plugin.version>1.2.1</meecrowave-maven-plugin.version>
     </properties>
+
 </project>

apache-olingo/olingo2/README.md

@@ -0,0 +1,4 @@
+### Relevant Articles:
+
+- [OData Protocol Guide](https://www.baeldung.com/odata)
+- [Intro to OData with Olingo](https://www.baeldung.com/olingo)

apache-olingo/olingo2/pom.xml

@@ -1,87 +1,87 @@
 <?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"
+         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">
+         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>
+    <modelVersion>4.0.0</modelVersion>
-	<groupId>org.baeldung.examples.olingo2</groupId>
+    <groupId>org.baeldung.examples.olingo2</groupId>
-	<artifactId>olingo2</artifactId>
+    <artifactId>olingo2</artifactId>
-	<name>olingo2</name>
+    <name>olingo2</name>
-	<description>Sample Olingo 2 Project</description>
+    <description>Sample Olingo 2 Project</description>
 
     <parent>
-        <artifactId>parent-boot-2</artifactId>
         <groupId>com.baeldung</groupId>
+        <artifactId>parent-boot-2</artifactId>
         <version>0.0.1-SNAPSHOT</version>
         <relativePath>../../parent-boot-2</relativePath>
     </parent>
 
-	<dependencies>
+    <dependencies>
-		<dependency>
+        <dependency>
-			<groupId>org.springframework.boot</groupId>
+            <groupId>org.springframework.boot</groupId>
-			<artifactId>spring-boot-starter-jersey</artifactId>
+            <artifactId>spring-boot-starter-jersey</artifactId>
-		</dependency>
+        </dependency>
-		<dependency>
+        <dependency>
-			<groupId>org.springframework.boot</groupId>
+            <groupId>org.springframework.boot</groupId>
-			<artifactId>spring-boot-starter-data-jpa</artifactId>
+            <artifactId>spring-boot-starter-data-jpa</artifactId>
-		</dependency>
+        </dependency>
-		<dependency>
+        <dependency>
-			<groupId>com.h2database</groupId>
+            <groupId>com.h2database</groupId>
-			<artifactId>h2</artifactId>
+            <artifactId>h2</artifactId>
-			<scope>runtime</scope>
+            <scope>runtime</scope>
-		</dependency>
+        </dependency>
-		<dependency>
+        <dependency>
-			<groupId>org.springframework.boot</groupId>
+            <groupId>org.springframework.boot</groupId>
-			<artifactId>spring-boot-configuration-processor</artifactId>
+            <artifactId>spring-boot-configuration-processor</artifactId>
-			<optional>true</optional>
+            <optional>true</optional>
-		</dependency>
+        </dependency>
-		<dependency>
+        <dependency>
-			<groupId>org.springframework.boot</groupId>
+            <groupId>org.springframework.boot</groupId>
-			<artifactId>spring-boot-starter-test</artifactId>
+            <artifactId>spring-boot-starter-test</artifactId>
-			<scope>test</scope>
+            <scope>test</scope>
-		</dependency>
+        </dependency>
 
-		<!-- Olingo 2 Dependencies -->
+        <!-- Olingo 2 Dependencies -->
-		<dependency>
+        <dependency>
-			<groupId>org.apache.olingo</groupId>
+            <groupId>org.apache.olingo</groupId>
-			<artifactId>olingo-odata2-core</artifactId>
+            <artifactId>olingo-odata2-core</artifactId>
-			<version>${olingo2.version}</version>
+            <version>${olingo2.version}</version>
-			<!-- Avoid jax-rs version conflict by excluding Olingo's version -->
+            <!-- Avoid jax-rs version conflict by excluding Olingo's version -->
-			<exclusions>
+            <exclusions>
-				<exclusion>
+                <exclusion>
-					<groupId>javax.ws.rs</groupId>
+                    <groupId>javax.ws.rs</groupId>
-					<artifactId>javax.ws.rs-api</artifactId>
+                    <artifactId>javax.ws.rs-api</artifactId>
-				</exclusion>
+                </exclusion>
-			</exclusions>
+            </exclusions>
-		</dependency>
+        </dependency>
-		<dependency>
+        <dependency>
-			<groupId>org.apache.olingo</groupId>
+            <groupId>org.apache.olingo</groupId>
-			<artifactId>olingo-odata2-jpa-processor-core</artifactId>
+            <artifactId>olingo-odata2-jpa-processor-core</artifactId>
-			<version>${olingo2.version}</version>
+            <version>${olingo2.version}</version>
-		</dependency>
+        </dependency>
-		<dependency>
+        <dependency>
-			<groupId>org.apache.olingo</groupId>
+            <groupId>org.apache.olingo</groupId>
-			<artifactId>olingo-odata2-jpa-processor-ref</artifactId>
+            <artifactId>olingo-odata2-jpa-processor-ref</artifactId>
-			<version>${olingo2.version}</version>
+            <version>${olingo2.version}</version>
-			<exclusions>
+            <exclusions>
-				<exclusion>
+                <exclusion>
-					<groupId>org.eclipse.persistence</groupId>
+                    <groupId>org.eclipse.persistence</groupId>
-					<artifactId>eclipselink</artifactId>
+                    <artifactId>eclipselink</artifactId>
-				</exclusion>
+                </exclusion>
-			</exclusions>
+            </exclusions>
-		</dependency>
+        </dependency>
-	</dependencies>
+    </dependencies>
 
-	<build>
+    <build>
-		<plugins>
+        <plugins>
-			<plugin>
+            <plugin>
-				<groupId>org.springframework.boot</groupId>
+                <groupId>org.springframework.boot</groupId>
-				<artifactId>spring-boot-maven-plugin</artifactId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
-			</plugin>
+            </plugin>
-		</plugins>
+        </plugins>
-	</build>
+    </build>
 
-	<properties>
+    <properties>
-		<olingo2.version>2.0.11</olingo2.version>
+        <olingo2.version>2.0.11</olingo2.version>
-	</properties>
+    </properties>
 
 </project>

apache-opennlp/pom.xml

@@ -1,6 +1,6 @@
 <?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">
+         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>apache-opennlp</artifactId>
     <version>1.0-SNAPSHOT</version>

apache-poi/pom.xml

@@ -1,5 +1,6 @@
+<?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">
+         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>apache-poi</artifactId>
     <version>0.0.1-SNAPSHOT</version>

apache-pulsar/pom.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.baeldung.pulsar</groupId>
     <artifactId>apache-pulsar</artifactId>
@@ -22,8 +22,9 @@
             <scope>compile</scope>
         </dependency>
     </dependencies>
-	
+
     <properties>
- 		<pulsar-client.version>2.1.1-incubating</pulsar-client.version>
+        <pulsar-client.version>2.1.1-incubating</pulsar-client.version>
     </properties>
+
 </project>

apache-shiro/pom.xml

@@ -6,10 +6,10 @@
     <artifactId>apache-shiro</artifactId>
     <version>1.0-SNAPSHOT</version>
     <name>apache-shiro</name>
-    
+
     <parent>
-        <artifactId>parent-boot-1</artifactId>
         <groupId>com.baeldung</groupId>
+        <artifactId>parent-boot-1</artifactId>
         <version>0.0.1-SNAPSHOT</version>
         <relativePath>../parent-boot-1</relativePath>
     </parent>

apache-solrj/pom.xml

@@ -1,5 +1,6 @@
+<?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">
+         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>apache-solrj</artifactId>
     <version>0.0.1-SNAPSHOT</version>

apache-spark/pom.xml

@@ -1,110 +1,112 @@
+<?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"
+         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">
+         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>
+    <modelVersion>4.0.0</modelVersion>
-	<artifactId>apache-spark</artifactId>
+    <artifactId>apache-spark</artifactId>
-	<version>1.0-SNAPSHOT</version>
+    <version>1.0-SNAPSHOT</version>
-	<name>apache-spark</name>
+    <name>apache-spark</name>
-	<packaging>jar</packaging>
+    <packaging>jar</packaging>
-	<url>http://maven.apache.org</url>
+    <url>http://maven.apache.org</url>
 
-	<parent>
+    <parent>
-		<groupId>com.baeldung</groupId>
+        <groupId>com.baeldung</groupId>
-		<artifactId>parent-modules</artifactId>
+        <artifactId>parent-modules</artifactId>
-		<version>1.0.0-SNAPSHOT</version>
+        <version>1.0.0-SNAPSHOT</version>
-	</parent>
+    </parent>
 
-	<dependencies>
+    <dependencies>
-		<dependency>
+        <dependency>
-			<groupId>org.apache.spark</groupId>
+            <groupId>org.apache.spark</groupId>
-			<artifactId>spark-core_2.11</artifactId>
+            <artifactId>spark-core_2.11</artifactId>
-			<version>${org.apache.spark.spark-core.version}</version>
+            <version>${org.apache.spark.spark-core.version}</version>
-			<scope>provided</scope>
+            <scope>provided</scope>
-		</dependency>
+        </dependency>
-		<dependency>
+        <dependency>
-			<groupId>org.apache.spark</groupId>
+            <groupId>org.apache.spark</groupId>
-			<artifactId>spark-sql_2.11</artifactId>
+            <artifactId>spark-sql_2.11</artifactId>
-			<version>${org.apache.spark.spark-sql.version}</version>
+            <version>${org.apache.spark.spark-sql.version}</version>
-			<scope>provided</scope>
+            <scope>provided</scope>
-		</dependency>
+        </dependency>
-		<dependency>
+        <dependency>
-			<groupId>org.apache.spark</groupId>
+            <groupId>org.apache.spark</groupId>
-			<artifactId>spark-graphx_2.11</artifactId>
+            <artifactId>spark-graphx_2.11</artifactId>
-			<version>${org.apache.spark.spark-graphx.version}</version>
+            <version>${org.apache.spark.spark-graphx.version}</version>
-			<scope>provided</scope>
+            <scope>provided</scope>
-		</dependency>
+        </dependency>
-		<dependency>
+        <dependency>
-			<groupId>graphframes</groupId>
+            <groupId>graphframes</groupId>
-			<artifactId>graphframes</artifactId>
+            <artifactId>graphframes</artifactId>
-			<version>${graphframes.version}</version>
+            <version>${graphframes.version}</version>
-			<scope>provided</scope>
+            <scope>provided</scope>
-		</dependency>
+        </dependency>
-		<dependency>
+        <dependency>
-			<groupId>org.apache.spark</groupId>
+            <groupId>org.apache.spark</groupId>
-			<artifactId>spark-streaming_2.11</artifactId>
+            <artifactId>spark-streaming_2.11</artifactId>
-			<version>${org.apache.spark.spark-streaming.version}</version>
+            <version>${org.apache.spark.spark-streaming.version}</version>
-			<scope>provided</scope>
+            <scope>provided</scope>
-		</dependency>
+        </dependency>
-		<dependency>
+        <dependency>
-			<groupId>org.apache.spark</groupId>
+            <groupId>org.apache.spark</groupId>
-			<artifactId>spark-mllib_2.11</artifactId>
+            <artifactId>spark-mllib_2.11</artifactId>
-			<version>${org.apache.spark.spark-mllib.version}</version>
+            <version>${org.apache.spark.spark-mllib.version}</version>
-			<scope>provided</scope>
+            <scope>provided</scope>
-		</dependency>
+        </dependency>
-		<dependency>
+        <dependency>
-			<groupId>org.apache.spark</groupId>
+            <groupId>org.apache.spark</groupId>
-			<artifactId>spark-streaming-kafka-0-10_2.11</artifactId>
+            <artifactId>spark-streaming-kafka-0-10_2.11</artifactId>
-			<version>${org.apache.spark.spark-streaming-kafka.version}</version>
+            <version>${org.apache.spark.spark-streaming-kafka.version}</version>
-		</dependency>
+        </dependency>
-		<dependency>
+        <dependency>
-			<groupId>com.datastax.spark</groupId>
+            <groupId>com.datastax.spark</groupId>
-			<artifactId>spark-cassandra-connector_2.11</artifactId>
+            <artifactId>spark-cassandra-connector_2.11</artifactId>
-			<version>${com.datastax.spark.spark-cassandra-connector.version}</version>
+            <version>${com.datastax.spark.spark-cassandra-connector.version}</version>
-		</dependency>
+        </dependency>
-		<dependency>
+        <dependency>
-			<groupId>com.datastax.spark</groupId>
+            <groupId>com.datastax.spark</groupId>
-			<artifactId>spark-cassandra-connector-java_2.11</artifactId>
+            <artifactId>spark-cassandra-connector-java_2.11</artifactId>
-			<version>${com.datastax.spark.spark-cassandra-connector-java.version}</version>
+            <version>${com.datastax.spark.spark-cassandra-connector-java.version}</version>
-		</dependency>
+        </dependency>
-	</dependencies>
+    </dependencies>
 
-	<build>
+    <build>
-		<plugins>
+        <plugins>
-			<plugin>
+            <plugin>
-				<artifactId>maven-assembly-plugin</artifactId>
+                <artifactId>maven-assembly-plugin</artifactId>
-				<executions>
+                <executions>
-					<execution>
+                    <execution>
-						<phase>package</phase>
+                        <phase>package</phase>
-						<goals>
+                        <goals>
-							<goal>single</goal>
+                            <goal>single</goal>
-						</goals>
+                        </goals>
-					</execution>
+                    </execution>
-				</executions>
+                </executions>
-				<configuration>
+                <configuration>
-					<descriptorRefs>
+                    <descriptorRefs>
-						<descriptorRef>jar-with-dependencies</descriptorRef>
+                        <descriptorRef>jar-with-dependencies</descriptorRef>
-					</descriptorRefs>
+                    </descriptorRefs>
-				</configuration>
+                </configuration>
-			</plugin>
+            </plugin>
-		</plugins>
+        </plugins>
-	</build>
+    </build>
 
-	<properties>
+    <repositories>
-		<org.apache.spark.spark-core.version>2.3.0</org.apache.spark.spark-core.version>
+        <repository>
-		<org.apache.spark.spark-sql.version>2.3.0</org.apache.spark.spark-sql.version>
+            <id>SparkPackagesRepo</id>
-		<org.apache.spark.spark-streaming.version>2.3.0</org.apache.spark.spark-streaming.version>
+            <url>http://dl.bintray.com/spark-packages/maven</url>
-		<org.apache.spark.spark-mllib.version>2.3.0</org.apache.spark.spark-mllib.version>
+        </repository>
-		<org.apache.spark.spark-graphx.version>2.3.0</org.apache.spark.spark-graphx.version>
+    </repositories>
-		<graphframes.version>0.7.0-spark2.4-s_2.11</graphframes.version>
+
-		<org.apache.spark.spark-streaming-kafka.version>2.3.0</org.apache.spark.spark-streaming-kafka.version>
+    <properties>
-		<com.datastax.spark.spark-cassandra-connector.version>2.3.0</com.datastax.spark.spark-cassandra-connector.version>
+        <org.apache.spark.spark-core.version>2.3.0</org.apache.spark.spark-core.version>
-		<com.datastax.spark.spark-cassandra-connector-java.version>1.5.2</com.datastax.spark.spark-cassandra-connector-java.version>
+        <org.apache.spark.spark-sql.version>2.3.0</org.apache.spark.spark-sql.version>
-	</properties>
+        <org.apache.spark.spark-streaming.version>2.3.0</org.apache.spark.spark-streaming.version>
+        <org.apache.spark.spark-mllib.version>2.3.0</org.apache.spark.spark-mllib.version>
+        <org.apache.spark.spark-graphx.version>2.3.0</org.apache.spark.spark-graphx.version>
+        <graphframes.version>0.7.0-spark2.4-s_2.11</graphframes.version>
+        <org.apache.spark.spark-streaming-kafka.version>2.3.0</org.apache.spark.spark-streaming-kafka.version>
+        <com.datastax.spark.spark-cassandra-connector.version>2.3.0</com.datastax.spark.spark-cassandra-connector.version>
+        <com.datastax.spark.spark-cassandra-connector-java.version>1.5.2</com.datastax.spark.spark-cassandra-connector-java.version>
+    </properties>
 
-	<repositories>
-		<repository>
-			<id>SparkPackagesRepo</id>
-			<url>http://dl.bintray.com/spark-packages/maven</url>
-		</repository>
-	</repositories>
 </project>

apache-tapestry/pom.xml

@@ -1,12 +1,14 @@
+<?xml version="1.0" encoding="UTF-8"?>
 <project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://maven.apache.org/POM/4.0.0">
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.baeldung</groupId>
     <artifactId>apache-tapestry</artifactId>
     <version>0.0.1-SNAPSHOT</version>
-    <packaging>war</packaging>
     <name>apache-tapestry</name>
-        <dependencies>
+    <packaging>war</packaging>
+
+    <dependencies>
         <!-- To set up an application with a database, change the artifactId below to
              tapestry-hibernate, and add a dependency on your JDBC driver. You'll also
              need to add Hibernate configuration files, such as hibernate.cfg.xml. -->
@@ -22,7 +24,7 @@
             <artifactId>slf4j-log4j12</artifactId>
             <version>${slf4j-release-version}</version>
         </dependency>
-        
+
         <dependency>
             <groupId>org.apache.tapestry</groupId>
             <artifactId>tapestry-webresources</artifactId>
@@ -71,8 +73,8 @@ of testing facilities designed for use with TestNG (http://testng.org/), so it's
             <version>${tapestry-release-version}</version>
             <scope>provided</scope>
         </dependency>
-
     </dependencies>
+
     <build>
         <finalName>apache-tapestry</finalName>
         <plugins>
@@ -142,6 +144,6 @@ of testing facilities designed for use with TestNG (http://testng.org/), so it's
         <servlet-api-release-version>2.5</servlet-api-release-version>
         <testng-release-version>6.8.21</testng-release-version>
         <slf4j-release-version>1.7.19</slf4j-release-version>
-
     </properties>
+
 </project>

apache-thrift/pom.xml

@@ -1,5 +1,6 @@
+<?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">
+         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>apache-thrift</artifactId>
     <version>0.0.1-SNAPSHOT</version>

apache-tika/pom.xml

@@ -1,10 +1,11 @@
+<?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">
+         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>apache-tika</artifactId>
     <version>0.0.1-SNAPSHOT</version>
     <name>apache-tika</name>
-    
+
     <parent>
         <groupId>com.baeldung</groupId>
         <artifactId>parent-modules</artifactId>

apache-velocity/pom.xml

@@ -1,8 +1,9 @@
+<?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/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
-    <version>0.1-SNAPSHOT</version>
     <artifactId>apache-velocity</artifactId>
+    <version>0.1-SNAPSHOT</version>
     <name>apache-velocity</name>
     <packaging>war</packaging>
 

apache-zookeeper/pom.xml

@@ -1,5 +1,6 @@
+<?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">
+         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>apache-zookeeper</artifactId>
     <version>0.0.1-SNAPSHOT</version>

asciidoctor/pom.xml

@@ -1,13 +1,13 @@
 <?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">
+         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>asciidoctor</artifactId>
     <name>asciidoctor</name>
 
     <parent>
-        <artifactId>parent-modules</artifactId>
         <groupId>com.baeldung</groupId>
+        <artifactId>parent-modules</artifactId>
         <version>1.0.0-SNAPSHOT</version>
     </parent>
 
@@ -63,7 +63,6 @@
     <properties>
         <asciidoctor-maven-plugin.version>1.5.6</asciidoctor-maven-plugin.version>
         <asciidoctorj.version>1.5.6</asciidoctorj.version>
-        
         <asciidoctorj-pdf.version>1.5.0-alpha.15</asciidoctorj-pdf.version>
         <asciidoctorj-pdf.plugin.version>1.5.0-alpha.15</asciidoctorj-pdf.plugin.version>
     </properties>

asm/pom.xml

@@ -1,6 +1,6 @@
 <?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">
+         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.examples</groupId>
     <artifactId>asm</artifactId>

atomix/pom.xml

@@ -1,11 +1,12 @@
+<?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">
+         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.atomix.io</groupId>
     <artifactId>atomix</artifactId>
     <version>0.0.1-SNAPSHOT</version>
     <name>atomix</name>
-    
+
     <parent>
         <groupId>com.baeldung</groupId>
         <artifactId>parent-modules</artifactId>

aws-lambda/pom.xml

@@ -1,6 +1,6 @@
 <?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">
+         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>aws-lambda</artifactId>
     <version>0.1.0-SNAPSHOT</version>
@@ -8,13 +8,12 @@
     <packaging>jar</packaging>
 
     <parent>
-        <artifactId>parent-modules</artifactId>
         <groupId>com.baeldung</groupId>
+        <artifactId>parent-modules</artifactId>
         <version>1.0.0-SNAPSHOT</version>
     </parent>
 
     <dependencies>
-
         <dependency>
             <groupId>com.amazonaws</groupId>
             <artifactId>aws-java-sdk-dynamodb</artifactId>
@@ -63,7 +62,7 @@
             <version>${json-simple.version}</version>
         </dependency>
     </dependencies>
-    
+
     <build>
         <plugins>
             <plugin>
@@ -84,7 +83,7 @@
             </plugin>
         </plugins>
     </build>
-    
+
     <properties>
         <json-simple.version>1.1.1</json-simple.version>
         <commons-io.version>2.5</commons-io.version>
@@ -94,5 +93,5 @@
         <aws-java-sdk.version>1.11.241</aws-java-sdk.version>
         <maven-shade-plugin.version>3.0.0</maven-shade-plugin.version>
     </properties>
-    
+
 </project>

aws-reactive/images/rective-upload.txt

@@ -0,0 +1,29 @@
+participant "Client 1" as C1
+participant "Client 2" as C2
+participant "Reactive Web App" as RWS
+participant "Backend" as S3
+C1 -> RWS: POST
+activate C1
+activate RWS
+RWS -> S3: Async POST
+deactivate RWS
+C2 -> RWS: POST
+activate C2
+activate RWS
+RWS -> S3: Async POST
+deactivate RWS
+S3 --> RWS: Async Result
+activate RWS
+RWS -->C2: Result
+deactivate RWS
+deactivate C2
+// First file EOF
+S3 --> RWS: Async Result
+activate RWS
+RWS -->C1: Result
+deactivate RWS
+deactivate C1
+
+
+
+

aws-reactive/images/thread-per-client.txt

@@ -0,0 +1,28 @@
+participant Client 1
+participant Client 2
+participant Controller
+participant Backend
+Client 1-> Controller: POST Data
+activate Client 1
+activate Controller
+Controller -> Backend: Save Data
+activate Backend
+note left of Controller #yellow: Controller blocked\nuntil result received
+Backend --> Controller: Result
+deactivate Backend
+Controller --> Client 1: Result
+deactivate Client 1
+deactivate Controller
+// 2nd Upload
+Client 2-> Controller: POST Data
+activate Client 2
+activate Controller
+Controller -> Backend: Save Data
+activate Backend
+note left of Controller #yellow: Controller blocket\nuntil result received
+Backend --> Controller: Result
+deactivate Backend
+Controller --> Client 2: Result
+deactivate Controller
+deactivate Client 2
+

aws-reactive/pom.xml

@@ -0,0 +1,105 @@
+<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+	
+	<artifactId>aws-reactive</artifactId>
+	<version>0.0.1-SNAPSHOT</version>
+	<name>aws-reactive</name>
+	<description>AWS Reactive Sample</description>
+
+	<properties>
+		<java.version>1.8</java.version>
+	</properties>
+
+	<dependencyManagement>
+		<dependencies>
+
+			<dependency>
+				<!-- Import dependency management from Spring Boot -->
+				<groupId>org.springframework.boot</groupId>
+				<artifactId>spring-boot-dependencies</artifactId>
+				<version>2.2.1.RELEASE</version>
+				<type>pom</type>
+				<scope>import</scope>
+			</dependency>
+
+			<dependency>
+				<groupId>software.amazon.awssdk</groupId>
+				<artifactId>bom</artifactId>
+				<version>2.10.27</version>
+				<type>pom</type>
+				<scope>import</scope>
+			</dependency>
+		</dependencies>
+	</dependencyManagement>
+
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-webflux</artifactId>
+		</dependency>
+
+		<dependency>
+			<groupId>software.amazon.awssdk</groupId>
+			<artifactId>s3</artifactId>
+			<scope>compile</scope>
+		</dependency>
+
+		<dependency>
+			<artifactId>netty-nio-client</artifactId>
+			<groupId>software.amazon.awssdk</groupId>
+			<scope>compile</scope>
+		</dependency>
+
+
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-test</artifactId>
+			<scope>test</scope>
+			<exclusions>
+				<exclusion>
+					<groupId>org.junit.vintage</groupId>
+					<artifactId>junit-vintage-engine</artifactId>
+				</exclusion>
+			</exclusions>
+		</dependency>
+
+
+		<dependency>
+			<groupId>io.projectreactor</groupId>
+			<artifactId>reactor-test</artifactId>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-devtools</artifactId>
+			<scope>runtime</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-configuration-processor</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.projectlombok</groupId>
+			<artifactId>lombok</artifactId>
+		</dependency>
+	</dependencies>
+
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.springframework.boot</groupId>
+				<artifactId>spring-boot-maven-plugin</artifactId>
+			</plugin>
+		</plugins>
+	</build>
+
+</project>

aws-reactive/src/main/java/com/baeldung/aws/reactive/s3/DownloadFailedException.java

@@ -0,0 +1,32 @@
+package com.baeldung.aws.reactive.s3;
+
+import java.util.Optional;
+
+import org.springframework.http.HttpStatus;
+
+import lombok.AllArgsConstructor;
+import software.amazon.awssdk.core.SdkResponse;
+import software.amazon.awssdk.http.SdkHttpResponse;
+
+@AllArgsConstructor
+public class DownloadFailedException extends RuntimeException {
+
+    private static final long serialVersionUID = 1L;
+
+    private int statusCode;
+    private Optional<String> statusText;
+
+    public DownloadFailedException(SdkResponse response) {
+
+        SdkHttpResponse httpResponse = response.sdkHttpResponse();
+        if (httpResponse != null) {
+            this.statusCode = httpResponse.statusCode();
+            this.statusText = httpResponse.statusText();
+        } else {
+            this.statusCode = HttpStatus.INTERNAL_SERVER_ERROR.value();
+            this.statusText = Optional.of("UNKNOWN");
+        }
+
+    }
+
+}

aws-reactive/src/main/java/com/baeldung/aws/reactive/s3/DownloadResource.java

@@ -0,0 +1,144 @@
+/**
+ * 
+ */
+package com.baeldung.aws.reactive.s3;
+
+import java.io.InputStream;
+import java.nio.ByteBuffer;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.concurrent.CompletableFuture;
+
+import org.springframework.core.io.buffer.DataBuffer;
+import org.springframework.core.io.buffer.DataBufferUtils;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.ResponseEntity;
+import org.springframework.http.ResponseEntity.BodyBuilder;
+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 lombok.extern.slf4j.Slf4j;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+import software.amazon.awssdk.core.ResponseBytes;
+import software.amazon.awssdk.core.SdkResponse;
+import software.amazon.awssdk.core.async.AsyncResponseTransformer;
+import software.amazon.awssdk.core.async.SdkPublisher;
+import software.amazon.awssdk.core.internal.async.ByteArrayAsyncResponseTransformer;
+import software.amazon.awssdk.http.SdkHttpResponse;
+import software.amazon.awssdk.services.s3.S3AsyncClient;
+import software.amazon.awssdk.services.s3.model.GetObjectRequest;
+import software.amazon.awssdk.services.s3.model.GetObjectResponse;
+
+/**
+ * @author Philippe
+ *
+ */
+@RestController
+@RequestMapping("/inbox")
+@Slf4j
+public class DownloadResource {
+    
+    
+    private final S3AsyncClient s3client;
+    private final S3ClientConfigurarionProperties s3config;
+
+    public DownloadResource(S3AsyncClient s3client, S3ClientConfigurarionProperties s3config) {
+        this.s3client = s3client;
+        this.s3config = s3config;        
+    }
+    
+    
+    @GetMapping(path="/{filekey}")
+    public Mono<ResponseEntity<Flux<ByteBuffer>>> downloadFile(@PathVariable("filekey") String filekey) {
+        
+        GetObjectRequest request = GetObjectRequest.builder()
+          .bucket(s3config.getBucket())
+          .key(filekey)
+          .build();
+        
+        return Mono.fromFuture(s3client.getObject(request,new FluxResponseProvider()))
+          .map( (response) -> {
+            checkResult(response.sdkResponse);
+            String filename = getMetadataItem(response.sdkResponse,"filename",filekey);            
+
+            log.info("[I65] filename={}, length={}",filename, response.sdkResponse.contentLength() );
+            
+            return ResponseEntity.ok()
+              .header(HttpHeaders.CONTENT_TYPE, response.sdkResponse.contentType())
+              .header(HttpHeaders.CONTENT_LENGTH, Long.toString(response.sdkResponse.contentLength()))
+              .header(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=\"" + filename + "\"")
+              .body(response.flux);
+          });
+    }
+
+    /**
+     * Lookup a metadata key in a case-insensitive way.
+     * @param sdkResponse
+     * @param key
+     * @param defaultValue
+     * @return
+     */
+    private String getMetadataItem(GetObjectResponse sdkResponse, String key, String defaultValue) {
+        for( Entry<String, String> entry : sdkResponse.metadata().entrySet()) {
+            if ( entry.getKey().equalsIgnoreCase(key)) {
+                return entry.getValue();
+            }
+        }
+        return defaultValue;
+    }
+
+
+    // Helper used to check return codes from an API call
+    private static void checkResult(GetObjectResponse response) {
+        SdkHttpResponse sdkResponse = response.sdkHttpResponse();
+        if ( sdkResponse != null && sdkResponse.isSuccessful()) {
+            return;
+        }
+        
+        throw new DownloadFailedException(response);
+    }
+    
+    
+    static class FluxResponseProvider implements AsyncResponseTransformer<GetObjectResponse,FluxResponse> {
+        
+        private FluxResponse response;
+
+        @Override
+        public CompletableFuture<FluxResponse> prepare() {
+            response = new FluxResponse();
+            return response.cf;
+        }
+
+        @Override
+        public void onResponse(GetObjectResponse sdkResponse) {            
+            this.response.sdkResponse = sdkResponse;
+        }
+
+        @Override
+        public void onStream(SdkPublisher<ByteBuffer> publisher) {
+            response.flux = Flux.from(publisher);
+            response.cf.complete(response);            
+        }
+
+        @Override
+        public void exceptionOccurred(Throwable error) {
+            response.cf.completeExceptionally(error);
+        }
+        
+    }
+    
+    /**
+     * Holds the API response and stream
+     * @author Philippe
+     */
+    static class FluxResponse {
+        
+        final CompletableFuture<FluxResponse> cf = new CompletableFuture<>();
+        GetObjectResponse sdkResponse;
+        Flux<ByteBuffer> flux;
+    }
+
+}

aws-reactive/src/main/java/com/baeldung/aws/reactive/s3/ReactiveS3Application.java

@@ -0,0 +1,13 @@
+package com.baeldung.aws.reactive.s3;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class ReactiveS3Application {
+
+    public static void main(String[] args) {
+        SpringApplication.run(ReactiveS3Application.class, args);
+    }
+
+}

aws-reactive/src/main/java/com/baeldung/aws/reactive/s3/S3ClientConfigurarionProperties.java

@@ -0,0 +1,28 @@
+package com.baeldung.aws.reactive.s3;
+
+import java.net.URI;
+
+import org.springframework.boot.context.properties.ConfigurationProperties;
+
+import lombok.Data;
+import software.amazon.awssdk.regions.Region;
+
+@ConfigurationProperties(prefix = "aws.s3")
+@Data
+public class S3ClientConfigurarionProperties {
+
+    private Region region = Region.US_EAST_1;
+    private URI endpoint = null;
+
+    private     String accessKeyId;
+    private String secretAccessKey;
+    
+    // Bucket name we'll be using as our backend storage
+    private String bucket;
+
+    // AWS S3 requires that file parts must have at least 5MB, except
+    // for the last part. This may change for other S3-compatible services, so let't
+    // define a configuration property for that
+    private int multipartMinPartSize = 5*1024*1024;
+
+}

aws-reactive/src/main/java/com/baeldung/aws/reactive/s3/S3ClientConfiguration.java

@@ -0,0 +1,65 @@
+package com.baeldung.aws.reactive.s3;
+
+import java.time.Duration;
+
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import software.amazon.awssdk.auth.credentials.AwsBasicCredentials;
+import software.amazon.awssdk.auth.credentials.AwsCredentials;
+import software.amazon.awssdk.auth.credentials.AwsCredentialsProvider;
+import software.amazon.awssdk.auth.credentials.DefaultCredentialsProvider;
+import software.amazon.awssdk.http.async.SdkAsyncHttpClient;
+import software.amazon.awssdk.http.nio.netty.NettyNioAsyncHttpClient;
+import software.amazon.awssdk.services.s3.S3AsyncClient;
+import software.amazon.awssdk.services.s3.S3AsyncClientBuilder;
+import software.amazon.awssdk.services.s3.S3Configuration;
+import software.amazon.awssdk.utils.StringUtils;
+
+@Configuration
+@EnableConfigurationProperties(S3ClientConfigurarionProperties.class)
+public class S3ClientConfiguration {
+
+    @Bean
+    public S3AsyncClient s3client(S3ClientConfigurarionProperties s3props, AwsCredentialsProvider credentialsProvider) {
+
+        SdkAsyncHttpClient httpClient = NettyNioAsyncHttpClient.builder()
+            .writeTimeout(Duration.ZERO)
+            .maxConcurrency(64)
+            .build();
+
+        S3Configuration serviceConfiguration = S3Configuration.builder()
+            .checksumValidationEnabled(false)
+            .chunkedEncodingEnabled(true)
+            .build();
+
+        S3AsyncClientBuilder b = S3AsyncClient.builder()
+            .httpClient(httpClient)
+            .region(s3props.getRegion())
+            .credentialsProvider(credentialsProvider)
+            .serviceConfiguration(serviceConfiguration);
+
+        if (s3props.getEndpoint() != null) {
+            b = b.endpointOverride(s3props.getEndpoint());
+        }
+
+        return b.build();
+    }
+
+    @Bean
+    public AwsCredentialsProvider awsCredentialsProvider(S3ClientConfigurarionProperties s3props) {
+
+        if (StringUtils.isBlank(s3props.getAccessKeyId())) {
+            // Return default provider
+            return DefaultCredentialsProvider.create();
+        } 
+        else {
+            // Return custom credentials provider
+            return () -> {
+                AwsCredentials creds = AwsBasicCredentials.create(s3props.getAccessKeyId(), s3props.getSecretAccessKey());
+                return creds;
+            };
+        }
+    }
+}

aws-reactive/src/main/java/com/baeldung/aws/reactive/s3/UploadFailedException.java

@@ -0,0 +1,32 @@
+package com.baeldung.aws.reactive.s3;
+
+import java.util.Optional;
+
+import org.springframework.http.HttpStatus;
+
+import lombok.AllArgsConstructor;
+import software.amazon.awssdk.core.SdkResponse;
+import software.amazon.awssdk.http.SdkHttpResponse;
+
+@AllArgsConstructor
+public class UploadFailedException extends RuntimeException {
+
+    private static final long serialVersionUID = 1L;
+
+    private int statusCode;
+    private Optional<String> statusText;
+
+    public UploadFailedException(SdkResponse response) {
+
+        SdkHttpResponse httpResponse = response.sdkHttpResponse();
+        if (httpResponse != null) {
+            this.statusCode = httpResponse.statusCode();
+            this.statusText = httpResponse.statusText();
+        } else {
+            this.statusCode = HttpStatus.INTERNAL_SERVER_ERROR.value();
+            this.statusText = Optional.of("UNKNOWN");
+        }
+
+    }
+
+}

aws-reactive/src/main/java/com/baeldung/aws/reactive/s3/UploadResource.java

@@ -0,0 +1,308 @@
+/**
+ * 
+ */
+package com.baeldung.aws.reactive.s3;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.UUID;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.stream.Collector;
+import java.util.stream.Collectors;
+
+import org.reactivestreams.Publisher;
+import org.springframework.core.io.buffer.DataBuffer;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
+import org.springframework.http.codec.multipart.FilePart;
+import org.springframework.http.codec.multipart.Part;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.PutMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestHeader;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestMethod;
+import org.springframework.web.bind.annotation.RestController;
+
+import lombok.Data;
+import lombok.extern.slf4j.Slf4j;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+import software.amazon.awssdk.core.SdkResponse;
+import software.amazon.awssdk.core.async.AsyncRequestBody;
+import software.amazon.awssdk.services.s3.S3AsyncClient;
+import software.amazon.awssdk.services.s3.model.CompleteMultipartUploadRequest;
+import software.amazon.awssdk.services.s3.model.CompleteMultipartUploadResponse;
+import software.amazon.awssdk.services.s3.model.CompletedMultipartUpload;
+import software.amazon.awssdk.services.s3.model.CompletedMultipartUpload.Builder;
+import software.amazon.awssdk.services.s3.model.CompletedPart;
+import software.amazon.awssdk.services.s3.model.CreateMultipartUploadRequest;
+import software.amazon.awssdk.services.s3.model.CreateMultipartUploadResponse;
+import software.amazon.awssdk.services.s3.model.PutObjectRequest;
+import software.amazon.awssdk.services.s3.model.PutObjectResponse;
+import software.amazon.awssdk.services.s3.model.UploadPartRequest;
+import software.amazon.awssdk.services.s3.model.UploadPartResponse;
+
+/**
+ * @author Philippe
+ *
+ */
+@RestController
+@RequestMapping("/inbox")
+@Slf4j
+public class UploadResource {
+
+    private final S3AsyncClient s3client;
+    private final S3ClientConfigurarionProperties s3config;
+
+    public UploadResource(S3AsyncClient s3client, S3ClientConfigurarionProperties s3config) {
+        this.s3client = s3client;
+        this.s3config = s3config;        
+    }
+    
+    /**
+     *  Standard file upload.
+     */
+    @PostMapping
+    public Mono<ResponseEntity<UploadResult>> uploadHandler(@RequestHeader HttpHeaders headers, @RequestBody Flux<ByteBuffer> body) {
+
+        long length = headers.getContentLength();
+        if (length < 0) {
+            throw new UploadFailedException(HttpStatus.BAD_REQUEST.value(), Optional.of("required header missing: Content-Length"));
+        }
+
+        String fileKey = UUID.randomUUID().toString();
+        Map<String, String> metadata = new HashMap<String, String>();
+        MediaType mediaType = headers.getContentType();
+
+        if (mediaType == null) {
+            mediaType = MediaType.APPLICATION_OCTET_STREAM;
+        }
+
+        log.info("[I95] uploadHandler: mediaType{}, length={}", mediaType, length);
+        CompletableFuture<PutObjectResponse> future = s3client
+          .putObject(PutObjectRequest.builder()
+            .bucket(s3config.getBucket())
+            .contentLength(length)
+            .key(fileKey.toString())
+            .contentType(mediaType.toString())
+            .metadata(metadata)
+            .build(), 
+            AsyncRequestBody.fromPublisher(body));
+        
+        return Mono.fromFuture(future)
+          .map((response) -> {
+              checkResult(response);
+              return ResponseEntity
+                .status(HttpStatus.CREATED)
+                .body(new UploadResult(HttpStatus.CREATED, new String[] {fileKey}));
+          });
+    }
+    
+
+    /**
+     * Multipart file upload
+     * @param bucket
+     * @param parts
+     * @param headers
+     * @return
+     */
+    @RequestMapping(consumes = MediaType.MULTIPART_FORM_DATA_VALUE, method = {RequestMethod.POST, RequestMethod.PUT})
+    public Mono<ResponseEntity<UploadResult>> multipartUploadHandler(@RequestHeader HttpHeaders headers, @RequestBody Flux<Part> parts  ) {
+                
+        return parts
+          .ofType(FilePart.class) // We'll ignore other data for now
+          .flatMap((part) -> saveFile(headers, s3config.getBucket(), part))
+          .collect(Collectors.toList())
+          .map((keys) -> ResponseEntity.status(HttpStatus.CREATED)
+            .body(new UploadResult(HttpStatus.CREATED,keys)));
+    }
+
+
+    /**
+     * Save file using a multipart upload. This method does not require any temporary
+     * storage at the REST service
+     * @param headers 
+     * @param bucket Bucket name
+     * @param part Uploaded file
+     * @return
+     */
+    protected Mono<String> saveFile(HttpHeaders headers,String bucket, FilePart part) {
+
+        // Generate a filekey for this upload
+        String filekey = UUID.randomUUID().toString();
+        
+        log.info("[I137] saveFile: filekey={}, filename={}", filekey, part.filename());
+        
+        // Gather metadata
+        Map<String, String> metadata = new HashMap<String, String>();
+        String filename = part.filename();
+        if ( filename == null ) {
+            filename = filekey;
+        }
+           
+        metadata.put("filename", filename);
+        
+        MediaType mt = part.headers().getContentType();
+        if ( mt == null ) {
+            mt = MediaType.APPLICATION_OCTET_STREAM;
+        }
+        
+        // Create multipart upload request
+        CompletableFuture<CreateMultipartUploadResponse> uploadRequest = s3client
+          .createMultipartUpload(CreateMultipartUploadRequest.builder()
+            .contentType(mt.toString())
+            .key(filekey)
+            .metadata(metadata)
+            .bucket(bucket)
+            .build());
+
+        // This variable will hold the upload state that we must keep
+        // around until all uploads complete
+        final UploadState uploadState = new UploadState(bucket,filekey);
+
+        return Mono
+          .fromFuture(uploadRequest)
+          .flatMapMany((response) -> {
+              checkResult(response);              
+              uploadState.uploadId = response.uploadId();
+              log.info("[I183] uploadId={}", response.uploadId());
+              return part.content();
+          })
+          .bufferUntil((buffer) -> {
+              uploadState.buffered += buffer.readableByteCount();
+              if ( uploadState.buffered >= s3config.getMultipartMinPartSize() ) {
+                  log.info("[I173] bufferUntil: returning true, bufferedBytes={}, partCounter={}, uploadId={}", uploadState.buffered, uploadState.partCounter, uploadState.uploadId);
+                  uploadState.buffered = 0;
+                  return true;
+              }
+              else {
+                  return false;
+              }
+          })
+          .map((buffers) -> concatBuffers(buffers))
+          .flatMap((buffer) -> uploadPart(uploadState,buffer))
+          .onBackpressureBuffer()
+          .reduce(uploadState,(state,completedPart) -> {
+              log.info("[I188] completed: partNumber={}, etag={}", completedPart.partNumber(), completedPart.eTag());
+              state.completedParts.put(completedPart.partNumber(), completedPart);              
+              return state;
+          })
+          .flatMap((state) -> completeUpload(state))
+          .map((response) -> {
+              checkResult(response);
+              return  uploadState.filekey;
+          });
+    }
+    
+    private static ByteBuffer concatBuffers(List<DataBuffer> buffers) {
+        log.info("[I198] creating BytBuffer from {} chunks", buffers.size());
+        
+        int partSize = 0;
+        for( DataBuffer b : buffers) {
+            partSize += b.readableByteCount();                  
+        }
+        
+        ByteBuffer partData = ByteBuffer.allocate(partSize);
+        buffers.forEach((buffer) -> {
+           partData.put(buffer.asByteBuffer());
+        });
+        
+        // Reset read pointer to first byte
+        partData.rewind();
+        
+        log.info("[I208] partData: size={}", partData.capacity());
+        return partData;
+        
+    }
+
+    /**
+     * Upload a single file part to the requested bucket
+     * @param uploadState
+     * @param buffer
+     * @return
+     */
+    private Mono<CompletedPart> uploadPart(UploadState uploadState, ByteBuffer buffer) {
+        final int partNumber = ++uploadState.partCounter;
+        log.info("[I218] uploadPart: partNumber={}, contentLength={}",partNumber, buffer.capacity());
+
+        CompletableFuture<UploadPartResponse> request = s3client.uploadPart(UploadPartRequest.builder()
+            .bucket(uploadState.bucket)
+            .key(uploadState.filekey)
+            .partNumber(partNumber)
+            .uploadId(uploadState.uploadId)
+            .contentLength((long) buffer.capacity())
+            .build(), 
+            AsyncRequestBody.fromPublisher(Mono.just(buffer)));
+        
+        return Mono
+          .fromFuture(request)
+          .map((uploadPartResult) -> {              
+              checkResult(uploadPartResult);
+              log.info("[I230] uploadPart complete: part={}, etag={}",partNumber,uploadPartResult.eTag());
+              return CompletedPart.builder()
+                .eTag(uploadPartResult.eTag())
+                .partNumber(partNumber)
+                .build();
+          });
+    }
+    
+    private Mono<CompleteMultipartUploadResponse> completeUpload(UploadState state) {        
+        log.info("[I202] completeUpload: bucket={}, filekey={}, completedParts.size={}", state.bucket, state.filekey, state.completedParts.size());        
+
+        CompletedMultipartUpload multipartUpload = CompletedMultipartUpload.builder()
+            .parts(state.completedParts.values())
+            .build();
+
+        return Mono.fromFuture(s3client.completeMultipartUpload(CompleteMultipartUploadRequest.builder()
+            .bucket(state.bucket)
+            .uploadId(state.uploadId)
+            .multipartUpload(multipartUpload)
+            .key(state.filekey)
+            .build()));
+    }
+    
+
+    /**
+     * check result from an API call.
+     * @param result Result from an API call
+     */
+    private static void checkResult(SdkResponse result) {
+        if (result.sdkHttpResponse() == null || !result.sdkHttpResponse().isSuccessful()) {
+            throw new UploadFailedException(result);
+        }        
+    }
+
+
+    /**
+     * Holds upload state during a multipart upload
+     */
+    static class UploadState {
+        final String bucket;
+        final String filekey;
+
+        String uploadId;
+        int partCounter;
+        Map<Integer, CompletedPart> completedParts = new HashMap<>();
+        int buffered = 0;
+
+        UploadState(String bucket, String filekey) {
+            this.bucket = bucket;
+            this.filekey = filekey;
+        }
+    }
+
+}

aws-reactive/src/main/java/com/baeldung/aws/reactive/s3/UploadResult.java

@@ -0,0 +1,25 @@
+package com.baeldung.aws.reactive.s3;
+
+import java.util.List;
+
+import org.springframework.http.HttpStatus;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+
+@Data
+@AllArgsConstructor
+@Builder
+public class UploadResult {
+    HttpStatus status;
+    String[] keys;
+
+    public UploadResult() {}
+    
+    public UploadResult(HttpStatus status, List<String> keys) {
+        this.status = status;
+        this.keys = keys == null ? new String[] {}: keys.toArray(new String[] {});
+
+    }
+}

aws-reactive/src/main/resources/application-minio.yml

@@ -0,0 +1,15 @@
+
+#
+# Minio profile
+#
+aws:
+  s3:
+    region: sa-east-1
+    endpoint: http://localhost:9000
+    accessKeyId: 8KLF8U60JER4AP23H0A6
+    secretAccessKey: vX4uM7e7nNGPqjcXycVVhceNR7NQkiMQkR9Hoctf
+    bucket: bucket1
+
+  
+    
+    

aws-reactive/src/main/resources/application.yml

@@ -0,0 +1,16 @@
+
+#
+# Configurações de acesso ao Minio
+#
+aws:
+  s3:
+    region: sa-east-1
+# When using AWS, the library will use one of the available
+# credential sources described in the documentation.     
+#    accessKeyId: ****
+#    secretAccessKey: ****
+    bucket: dev1.token.com.br
+    
+    
+    
+    

aws-reactive/src/test/java/com/baeldung/aws/reactive/s3/ReactiveS3ApplicationLiveTest.java

@@ -0,0 +1,85 @@
+package com.baeldung.aws.reactive.s3;
+
+import static org.junit.Assert.assertTrue;
+
+import java.io.File;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
+import org.springframework.boot.test.web.client.TestRestTemplate;
+import org.springframework.boot.web.server.LocalServerPort;
+import org.springframework.core.io.Resource;
+import org.springframework.http.ContentDisposition;
+import org.springframework.http.HttpEntity;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
+import org.springframework.test.context.ActiveProfiles;
+import org.springframework.util.LinkedMultiValueMap;
+import org.springframework.util.MultiValueMap;
+import org.springframework.util.ResourceUtils;
+
+import static org.junit.Assert.*;
+
+@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
+@ActiveProfiles("minio")
+class ReactiveS3ApplicationLiveTest {
+    
+    @Autowired
+    private TestRestTemplate restTemplate;
+    
+    @LocalServerPort
+    private int serverPort;
+    
+
+    @Test
+    void whenUploadSingleFile_thenSuccess() throws Exception {
+        
+        String url = "http://localhost:" + serverPort + "/inbox";        
+        byte[] data = Files.readAllBytes(Paths.get("src/test/resources/testimage1.png"));         
+        UploadResult result = restTemplate.postForObject(url, data , UploadResult.class);
+        
+        assertEquals("Expected CREATED (202)", result.getStatus(), HttpStatus.CREATED );
+        
+    }
+    
+    @Test
+    void whenUploadMultipleFiles_thenSuccess() throws Exception {
+        
+        
+        MultiValueMap<String, Object> body = new LinkedMultiValueMap<>();
+        addFileEntity("f1", body, new File("src/test/resources/testimage1.png"));
+        addFileEntity("f2", body, new File("src/test/resources/testimage2.png"));
+        
+        HttpEntity<MultiValueMap<String, Object>> requestEntity = new HttpEntity<>(body);
+        String url = "http://localhost:" + serverPort + "/inbox";        
+        
+        ResponseEntity<UploadResult> result = restTemplate.postForEntity(url, requestEntity, UploadResult.class);
+
+        assertEquals("Http Code",HttpStatus.CREATED, result.getStatusCode() );
+        assertEquals("File keys",2, result.getBody().getKeys().length);
+        
+    }
+
+    private void addFileEntity(String name, MultiValueMap<String, Object> body, File file) throws Exception {
+
+        byte[] data = Files.readAllBytes(file.toPath());
+        MultiValueMap<String, String> headers = new LinkedMultiValueMap<>();
+        ContentDisposition contentDispositionHeader = ContentDisposition.builder("form-data")
+          .name(name)
+          .filename(file.getName())
+          .build();
+        
+        headers.add(HttpHeaders.CONTENT_DISPOSITION, contentDispositionHeader.toString());
+        
+        HttpEntity<byte[]> fileEntity = new HttpEntity<>(data, headers);
+        body.add(name, fileEntity);
+    }
+
+    
+}

aws/pom.xml

@@ -1,5 +1,6 @@
+<?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">
+         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>aws</artifactId>
     <version>0.1.0-SNAPSHOT</version>
@@ -18,7 +19,7 @@
             <artifactId>aws-java-sdk</artifactId>
             <version>${aws-java-sdk.version}</version>
         </dependency>
-       <dependency>
+        <dependency>
             <groupId>org.mockito</groupId>
             <artifactId>mockito-core</artifactId>
             <version>${mockito-core.version}</version>

axon/pom.xml

@@ -1,6 +1,6 @@
 <?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">
+         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>axon</artifactId>
     <name>axon</name>

azure/pom.xml

@@ -1,16 +1,16 @@
 <?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">
+         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>azure</artifactId>
     <version>0.1</version>
     <name>azure</name>
-    <description>Demo project for Spring Boot on Azure</description>
     <packaging>war</packaging>
+    <description>Demo project for Spring Boot on Azure</description>
 
     <parent>
-        <artifactId>parent-boot-2</artifactId>
         <groupId>com.baeldung</groupId>
+        <artifactId>parent-boot-2</artifactId>
         <version>0.0.1-SNAPSHOT</version>
         <relativePath>../parent-boot-2</relativePath>
     </parent>
@@ -43,7 +43,6 @@
             <artifactId>mysql-connector-java</artifactId>
             <scope>runtime</scope>
         </dependency>
-
     </dependencies>
 
     <build>

bazel/bazelapp/README.md

@@ -0,0 +1,3 @@
+### Relevant Articles:
+
+- [Building Java Applications with Bazel](https://www.baeldung.com/bazel-build-tool)

bazel/bazelapp/pom.xml

@@ -5,10 +5,10 @@
     <modelVersion>4.0.0</modelVersion>
     <artifactId>bazelapp</artifactId>
     <name>bazelapp</name>
-	
+
     <parent>
-        <artifactId>bazel</artifactId>
         <groupId>com.baeldung</groupId>
+        <artifactId>bazel</artifactId>
         <version>1.0.0-SNAPSHOT</version>
     </parent>
 

bazel/bazelgreeting/README.md

@@ -0,0 +1,3 @@
+### Relevant Articles:
+
+- [Building Java Applications with Bazel](https://www.baeldung.com/bazel-build-tool)

bazel/bazelgreeting/pom.xml

@@ -5,12 +5,11 @@
     <modelVersion>4.0.0</modelVersion>
     <artifactId>bazelgreeting</artifactId>
     <name>bazelgreeting</name>
-	
+
     <parent>
-        <artifactId>bazel</artifactId>
         <groupId>com.baeldung</groupId>
+        <artifactId>bazel</artifactId>
         <version>1.0.0-SNAPSHOT</version>
     </parent>
 
-
 </project>

bazel/pom.xml

@@ -4,19 +4,18 @@
          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>bazel</artifactId>
-    <packaging>pom</packaging>
     <name>bazel</name>
-	
+    <packaging>pom</packaging>
+
     <parent>
-        <artifactId>parent-modules</artifactId>
         <groupId>com.baeldung</groupId>
+        <artifactId>parent-modules</artifactId>
         <version>1.0.0-SNAPSHOT</version>
     </parent>
-	
+
     <modules>
         <module>bazelgreeting</module>
         <module>bazelapp</module>
     </modules>
 
-
 </project>

blade/pom.xml

@@ -1,16 +1,16 @@
+<?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"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
-
     <modelVersion>4.0.0</modelVersion>
     <artifactId>blade</artifactId>
     <name>blade</name>
 
-	<parent>
+    <parent>
-		<groupId>com.baeldung</groupId>
+        <groupId>com.baeldung</groupId>
-		<artifactId>parent-modules</artifactId>
+        <artifactId>parent-modules</artifactId>
-		<version>1.0.0-SNAPSHOT</version>
+        <version>1.0.0-SNAPSHOT</version>
-	</parent>
+    </parent>
 
     <dependencies>
         <dependency>
@@ -65,8 +65,9 @@
             <scope>test</scope>
         </dependency>
     </dependencies>
+
     <build>
-        <finalName>sample-blade-app</finalName>
+        <finalName>blade</finalName>
         <plugins>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
@@ -121,7 +122,6 @@
                 </executions>
             </plugin>
 
-
             <plugin>
                 <artifactId>maven-assembly-plugin</artifactId>
                 <version>3.1.0</version>
@@ -149,17 +149,18 @@
             </plugin>
         </plugins>
     </build>
-	
+
     <properties>
-		<blade-mvc.version>2.0.14.RELEASE</blade-mvc.version>
+        <blade-mvc.version>2.0.14.RELEASE</blade-mvc.version>
-		<bootstrap.version>4.2.1</bootstrap.version>
+        <bootstrap.version>4.2.1</bootstrap.version>
-		<commons-lang3.version>3.8.1</commons-lang3.version>
+        <commons-lang3.version>3.8.1</commons-lang3.version>
-		<lombok.version>1.18.4</lombok.version>
+        <lombok.version>1.18.4</lombok.version>
-		<httpclient.version>4.5.6</httpclient.version>
+        <httpclient.version>4.5.6</httpclient.version>
-		<httpmime.version>4.5.6</httpmime.version>
+        <httpmime.version>4.5.6</httpmime.version>
-		<httpcore.version>4.4.10</httpcore.version>
+        <httpcore.version>4.4.10</httpcore.version>
-		<assertj-core.version>3.11.1</assertj-core.version>
+        <assertj-core.version>3.11.1</assertj-core.version>
-		<maven-failsafe-plugin.version>3.0.0-M3</maven-failsafe-plugin.version>
+        <maven-failsafe-plugin.version>3.0.0-M3</maven-failsafe-plugin.version>
-		<process-exec-maven-plugin.version>0.7</process-exec-maven-plugin.version>
+        <process-exec-maven-plugin.version>0.7</process-exec-maven-plugin.version>
     </properties>
+
 </project>

bootique/pom.xml

@@ -1,5 +1,6 @@
+<?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/maven-v4_0_0.xsd">
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.baeldung.bootique</groupId>
     <artifactId>bootique</artifactId>

cas/cas-secured-app/pom.xml

@@ -1,15 +1,15 @@
 <?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">
+         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>cas-secured-app</artifactId>
     <name>cas-secured-app</name>
-    <description>Demo project for CAS</description>
     <packaging>jar</packaging>
+    <description>Demo project for CAS</description>
 
     <parent>
-        <artifactId>parent-boot-1</artifactId>
         <groupId>com.baeldung</groupId>
+        <artifactId>parent-boot-1</artifactId>
         <version>0.0.1-SNAPSHOT</version>
         <relativePath>../../parent-boot-1</relativePath>
     </parent>

cas/cas-server/README.md

@@ -98,4 +98,8 @@ Invokes the CAS Command Line Shell. For a list of commands either use no argumen
 
 ```bash
 ./build.sh cli
-```
+```
+
+### Relevant Articles:
+
+- [CAS SSO With Spring Security](https://www.baeldung.com/spring-security-cas-sso)

cas/cas-server/pom.xml

@@ -1,6 +1,6 @@
 <?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 ">
+         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>cas-server</artifactId>
     <version>1.0</version>
@@ -8,12 +8,12 @@
     <packaging>war</packaging>
 
     <parent>
-        <artifactId>parent-boot-1</artifactId>
         <groupId>com.baeldung</groupId>
+        <artifactId>parent-boot-1</artifactId>
         <version>0.0.1-SNAPSHOT</version>
         <relativePath>../../parent-boot-1</relativePath>
     </parent>
-    
+
     <dependencies>
         <dependency>
             <groupId>org.apereo.cas</groupId>
@@ -198,7 +198,7 @@
 
         <wrapper-maven-plugin.version>0.0.4</wrapper-maven-plugin.version>
         <maven-war-plugin.version>2.6</maven-war-plugin.version>
-        
+
         <echo-maven-plugin.version>0.3.0</echo-maven-plugin.version>
         <pgpverify-maven-plugin.version>1.1.0</pgpverify-maven-plugin.version>
     </properties>

cas/pom.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://maven.apache.org/POM/4.0.0"
-    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+         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>cas</artifactId>
     <name>cas</name>

cdi/pom.xml

@@ -5,7 +5,7 @@
     <artifactId>cdi</artifactId>
     <version>1.0-SNAPSHOT</version>
     <name>cdi</name>
-    
+
     <parent>
         <groupId>com.baeldung</groupId>
         <artifactId>parent-spring-4</artifactId>
@@ -23,7 +23,7 @@
             <groupId>org.jboss.weld.se</groupId>
             <artifactId>weld-se-core</artifactId>
             <version>${weld-se-core.version}</version>
-        </dependency>  
+        </dependency>
         <dependency>
             <groupId>org.hamcrest</groupId>
             <artifactId>hamcrest-core</artifactId>
@@ -53,7 +53,7 @@
             <scope>test</scope>
         </dependency>
     </dependencies>
-	
+
     <properties>
         <cdi-api.version>2.0.SP1</cdi-api.version>
         <weld-se-core.version>3.0.5.Final</weld-se-core.version>
@@ -61,4 +61,5 @@
         <assertj-core.version>3.10.0</assertj-core.version>
         <spring.version>5.1.2.RELEASE</spring.version>
     </properties>
+
 </project>

checker-plugin/pom.xml

@@ -1,3 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
 <project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://maven.apache.org/POM/4.0.0"
          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>

cloud-foundry-uaa/cf-uaa-oauth2-client/pom.xml

@@ -8,8 +8,8 @@
     <description>Demo project for Spring Boot</description>
 
     <parent>
-        <artifactId>parent-boot-2</artifactId>
         <groupId>com.baeldung</groupId>
+        <artifactId>parent-boot-2</artifactId>
         <version>0.0.1-SNAPSHOT</version>
         <relativePath>../../parent-boot-2</relativePath>
     </parent>
@@ -33,5 +33,5 @@
             </plugin>
         </plugins>
     </build>
-	
+
 </project>

cloud-foundry-uaa/cf-uaa-oauth2-resource-server/pom.xml

@@ -8,12 +8,12 @@
     <description>Demo project for Spring Boot</description>
 
     <parent>
-        <artifactId>parent-boot-2</artifactId>
         <groupId>com.baeldung</groupId>
+        <artifactId>parent-boot-2</artifactId>
         <version>0.0.1-SNAPSHOT</version>
         <relativePath>../../parent-boot-2</relativePath>
     </parent>
-	
+
     <dependencies>
         <dependency>
             <groupId>org.springframework.boot</groupId>

code-generation/pom.xml

@@ -1,5 +1,6 @@
+<?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/maven-v4_0_0.xsd">
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>code-generation</artifactId>
     <version>1.0</version>

core-groovy-2/pom.xml

@@ -180,9 +180,10 @@
         <junit.platform.version>1.0.0</junit.platform.version>
         <hsqldb.version>2.4.0</hsqldb.version>
         <spock-core.version>1.1-groovy-2.4</spock-core.version>
-        <groovy-wslite.version>1.1.3</groovy-wslite.version>        
+        <groovy-wslite.version>1.1.3</groovy-wslite.version>
         <logback.version>1.2.3</logback.version>
         <groovy.version>2.5.7</groovy.version>
     </properties>
+
 </project>
 

core-groovy-collections/pom.xml

@@ -1,6 +1,6 @@
 <?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">
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-groovy-collections</artifactId>
     <version>1.0-SNAPSHOT</version>
@@ -101,11 +101,11 @@
                 <artifactId>maven-surefire-plugin</artifactId>
                 <version>2.20.1</version>
                 <configuration>
-                <useFile>false</useFile>
+                    <useFile>false</useFile>
-                <includes>
+                    <includes>
-                    <include>**/*Test.java</include>
+                        <include>**/*Test.java</include>
-                    <include>**/*Spec.java</include>
+                        <include>**/*Spec.java</include>
-                </includes>
+                    </includes>
                 </configuration>
             </plugin>
         </plugins>
@@ -127,5 +127,6 @@
         <spock-core.version>1.1-groovy-2.4</spock-core.version>
         <gmavenplus-plugin.version>1.6</gmavenplus-plugin.version>
     </properties>
+
 </project>
 

core-groovy/pom.xml

@@ -1,6 +1,6 @@
 <?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">
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-groovy</artifactId>
     <version>1.0-SNAPSHOT</version>
@@ -116,5 +116,6 @@
         <spock-core.version>1.1-groovy-2.4</spock-core.version>
         <gmavenplus-plugin.version>1.6</gmavenplus-plugin.version>
     </properties>
+
 </project>
 

core-java-modules/core-java-10/pom.xml

@@ -1,7 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>
 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+         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>core-java-10</artifactId>
     <version>0.1.0-SNAPSHOT</version>
     <name>core-java-10</name>

core-java-modules/core-java-11/pom.xml

@@ -1,9 +1,8 @@
-<project
+<?xml version="1.0" encoding="UTF-8"?>
-        xmlns="http://maven.apache.org/POM/4.0.0"
+<project xmlns="http://maven.apache.org/POM/4.0.0"
-        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         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">
+         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>core-java-11</artifactId>
     <version>0.1.0-SNAPSHOT</version>
     <name>core-java-11</name>
@@ -110,4 +109,5 @@
         <uberjar.name>benchmarks</uberjar.name>
         <jmh.version>1.22</jmh.version>
     </properties>
+
 </project>

core-java-modules/core-java-12/pom.xml

@@ -1,9 +1,8 @@
 <?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"
+         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">
+         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>core-java-12</artifactId>
     <version>0.1.0-SNAPSHOT</version>
     <name>core-java-12</name>

core-java-modules/core-java-13/pom.xml

@@ -0,0 +1,58 @@
+<?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>core-java-13</artifactId>
+    <version>0.1.0-SNAPSHOT</version>
+    <name>core-java-13</name>
+    <packaging>jar</packaging>
+    <url>http://maven.apache.org</url>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+        <relativePath>../../</relativePath>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${assertj.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>${maven-compiler-plugin.version}</version>
+                <configuration>
+                    <source>${maven.compiler.source.version}</source>
+                    <target>${maven.compiler.target.version}</target>
+                    <release>13</release>
+                    <compilerArgs>--enable-preview</compilerArgs>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-surefire-plugin</artifactId>
+                <version>3.0.0-M3</version>
+                <configuration>
+                    <argLine>--enable-preview</argLine>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+    <properties>
+        <maven.compiler.source.version>13</maven.compiler.source.version>
+        <maven.compiler.target.version>13</maven.compiler.target.version>
+        <assertj.version>3.6.1</assertj.version>
+    </properties>
+
+</project>

core-java-modules/core-java-13/src/test/java/com/baeldung/switchExpression/SwitchExpressionsUnitTest.java

@@ -0,0 +1,76 @@
+package com.baeldung.switchExpression;
+
+import static java.time.Month.AUGUST;
+import static java.time.Month.JUNE;
+
+import static org.junit.Assert.assertEquals;
+
+import java.time.Month;
+import java.util.function.Function;
+
+import org.junit.Test;
+
+public class SwitchExpressionsUnitTest {
+
+  @Test
+  @SuppressWarnings ("preview")
+  public void whenSwitchingOverMonthJune_thenWillReturn3() {
+
+    var month = JUNE;
+
+    var result = switch (month) {
+      case JANUARY, JUNE, JULY -> 3;
+      case FEBRUARY, SEPTEMBER, OCTOBER, NOVEMBER, DECEMBER -> 1;
+      case MARCH, MAY, APRIL -> 2;
+      default -> 0;
+    };
+
+    assertEquals(result, 3);
+  }
+
+  @Test
+  @SuppressWarnings ("preview")
+  public void whenSwitchingOverMonthAugust_thenWillReturn24() {
+    var month = AUGUST;
+
+    var result = switch (month) {
+      case JANUARY, JUNE, JULY -> 3;
+      case FEBRUARY, SEPTEMBER, OCTOBER, NOVEMBER, DECEMBER -> 1;
+      case MARCH, MAY, APRIL, AUGUST -> {
+        int monthLength = month.toString().length();
+        yield monthLength * 4;
+      }
+      default -> 0;
+    };
+
+    assertEquals(24, result);
+  }
+
+  @Test
+  @SuppressWarnings ("preview")
+  public void whenSwitchingOverMonthJanuary_thenWillReturn3() {
+
+    Function<Month, Integer> func = (month) -> {
+      switch (month) {
+        case JANUARY, JUNE, JULY -> { return 3; }
+        default -> { return 0; }
+      }
+    };
+
+    assertEquals(Integer.valueOf(3), func.apply(Month.JANUARY));
+  }
+
+  @Test
+  @SuppressWarnings ("preview")
+  public void whenSwitchingOverMonthAugust_thenWillReturn2() {
+    var month = AUGUST;
+
+    var result = switch (month) {
+      case JANUARY, JUNE, JULY -> 3;
+      case FEBRUARY, SEPTEMBER, OCTOBER, NOVEMBER, DECEMBER -> 1;
+      case MARCH, MAY, APRIL, AUGUST -> 2;
+    };
+
+    assertEquals(result, 2);
+  }
+}