Merge pull request #1 from eugenp/master

Updated

.gitignore

@@ -65,6 +65,7 @@ core-java-io/target_link.txt
 core-java/src/main/java/com/baeldung/manifest/MANIFEST.MF
 ethereum/logs/
 jmeter/src/main/resources/*-JMeter.csv
+ninja/devDb.mv.db
 
 **/node_modules/
 **/dist
@@ -72,8 +73,6 @@ jmeter/src/main/resources/*-JMeter.csv
 **/out-tsc
 **/nbproject/
 **/nb-configuration.xml
-core-scala/.cache-main
-core-scala/.cache-tests
 
 
 persistence-modules/hibernate5/transaction.log

README.md

@@ -22,10 +22,38 @@ This project is **a collection of small and focused tutorials** - each covering
 A strong focus of these is, of course, the Spring Framework - Spring, Spring Boot and Spring Security. 
 In additional to Spring, the modules here are covering a number of aspects in Java. 
 
+Profile based segregation
+====================
+
+We are using maven build profiles to segregate the huge list of individual projects we have in our repository.
+
+The projects are broadly divided into 3 list: first, second and heavy. 
+
+Next, they are segregated further on the basis of tests that we want to execute.
+
+Therefore, we have a total of 6 profiles:
+
+| Profile                 | Includes                    | Type of test enabled |
+| ----------------------- | --------------------------- | -------------------- |
+| default-first           | First set of projects       | *UnitTest            |
+| integration-lite-first  | First set of projects       | *IntegrationTest     |
+| default-second          | Second set of projects      | *UnitTest            |
+| integration-lite-second | Second set of projects      | *IntegrationTest     |
+| default-heavy           | Heavy/long running projects | *UnitTest            |
+| integration-heavy       | Heavy/long running projects | *IntegrationTest     |
 
 Building the project
 ====================
-To do the full build, do: `mvn clean install`
+
+Though it should not be needed often to build the entire repository at once because we are usually concerned with a specific module.
+
+But if we want to, we can invoke the below command from the root of the repository if we want to build the entire repository with only Unit Tests enabled:
+
+`mvn clean install -Pdefault-first,default-second,default-heavy`
+
+or if we want to build the entire repository with Integration Tests enabled, we can do:
+
+`mvn clean install -Pintegration-lite-first,integration-lite-second,integration-heavy`
 
 
 Building a single module
@@ -46,8 +74,18 @@ When you're working with an individual module, there's no need to import all of
 
 Running Tests
 =============
-The command `mvn clean install` will run the unit tests in a module.
-To run the integration tests, use the command `mvn clean install -Pintegration-lite-first`
+The command `mvn clean install` from within a module will run the unit tests in that module.
+For Spring modules this will also run the `SpringContextTest` if present.
+
+To run the integration tests, use the command:
+
+`mvn clean install -Pintegration-lite-first` or 
+
+`mvn clean install -Pintegration-lite-second` or 
+
+`mvn clean install -Pintegration-heavy`
+
+depending on the list where our module exists
 
 
 

akka-http/pom.xml

@@ -1,7 +1,8 @@
 <?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">
+<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">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>akka-http</artifactId>
     <name>akka-http</name>

akka-http/src/test/java/com/baeldung/akkahttp/UserServerUnitTest.java

@@ -7,6 +7,8 @@ import akka.http.javadsl.model.HttpEntities;
 import akka.http.javadsl.model.HttpRequest;
 import akka.http.javadsl.testkit.JUnitRouteTest;
 import akka.http.javadsl.testkit.TestRoute;
+
+import org.junit.Ignore;
 import org.junit.Test;
 
 public class UserServerUnitTest extends JUnitRouteTest {
@@ -17,6 +19,7 @@ public class UserServerUnitTest extends JUnitRouteTest {
 
   TestRoute appRoute = testRoute(new UserServer(userActorRef).routes());
 
+  @Ignore
   @Test
   public void whenRequest_thenActorResponds() {
 
@@ -28,10 +31,10 @@ public class UserServerUnitTest extends JUnitRouteTest {
             .assertStatusCode(404);
 
     appRoute.run(HttpRequest.DELETE("/users/1"))
-            .assertStatusCode(200);
+            .assertStatusCode(405);
 
     appRoute.run(HttpRequest.DELETE("/users/42"))
-            .assertStatusCode(200);
+            .assertStatusCode(405);
 
     appRoute.run(HttpRequest.POST("/users")
             .withEntity(HttpEntities.create(ContentTypes.APPLICATION_JSON, zaphod())))

akka-streams/pom.xml

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>akka-streams</artifactId>
     <name>akka-streams</name>

algorithms-genetic/pom.xml

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>algorithms-genetic</artifactId>
     <version>0.0.1-SNAPSHOT</version>

algorithms-miscellaneous-1/pom.xml

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>algorithms-miscellaneous-1</artifactId>
     <version>0.0.1-SNAPSHOT</version>
@@ -64,7 +66,7 @@
             <plugin>
                 <groupId>org.codehaus.mojo</groupId>
                 <artifactId>cobertura-maven-plugin</artifactId>
-                <version>2.7</version>
+                <version>${cobertura.plugin.version}</version>
                 <configuration>
                     <instrumentation>
                         <ignores>
@@ -85,6 +87,7 @@
         <commons-codec.version>1.11</commons-codec.version>
         <guava.version>27.0.1-jre</guava.version>
         <combinatoricslib3.version>3.3.0</combinatoricslib3.version>
+        <cobertura.plugin.version>2.7</cobertura.plugin.version>
     </properties>
 
 </project>

algorithms-miscellaneous-2/README.md

@@ -13,4 +13,5 @@ This module contains articles about algorithms. Some classes of algorithms, e.g.
 - [Create a Sudoku Solver in Java](https://www.baeldung.com/java-sudoku)
 - [Displaying Money Amounts in Words](https://www.baeldung.com/java-money-into-words)
 - [A Collaborative Filtering Recommendation System in Java](https://www.baeldung.com/java-collaborative-filtering-recommendations)
+- [Implementing A* Pathfinding in Java](https://www.baeldung.com/java-a-star-pathfinding)
 - More articles: [[<-- prev]](/../algorithms-miscellaneous-1) [[next -->]](/../algorithms-miscellaneous-3)

algorithms-miscellaneous-2/pom.xml

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>algorithms-miscellaneous-2</artifactId>
     <version>0.0.1-SNAPSHOT</version>

algorithms-miscellaneous-2/src/main/java/com/baeldung/algorithms/slope_one/SlopeOne.java

@@ -98,7 +98,7 @@ public class SlopeOne {
             for (Item j : InputData.items) {
                 if (e.getValue().containsKey(j)) {
                     clean.put(j, e.getValue().get(j));
-                } else {
+                } else if (!clean.containsKey(j)) {
                     clean.put(j, -1.0);
                 }
             }

algorithms-miscellaneous-3/README.md

@@ -13,6 +13,5 @@ This module contains articles about algorithms. Some classes of algorithms, e.g.
 - [Checking if a Java Graph has a Cycle](https://www.baeldung.com/java-graph-has-a-cycle)
 - [A Guide to the Folding Technique in Java](https://www.baeldung.com/folding-hashing-technique)
 - [Creating a Triangle with for Loops in Java](https://www.baeldung.com/java-print-triangle)
-- [Efficient Word Frequency Calculator in Java](https://www.baeldung.com/java-word-frequency)
 - [The K-Means Clustering Algorithm in Java](https://www.baeldung.com/java-k-means-clustering-algorithm)
 - More articles: [[<-- prev]](/algorithms-miscellaneous-2) [[next -->]](/algorithms-miscellaneous-4)

algorithms-miscellaneous-3/pom.xml

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>algorithms-miscellaneous-3</artifactId>
     <version>0.0.1-SNAPSHOT</version>
@@ -46,13 +48,13 @@
         <dependency>
             <groupId>org.apache.commons</groupId>
             <artifactId>commons-lang3</artifactId>
-            <version>3.8.1</version>
+            <version>${commons.lang3.version}</version>
         </dependency>
 
         <dependency>
             <groupId>pl.pragmatists</groupId>
             <artifactId>JUnitParams</artifactId>
-            <version>1.1.0</version>
+            <version>${JUnitParams.version}</version>
             <scope>test</scope>
         </dependency>
         <dependency>
@@ -91,6 +93,8 @@
         <retrofit.version>2.6.0</retrofit.version>
         <jmh-core.version>1.19</jmh-core.version>
         <jmh-generator.version>1.19</jmh-generator.version>
+        <commons.lang3.version>3.8.1</commons.lang3.version>
+        <JUnitParams.version>1.1.0</JUnitParams.version>
     </properties>
 
 </project>

algorithms-miscellaneous-4/pom.xml

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>algorithms-miscellaneous-4</artifactId>
     <version>0.0.1-SNAPSHOT</version>

algorithms-miscellaneous-5/README.md

@@ -10,6 +10,14 @@ This module contains articles about algorithms. Some classes of algorithms, e.g.
 - [Find If Two Numbers Are Relatively Prime in Java](https://www.baeldung.com/java-two-relatively-prime-numbers)
 - [Knapsack Problem Implementation in Java](https://www.baeldung.com/java-knapsack)
 - [How to Determine if a Binary Tree is Balanced](https://www.baeldung.com/java-balanced-binary-tree)
-- [The Caesar Cipher in Java](https://www.baeldung.com/java-caesar-cipher)
 - [Overview of Combinatorial Problems in Java](https://www.baeldung.com/java-combinatorial-algorithms)
+- [Prim’s Algorithm](https://www.baeldung.com/java-prim-algorithm)
+- [Maximum Subarray Problem](https://www.baeldung.com/java-maximum-subarray)
+- [How to Merge Two Sorted Arrays](https://www.baeldung.com/java-merge-sorted-arrays)
+- [Median of Stream of Integers using Heap](https://www.baeldung.com/java-stream-integers-median-using-heap)
+- [Kruskal’s Algorithm for Spanning Trees](https://www.baeldung.com/java-spanning-trees-kruskal)
+- [Balanced Brackets Algorithm in Java](https://www.baeldung.com/java-balanced-brackets-algorithm)
+- [Efficiently Merge Sorted Java Sequences](https://www.baeldung.com/java-merge-sorted-sequences)
+- [Introduction to Greedy Algorithms with Java](https://www.baeldung.com/java-greedy-algorithms)
+- [The Caesar Cipher in Java](https://www.baeldung.com/java-caesar-cipher)
 - More articles: [[<-- prev]](/../algorithms-miscellaneous-4)

algorithms-miscellaneous-5/pom.xml

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>algorithms-miscellaneous-5</artifactId>
     <version>0.0.1-SNAPSHOT</version>
@@ -37,7 +39,12 @@
         <dependency>
             <groupId>com.google.guava</groupId>
             <artifactId>guava</artifactId>
-            <version>28.1-jre</version>
+            <version>${guava.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.platform</groupId>
+            <artifactId>junit-platform-commons</artifactId>
+            <version>${junit.platform.version}</version>
         </dependency>
 
         <dependency>
@@ -65,6 +72,8 @@
         <org.assertj.core.version>3.9.0</org.assertj.core.version>
         <commons-codec.version>1.11</commons-codec.version>
         <commons-math3.version>3.6.1</commons-math3.version>
+        <guava.version>28.1-jre</guava.version>
+        <junit.platform.version>1.6.0</junit.platform.version>
     </properties>
 
 </project>

algorithms-miscellaneous-5/src/main/java/com/baeldung/algorithms/balancedbrackets/BalancedBracketsUsingDeque.java

@@ -0,0 +1,36 @@
+package com.baeldung.algorithms.balancedbrackets;
+
+import java.util.Deque;
+import java.util.LinkedList;
+
+public class BalancedBracketsUsingDeque {
+
+    public boolean isBalanced(String str) {
+        if (null == str || ((str.length() % 2) != 0)) {
+            return false;
+        } else {
+            char[] ch = str.toCharArray();
+            for (char c : ch) {
+                if (!(c == '{' || c == '[' || c == '(' || c == '}' || c == ']' || c == ')')) {
+                    return false;
+                }
+
+            }
+        }
+
+        Deque<Character> deque = new LinkedList<>();
+        for (char ch : str.toCharArray()) {
+            if (ch == '{' || ch == '[' || ch == '(') {
+                deque.addFirst(ch);
+            } else {
+                if (!deque.isEmpty() && ((deque.peekFirst() == '{' && ch == '}') || (deque.peekFirst() == '[' && ch == ']') || (deque.peekFirst() == '(' && ch == ')'))) {
+                    deque.removeFirst();
+                } else {
+                    return false;
+                }
+            }
+        }
+
+        return true;
+    }
+}

algorithms-miscellaneous-5/src/main/java/com/baeldung/algorithms/balancedbrackets/BalancedBracketsUsingString.java

@@ -0,0 +1,27 @@
+package com.baeldung.algorithms.balancedbrackets;
+
+public class BalancedBracketsUsingString {
+
+    public boolean isBalanced(String str) {
+        if (null == str || ((str.length() % 2) != 0)) {
+            return false;
+        } else {
+            char[] ch = str.toCharArray();
+            for (char c : ch) {
+                if (!(c == '{' || c == '[' || c == '(' || c == '}' || c == ']' || c == ')')) {
+                    return false;
+                }
+
+            }
+        }
+
+        while (str.contains("()") || str.contains("[]") || str.contains("{}")) {
+            str = str.replaceAll("\\(\\)", "")
+                .replaceAll("\\[\\]", "")
+                .replaceAll("\\{\\}", "");
+        }
+        return (str.length() == 0);
+
+    }
+
+}

algorithms-miscellaneous-5/src/test/java/com/baeldung/algorithms/balancedbrackets/BalancedBracketsUsingDequeUnitTest.java

@@ -0,0 +1,76 @@
+package com.baeldung.algorithms.balancedbrackets;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class BalancedBracketsUsingDequeUnitTest {
+    private BalancedBracketsUsingDeque balancedBracketsUsingDeque;
+
+    @Before
+    public void setup() {
+        balancedBracketsUsingDeque = new BalancedBracketsUsingDeque();
+    }
+
+    @Test
+    public void givenNullInput_whenCheckingForBalance_shouldReturnFalse() {
+        boolean result = balancedBracketsUsingDeque.isBalanced(null);
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    public void givenEmptyString_whenCheckingForBalance_shouldReturnTrue() {
+        boolean result = balancedBracketsUsingDeque.isBalanced("");
+        assertThat(result).isTrue();
+    }
+
+    @Test
+    public void givenInvalidCharacterString_whenCheckingForBalance_shouldReturnFalse() {
+        boolean result = balancedBracketsUsingDeque.isBalanced("abc[](){}");
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    public void givenOddLengthString_whenCheckingForBalance_shouldReturnFalse() {
+        boolean result = balancedBracketsUsingDeque.isBalanced("{{[]()}}}");
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    public void givenEvenLengthString_whenCheckingForBalance_shouldReturnFalse() {
+        boolean result = balancedBracketsUsingDeque.isBalanced("{{[]()}}}}");
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    public void givenEvenLengthUnbalancedString_whenCheckingForBalance_shouldReturnFalse() {
+        boolean result = balancedBracketsUsingDeque.isBalanced("{[(])}");
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    public void givenEvenLengthBalancedString_whenCheckingForBalance_shouldReturnTrue() {
+        boolean result = balancedBracketsUsingDeque.isBalanced("{[()]}");
+        assertThat(result).isTrue();
+    }
+
+    @Test
+    public void givenBalancedString_whenCheckingForBalance_shouldReturnTrue() {
+        boolean result = balancedBracketsUsingDeque.isBalanced("{{[[(())]]}}");
+        assertThat(result).isTrue();
+    }
+
+    @Test
+    public void givenAnotherBalancedString_whenCheckingForBalance_shouldReturnTrue() {
+        boolean result = balancedBracketsUsingDeque.isBalanced("{{([])}}");
+        assertThat(result).isTrue();
+    }
+
+    @Test
+    public void givenUnBalancedString_whenCheckingForBalance_shouldReturnFalse() {
+        boolean result = balancedBracketsUsingDeque.isBalanced("{{)[](}}");
+        assertThat(result).isFalse();
+    }
+
+}

algorithms-miscellaneous-5/src/test/java/com/baeldung/algorithms/balancedbrackets/BalancedBracketsUsingStringUnitTest.java

@@ -0,0 +1,76 @@
+package com.baeldung.algorithms.balancedbrackets;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class BalancedBracketsUsingStringUnitTest {
+    private BalancedBracketsUsingString balancedBracketsUsingString;
+
+    @Before
+    public void setup() {
+        balancedBracketsUsingString = new BalancedBracketsUsingString();
+    }
+
+    @Test
+    public void givenNullInput_whenCheckingForBalance_shouldReturnFalse() {
+        boolean result = balancedBracketsUsingString.isBalanced(null);
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    public void givenEmptyString_whenCheckingForBalance_shouldReturnTrue() {
+        boolean result = balancedBracketsUsingString.isBalanced("");
+        assertThat(result).isTrue();
+    }
+
+    @Test
+    public void givenInvalidCharacterString_whenCheckingForBalance_shouldReturnFalse() {
+        boolean result = balancedBracketsUsingString.isBalanced("abc[](){}");
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    public void givenOddLengthString_whenCheckingForBalance_shouldReturnFalse() {
+        boolean result = balancedBracketsUsingString.isBalanced("{{[]()}}}");
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    public void givenEvenLengthString_whenCheckingForBalance_shouldReturnFalse() {
+        boolean result = balancedBracketsUsingString.isBalanced("{{[]()}}}}");
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    public void givenEvenLengthUnbalancedString_whenCheckingForBalance_shouldReturnFalse() {
+        boolean result = balancedBracketsUsingString.isBalanced("{[(])}");
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    public void givenEvenLengthBalancedString_whenCheckingForBalance_shouldReturnTrue() {
+        boolean result = balancedBracketsUsingString.isBalanced("{[()]}");
+        assertThat(result).isTrue();
+    }
+
+    @Test
+    public void givenBalancedString_whenCheckingForBalance_shouldReturnTrue() {
+        boolean result = balancedBracketsUsingString.isBalanced("{{[[(())]]}}");
+        assertThat(result).isTrue();
+    }
+
+    @Test
+    public void givenAnotherBalancedString_whenCheckingForBalance_shouldReturnTrue() {
+        boolean result = balancedBracketsUsingString.isBalanced("{{([])}}");
+        assertThat(result).isTrue();
+    }
+
+    @Test
+    public void givenUnBalancedString_whenCheckingForBalance_shouldReturnFalse() {
+        boolean result = balancedBracketsUsingString.isBalanced("{{)[](}}");
+        assertThat(result).isFalse();
+    }
+
+}

algorithms-miscellaneous-5/src/test/resources/input.json

@@ -0,0 +1,41 @@
+{
+	"nodes": 5,
+	"edges": 7,
+	"edgeList": [
+		{
+			"first": 0,
+			"second": 1,
+			"weight": 8
+		},
+		{
+			"first": 0,
+			"second": 2,
+			"weight": 5
+		},
+		{
+			"first": 1,
+			"second": 2,
+			"weight": 9
+		},
+		{
+			"first": 1,
+			"second": 3,
+			"weight": 11
+		},
+		{
+			"first": 2,
+			"second": 3,
+			"weight": 15
+		},
+		{
+			"first": 2,
+			"second": 4,
+			"weight": 10
+		},
+		{
+			"first": 3,
+			"second": 4,
+			"weight": 7
+		}
+	]
+}

algorithms-miscellaneous-6/pom.xml

@@ -0,0 +1,27 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>algorithms-miscellaneous-6</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <name>algorithms-miscellaneous-6</name>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+    
+    <dependencies>
+    <dependency>
+            <groupId>com.google.guava</groupId>
+            <artifactId>guava</artifactId>
+            <version>${guava.version}</version>
+        </dependency>
+    </dependencies>
+    
+    <properties>
+        <guava.version>28.1-jre</guava.version>
+    </properties>
+
+</project>

algorithms-miscellaneous-6/src/main/java/com/baeldung/algorithms/boruvka/BoruvkaMST.java

@@ -0,0 +1,84 @@
+package com.baeldung.algorithms.boruvka;
+
+import com.google.common.graph.EndpointPair;
+import com.google.common.graph.MutableValueGraph;
+import com.google.common.graph.ValueGraphBuilder;
+
+public class BoruvkaMST {
+
+    private static MutableValueGraph<Integer, Integer> mst = ValueGraphBuilder.undirected()
+        .build();
+    private static int totalWeight;
+
+    public BoruvkaMST(MutableValueGraph<Integer, Integer> graph) {
+
+        int size = graph.nodes().size();
+
+        UnionFind uf = new UnionFind(size);
+
+        // repeat at most log N times or until we have N-1 edges
+        for (int t = 1; t < size && mst.edges().size() < size - 1; t = t + t) {
+            
+            EndpointPair<Integer>[] closestEdgeArray = new EndpointPair[size];
+
+            // foreach tree in graph, find closest edge
+            for (EndpointPair<Integer> edge : graph.edges()) {
+                int u = edge.nodeU();
+                int v = edge.nodeV();
+                int uParent = uf.find(u);
+                int vParent = uf.find(v);
+                if (uParent == vParent) {
+                    continue; // same tree
+                }
+
+                int weight = graph.edgeValueOrDefault(u, v, 0);
+
+                if (closestEdgeArray[uParent] == null) {
+                    closestEdgeArray[uParent] = edge;
+                }
+                if (closestEdgeArray[vParent] == null) {
+                    closestEdgeArray[vParent] = edge;
+                }
+
+                int uParentWeight = graph.edgeValueOrDefault(closestEdgeArray[uParent].nodeU(), closestEdgeArray[uParent].nodeV(), 0);
+                int vParentWeight = graph.edgeValueOrDefault(closestEdgeArray[vParent].nodeU(), closestEdgeArray[vParent].nodeV(), 0);
+
+                if (weight < uParentWeight) {
+                    closestEdgeArray[uParent] = edge;
+                }
+                if (weight < vParentWeight) {
+                    closestEdgeArray[vParent] = edge;
+                }
+            }
+
+            // add newly discovered edges to MST
+            for (int i = 0; i < size; i++) {
+                EndpointPair<Integer> edge = closestEdgeArray[i];
+                if (edge != null) {
+                    int u = edge.nodeU();
+                    int v = edge.nodeV();
+                    int weight = graph.edgeValueOrDefault(u, v, 0);
+                    // don't add the same edge twice
+                    if (uf.find(u) != uf.find(v)) {
+                        mst.putEdgeValue(u, v, weight);
+                        totalWeight += weight;
+                        uf.union(u, v);
+                    }
+                }
+            }
+        }
+    }
+
+    public MutableValueGraph<Integer, Integer> getMST() {
+        return mst;
+    }
+
+    public int getTotalWeight() {
+        return totalWeight;
+    }
+
+    public String toString() {
+        return "MST: " + mst.toString() + " | Total Weight: " + totalWeight;
+    }
+
+}

algorithms-miscellaneous-6/src/main/java/com/baeldung/algorithms/boruvka/UnionFind.java

@@ -0,0 +1,39 @@
+package com.baeldung.algorithms.boruvka;
+
+public class UnionFind {
+    private int[] parents;
+    private int[] ranks;
+
+    public UnionFind(int n) {
+        parents = new int[n];
+        ranks = new int[n];
+        for (int i = 0; i < n; i++) {
+            parents[i] = i;
+            ranks[i] = 0;
+        }
+    }
+
+    public int find(int u) {
+        while (u != parents[u]) {
+            u = parents[u];
+        }
+        return u;
+    }
+
+    public void union(int u, int v) {
+        int uParent = find(u);
+        int vParent = find(v);
+        if (uParent == vParent) {
+            return;
+        }
+
+        if (ranks[uParent] < ranks[vParent]) {
+            parents[uParent] = vParent;
+        } else if (ranks[uParent] > ranks[vParent]) {
+            parents[vParent] = uParent;
+        } else {
+            parents[vParent] = uParent;
+            ranks[uParent]++;
+        }
+    }
+}

algorithms-miscellaneous-6/src/main/java/com/baeldung/algorithms/gradientdescent/GradientDescent.java

@@ -0,0 +1,33 @@
+package com.baeldung.algorithms.gradientdescent;
+
+import java.util.function.Function;
+
+public class GradientDescent {
+
+    private final double precision = 0.000001;
+
+    public double findLocalMinimum(Function<Double, Double> f, double initialX) {
+        double stepCoefficient = 0.1;
+        double previousStep = 1.0;
+        double currentX = initialX;
+        double previousX = initialX;
+        double previousY = f.apply(previousX);
+        int iter = 100;
+
+        currentX += stepCoefficient * previousY;
+
+        while (previousStep > precision && iter > 0) {
+            iter--;
+            double currentY = f.apply(currentX);
+            if (currentY > previousY) {
+                stepCoefficient = -stepCoefficient / 2;
+            }
+            previousX = currentX;
+            currentX += stepCoefficient * previousY;
+            previousY = currentY;
+            previousStep = StrictMath.abs(currentX - previousX);
+        }
+        return currentX;
+    }
+
+}

algorithms-miscellaneous-6/src/test/java/com/baeldung/algorithms/boruvka/BoruvkaUnitTest.java

@@ -0,0 +1,37 @@
+package com.baeldung.algorithms.boruvka;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import com.google.common.graph.MutableValueGraph;
+import com.google.common.graph.ValueGraphBuilder;
+
+public class BoruvkaUnitTest {
+
+    private MutableValueGraph<Integer, Integer> graph;
+
+    @Before
+    public void setup() {
+        graph = ValueGraphBuilder.undirected()
+            .build();
+        graph.putEdgeValue(0, 1, 8);
+        graph.putEdgeValue(0, 2, 5);
+        graph.putEdgeValue(1, 2, 9);
+        graph.putEdgeValue(1, 3, 11);
+        graph.putEdgeValue(2, 3, 15);
+        graph.putEdgeValue(2, 4, 10);
+        graph.putEdgeValue(3, 4, 7);
+    }
+
+    @Test
+    public void givenInputGraph_whenBoruvkaPerformed_thenMinimumSpanningTree() {
+        BoruvkaMST boruvkaMST = new BoruvkaMST(graph);
+        MutableValueGraph<Integer, Integer> mst = boruvkaMST.getMST();
+
+        assertEquals(30, boruvkaMST.getTotalWeight());
+        assertEquals(4, mst.edges().size());
+    }
+
+}

algorithms-miscellaneous-6/src/test/java/com/baeldung/algorithms/gradientdescent/GradientDescentUnitTest.java

@@ -0,0 +1,20 @@
+package com.baeldung.algorithms.gradientdescent;
+
+import static org.junit.Assert.assertTrue;
+
+import java.util.function.Function;
+
+import org.junit.Test;
+
+public class GradientDescentUnitTest {
+
+    @Test
+    public void givenFunction_whenStartingPointIsOne_thenLocalMinimumIsFound() {
+        Function<Double, Double> df = x ->
+            StrictMath.abs(StrictMath.pow(x, 3)) - (3 * StrictMath.pow(x, 2)) + x;
+        GradientDescent gd = new GradientDescent();
+        double res = gd.findLocalMinimum(df, 1);
+        assertTrue(res > 1.78);
+        assertTrue(res < 1.84);
+    }
+}

algorithms-searching/README.md

@@ -10,3 +10,4 @@ This module contains articles about searching algorithms.
 - [String Search Algorithms for Large Texts](https://www.baeldung.com/java-full-text-search-algorithms)
 - [Monte Carlo Tree Search for Tic-Tac-Toe Game](https://www.baeldung.com/java-monte-carlo-tree-search)
 - [Range Search Algorithm in Java](https://www.baeldung.com/java-range-search)
+- [Fast Pattern Matching of Strings Using Suffix Tree](https://www.baeldung.com/java-pattern-matching-suffix-tree)

algorithms-searching/pom.xml

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>algorithms-searching</artifactId>
     <version>0.0.1-SNAPSHOT</version>

algorithms-searching/src/main/java/com/baeldung/algorithms/suffixtree/Node.java

@@ -0,0 +1,57 @@
+package com.baeldung.algorithms.suffixtree;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class Node {
+    private String text;
+    private List<Node> children;
+    private int position;
+
+    public Node(String word, int position) {
+        this.text = word;
+        this.position = position;
+        this.children = new ArrayList<>();
+    }
+
+    public String getText() {
+        return text;
+    }
+
+    public void setText(String text) {
+        this.text = text;
+    }
+
+    public int getPosition() {
+        return position;
+    }
+
+    public void setPosition(int position) {
+        this.position = position;
+    }
+
+    public List<Node> getChildren() {
+        return children;
+    }
+
+    public void setChildren(List<Node> children) {
+        this.children = children;
+    }
+
+    public String printTree(String depthIndicator) {
+        String str = "";
+        String positionStr = position > -1 ? "[" + String.valueOf(position) + "]" : "";
+        str += depthIndicator + text + positionStr + "\n";
+
+        for (int i = 0; i < children.size(); i++) {
+            str += children.get(i)
+                .printTree(depthIndicator + "\t");
+        }
+        return str;
+    }
+
+    @Override
+    public String toString() {
+        return printTree("");
+    }
+}

algorithms-searching/src/main/java/com/baeldung/algorithms/suffixtree/SuffixTree.java

@@ -0,0 +1,175 @@
+package com.baeldung.algorithms.suffixtree;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class SuffixTree {
+    private static final Logger LOGGER = LoggerFactory.getLogger(SuffixTree.class);
+    private static final String WORD_TERMINATION = "$";
+    private static final int POSITION_UNDEFINED = -1;
+    private Node root;
+    private String fullText;
+
+    public SuffixTree(String text) {
+        root = new Node("", POSITION_UNDEFINED);
+        for (int i = 0; i < text.length(); i++) {
+            addSuffix(text.substring(i) + WORD_TERMINATION, i);
+        }
+        fullText = text;
+    }
+
+    public List<String> searchText(String pattern) {
+        LOGGER.info("Searching for pattern \"{}\"", pattern);
+        List<String> result = new ArrayList<>();
+        List<Node> nodes = getAllNodesInTraversePath(pattern, root, false);
+
+        if (nodes.size() > 0) {
+            Node lastNode = nodes.get(nodes.size() - 1);
+            if (lastNode != null) {
+                List<Integer> positions = getPositions(lastNode);
+                positions = positions.stream()
+                    .sorted()
+                    .collect(Collectors.toList());
+                positions.forEach(m -> result.add((markPatternInText(m, pattern))));
+            }
+        }
+        return result;
+    }
+
+    private void addSuffix(String suffix, int position) {
+        LOGGER.info(">>>>>>>>>>>> Adding new suffix {}", suffix);
+        List<Node> nodes = getAllNodesInTraversePath(suffix, root, true);
+        if (nodes.size() == 0) {
+            addChildNode(root, suffix, position);
+            LOGGER.info("{}", printTree());
+        } else {
+            Node lastNode = nodes.remove(nodes.size() - 1);
+            String newText = suffix;
+            if (nodes.size() > 0) {
+                String existingSuffixUptoLastNode = nodes.stream()
+                    .map(a -> a.getText())
+                    .reduce("", String::concat);
+
+                // Remove prefix from newText already included in parent
+                newText = newText.substring(existingSuffixUptoLastNode.length());
+            }
+            extendNode(lastNode, newText, position);
+            LOGGER.info("{}", printTree());
+        }
+    }
+
+    private List<Integer> getPositions(Node node) {
+        List<Integer> positions = new ArrayList<>();
+        if (node.getText()
+            .endsWith(WORD_TERMINATION)) {
+            positions.add(node.getPosition());
+        }
+        for (int i = 0; i < node.getChildren()
+            .size(); i++) {
+            positions.addAll(getPositions(node.getChildren()
+                .get(i)));
+        }
+        return positions;
+    }
+
+    private String markPatternInText(Integer startPosition, String pattern) {
+        String matchingTextLHS = fullText.substring(0, startPosition);
+        String matchingText = fullText.substring(startPosition, startPosition + pattern.length());
+        String matchingTextRHS = fullText.substring(startPosition + pattern.length());
+        return matchingTextLHS + "[" + matchingText + "]" + matchingTextRHS;
+    }
+
+    private void addChildNode(Node parentNode, String text, int position) {
+        parentNode.getChildren()
+            .add(new Node(text, position));
+    }
+
+    private void extendNode(Node node, String newText, int position) {
+        String currentText = node.getText();
+        String commonPrefix = getLongestCommonPrefix(currentText, newText);
+
+        if (commonPrefix != currentText) {
+            String parentText = currentText.substring(0, commonPrefix.length());
+            String childText = currentText.substring(commonPrefix.length());
+            splitNodeToParentAndChild(node, parentText, childText);
+        }
+
+        String remainingText = newText.substring(commonPrefix.length());
+        addChildNode(node, remainingText, position);
+    }
+
+    private void splitNodeToParentAndChild(Node parentNode, String parentNewText, String childNewText) {
+        Node childNode = new Node(childNewText, parentNode.getPosition());
+
+        if (parentNode.getChildren()
+            .size() > 0) {
+            while (parentNode.getChildren()
+                .size() > 0) {
+                childNode.getChildren()
+                    .add(parentNode.getChildren()
+                        .remove(0));
+            }
+        }
+
+        parentNode.getChildren()
+            .add(childNode);
+        parentNode.setText(parentNewText);
+        parentNode.setPosition(POSITION_UNDEFINED);
+    }
+
+    private String getLongestCommonPrefix(String str1, String str2) {
+        int compareLength = Math.min(str1.length(), str2.length());
+        for (int i = 0; i < compareLength; i++) {
+            if (str1.charAt(i) != str2.charAt(i)) {
+                return str1.substring(0, i);
+            }
+        }
+        return str1.substring(0, compareLength);
+    }
+
+    private List<Node> getAllNodesInTraversePath(String pattern, Node startNode, boolean isAllowPartialMatch) {
+        List<Node> nodes = new ArrayList<>();
+        for (int i = 0; i < startNode.getChildren()
+            .size(); i++) {
+            Node currentNode = startNode.getChildren()
+                .get(i);
+            String nodeText = currentNode.getText();
+            if (pattern.charAt(0) == nodeText.charAt(0)) {
+                if (isAllowPartialMatch && pattern.length() <= nodeText.length()) {
+                    nodes.add(currentNode);
+                    return nodes;
+                }
+
+                int compareLength = Math.min(nodeText.length(), pattern.length());
+                for (int j = 1; j < compareLength; j++) {
+                    if (pattern.charAt(j) != nodeText.charAt(j)) {
+                        if (isAllowPartialMatch) {
+                            nodes.add(currentNode);
+                        }
+                        return nodes;
+                    }
+                }
+
+                nodes.add(currentNode);
+                if (pattern.length() > compareLength) {
+                    List<Node> nodes2 = getAllNodesInTraversePath(pattern.substring(compareLength), currentNode, isAllowPartialMatch);
+                    if (nodes2.size() > 0) {
+                        nodes.addAll(nodes2);
+                    } else if (!isAllowPartialMatch) {
+                        nodes.add(null);
+                    }
+                }
+                return nodes;
+            }
+        }
+        return nodes;
+    }
+
+    public String printTree() {
+        return root.printTree("");
+    }
+}

algorithms-searching/src/test/java/com/baeldung/algorithms/suffixtree/SuffixTreeUnitTest.java

@@ -0,0 +1,77 @@
+package com.baeldung.algorithms.suffixtree;
+
+import java.util.List;
+
+import org.junit.Assert;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class SuffixTreeUnitTest {
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(SuffixTreeUnitTest.class);
+
+    private static SuffixTree suffixTree;
+
+    @BeforeClass
+    public static void setUp() {
+        suffixTree = new SuffixTree("havanabanana");
+        printTree();
+    }
+
+    @Test
+    public void givenSuffixTree_whenSearchingForA_thenReturn6Matches() {
+        List<String> matches = suffixTree.searchText("a");
+        matches.stream()
+            .forEach(m -> LOGGER.info(m));
+        Assert.assertArrayEquals(new String[] { "h[a]vanabanana", "hav[a]nabanana", "havan[a]banana", "havanab[a]nana", "havanaban[a]na", "havanabanan[a]" }, matches.toArray());
+    }
+
+    @Test
+    public void givenSuffixTree_whenSearchingForNab_thenReturn1Match() {
+        List<String> matches = suffixTree.searchText("nab");
+        matches.stream()
+            .forEach(m -> LOGGER.info(m));
+        Assert.assertArrayEquals(new String[] { "hava[nab]anana" }, matches.toArray());
+    }
+
+    @Test
+    public void givenSuffixTree_whenSearchingForNag_thenReturnNoMatches() {
+        List<String> matches = suffixTree.searchText("nag");
+        matches.stream()
+            .forEach(m -> LOGGER.info(m));
+        Assert.assertArrayEquals(new String[] {}, matches.toArray());
+    }
+
+    @Test
+    public void givenSuffixTree_whenSearchingForBanana_thenReturn2Matches() {
+        List<String> matches = suffixTree.searchText("ana");
+        matches.stream()
+            .forEach(m -> LOGGER.info(m));
+        Assert.assertArrayEquals(new String[] { "hav[ana]banana", "havanab[ana]na", "havanaban[ana]" }, matches.toArray());
+    }
+
+    @Test
+    public void givenSuffixTree_whenSearchingForNa_thenReturn4Matches() {
+        List<String> matches = suffixTree.searchText("na");
+        matches.stream()
+            .forEach(m -> LOGGER.info(m));
+        Assert.assertArrayEquals(new String[] { "hava[na]banana", "havanaba[na]na", "havanabana[na]" }, matches.toArray());
+    }
+
+    @Test
+    public void givenSuffixTree_whenSearchingForX_thenReturnNoMatches() {
+        List<String> matches = suffixTree.searchText("x");
+        matches.stream()
+            .forEach(m -> LOGGER.info(m));
+        Assert.assertArrayEquals(new String[] {}, matches.toArray());
+    }
+
+    private static void printTree() {
+        suffixTree.printTree();
+
+        LOGGER.info("\n" + suffixTree.printTree());
+        LOGGER.info("==============================================");
+    }
+}

algorithms-sorting-2/README.md

@@ -0,0 +1,3 @@
+### Relevant Articles:
+
+- [Partitioning and Sorting Arrays with Many Repeated Entries](https://www.baeldung.com/java-sorting-arrays-with-repeated-entries)

algorithms-sorting-2/pom.xml

@@ -1,5 +1,7 @@
-<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">
+<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">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>algorithms-sorting-2</artifactId>
     <version>0.0.1-SNAPSHOT</version>

algorithms-sorting/pom.xml

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>algorithms-sorting</artifactId>
     <version>0.0.1-SNAPSHOT</version>

animal-sniffer-mvn-plugin/pom.xml

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>animal-sniffer-mvn-plugin</artifactId>
     <version>1.0-SNAPSHOT</version>
@@ -44,5 +46,5 @@
         <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

@@ -1,6 +1,8 @@
 <?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">
+<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">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>annotation-processing</artifactId>
     <name>annotation-processing</name>

annotations/annotation-user/pom.xml

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>annotation-user</artifactId>
     <name>annotation-user</name>

annotations/pom.xml

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>annotations</artifactId>
     <name>annotations</name>

antlr/pom.xml

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>antlr</artifactId>
     <name>antlr</name>
@@ -58,5 +60,5 @@
         <antlr.version>4.7.1</antlr.version>
         <mojo.version>3.0.0</mojo.version>
     </properties>
-    
+
 </project>

apache-avro/pom.xml

@@ -1,7 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>apache-avro</artifactId>
     <version>0.0.1-SNAPSHOT</version>

apache-beam/README.md

@@ -0,0 +1,3 @@
+### Relevant Articles:
+
+- [Introduction to Apache Beam](https://www.baeldung.com/apache-beam)

apache-beam/pom.xml

@@ -0,0 +1,43 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <groupId>com.baeldung.apache</groupId>
+    <artifactId>apache-beam</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.apache.beam</groupId>
+            <artifactId>beam-sdks-java-core</artifactId>
+            <version>${beam.version}</version>
+        </dependency>
+        <!-- runtime scoped -->
+        <dependency>
+            <groupId>org.apache.beam</groupId>
+            <artifactId>beam-runners-direct-java</artifactId>
+            <version>${beam.version}</version>
+            <scope>runtime</scope>
+        </dependency>
+        <!-- test scoped -->
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${assertj.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <properties>
+        <beam.version>2.19.0</beam.version>
+        <assertj.version>3.6.1</assertj.version>
+    </properties>
+
+</project>

apache-beam/src/main/java/com/baeldung/apache/beam/intro/WordCount.java

@@ -0,0 +1,71 @@
+package com.baeldung.apache.beam.intro;
+
+import java.util.Arrays;
+
+import org.apache.beam.sdk.Pipeline;
+import org.apache.beam.sdk.io.TextIO;
+import org.apache.beam.sdk.options.PipelineOptions;
+import org.apache.beam.sdk.options.PipelineOptionsFactory;
+import org.apache.beam.sdk.transforms.Count;
+import org.apache.beam.sdk.transforms.Filter;
+import org.apache.beam.sdk.transforms.FlatMapElements;
+import org.apache.beam.sdk.transforms.MapElements;
+import org.apache.beam.sdk.values.KV;
+import org.apache.beam.sdk.values.PCollection;
+import org.apache.beam.sdk.values.TypeDescriptors;
+
+public class WordCount {
+    
+    public static boolean wordCount(String inputFilePath, String outputFilePath) {
+        // We use default options
+        PipelineOptions options = PipelineOptionsFactory.create();
+        // to create the pipeline
+        Pipeline p = Pipeline.create(options);
+        // Here is our workflow graph
+        PCollection<KV<String, Long>> wordCount = p
+            .apply("(1) Read all lines", TextIO.read().from(inputFilePath))
+            .apply("(2) Flatmap to a list of words", FlatMapElements.into(TypeDescriptors.strings())
+                .via(line -> Arrays.asList(line.split("\\s"))))
+            .apply("(3) Lowercase all", MapElements.into(TypeDescriptors.strings())
+                .via(word -> word.toLowerCase()))
+            .apply("(4) Trim punctuations", MapElements.into(TypeDescriptors.strings())
+                .via(word -> trim(word)))
+            .apply("(5) Filter stopwords", Filter.by(word -> !isStopWord(word)))
+            .apply("(6) Count words", Count.perElement());
+        // We convert the PCollection to String so that we can write it to file
+        wordCount.apply(MapElements.into(TypeDescriptors.strings())
+                .via(count -> count.getKey() + " --> " + count.getValue()))
+            .apply(TextIO.write().to(outputFilePath));
+        // Finally we must run the pipeline, otherwise it's only a definition
+        p.run().waitUntilFinish();  
+        return true;
+    }
+    
+    public static boolean isStopWord(String word) {
+        String[] stopwords = {"am", "are", "is", "i", "you", "me",
+                               "he", "she", "they", "them", "was",
+                               "were", "from", "in", "of", "to", "be",
+                               "him", "her", "us", "and", "or"};
+        for (String stopword : stopwords) {
+            if (stopword.compareTo(word) == 0) {
+                return true;
+            }
+        }
+        return false;
+    }
+    
+    public static String trim(String word) {
+        return word.replace("(","")
+            .replace(")", "")
+            .replace(",", "")
+            .replace(".", "")
+            .replace("\"", "")
+            .replace("'", "")
+            .replace(":", "")
+            .replace(";", "")
+            .replace("-", "")
+            .replace("?", "")
+            .replace("!", "");
+    }
+
+}

apache-beam/src/test/java/com/baeldung/apache/beam/intro/WordCountUnitTest.java

@@ -0,0 +1,19 @@
+package com.baeldung.apache.beam.intro;
+
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Ignore;
+import org.junit.Test;
+
+import com.baeldung.apache.beam.intro.WordCount;
+
+public class WordCountUnitTest {
+    
+    @Test
+    // @Ignore
+    public void givenInputFile_whenWordCountRuns_thenJobFinishWithoutError() {
+        boolean jobDone = WordCount.wordCount("src/test/resources/wordcount.txt", "target/output");
+        assertTrue(jobDone);
+    }
+
+}

apache-beam/src/test/resources/wordcount.txt

@@ -0,0 +1,16 @@
+We've all heard the scare stories about North Korea: the homemade nuclear arsenal built while their people starve and then aimed imprecisely at the rest of the world, a 
+leader so deluded he makes L Ron Hubbard look like a man excessively overburdened with self-doubt and their deep-seated belief that foreign capitalists will invade at any 
+moment and steal all their bauxite.
+The popular portrayal of this Marxist nation is something like one of the more harrowing episodes of M*A*S*H, only with the cast of wacky characters replaced by twitchy, 
+heavily armed Stalinist meth addicts
+Cracked would like to take a moment to celebrate the good things about North Korea though, the things that the country's enemies prefer to suppress as part of their politically 
+motivated jealousy. Like how no different to you and me, there's nothing every North Korean likes more after an 18 hour shift at the phosphorus plant than a nice beer to go with 
+his dried fish ration. Ever attentive to its people's needs and in the twinkling of a decade, North Korea's leadership bought, disassembled, transported and rebuilt a British 
+brewery in order to discover and reproduce the secrets of beer and then brew the sweet nectar for its hardworking people, up to 18 bottles at a time. And with minimal fatalities. 
+When was the last time YOUR leader got a beer for YOU, American? (NB do not answer this question if you are Henry Louis Gates).
+Or how about the fried chicken restaurant that downtown Pyongyang boasts? Yes real chicken, fried and then delivered to your sleeping cube, with optional beer if you like! You 
+don't even have to remove the feathers or pull out the gizzard yourself. Mostly. Americans must eat their fried chicken from a bucket, like swine, sold by a company so secretive 
+that even the very blend of seasoning used is intentionally kept from them. And they call North Korea paranoid?
+And how many nations would entertain the syphilitic, bourgeois ramblings of Bill Clinton let alone permit him anywhere near their proud womenfolk? Only wise Kim Jong Il could see 
+past Bill's many, many imperfections and treat him with the pity and kindness he deserves, accepting his feeble pleas to pardon the American spies rightly convicted of photographing 
+the nation's sensitive beetroot fields.

apache-bval/pom.xml

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>apache-bval</artifactId>
     <version>0.0.1-SNAPSHOT</version>

apache-curator/pom.xml

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>apache-curator</artifactId>
     <version>0.0.1-SNAPSHOT</version>

apache-cxf/cxf-aegis/README.md

@@ -1,3 +0,0 @@
-### 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

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>cxf-aegis</artifactId>
     <name>cxf-aegis</name>

apache-cxf/cxf-introduction/pom.xml

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>cxf-introduction</artifactId>
     <name>cxf-introduction</name>

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

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>cxf-jaxrs-implementation</artifactId>
     <name>cxf-jaxrs-implementation</name>

apache-cxf/cxf-spring/pom.xml

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>cxf-spring</artifactId>
     <name>cxf-spring</name>

apache-cxf/pom.xml

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>apache-cxf</artifactId>
     <version>0.0.1-SNAPSHOT</version>

apache-cxf/sse-jaxrs/pom.xml

@@ -1,7 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>sse-jaxrs</artifactId>
     <name>sse-jaxrs</name>

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

@@ -1,7 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>sse-jaxrs-client</artifactId>
     <name>sse-jaxrs-client</name>

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

@@ -1,12 +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">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>sse-jaxrs-server</artifactId>
     <name>sse-jaxrs-server</name>
     <packaging>war</packaging>
-    
+
     <parent>
         <groupId>com.baeldung</groupId>
         <artifactId>sse-jaxrs</artifactId>
@@ -18,19 +19,19 @@
         <dependency>
             <groupId>javax.ws.rs</groupId>
             <artifactId>javax.ws.rs-api</artifactId>
-            <version>2.1</version>
+            <version>${rs-api.version}</version>
             <scope>provided</scope>
         </dependency>
         <dependency>
             <groupId>javax.enterprise</groupId>
             <artifactId>cdi-api</artifactId>
-            <version>2.0</version>
+            <version>${cdi-api.version}</version>
             <scope>provided</scope>
         </dependency>
         <dependency>
             <groupId>javax.json.bind</groupId>
             <artifactId>javax.json.bind-api</artifactId>
-            <version>1.0</version>
+            <version>${bind-api.version}</version>
             <scope>provided</scope>
         </dependency>
 
@@ -80,6 +81,9 @@
         <liberty-maven-plugin.version>2.4.2</liberty-maven-plugin.version>
         <failOnMissingWebXml>false</failOnMissingWebXml>
         <openliberty-version>18.0.0.2</openliberty-version>
+        <rs-api.version>2.1</rs-api.version>
+        <cdi-api.version>2.0</cdi-api.version>
+        <bind-api.version>1.0</bind-api.version>
     </properties>
 
 </project>

apache-fop/README.md

@@ -1,5 +0,0 @@
-## Apache FOP
-
-This module contains articles about Apache FOP
-
-### Relevant Articles: 

apache-fop/pom.xml

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>apache-fop</artifactId>
     <version>0.1-SNAPSHOT</version>

apache-geode/pom.xml

@@ -1,7 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>apache-geode</artifactId>
     <version>1.0-SNAPSHOT</version>

apache-meecrowave/pom.xml

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>apache-meecrowave</artifactId>
     <version>0.0.1</version>

apache-olingo/olingo2/README.md

@@ -1,4 +0,0 @@
-### 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

@@ -1,7 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.baeldung.examples.olingo2</groupId>
     <artifactId>olingo2</artifactId>

apache-opennlp/pom.xml

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>apache-opennlp</artifactId>
     <version>1.0-SNAPSHOT</version>

apache-poi/README.md

@@ -6,3 +6,6 @@ This module contains articles about Apache POI
 - [Microsoft Word Processing in Java with Apache POI](https://www.baeldung.com/java-microsoft-word-with-apache-poi)
 - [Working with Microsoft Excel in Java](https://www.baeldung.com/java-microsoft-excel)
 - [Creating a MS PowerPoint Presentation in Java](https://www.baeldung.com/apache-poi-slideshow)
+- [Merge Cells in Excel Using Apache POI](https://www.baeldung.com/java-apache-poi-merge-cells)
+- [Get String Value of Excel Cell with Apache POI](https://www.baeldung.com/java-apache-poi-cell-string-value)
+- [Read Excel Cell Value Rather Than Formula With Apache POI](https://www.baeldung.com/apache-poi-read-cell-value-formula)

apache-poi/pom.xml

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>apache-poi</artifactId>
     <version>0.0.1-SNAPSHOT</version>

apache-poi/src/test/java/com/baeldung/poi/excel/merge/ExcelCellMergerUnitTest.java

@@ -0,0 +1,53 @@
+package com.baeldung.poi.excel.merge;
+
+import static org.junit.Assert.assertEquals;
+
+import java.io.IOException;
+import java.net.URISyntaxException;
+import java.nio.file.Paths;
+
+import org.apache.poi.ss.usermodel.Sheet;
+import org.apache.poi.ss.usermodel.Workbook;
+import org.apache.poi.ss.util.CellRangeAddress;
+import org.apache.poi.xssf.usermodel.XSSFWorkbook;
+import org.junit.Before;
+import org.junit.Test;
+
+public class ExcelCellMergerUnitTest {
+    private static final String FILE_NAME = "ExcelCellFormatterTest.xlsx";
+    private String fileLocation;
+
+    @Before
+    public void setup() throws IOException, URISyntaxException {
+            fileLocation = Paths.get(ClassLoader.getSystemResource(FILE_NAME).toURI()).toString();
+    }
+
+    @Test
+    public void givenCellIndex_whenAddMergeRegion_thenMergeRegionCreated() throws IOException {
+        Workbook workbook = new XSSFWorkbook(fileLocation);
+        Sheet sheet = workbook.getSheetAt(0);
+
+        assertEquals(0, sheet.getNumMergedRegions());
+        int firstRow = 0; 
+        int lastRow = 0; 
+        int firstCol = 0; 
+        int lastCol = 2;
+        sheet.addMergedRegion(new CellRangeAddress(firstRow, lastRow, firstCol, lastCol));
+        assertEquals(1, sheet.getNumMergedRegions());
+
+        workbook.close();
+    }
+
+    @Test
+    public void givenCellRefString_whenAddMergeRegion_thenMergeRegionCreated() throws IOException {
+        Workbook workbook = new XSSFWorkbook(fileLocation);
+        Sheet sheet = workbook.getSheetAt(0);
+
+        assertEquals(0, sheet.getNumMergedRegions());        
+        sheet.addMergedRegion(CellRangeAddress.valueOf("A1:C1"));
+        assertEquals(1, sheet.getNumMergedRegions());
+
+        workbook.close();
+    }
+
+}

apache-pulsar/pom.xml

@@ -1,6 +1,8 @@
 <?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">
+<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">
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.baeldung.pulsar</groupId>
     <artifactId>apache-pulsar</artifactId>

apache-rocketmq/README.md

@@ -3,3 +3,5 @@
 This module contains articles about Apache RocketMQ
 
 ### Relevant Articles: 
+
+- [Apache RocketMQ with Spring Boot](https://www.baeldung.com/apache-rocketmq-spring-boot)

apache-rocketmq/pom.xml

@@ -1,7 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>apache-rocketmq</artifactId>
     <version>1.0-SNAPSHOT</version>
@@ -17,11 +18,12 @@
         <dependency>
             <groupId>org.apache.rocketmq</groupId>
             <artifactId>rocketmq-spring-boot-starter</artifactId>
-            <version>2.0.4</version>
+            <version>${rocketmq.version}</version>
         </dependency>
     </dependencies>
 
     <properties>
         <geode.core>1.6.0</geode.core>
+        <rocketmq.version>2.0.4</rocketmq.version>
     </properties>
 </project>

apache-shiro/pom.xml

@@ -1,7 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>apache-shiro</artifactId>
     <version>1.0-SNAPSHOT</version>

apache-solrj/pom.xml

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>apache-solrj</artifactId>
     <version>0.0.1-SNAPSHOT</version>

apache-spark/README.md

@@ -7,4 +7,4 @@ This module contains articles about Apache Spark
 - [Introduction to Apache Spark](https://www.baeldung.com/apache-spark)
 - [Building a Data Pipeline with Kafka, Spark Streaming and Cassandra](https://www.baeldung.com/kafka-spark-data-pipeline)
 - [Machine Learning with Spark MLlib](https://www.baeldung.com/spark-mlib-machine-learning)
-
+- [Introduction to Spark Graph Processing with GraphFrames](https://www.baeldung.com/spark-graph-graphframes)

apache-spark/pom.xml

@@ -1,7 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>apache-spark</artifactId>
     <version>1.0-SNAPSHOT</version>

apache-tapestry/README.md

@@ -0,0 +1,3 @@
+### Relevant Articles
+
+- [Intro to Apache Tapestry](https://www.baeldung.com/apache-tapestry)

apache-tapestry/pom.xml

@@ -1,6 +1,8 @@
 <?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">
+<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>
@@ -9,9 +11,8 @@
     <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. -->
+        <!-- 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. -->
         <dependency>
             <groupId>org.apache.tapestry</groupId>
             <artifactId>tapestry-core</artifactId>
@@ -32,17 +33,10 @@
         </dependency>
 
         <!-- Uncomment this to add support for file uploads: -->
-        <!--
-         <dependency>
-            <groupId>org.apache.tapestry</groupId>
-            <artifactId>tapestry-upload</artifactId>
-            <version>${tapestry-release-version}</version>
-        </dependency>
-        -->
+        <!-- <dependency> <groupId>org.apache.tapestry</groupId> <artifactId>tapestry-upload</artifactId> <version>${tapestry-release-version}</version> </dependency> -->
 
-        <!-- A dependency on either JUnit or TestNG is required, or the surefire plugin (which runs the tests)
-will fail, preventing Maven from packaging the WAR. Tapestry includes a large number
-of testing facilities designed for use with TestNG (http://testng.org/), so it's recommended. -->
+        <!-- A dependency on either JUnit or TestNG is required, or the surefire plugin (which runs the tests) will fail, preventing Maven from packaging the WAR. Tapestry includes 
+            a large number of testing facilities designed for use with TestNG (http://testng.org/), so it's recommended. -->
         <dependency>
             <groupId>org.testng</groupId>
             <artifactId>testng</artifactId>
@@ -57,8 +51,7 @@ of testing facilities designed for use with TestNG (http://testng.org/), so it's
             <scope>test</scope>
         </dependency>
 
-        <!-- Provided by the servlet container, but sometimes referenced in the application
-       code. -->
+        <!-- Provided by the servlet container, but sometimes referenced in the application code. -->
         <dependency>
             <groupId>javax.servlet</groupId>
             <artifactId>servlet-api</artifactId>
@@ -81,10 +74,10 @@ of testing facilities designed for use with TestNG (http://testng.org/), so it's
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-compiler-plugin</artifactId>
-                <version>2.3.2</version>
+                <version>${compiler.plugin.version}</version>
                 <configuration>
-                    <source>1.8</source>
-                    <target>1.8</target>
+                    <source>${source.version}</source>
+                    <target>${target.version}</target>
                     <optimize>true</optimize>
                 </configuration>
             </plugin>
@@ -92,7 +85,7 @@ of testing facilities designed for use with TestNG (http://testng.org/), so it's
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-surefire-plugin</artifactId>
-                <version>2.7.2</version>
+                <version>${compiler.surefire.version}</version>
                 <configuration>
                     <systemPropertyVariables>
                         <tapestry.execution-mode>Qa</tapestry.execution-mode>
@@ -104,12 +97,11 @@ of testing facilities designed for use with TestNG (http://testng.org/), so it's
             <plugin>
                 <groupId>org.mortbay.jetty</groupId>
                 <artifactId>maven-jetty-plugin</artifactId>
-                <version>6.1.16</version>
+                <version>${compiler.jetty.version}</version>
                 <configuration>
                     <!-- Log to the console. -->
                     <requestLog implementation="org.mortbay.jetty.NCSARequestLog">
-                        <!-- This doesn't do anything for Jetty, but is a workaround for a Maven bug
-                             that prevents the requestLog from being set. -->
+                        <!-- This doesn't do anything for Jetty, but is a workaround for a Maven bug that prevents the requestLog from being set. -->
                         <append>true</append>
                     </requestLog>
                     <systemProperties>
@@ -123,7 +115,7 @@ of testing facilities designed for use with TestNG (http://testng.org/), so it's
         </plugins>
     </build>
 
-    <reporting/>
+    <reporting />
 
     <repositories>
         <repository>
@@ -131,8 +123,7 @@ of testing facilities designed for use with TestNG (http://testng.org/), so it's
             <url>http://repository.jboss.org/nexus/content/groups/public/</url>
         </repository>
 
-        <!-- This repository is only needed when the Tapestry version is a preview release, rather
-             than a final release. -->
+        <!-- This repository is only needed when the Tapestry version is a preview release, rather than a final release. -->
         <repository>
             <id>apache-staging</id>
             <url>https://repository.apache.org/content/groups/staging/</url>
@@ -140,6 +131,11 @@ of testing facilities designed for use with TestNG (http://testng.org/), so it's
     </repositories>
 
     <properties>
+        <compiler.jetty.version>6.1.16</compiler.jetty.version>
+        <compiler.surefire.version>2.7.2</compiler.surefire.version>
+        <compiler.plugin.version>2.3.2</compiler.plugin.version>
+        <source.version>1.8</source.version>
+        <target.version>1.8</target.version>
         <tapestry-release-version>5.4.5</tapestry-release-version>
         <servlet-api-release-version>2.5</servlet-api-release-version>
         <testng-release-version>6.8.21</testng-release-version>

apache-thrift/pom.xml

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>apache-thrift</artifactId>
     <version>0.0.1-SNAPSHOT</version>

apache-tika/pom.xml

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>apache-tika</artifactId>
     <version>0.0.1-SNAPSHOT</version>

apache-velocity/pom.xml

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>apache-velocity</artifactId>
     <version>0.1-SNAPSHOT</version>

apache-zookeeper/pom.xml

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>apache-zookeeper</artifactId>
     <version>0.0.1-SNAPSHOT</version>

asciidoctor/pom.xml

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>asciidoctor</artifactId>
     <name>asciidoctor</name>

asm/pom.xml

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.baeldung.examples</groupId>
     <artifactId>asm</artifactId>

atomix/pom.xml

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.atomix.io</groupId>
     <artifactId>atomix</artifactId>

aws-lambda/pom.xml

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>aws-lambda</artifactId>
     <version>0.1.0-SNAPSHOT</version>

aws-reactive/README.md

@@ -0,0 +1,3 @@
+### Relevant Articles:
+
+- [AWS S3 with Java – Reactive Support](https://www.baeldung.com/java-aws-s3-reactive)

aws-reactive/pom.xml

@@ -1,105 +1,107 @@
 <?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>
-	
+<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>
+    <artifactId>aws-reactive</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <name>aws-reactive</name>
+    <description>AWS Reactive Sample</description>
 
-	<dependencyManagement>
-		<dependencies>
+    <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>
+                <!-- Import dependency management from Spring Boot -->
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-dependencies</artifactId>
+                <version>${spring.version}</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>
+            <dependency>
+                <groupId>software.amazon.awssdk</groupId>
+                <artifactId>bom</artifactId>
+                <version>${awssdk.version}</version>
+                <type>pom</type>
+                <scope>import</scope>
+            </dependency>
+        </dependencies>
+    </dependencyManagement>
 
-	<dependencies>
-		<dependency>
-			<groupId>org.springframework.boot</groupId>
-			<artifactId>spring-boot-starter-webflux</artifactId>
-		</dependency>
+    <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>
+            <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>
+            <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>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>
+        <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>
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+            </plugin>
+        </plugins>
+    </build>
 
+    <properties>
+        <java.version>1.8</java.version>
+        <spring.version>2.2.1.RELEASE</spring.version>
+        <awssdk.version>2.10.27</awssdk.version>
+    </properties>
 </project>

aws/pom.xml

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>aws</artifactId>
     <version>0.1.0-SNAPSHOT</version>

axon/pom.xml

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>axon</artifactId>
     <name>axon</name>

azure/pom.xml

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>azure</artifactId>
     <version>0.1</version>

azure/src/main/resources/application.properties

@@ -5,7 +5,7 @@ spring.jpa.hibernate.ddl-auto=create
 logging.file=azure.log
 logging.level.root=info
 
-spring.datasource.url=jdbc:h2:file:~/test
+spring.datasource.url=jdbc:h2:mem:azure-test-db
 spring.datasource.username=sa
 spring.datasource.password=
 

bazel/bazelapp/pom.xml

@@ -1,7 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>bazelapp</artifactId>
     <name>bazelapp</name>

bazel/bazelgreeting/README.md

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

bazel/bazelgreeting/pom.xml

@@ -1,7 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>bazelgreeting</artifactId>
     <name>bazelgreeting</name>

bazel/pom.xml

@@ -1,7 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>bazel</artifactId>
     <name>bazel</name>

blade/pom.xml

@@ -1,7 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>blade</artifactId>
     <name>blade</name>
@@ -106,7 +107,7 @@
                             <arguments>
                                 <argument>java</argument>
                                 <argument>-jar</argument>
-                                <argument>sample-blade-app.jar</argument>
+                                <argument>blade.jar</argument>
                             </arguments>
                         </configuration>
                     </execution>
@@ -124,7 +125,7 @@
 
             <plugin>
                 <artifactId>maven-assembly-plugin</artifactId>
-                <version>3.1.0</version>
+                <version>${assembly.plugin.version}</version>
                 <configuration>
                     <finalName>${project.build.finalName}</finalName>
                     <appendAssemblyId>false</appendAssemblyId>
@@ -161,6 +162,7 @@
         <assertj-core.version>3.11.1</assertj-core.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>
+        <assembly.plugin.version>3.1.0</assembly.plugin.version>
     </properties>
 
 </project>

bootique/pom.xml

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.baeldung.bootique</groupId>
     <artifactId>bootique</artifactId>

cas/cas-secured-app/pom.xml

@@ -1,6 +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"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>cas-secured-app</artifactId>
     <name>cas-secured-app</name>
@@ -9,11 +11,15 @@
 
     <parent>
         <groupId>com.baeldung</groupId>
-        <artifactId>parent-boot-1</artifactId>
+        <artifactId>parent-boot-2</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../../parent-boot-1</relativePath>
+        <relativePath>../../parent-boot-2</relativePath>
     </parent>
 
+    <properties>
+        <spring-boot.version>2.2.6.RELEASE</spring-boot.version>
+    </properties>
+
     <dependencies>
         <dependency>
             <groupId>org.springframework.boot</groupId>

cas/cas-secured-app/src/main/java/com/baeldung/cassecuredapp/CasSecuredAppApplication.java

@@ -1,91 +0,0 @@
-package com.baeldung.cassecuredapp;
-
-import org.jasig.cas.client.session.SingleSignOutFilter;
-import org.jasig.cas.client.session.SingleSignOutHttpSessionListener;
-import org.jasig.cas.client.validation.Cas30ServiceTicketValidator;
-import org.jasig.cas.client.validation.TicketValidator;
-import org.springframework.boot.SpringApplication;
-import org.springframework.boot.autoconfigure.SpringBootApplication;
-import org.springframework.context.annotation.Bean;
-import org.springframework.context.annotation.Primary;
-import org.springframework.context.event.EventListener;
-import org.springframework.security.cas.ServiceProperties;
-import org.springframework.security.cas.authentication.CasAuthenticationProvider;
-import org.springframework.security.cas.web.CasAuthenticationEntryPoint;
-import org.springframework.security.core.authority.AuthorityUtils;
-import org.springframework.security.core.context.SecurityContextHolder;
-import org.springframework.security.core.userdetails.User;
-import org.springframework.security.web.AuthenticationEntryPoint;
-import org.springframework.security.web.authentication.logout.LogoutFilter;
-import org.springframework.security.web.authentication.logout.SecurityContextLogoutHandler;
-
-import javax.servlet.http.HttpSessionEvent;
-
-@SpringBootApplication
-public class CasSecuredAppApplication {
-
-	public static void main(String[] args) {
-		SpringApplication.run(CasSecuredAppApplication.class, args);
-	}
-
-	@Bean
-	public ServiceProperties serviceProperties() {
-	  ServiceProperties serviceProperties = new ServiceProperties();
-	  serviceProperties.setService("http://localhost:9000/login/cas");
-	  serviceProperties.setSendRenew(false);
-	  return serviceProperties;
-	}
-
-	@Bean
-	@Primary
-	public AuthenticationEntryPoint authenticationEntryPoint(ServiceProperties sP) {
-	  CasAuthenticationEntryPoint entryPoint = new CasAuthenticationEntryPoint();
-	  entryPoint.setLoginUrl("https://localhost:6443/cas/login");
-	  entryPoint.setServiceProperties(sP);
-	  return entryPoint;
-	}
-
-	@Bean
-	public TicketValidator ticketValidator() {
-	  return new Cas30ServiceTicketValidator("https://localhost:6443/cas");
-	}
-
-	@Bean
-	public CasAuthenticationProvider casAuthenticationProvider() {
-	  CasAuthenticationProvider provider = new CasAuthenticationProvider();
-	  provider.setServiceProperties(serviceProperties());
-	  provider.setTicketValidator(ticketValidator());
-	  provider.setUserDetailsService((s) -> new User("test@test.com", "smatt",
-        true, true, true, true,
-        AuthorityUtils.createAuthorityList("ROLE_ADMIN")));
-	  provider.setKey("CAS_PROVIDER_LOCALHOST_9000");
-	  return provider;
-	}
-
-
-	@Bean
-	public SecurityContextLogoutHandler securityContextLogoutHandler() {
-	  return new SecurityContextLogoutHandler();
-	}
-
-	@Bean
-	public LogoutFilter logoutFilter() {
-	  LogoutFilter logoutFilter = new LogoutFilter(
-	    "https://localhost:6443/cas/logout", securityContextLogoutHandler());
-	  logoutFilter.setFilterProcessesUrl("/logout/cas");
-	  return logoutFilter;
-	}
-
-	@Bean
-	public SingleSignOutFilter singleSignOutFilter() {
-	  SingleSignOutFilter singleSignOutFilter = new SingleSignOutFilter();
-	  singleSignOutFilter.setCasServerUrlPrefix("https://localhost:6443/cas");
-	  singleSignOutFilter.setIgnoreInitConfiguration(true);
-	  return singleSignOutFilter;
-	}
-
-	@EventListener
-	public SingleSignOutHttpSessionListener singleSignOutHttpSessionListener(HttpSessionEvent event) {
-	  return new SingleSignOutHttpSessionListener();
-	}
-}

cas/cas-secured-app/src/main/java/com/baeldung/cassecuredapp/CasSecuredApplication.java

@@ -0,0 +1,97 @@
+package com.baeldung.cassecuredapp;
+
+import org.jasig.cas.client.session.SingleSignOutFilter;
+import org.jasig.cas.client.session.SingleSignOutHttpSessionListener;
+import org.jasig.cas.client.validation.Cas30ServiceTicketValidator;
+import org.jasig.cas.client.validation.TicketValidator;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Primary;
+import org.springframework.context.event.EventListener;
+import org.springframework.security.authentication.AuthenticationManager;
+import org.springframework.security.cas.ServiceProperties;
+import org.springframework.security.cas.authentication.CasAuthenticationProvider;
+import org.springframework.security.cas.web.CasAuthenticationEntryPoint;
+import org.springframework.security.cas.web.CasAuthenticationFilter;
+import org.springframework.security.core.authority.AuthorityUtils;
+import org.springframework.security.core.userdetails.User;
+import org.springframework.security.web.AuthenticationEntryPoint;
+import org.springframework.security.web.authentication.SavedRequestAwareAuthenticationSuccessHandler;
+import org.springframework.security.web.authentication.logout.LogoutFilter;
+import org.springframework.security.web.authentication.logout.SecurityContextLogoutHandler;
+
+import javax.servlet.http.HttpSessionEvent;
+
+@SpringBootApplication
+public class CasSecuredApplication {
+
+    private static final Logger logger = LoggerFactory.getLogger(CasSecuredApplication.class);
+
+    public static void main(String... args) {
+        SpringApplication.run(CasSecuredApplication.class, args);
+    }
+
+    @Bean
+    public CasAuthenticationFilter casAuthenticationFilter(
+      AuthenticationManager authenticationManager,
+      ServiceProperties serviceProperties) throws Exception {
+        CasAuthenticationFilter filter = new CasAuthenticationFilter();
+        filter.setAuthenticationManager(authenticationManager);
+        filter.setServiceProperties(serviceProperties);
+        return filter;
+    }
+
+    @Bean
+    public ServiceProperties serviceProperties() {
+        logger.info("service properties");
+        ServiceProperties serviceProperties = new ServiceProperties();
+        serviceProperties.setService("http://cas-client:8900/login/cas");
+        serviceProperties.setSendRenew(false);
+        return serviceProperties;
+    }
+
+    @Bean
+    public TicketValidator ticketValidator() {
+        return new Cas30ServiceTicketValidator("https://localhost:8443");
+    }
+
+    @Bean
+    public CasAuthenticationProvider casAuthenticationProvider(
+      TicketValidator ticketValidator,
+      ServiceProperties serviceProperties) {
+        CasAuthenticationProvider provider = new CasAuthenticationProvider();
+        provider.setServiceProperties(serviceProperties);
+        provider.setTicketValidator(ticketValidator);
+        provider.setUserDetailsService(
+          s -> new User("test@test.com", "Mellon", true, true, true, true,
+          AuthorityUtils.createAuthorityList("ROLE_ADMIN")));
+        provider.setKey("CAS_PROVIDER_LOCALHOST_8900");
+        return provider;
+    }
+
+
+    @Bean
+    public SecurityContextLogoutHandler securityContextLogoutHandler() {
+        return new SecurityContextLogoutHandler();
+    }
+
+    @Bean
+    public LogoutFilter logoutFilter() {
+        LogoutFilter logoutFilter = new LogoutFilter("https://localhost:8443/logout", securityContextLogoutHandler());
+        logoutFilter.setFilterProcessesUrl("/logout/cas");
+        return logoutFilter;
+    }
+
+    @Bean
+    public SingleSignOutFilter singleSignOutFilter() {
+        SingleSignOutFilter singleSignOutFilter = new SingleSignOutFilter();
+        singleSignOutFilter.setCasServerUrlPrefix("https://localhost:8443");
+        singleSignOutFilter.setLogoutCallbackPath("/exit/cas");
+        singleSignOutFilter.setIgnoreInitConfiguration(true);
+        return singleSignOutFilter;
+    }
+
+}

cas/cas-secured-app/src/main/java/com/baeldung/cassecuredapp/config/SecurityConfig.java

@@ -1,83 +0,0 @@
-package com.baeldung.cassecuredapp.config;
-
-import org.jasig.cas.client.session.SingleSignOutFilter;
-import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.context.annotation.Bean;
-import org.springframework.context.annotation.Configuration;
-import org.springframework.security.authentication.AuthenticationManager;
-import org.springframework.security.authentication.AuthenticationProvider;
-import org.springframework.security.authentication.ProviderManager;
-import org.springframework.security.cas.ServiceProperties;
-import org.springframework.security.cas.authentication.CasAuthenticationProvider;
-import org.springframework.security.cas.web.CasAuthenticationFilter;
-import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder;
-import org.springframework.security.config.annotation.web.builders.HttpSecurity;
-import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
-import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
-import org.springframework.security.web.AuthenticationEntryPoint;
-import org.springframework.security.web.authentication.logout.LogoutFilter;
-
-import java.util.Arrays;
-
-@EnableWebSecurity
-@Configuration
-public class SecurityConfig extends WebSecurityConfigurerAdapter {
-
-    private AuthenticationProvider authenticationProvider;
-    private AuthenticationEntryPoint authenticationEntryPoint;
-    private SingleSignOutFilter singleSignOutFilter;
-    private LogoutFilter logoutFilter;
-
-    @Autowired
-    public SecurityConfig(CasAuthenticationProvider casAuthenticationProvider, AuthenticationEntryPoint eP,
-                          LogoutFilter lF
-                          , SingleSignOutFilter ssF
-    ) {
-        this.authenticationProvider = casAuthenticationProvider;
-        this.authenticationEntryPoint = eP;
-
-        this.logoutFilter = lF;
-        this.singleSignOutFilter = ssF;
-
-    }
-
-    @Override
-    protected void configure(HttpSecurity http) throws Exception {
-      http
-        .authorizeRequests()
-        .regexMatchers("/secured.*", "/login")
-        .authenticated()
-        .and()
-        .authorizeRequests()
-        .regexMatchers("/")
-        .permitAll()
-        .and()
-        .httpBasic()
-        .authenticationEntryPoint(authenticationEntryPoint)
-        .and()
-        .logout().logoutSuccessUrl("/logout")
-        .and()
-        .addFilterBefore(singleSignOutFilter, CasAuthenticationFilter.class)
-        .addFilterBefore(logoutFilter, LogoutFilter.class);
-
-    }
-
-    @Override
-    protected void configure(AuthenticationManagerBuilder auth) throws Exception {
-      auth.authenticationProvider(authenticationProvider);
-    }
-
-    @Override
-    protected AuthenticationManager authenticationManager() throws Exception {
-      return new ProviderManager(Arrays.asList(authenticationProvider));
-    }
-
-    @Bean
-    public CasAuthenticationFilter casAuthenticationFilter(ServiceProperties sP) throws Exception {
-      CasAuthenticationFilter filter = new CasAuthenticationFilter();
-      filter.setServiceProperties(sP);
-      filter.setAuthenticationManager(authenticationManager());
-      return filter;
-    }
-
-}

cas/cas-secured-app/src/main/java/com/baeldung/cassecuredapp/config/WebSecurityConfig.java

@@ -0,0 +1,79 @@
+package com.baeldung.cassecuredapp.config;
+
+import org.jasig.cas.client.session.SingleSignOutFilter;
+import org.jasig.cas.client.validation.Cas30ServiceTicketValidator;
+import org.jasig.cas.client.validation.TicketValidator;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Primary;
+import org.springframework.security.authentication.AuthenticationManager;
+import org.springframework.security.authentication.ProviderManager;
+import org.springframework.security.cas.ServiceProperties;
+import org.springframework.security.cas.authentication.CasAuthenticationProvider;
+import org.springframework.security.cas.web.CasAuthenticationEntryPoint;
+import org.springframework.security.cas.web.CasAuthenticationFilter;
+import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder;
+import org.springframework.security.config.annotation.web.builders.HttpSecurity;
+import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
+import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
+import org.springframework.security.core.authority.AuthorityUtils;
+import org.springframework.security.core.userdetails.User;
+import org.springframework.security.web.AuthenticationEntryPoint;
+import org.springframework.security.web.authentication.logout.LogoutFilter;
+
+import java.util.Collections;
+
+@EnableWebSecurity
+public class WebSecurityConfig extends WebSecurityConfigurerAdapter {
+
+    private Logger logger = LoggerFactory.getLogger(WebSecurityConfig.class);
+    private SingleSignOutFilter singleSignOutFilter;
+    private LogoutFilter logoutFilter;
+    private CasAuthenticationProvider casAuthenticationProvider;
+    private ServiceProperties serviceProperties;
+
+    @Autowired
+    public WebSecurityConfig(SingleSignOutFilter singleSignOutFilter, LogoutFilter logoutFilter,
+                             CasAuthenticationProvider casAuthenticationProvider,
+                             ServiceProperties serviceProperties) {
+        this.logoutFilter = logoutFilter;
+        this.singleSignOutFilter = singleSignOutFilter;
+        this.serviceProperties = serviceProperties;
+        this.casAuthenticationProvider = casAuthenticationProvider;
+    }
+
+
+    @Override
+    protected void configure(HttpSecurity http) throws Exception {
+        http.authorizeRequests().antMatchers( "/secured", "/login").authenticated()
+          .and()
+          .exceptionHandling().authenticationEntryPoint(authenticationEntryPoint())
+          .and()
+          .addFilterBefore(singleSignOutFilter, CasAuthenticationFilter.class)
+          .addFilterBefore(logoutFilter, LogoutFilter.class)
+          .csrf().ignoringAntMatchers("/exit/cas");
+    }
+
+    @Override
+    protected void configure(AuthenticationManagerBuilder auth) throws Exception {
+        auth.authenticationProvider(casAuthenticationProvider);
+    }
+
+    @Bean
+    @Override
+    protected AuthenticationManager authenticationManager() throws Exception {
+        return new ProviderManager(Collections.singletonList(casAuthenticationProvider));
+    }
+
+    public AuthenticationEntryPoint authenticationEntryPoint() {
+        CasAuthenticationEntryPoint entryPoint = new CasAuthenticationEntryPoint();
+        entryPoint.setLoginUrl("https://localhost:8443/login");
+        entryPoint.setServiceProperties(serviceProperties);
+        return entryPoint;
+    }
+
+
+
+}