Merge pull request #3 from eugenp/master

Update

.gitignore

@@ -19,6 +19,7 @@
 .idea/
 *.iml
 *.iws
+out/
 
 # Mac
 .DS_Store
@@ -27,6 +28,9 @@
 log/
 target/
 
+# Gradle
+.gradle/
+
 spring-openid/src/main/resources/application.properties
 .recommenders/
 /spring-hibernate4/nbproject/

akka-streams/pom.xml

@@ -14,18 +14,19 @@
     <dependencies>
         <dependency>
             <groupId>com.typesafe.akka</groupId>
-            <artifactId>akka-stream_2.11</artifactId>
+            <artifactId>akka-stream_${scala.version}</artifactId>
             <version>${akkastreams.version}</version>
         </dependency>
         <dependency>
             <groupId>com.typesafe.akka</groupId>
-            <artifactId>akka-stream-testkit_2.11</artifactId>
+            <artifactId>akka-stream-testkit_${scala.version}</artifactId>
             <version>${akkastreams.version}</version>
         </dependency>
     </dependencies>
 
     <properties>
         <akkastreams.version>2.5.2</akkastreams.version>
+        <scala.version>2.11</scala.version>
     </properties>
 
 </project>

algorithms-miscellaneous-1/README.md

@@ -14,6 +14,5 @@
 - [Calculate Factorial in Java](https://www.baeldung.com/java-calculate-factorial)
 - [Find Substrings That Are Palindromes in Java](https://www.baeldung.com/java-palindrome-substrings)
 - [Find the Longest Substring without Repeating Characters](https://www.baeldung.com/java-longest-substring-without-repeated-characters)
-- [Java Two Pointer Technique](https://www.baeldung.com/java-two-pointer-technique)
 - [Permutations of an Array in Java](https://www.baeldung.com/java-array-permutations)
-- [Implementing Simple State Machines with Java Enums](https://www.baeldung.com/java-enum-simple-state-machine)
+- [Generate Combinations in Java](https://www.baeldung.com/java-combinations-algorithm)

algorithms-miscellaneous-2/README.md

@@ -8,9 +8,6 @@
 - [Create a Sudoku Solver in Java](http://www.baeldung.com/java-sudoku)
 - [Displaying Money Amounts in Words](http://www.baeldung.com/java-money-into-words)
 - [A Collaborative Filtering Recommendation System in Java](http://www.baeldung.com/java-collaborative-filtering-recommendations)
-- [Converting Between Roman and Arabic Numerals in Java](http://www.baeldung.com/java-convert-roman-arabic)
-- [Practical Java Examples of the Big O Notation](http://www.baeldung.com/java-algorithm-complexity)
-- [An Introduction to the Theory of Big-O Notation](http://www.baeldung.com/big-o-notation)
 - [Check If Two Rectangles Overlap In Java](https://www.baeldung.com/java-check-if-two-rectangles-overlap)
 - [Calculate the Distance Between Two Points in Java](https://www.baeldung.com/java-distance-between-two-points)
 - [Find the Intersection of Two Lines in Java](https://www.baeldung.com/java-intersection-of-two-lines)

algorithms-miscellaneous-2/src/main/java/com/baeldung/algorithms/relativelyprime/RelativelyPrime.java

@@ -0,0 +1,45 @@
+package com.baeldung.algorithms.relativelyprime;
+
+import java.math.BigInteger;
+
+class RelativelyPrime {
+
+    static boolean iterativeRelativelyPrime(int a, int b) {
+        return iterativeGCD(a, b) == 1;
+    }
+
+    static boolean recursiveRelativelyPrime(int a, int b) {
+        return recursiveGCD(a, b) == 1;
+    }
+
+    static boolean bigIntegerRelativelyPrime(int a, int b) {
+        return BigInteger.valueOf(a).gcd(BigInteger.valueOf(b)).equals(BigInteger.ONE);
+    }
+
+    private static int iterativeGCD(int a, int b) {
+        int tmp;
+        while (b != 0) {
+            if (a < b) {
+                tmp = a;
+                a = b;
+                b = tmp;
+            }
+            tmp = b;
+            b = a % b;
+            a = tmp;
+        }
+        return a;
+    }
+
+    private static int recursiveGCD(int a, int b) {
+        if (b == 0) {
+            return a;
+        }
+        if (a < b) {
+            return recursiveGCD(b, a);
+        }
+        return recursiveGCD(b, a % b);
+    }
+
+
+}

algorithms-miscellaneous-2/src/main/java/com/baeldung/algorithms/reversingtree/TreeNode.java

@@ -0,0 +1,42 @@
+package com.baeldung.algorithms.reversingtree;
+
+public class TreeNode {
+
+    private int value;
+    private TreeNode rightChild;
+    private TreeNode leftChild;
+
+    public int getValue() {
+        return value;
+    }
+
+    public void setValue(int value) {
+        this.value = value;
+    }
+
+    public TreeNode getRightChild() {
+        return rightChild;
+    }
+
+    public void setRightChild(TreeNode rightChild) {
+        this.rightChild = rightChild;
+    }
+
+    public TreeNode getLeftChild() {
+        return leftChild;
+    }
+
+    public void setLeftChild(TreeNode leftChild) {
+        this.leftChild = leftChild;
+    }
+
+    public TreeNode(int value, TreeNode leftChild, TreeNode rightChild) {
+        this.value = value;
+        this.rightChild = rightChild;
+        this.leftChild = leftChild;
+    }
+
+    public TreeNode(int value) {
+        this.value = value;
+    }
+}

algorithms-miscellaneous-2/src/main/java/com/baeldung/algorithms/reversingtree/TreeReverser.java

@@ -0,0 +1,53 @@
+package com.baeldung.algorithms.reversingtree;
+
+import java.util.LinkedList;
+
+public class TreeReverser {
+
+    public void reverseRecursive(TreeNode treeNode) {
+        if (treeNode == null) {
+            return;
+        }
+
+        TreeNode temp = treeNode.getLeftChild();
+        treeNode.setLeftChild(treeNode.getRightChild());
+        treeNode.setRightChild(temp);
+
+        reverseRecursive(treeNode.getLeftChild());
+        reverseRecursive(treeNode.getRightChild());
+    }
+
+    public void reverseIterative(TreeNode treeNode) {
+        LinkedList<TreeNode> queue = new LinkedList<TreeNode>();
+
+        if (treeNode != null) {
+            queue.add(treeNode);
+        }
+
+        while (!queue.isEmpty()) {
+
+            TreeNode node = queue.poll();
+            if (node.getLeftChild() != null)
+                queue.add(node.getLeftChild());
+            if (node.getRightChild() != null)
+                queue.add(node.getRightChild());
+
+            TreeNode temp = node.getLeftChild();
+            node.setLeftChild(node.getRightChild());
+            node.setRightChild(temp);
+        }
+    }
+
+    public String toString(TreeNode root) {
+        if (root == null) {
+            return "";
+        }
+
+        StringBuffer buffer = new StringBuffer(String.valueOf(root.getValue())).append(" ");
+
+        buffer.append(toString(root.getLeftChild()));
+        buffer.append(toString(root.getRightChild()));
+
+        return buffer.toString();
+    }
+}

algorithms-miscellaneous-2/src/test/java/com/baeldung/algorithms/relativelyprime/RelativelyPrimeUnitTest.java

@@ -0,0 +1,51 @@
+package com.baeldung.algorithms.relativelyprime;
+
+import org.junit.Test;
+
+import static com.baeldung.algorithms.relativelyprime.RelativelyPrime.*;
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class RelativelyPrimeUnitTest {
+
+    @Test
+    public void givenNonRelativelyPrimeNumbers_whenCheckingIteratively_shouldReturnFalse() {
+
+        boolean result = iterativeRelativelyPrime(45, 35);
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    public void givenRelativelyPrimeNumbers_whenCheckingIteratively_shouldReturnTrue() {
+
+        boolean result = iterativeRelativelyPrime(500, 501);
+        assertThat(result).isTrue();
+    }
+
+    @Test
+    public void givenNonRelativelyPrimeNumbers_whenCheckingRecursively_shouldReturnFalse() {
+
+        boolean result = recursiveRelativelyPrime(45, 35);
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    public void givenRelativelyPrimeNumbers_whenCheckingRecursively_shouldReturnTrue() {
+
+        boolean result = recursiveRelativelyPrime(500, 501);
+        assertThat(result).isTrue();
+    }
+
+    @Test
+    public void givenNonRelativelyPrimeNumbers_whenCheckingUsingBigIntegers_shouldReturnFalse() {
+
+        boolean result = bigIntegerRelativelyPrime(45, 35);
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    public void givenRelativelyPrimeNumbers_whenCheckingBigIntegers_shouldReturnTrue() {
+
+        boolean result = bigIntegerRelativelyPrime(500, 501);
+        assertThat(result).isTrue();
+    }
+}

algorithms-miscellaneous-2/src/test/java/com/baeldung/algorithms/reversingtree/TreeReverserUnitTest.java

@@ -0,0 +1,47 @@
+package com.baeldung.algorithms.reversingtree;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+public class TreeReverserUnitTest {
+
+    @Test
+    public void givenTreeWhenReversingRecursivelyThenReversed() {
+        TreeReverser reverser = new TreeReverser();
+
+        TreeNode treeNode = createBinaryTree();
+
+        reverser.reverseRecursive(treeNode);
+
+        assertEquals("4 7 9 6 2 3 1", reverser.toString(treeNode)
+            .trim());
+    }
+
+    @Test
+    public void givenTreeWhenReversingIterativelyThenReversed() {
+        TreeReverser reverser = new TreeReverser();
+
+        TreeNode treeNode = createBinaryTree();
+
+        reverser.reverseIterative(treeNode);
+
+        assertEquals("4 7 9 6 2 3 1", reverser.toString(treeNode)
+            .trim());
+    }
+
+    private TreeNode createBinaryTree() {
+
+        TreeNode leaf1 = new TreeNode(1);
+        TreeNode leaf2 = new TreeNode(3);
+        TreeNode leaf3 = new TreeNode(6);
+        TreeNode leaf4 = new TreeNode(9);
+
+        TreeNode nodeRight = new TreeNode(7, leaf3, leaf4);
+        TreeNode nodeLeft = new TreeNode(2, leaf1, leaf2);
+
+        TreeNode root = new TreeNode(4, nodeLeft, nodeRight);
+
+        return root;
+    }
+}

algorithms-miscellaneous-3/.gitignore

@@ -0,0 +1,4 @@
+/target/
+.settings/
+.classpath
+.project

algorithms-miscellaneous-3/README.md

@@ -0,0 +1,7 @@
+## Relevant articles:
+
+- [Java Two Pointer Technique](https://www.baeldung.com/java-two-pointer-technique)
+- [Implementing Simple State Machines with Java Enums](https://www.baeldung.com/java-enum-simple-state-machine)
+- [Converting Between Roman and Arabic Numerals in Java](http://www.baeldung.com/java-convert-roman-arabic)
+- [Practical Java Examples of the Big O Notation](http://www.baeldung.com/java-algorithm-complexity)
+- [An Introduction to the Theory of Big-O Notation](http://www.baeldung.com/big-o-notation)

algorithms-miscellaneous-3/pom.xml

@@ -0,0 +1,39 @@
+<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>
+    <name>algorithms-miscellaneous-3</name>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${org.assertj.core.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <pluginManagement>
+            <plugins>
+                <plugin>
+                    <groupId>org.codehaus.mojo</groupId>
+                    <artifactId>exec-maven-plugin</artifactId>
+                    <version>${exec-maven-plugin.version}</version>
+                </plugin>
+            </plugins>
+        </pluginManagement>
+    </build>
+
+    <properties>
+        <org.assertj.core.version>3.9.0</org.assertj.core.version>
+    </properties>
+
+</project>

antlr/pom.xml

@@ -10,6 +10,14 @@
         <version>1.0.0-SNAPSHOT</version>
     </parent>
 
+    <dependencies>
+        <dependency>
+            <groupId>org.antlr</groupId>
+            <artifactId>antlr4-runtime</artifactId>
+            <version>${antlr.version}</version>
+        </dependency>
+    </dependencies>
+
     <build>
         <plugins>
             <plugin>
@@ -44,13 +52,7 @@
             </plugin>
         </plugins>
     </build>
-    <dependencies>
-        <dependency>
-            <groupId>org.antlr</groupId>
-            <artifactId>antlr4-runtime</artifactId>
-            <version>${antlr.version}</version>
-        </dependency>
-    </dependencies>
+    	
     <properties>
         <antlr.version>4.7.1</antlr.version>
         <mojo.version>3.0.0</mojo.version>

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

@@ -12,9 +12,18 @@
         <version>0.0.1-SNAPSHOT</version>
     </parent>
 
-    <properties>
-        <cxf-version>3.2.0</cxf-version>
-    </properties>
+    <dependencies>
+        <dependency>
+            <groupId>org.apache.cxf</groupId>
+            <artifactId>cxf-rt-rs-client</artifactId>
+            <version>${cxf-version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.cxf</groupId>
+            <artifactId>cxf-rt-rs-sse</artifactId>
+            <version>${cxf-version}</version>
+        </dependency>
+    </dependencies>
 
     <build>
         <plugins>
@@ -45,17 +54,8 @@
         </plugins>
     </build>
 
-    <dependencies>
-        <dependency>
-            <groupId>org.apache.cxf</groupId>
-            <artifactId>cxf-rt-rs-client</artifactId>
-            <version>${cxf-version}</version>
-        </dependency>
-        <dependency>
-            <groupId>org.apache.cxf</groupId>
-            <artifactId>cxf-rt-rs-sse</artifactId>
-            <version>${cxf-version}</version>
-        </dependency>
-    </dependencies>
+    <properties>
+        <cxf-version>3.2.0</cxf-version>
+    </properties>
 
 </project>

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

@@ -13,11 +13,28 @@
         <version>0.0.1-SNAPSHOT</version>
     </parent>
 
-    <properties>
-        <liberty-maven-plugin.version>2.4.2</liberty-maven-plugin.version>
-        <failOnMissingWebXml>false</failOnMissingWebXml>
-        <openliberty-version>18.0.0.2</openliberty-version>
-    </properties>
+    <dependencies>
+
+        <dependency>
+            <groupId>javax.ws.rs</groupId>
+            <artifactId>javax.ws.rs-api</artifactId>
+            <version>2.1</version>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>javax.enterprise</groupId>
+            <artifactId>cdi-api</artifactId>
+            <version>2.0</version>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>javax.json.bind</groupId>
+            <artifactId>javax.json.bind-api</artifactId>
+            <version>1.0</version>
+            <scope>provided</scope>
+        </dependency>
+
+    </dependencies>
 
     <build>
         <finalName>${project.artifactId}</finalName>
@@ -59,27 +76,10 @@
         </plugins>
     </build>
 
-    <dependencies>
-
-        <dependency>
-            <groupId>javax.ws.rs</groupId>
-            <artifactId>javax.ws.rs-api</artifactId>
-            <version>2.1</version>
-            <scope>provided</scope>
-        </dependency>
-        <dependency>
-            <groupId>javax.enterprise</groupId>
-            <artifactId>cdi-api</artifactId>
-            <version>2.0</version>
-            <scope>provided</scope>
-        </dependency>
-        <dependency>
-            <groupId>javax.json.bind</groupId>
-            <artifactId>javax.json.bind-api</artifactId>
-            <version>1.0</version>
-            <scope>provided</scope>
-        </dependency>
-
-    </dependencies>
+    <properties>
+        <liberty-maven-plugin.version>2.4.2</liberty-maven-plugin.version>
+        <failOnMissingWebXml>false</failOnMissingWebXml>
+        <openliberty-version>18.0.0.2</openliberty-version>
+    </properties>
 
 </project>

apache-fop/README.md

@@ -3,7 +3,3 @@
 ## Core Java Cookbooks and Examples
 
 ### Relevant Articles: 
-- [Immutable ArrayList in Java](http://www.baeldung.com/java-immutable-list)
-- [Java - Reading a Large File Efficiently](http://www.baeldung.com/java-read-lines-large-file)
-- [Java InputStream to String](http://www.baeldung.com/convert-input-stream-to-string)
-

apache-meecrowave/pom.xml

@@ -6,6 +6,12 @@
     <version>0.0.1</version>
     <name>apache-meecrowave</name>
     <description>A sample REST API application with Meecrowave</description>
+    
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
 
     <dependencies>
         <!-- https://mvnrepository.com/artifact/org.apache.meecrowave/meecrowave-core -->

apache-meecrowave/src/test/java/com/baeldung/meecrowave/ArticleEndpointsUnitTest.java

@@ -17,7 +17,7 @@ import okhttp3.Request;
 import okhttp3.Response;
 
 @RunWith(MonoMeecrowave.Runner.class)
-public class ArticleEndpointsTest {
+public class ArticleEndpointsUnitTest {
     
     @ConfigurationInject
     private Meecrowave.Builder config;

autovalue/src/main/java/com/baeldung/autofactory/provided/IntermediateAssembler.java

@@ -1,8 +1,9 @@
 package com.baeldung.autofactory.provided;
 
+import com.baeldung.autofactory.model.Camera;
 import com.google.auto.factory.AutoFactory;
 import com.google.auto.factory.Provided;
-import javafx.scene.Camera;
+
 
 import javax.inject.Provider;
 

azure/README.md

@@ -1,4 +1,4 @@
 ### Relevant Articles:
 
-- [Deploy Spring Boot App to Azure](http://www.baeldung.com/spring-boot-azure)
+- [Deploy a Spring Boot App to Azure](http://www.baeldung.com/spring-boot-azure)
 

blade/README.md

@@ -1,5 +1,5 @@
 ### Relevant Articles: 
 
-- [Blade - A Complete GuideBook](http://www.baeldung.com/blade) 
+- [Blade – A Complete Guidebook](http://www.baeldung.com/blade) 
 
-Run Integration Tests with `mvn integration-test`
+Run Integration Tests with `mvn integration-test`

cloud-foundry-uaa/README.md

@@ -0,0 +1,3 @@
+### Revelant Articles
+
+- [A Quick Guide To Using Cloud Foundry UAA](https://www.baeldung.com/cloud-foundry-uaa)

cloud-foundry-uaa/cf-uaa-config/uaa.yml

@@ -0,0 +1,68 @@
+issuer:
+  uri: http://localhost:8080/uaa
+
+spring_profiles: default,hsqldb
+  
+encryption:
+  active_key_label: CHANGE-THIS-KEY
+  encryption_keys:
+    - label: CHANGE-THIS-KEY
+      passphrase: CHANGEME
+
+login:
+  serviceProviderKey: |
+    -----BEGIN RSA PRIVATE KEY-----
+    MIICXQIBAAKBgQDHtC5gUXxBKpEqZTLkNvFwNGnNIkggNOwOQVNbpO0WVHIivig5
+    L39WqS9u0hnA+O7MCA/KlrAR4bXaeVVhwfUPYBKIpaaTWFQR5cTR1UFZJL/OF9vA
+    fpOwznoD66DDCnQVpbCjtDYWX+x6imxn8HCYxhMol6ZnTbSsFW6VZjFMjQIDAQAB
+    AoGAVOj2Yvuigi6wJD99AO2fgF64sYCm/BKkX3dFEw0vxTPIh58kiRP554Xt5ges
+    7ZCqL9QpqrChUikO4kJ+nB8Uq2AvaZHbpCEUmbip06IlgdA440o0r0CPo1mgNxGu
+    lhiWRN43Lruzfh9qKPhleg2dvyFGQxy5Gk6KW/t8IS4x4r0CQQD/dceBA+Ndj3Xp
+    ubHfxqNz4GTOxndc/AXAowPGpge2zpgIc7f50t8OHhG6XhsfJ0wyQEEvodDhZPYX
+    kKBnXNHzAkEAyCA76vAwuxqAd3MObhiebniAU3SnPf2u4fdL1EOm92dyFs1JxyyL
+    gu/DsjPjx6tRtn4YAalxCzmAMXFSb1qHfwJBAM3qx3z0gGKbUEWtPHcP7BNsrnWK
+    vw6By7VC8bk/ffpaP2yYspS66Le9fzbFwoDzMVVUO/dELVZyBnhqSRHoXQcCQQCe
+    A2WL8S5o7Vn19rC0GVgu3ZJlUrwiZEVLQdlrticFPXaFrn3Md82ICww3jmURaKHS
+    N+l4lnMda79eSp3OMmq9AkA0p79BvYsLshUJJnvbk76pCjR28PK4dV1gSDUEqQMB
+    qy45ptdwJLqLJCeNoR0JUcDNIRhOCuOPND7pcMtX6hI/
+    -----END RSA PRIVATE KEY-----
+  serviceProviderKeyPassword: password
+  serviceProviderCertificate: |
+    -----BEGIN CERTIFICATE-----
+    MIIDSTCCArKgAwIBAgIBADANBgkqhkiG9w0BAQQFADB8MQswCQYDVQQGEwJhdzEO
+    MAwGA1UECBMFYXJ1YmExDjAMBgNVBAoTBWFydWJhMQ4wDAYDVQQHEwVhcnViYTEO
+    MAwGA1UECxMFYXJ1YmExDjAMBgNVBAMTBWFydWJhMR0wGwYJKoZIhvcNAQkBFg5h
+    cnViYUBhcnViYS5hcjAeFw0xNTExMjAyMjI2MjdaFw0xNjExMTkyMjI2MjdaMHwx
+    CzAJBgNVBAYTAmF3MQ4wDAYDVQQIEwVhcnViYTEOMAwGA1UEChMFYXJ1YmExDjAM
+    BgNVBAcTBWFydWJhMQ4wDAYDVQQLEwVhcnViYTEOMAwGA1UEAxMFYXJ1YmExHTAb
+    BgkqhkiG9w0BCQEWDmFydWJhQGFydWJhLmFyMIGfMA0GCSqGSIb3DQEBAQUAA4GN
+    ADCBiQKBgQDHtC5gUXxBKpEqZTLkNvFwNGnNIkggNOwOQVNbpO0WVHIivig5L39W
+    qS9u0hnA+O7MCA/KlrAR4bXaeVVhwfUPYBKIpaaTWFQR5cTR1UFZJL/OF9vAfpOw
+    znoD66DDCnQVpbCjtDYWX+x6imxn8HCYxhMol6ZnTbSsFW6VZjFMjQIDAQABo4Ha
+    MIHXMB0GA1UdDgQWBBTx0lDzjH/iOBnOSQaSEWQLx1syGDCBpwYDVR0jBIGfMIGc
+    gBTx0lDzjH/iOBnOSQaSEWQLx1syGKGBgKR+MHwxCzAJBgNVBAYTAmF3MQ4wDAYD
+    VQQIEwVhcnViYTEOMAwGA1UEChMFYXJ1YmExDjAMBgNVBAcTBWFydWJhMQ4wDAYD
+    VQQLEwVhcnViYTEOMAwGA1UEAxMFYXJ1YmExHTAbBgkqhkiG9w0BCQEWDmFydWJh
+    QGFydWJhLmFyggEAMAwGA1UdEwQFMAMBAf8wDQYJKoZIhvcNAQEEBQADgYEAYvBJ
+    0HOZbbHClXmGUjGs+GS+xC1FO/am2suCSYqNB9dyMXfOWiJ1+TLJk+o/YZt8vuxC
+    KdcZYgl4l/L6PxJ982SRhc83ZW2dkAZI4M0/Ud3oePe84k8jm3A7EvH5wi5hvCkK
+    RpuRBwn3Ei+jCRouxTbzKPsuCVB+1sNyxMTXzf0=
+    -----END CERTIFICATE-----
+
+#The secret that an external login server will use to authenticate to the uaa using the id `login`
+LOGIN_SECRET: loginsecret
+
+jwt:
+  token:
+    signing-key: |
+      -----BEGIN RSA PRIVATE KEY-----
+      MIIEpAIBAAKCAQEAqUeygEfDGxI6c1VDQ6xIyUSLrP6iz1y97iHFbtXSxXaArL4a
+      ...
+      v6Mtt5LcRAAVP7pemunTdju4h8Q/noKYlVDVL30uLYUfKBL4UKfOBw==
+      -----END RSA PRIVATE KEY-----
+    verification-key: |
+      -----BEGIN PUBLIC KEY-----
+      MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAqUeygEfDGxI6c1VDQ6xI
+      ...
+      AwIDAQAB
+      -----END PUBLIC KEY-----

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

@@ -0,0 +1,41 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <groupId>com.example</groupId>
+    <artifactId>cf-uaa-oauth2-client</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <name>uaa-client-webapp</name>
+    <description>Demo project for Spring Boot</description>
+
+    <parent>
+        <artifactId>parent-boot-2</artifactId>
+        <groupId>com.baeldung</groupId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../../parent-boot-2</relativePath>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-oauth2-client</artifactId>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+            </plugin>
+        </plugins>
+    </build>
+
+    <properties>
+        <java.version>1.8</java.version>
+    </properties>
+</project>

cloud-foundry-uaa/cf-uaa-oauth2-client/src/main/java/com/baeldung/cfuaa/oauth2/client/CFUAAOAuth2ClientApplication.java

@@ -0,0 +1,13 @@
+package com.baeldung.cfuaa.oauth2.client;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class CFUAAOAuth2ClientApplication {
+
+	public static void main(String[] args) {
+		SpringApplication.run(CFUAAOAuth2ClientApplication.class, args);
+	}
+
+}

cloud-foundry-uaa/cf-uaa-oauth2-client/src/main/java/com/baeldung/cfuaa/oauth2/client/CFUAAOAuth2ClientController.java

@@ -0,0 +1,80 @@
+package com.baeldung.cfuaa.oauth2.client;
+
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.http.HttpEntity;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpMethod;
+import org.springframework.http.ResponseEntity;
+import org.springframework.security.oauth2.client.OAuth2AuthorizedClient;
+import org.springframework.security.oauth2.client.OAuth2AuthorizedClientService;
+import org.springframework.security.oauth2.client.authentication.OAuth2AuthenticationToken;
+import org.springframework.security.oauth2.core.OAuth2AccessToken;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.client.HttpClientErrorException;
+import org.springframework.web.client.RestTemplate;
+
+@RestController
+public class CFUAAOAuth2ClientController {
+
+    @Value("${resource.server.url}")
+    private String remoteResourceServer;
+
+    private RestTemplate restTemplate;
+
+    private OAuth2AuthorizedClientService authorizedClientService;
+
+    public CFUAAOAuth2ClientController(OAuth2AuthorizedClientService authorizedClientService) {
+        this.authorizedClientService = authorizedClientService;
+        this.restTemplate = new RestTemplate();
+    }
+
+    @RequestMapping("/")
+    public String index(OAuth2AuthenticationToken authenticationToken) {
+        OAuth2AuthorizedClient oAuth2AuthorizedClient = this.authorizedClientService.loadAuthorizedClient(authenticationToken.getAuthorizedClientRegistrationId(), authenticationToken.getName());
+        OAuth2AccessToken oAuth2AccessToken = oAuth2AuthorizedClient.getAccessToken();
+
+        String response = "Hello, " + authenticationToken.getPrincipal().getName();
+        response += "</br></br>";
+        response += "Here is your accees token :</br>" + oAuth2AccessToken.getTokenValue();
+        response += "</br>";
+        response += "</br>You can use it to call these Resource Server APIs:";
+        response += "</br></br>";
+        response += "<a href='/read'>Call Resource Server Read API</a>";
+        response += "</br>";
+        response += "<a href='/write'>Call Resource Server Write API</a>";
+        return response;
+    }
+
+    @RequestMapping("/read")
+    public String read(OAuth2AuthenticationToken authenticationToken) {
+        String url = remoteResourceServer + "/read";
+        return callResourceServer(authenticationToken, url);
+    }
+
+    @RequestMapping("/write")
+    public String write(OAuth2AuthenticationToken authenticationToken) {
+        String url = remoteResourceServer + "/write";
+        return callResourceServer(authenticationToken, url);
+    }
+
+    private String callResourceServer(OAuth2AuthenticationToken authenticationToken, String url) {
+        OAuth2AuthorizedClient oAuth2AuthorizedClient = this.authorizedClientService.loadAuthorizedClient(authenticationToken.getAuthorizedClientRegistrationId(), authenticationToken.getName());
+        OAuth2AccessToken oAuth2AccessToken = oAuth2AuthorizedClient.getAccessToken();
+
+        HttpHeaders headers = new HttpHeaders();
+        headers.add("Authorization", "Bearer " + oAuth2AccessToken.getTokenValue());
+
+        HttpEntity<String> entity = new HttpEntity<>("parameters", headers);
+        ResponseEntity<String> responseEntity = null;
+
+        String response = null;
+        try {
+            responseEntity = restTemplate.exchange(url, HttpMethod.GET, entity, String.class);
+            response = responseEntity.getBody();
+        } catch (HttpClientErrorException e) {
+            response = e.getMessage();
+        }
+        return response;
+    }
+}

cloud-foundry-uaa/cf-uaa-oauth2-client/src/main/resources/application.properties

@@ -0,0 +1,11 @@
+server.port=8081
+
+resource.server.url=http://localhost:8082
+
+spring.security.oauth2.client.registration.uaa.client-name=Web App Client
+spring.security.oauth2.client.registration.uaa.client-id=webappclient
+spring.security.oauth2.client.registration.uaa.client-secret=webappclientsecret
+spring.security.oauth2.client.registration.uaa.scope=resource.read,resource.write,openid,profile
+
+spring.security.oauth2.client.provider.uaa.issuer-uri=http://localhost:8080/uaa/oauth/token
+

cloud-foundry-uaa/cf-uaa-oauth2-client/src/main/resources/templates/index.html

@@ -0,0 +1 @@
+tintin

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

@@ -0,0 +1,42 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <groupId>com.baeldung.cfuaa</groupId>
+    <artifactId>cf-uaa-oauth2-resource-server</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <name>cf-uaa-oauth2-resource-server</name>
+    <description>Demo project for Spring Boot</description>
+
+    <parent>
+        <artifactId>parent-boot-2</artifactId>
+        <groupId>com.baeldung</groupId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../../parent-boot-2</relativePath>
+    </parent>
+	
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-oauth2-resource-server</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+            </plugin>
+        </plugins>
+    </build>
+
+    <properties>
+        <java.version>1.8</java.version>
+    </properties>
+
+</project>

cloud-foundry-uaa/cf-uaa-oauth2-resource-server/src/main/java/com/baeldung/cfuaa/oauth2/resourceserver/CFUAAOAuth2ResourceServerApplication.java

@@ -0,0 +1,13 @@
+package com.baeldung.cfuaa.oauth2.resourceserver;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class CFUAAOAuth2ResourceServerApplication {
+
+	public static void main(String[] args) {
+		SpringApplication.run(CFUAAOAuth2ResourceServerApplication.class, args);
+	}
+
+}

cloud-foundry-uaa/cf-uaa-oauth2-resource-server/src/main/java/com/baeldung/cfuaa/oauth2/resourceserver/CFUAAOAuth2ResourceServerRestController.java

@@ -0,0 +1,28 @@
+package com.baeldung.cfuaa.oauth2.resourceserver;
+
+import org.springframework.security.core.annotation.AuthenticationPrincipal;
+import org.springframework.security.oauth2.jwt.Jwt;
+import org.springframework.security.oauth2.server.resource.authentication.JwtAuthenticationToken;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.security.Principal;
+
+@RestController
+public class CFUAAOAuth2ResourceServerRestController {
+
+    @GetMapping("/")
+    public String index(@AuthenticationPrincipal Jwt jwt) {
+        return String.format("Hello, %s!", jwt.getSubject());
+    }
+
+    @GetMapping("/read")
+    public String read(JwtAuthenticationToken jwtAuthenticationToken) {
+        return "Hello write: " + jwtAuthenticationToken.getTokenAttributes();
+    }
+
+    @GetMapping("/write")
+    public String write(Principal principal) {
+        return "Hello write: " + principal.getName();
+    }
+}

cloud-foundry-uaa/cf-uaa-oauth2-resource-server/src/main/java/com/baeldung/cfuaa/oauth2/resourceserver/CFUAAOAuth2ResourceServerSecurityConfiguration.java

@@ -0,0 +1,21 @@
+package com.baeldung.cfuaa.oauth2.resourceserver;
+
+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;
+
+@EnableWebSecurity
+public class CFUAAOAuth2ResourceServerSecurityConfiguration extends WebSecurityConfigurerAdapter {
+
+	@Override
+	protected void configure(HttpSecurity http) throws Exception {
+		http
+			.authorizeRequests()
+                .antMatchers("/read/**").hasAuthority("SCOPE_resource.read")
+                .antMatchers("/write/**").hasAuthority("SCOPE_resource.write")
+                .anyRequest().authenticated()
+				.and()
+			.oauth2ResourceServer()
+				.jwt();
+	}
+}

cloud-foundry-uaa/cf-uaa-oauth2-resource-server/src/main/resources/application.properties

@@ -0,0 +1,3 @@
+server.port=8082
+
+spring.security.oauth2.resourceserver.jwt.issuer-uri=http://localhost:8080/uaa/oauth/token

core-groovy-2/README.md

@@ -0,0 +1,7 @@
+# Groovy
+
+## Relevant articles:
+
+- [String Matching in Groovy](http://www.baeldung.com/)
+- [Groovy def Keyword]
+

core-groovy-2/pom.xml

@@ -0,0 +1,131 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>core-groovy-2</artifactId>
+    <version>1.0-SNAPSHOT</version>
+    <name>core-groovy-2</name>
+    <packaging>jar</packaging>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.codehaus.groovy</groupId>
+            <artifactId>groovy</artifactId>
+            <version>${groovy.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.codehaus.groovy</groupId>
+            <artifactId>groovy-all</artifactId>
+            <version>${groovy-all.version}</version>
+            <type>pom</type>
+        </dependency>
+        <dependency>
+            <groupId>org.codehaus.groovy</groupId>
+            <artifactId>groovy-dateutil</artifactId>
+            <version>${groovy.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.codehaus.groovy</groupId>
+            <artifactId>groovy-sql</artifactId>
+            <version>${groovy-sql.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.platform</groupId>
+            <artifactId>junit-platform-runner</artifactId>
+            <version>${junit.platform.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.hsqldb</groupId>
+            <artifactId>hsqldb</artifactId>
+            <version>${hsqldb.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.spockframework</groupId>
+            <artifactId>spock-core</artifactId>
+            <version>${spock-core.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.codehaus.gmavenplus</groupId>
+                <artifactId>gmavenplus-plugin</artifactId>
+                <version>${gmavenplus-plugin.version}</version>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>addSources</goal>
+                            <goal>addTestSources</goal>
+                            <goal>compile</goal>
+                            <goal>compileTests</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+            <plugin>
+                <artifactId>maven-failsafe-plugin</artifactId>
+                <version>${maven-failsafe-plugin.version}</version>
+                <dependencies>
+                    <dependency>
+                        <groupId>org.junit.platform</groupId>
+                        <artifactId>junit-platform-surefire-provider</artifactId>
+                        <version>${junit.platform.version}</version>
+                    </dependency>
+                </dependencies>
+                <executions>
+                    <execution>
+                        <id>junit5</id>
+                        <goals>
+                            <goal>integration-test</goal>
+                            <goal>verify</goal>
+                        </goals>
+                        <configuration>
+                            <includes>
+                                <include>**/*Test5.java</include>
+                            </includes>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+            <plugin>
+                <artifactId>maven-surefire-plugin</artifactId>
+                <version>2.20.1</version>
+                <configuration>
+                <useFile>false</useFile>
+                <includes>
+                    <include>**/*Test.java</include>
+                    <include>**/*Spec.java</include>
+                </includes>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+    <repositories>
+        <repository>
+            <id>central</id>
+            <url>http://jcenter.bintray.com</url>
+        </repository>
+    </repositories>
+
+    <properties>
+        <junit.platform.version>1.0.0</junit.platform.version>
+        <groovy.version>2.5.6</groovy.version>
+        <groovy-all.version>2.5.6</groovy-all.version>
+        <groovy-sql.version>2.5.6</groovy-sql.version>
+        <hsqldb.version>2.4.0</hsqldb.version>
+        <spock-core.version>1.1-groovy-2.4</spock-core.version>
+        <gmavenplus-plugin.version>1.6</gmavenplus-plugin.version>
+    </properties>
+</project>
+

core-groovy-2/src/test/groovy/com/baeldung/defkeyword/DefUnitTest.groovy

@@ -0,0 +1,79 @@
+package com.baeldung.defkeyword
+
+import org.codehaus.groovy.runtime.NullObject
+import org.codehaus.groovy.runtime.typehandling.GroovyCastException
+
+import groovy.transform.TypeChecked
+import groovy.transform.TypeCheckingMode
+
+@TypeChecked
+class DefUnitTest extends GroovyTestCase {
+    
+    def id
+    def firstName = "Samwell"
+    def listOfCountries = ['USA', 'UK', 'FRANCE', 'INDIA']
+    
+    @TypeChecked(TypeCheckingMode.SKIP)
+    def multiply(x, y) {
+        return x*y
+    }
+        
+    @TypeChecked(TypeCheckingMode.SKIP)
+    void testDefVariableDeclaration() {
+        
+        def list
+        assert list.getClass() == org.codehaus.groovy.runtime.NullObject
+        assert list.is(null)
+        
+        list = [1,2,4]
+        assert list instanceof ArrayList
+    }
+    
+    @TypeChecked(TypeCheckingMode.SKIP)
+    void testTypeVariables() {   
+        int rate = 200
+        try {
+            rate = [12] //GroovyCastException
+            rate = "nill" //GroovyCastException
+        } catch(GroovyCastException) {
+            println "Cannot assign anything other than integer"
+        }
+    }
+     
+    @TypeChecked(TypeCheckingMode.SKIP)
+    void testDefVariableMultipleAssignment() {
+        def rate
+        assert rate == null
+        assert rate.getClass() == org.codehaus.groovy.runtime.NullObject
+        
+        rate = 12
+        assert rate instanceof Integer
+        
+        rate = "Not Available"
+        assert rate instanceof String
+        
+        rate = [1, 4]
+        assert rate instanceof List
+        
+        assert divide(12, 3) instanceof BigDecimal
+        assert divide(1, 0) instanceof String
+
+    }
+    
+    def divide(int x, int y) {
+        if(y==0) {
+            return "Should not divide by 0"
+        } else {
+            return x/y
+        }
+    }
+    
+    def greetMsg() {
+        println "Hello! I am Groovy"
+    }
+    
+    void testDefVsType() {
+        def int count
+        assert count instanceof Integer
+    }
+}

core-groovy-2/src/test/groovy/com/baeldung/strings/StringMatchingSpec.groovy

@@ -0,0 +1,44 @@
+package com.baeldung.strings
+
+import spock.lang.Specification
+
+import java.util.regex.Pattern
+
+class StringMatchingSpec extends Specification {
+
+    def "pattern operator example"() {
+        given: "a pattern"
+        def p = ~'foo'
+
+        expect:
+        p instanceof Pattern
+
+        and: "you can use slash strings to avoid escaping of blackslash"
+        def digitPattern = ~/\d*/
+        digitPattern.matcher('4711').matches()
+    }
+
+    def "match operator example"() {
+        expect:
+        'foobar' ==~ /.*oba.*/
+
+        and: "matching is strict"
+        !('foobar' ==~ /foo/)
+    }
+
+    def "find operator example"() {
+        when: "using the find operator"
+        def matcher = 'foo and bar, baz and buz' =~ /(\w+) and (\w+)/
+
+        then: "will find groups"
+        matcher.size() == 2
+
+        and: "can access groups using array"
+        matcher[0][0] == 'foo and bar'
+        matcher[1][2] == 'buz'
+
+        and: "you can use it as a predicate"
+        'foobarbaz' =~ /bar/
+    }
+
+}

core-groovy-collections/README.md

@@ -0,0 +1,6 @@
+# Groovy
+
+## Relevant articles:
+
+- [Maps in Groovy](http://www.baeldung.com/)
+

core-groovy-collections/pom.xml

@@ -0,0 +1,131 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>core-groovy-collections</artifactId>
+    <version>1.0-SNAPSHOT</version>
+    <name>core-groovy-collections</name>
+    <packaging>jar</packaging>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.codehaus.groovy</groupId>
+            <artifactId>groovy</artifactId>
+            <version>${groovy.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.codehaus.groovy</groupId>
+            <artifactId>groovy-all</artifactId>
+            <version>${groovy-all.version}</version>
+            <type>pom</type>
+        </dependency>
+        <dependency>
+            <groupId>org.codehaus.groovy</groupId>
+            <artifactId>groovy-dateutil</artifactId>
+            <version>${groovy.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.codehaus.groovy</groupId>
+            <artifactId>groovy-sql</artifactId>
+            <version>${groovy-sql.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.platform</groupId>
+            <artifactId>junit-platform-runner</artifactId>
+            <version>${junit.platform.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.hsqldb</groupId>
+            <artifactId>hsqldb</artifactId>
+            <version>${hsqldb.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.spockframework</groupId>
+            <artifactId>spock-core</artifactId>
+            <version>${spock-core.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.codehaus.gmavenplus</groupId>
+                <artifactId>gmavenplus-plugin</artifactId>
+                <version>${gmavenplus-plugin.version}</version>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>addSources</goal>
+                            <goal>addTestSources</goal>
+                            <goal>compile</goal>
+                            <goal>compileTests</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+            <plugin>
+                <artifactId>maven-failsafe-plugin</artifactId>
+                <version>${maven-failsafe-plugin.version}</version>
+                <dependencies>
+                    <dependency>
+                        <groupId>org.junit.platform</groupId>
+                        <artifactId>junit-platform-surefire-provider</artifactId>
+                        <version>${junit.platform.version}</version>
+                    </dependency>
+                </dependencies>
+                <executions>
+                    <execution>
+                        <id>junit5</id>
+                        <goals>
+                            <goal>integration-test</goal>
+                            <goal>verify</goal>
+                        </goals>
+                        <configuration>
+                            <includes>
+                                <include>**/*Test5.java</include>
+                            </includes>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+            <plugin>
+                <artifactId>maven-surefire-plugin</artifactId>
+                <version>2.20.1</version>
+                <configuration>
+                <useFile>false</useFile>
+                <includes>
+                    <include>**/*Test.java</include>
+                    <include>**/*Spec.java</include>
+                </includes>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+    <repositories>
+        <repository>
+            <id>central</id>
+            <url>http://jcenter.bintray.com</url>
+        </repository>
+    </repositories>
+
+    <properties>
+        <junit.platform.version>1.0.0</junit.platform.version>
+        <groovy.version>2.5.6</groovy.version>
+        <groovy-all.version>2.5.6</groovy-all.version>
+        <groovy-sql.version>2.5.6</groovy-sql.version>
+        <hsqldb.version>2.4.0</hsqldb.version>
+        <spock-core.version>1.1-groovy-2.4</spock-core.version>
+        <gmavenplus-plugin.version>1.6</gmavenplus-plugin.version>
+    </properties>
+</project>
+

core-groovy-collections/src/test/groovy/com/baeldung/map/MapTest.groovy

@@ -0,0 +1,148 @@
+package com.baeldung.map;
+
+import static groovy.test.GroovyAssert.*
+import org.junit.Test
+
+class MapTest{
+
+    @Test
+    void createMap() {
+
+        def emptyMap = [:]
+        assertNotNull(emptyMap)
+
+        assertTrue(emptyMap instanceof java.util.LinkedHashMap)
+
+        def map = [name:"Jerry", age: 42, city: "New York"]
+        assertTrue(map.size() == 3)
+    }
+
+    @Test
+    void addItemsToMap() {
+
+        def map = [name:"Jerry"]
+
+        map["age"] = 42
+
+        map.city = "New York"
+
+        def hobbyLiteral = "hobby"
+        def hobbyMap = [(hobbyLiteral): "Singing"]
+        map.putAll(hobbyMap)
+
+        assertTrue(map == [name:"Jerry", age: 42, city: "New York", hobby:"Singing"])
+        assertTrue(hobbyMap.hobby == "Singing")
+        assertTrue(hobbyMap[hobbyLiteral] == "Singing")
+        
+        map.plus([1:20]) // returns new map
+
+        map << [2:30]
+
+    }
+
+    @Test
+    void getItemsFromMap() {
+
+        def map = [name:"Jerry", age: 42, city: "New York", hobby:"Singing"]
+
+        assertTrue(map["name"] == "Jerry")
+
+        assertTrue(map.name == "Jerry")
+
+        def propertyAge = "age"
+        assertTrue(map[propertyAge] == 42)
+    }
+
+    @Test
+    void removeItemsFromMap() {
+
+        def map = [1:20, a:30, 2:42, 4:34, ba:67, 6:39, 7:49]
+
+        def minusMap = map.minus([2:42, 4:34]);
+        assertTrue(minusMap == [1:20, a:30, ba:67, 6:39, 7:49])
+
+        minusMap.removeAll{it -> it.key instanceof String}
+        assertTrue( minusMap == [ 1:20, 6:39, 7:49])
+
+        minusMap.retainAll{it -> it.value %2 == 0}
+        assertTrue( minusMap == [1:20])
+    }
+
+    @Test
+    void iteratingOnMaps(){
+        def map = [name:"Jerry", age: 42, city: "New York", hobby:"Singing"]
+
+        map.each{ entry -> println "$entry.key: $entry.value" }
+
+        map.eachWithIndex{ entry, i -> println "$i $entry.key: $entry.value" }
+
+        map.eachWithIndex{ key, value, i -> println "$i $key: $value" }
+    }
+
+    @Test
+    void filteringAndSearchingMaps(){
+        def map = [name:"Jerry", age: 42, city: "New York", hobby:"Singing"]
+
+        assertTrue(map.find{ it.value == "New York"}.key == "city")
+
+        assertTrue(map.findAll{ it.value == "New York"} == [city : "New York"])
+
+        map.grep{it.value == "New York"}.each{ it -> assertTrue(it.key == "city" && it.value == "New York")}
+
+        assertTrue(map.every{it -> it.value instanceof String} == false)
+
+        assertTrue(map.any{it -> it.value instanceof String} == true)
+    }
+
+    @Test
+    void collect(){
+
+        def map = [1: [name:"Jerry", age: 42, city: "New York"],
+            2: [name:"Long", age: 25, city: "New York"],
+            3: [name:"Dustin", age: 29, city: "New York"],
+            4: [name:"Dustin", age: 34, city: "New York"]]
+
+        def names = map.collect{entry -> entry.value.name} // returns only list
+        assertTrue(names == ["Jerry", "Long", "Dustin", "Dustin"])
+
+        def uniqueNames = map.collect([] as HashSet){entry -> entry.value.name}
+        assertTrue(uniqueNames == ["Jerry", "Long", "Dustin"] as Set)
+
+        def idNames = map.collectEntries{key, value -> [key, value.name]}
+        assertTrue(idNames == [1:"Jerry", 2: "Long", 3:"Dustin", 4: "Dustin"])
+
+        def below30Names = map.findAll{it.value.age < 30}.collect{key, value -> value.name}
+        assertTrue(below30Names == ["Long", "Dustin"])
+
+
+    }
+
+    @Test
+    void group(){
+        def map = [1:20, 2: 40, 3: 11, 4: 93]
+
+        def subMap = map.groupBy{it.value % 2}
+        println subMap
+        assertTrue(subMap == [0:[1:20, 2:40 ], 1:[3:11, 4:93]])
+
+        def keySubMap = map.subMap([1, 2])
+        assertTrue(keySubMap == [1:20, 2:40])
+
+    }
+
+    @Test
+    void sorting(){
+        def map = [ab:20, a: 40, cb: 11, ba: 93]
+
+        def naturallyOrderedMap = map.sort()
+        assertTrue([a:40, ab:20, ba:93, cb:11] == naturallyOrderedMap)
+
+        def compSortedMap = map.sort({ k1, k2 -> k1 <=> k2 } as Comparator)
+        assertTrue([a:40, ab:20, ba:93, cb:11] == compSortedMap)
+
+        def cloSortedMap = map.sort({ it1, it2 -> it1.value <=> it1.value })
+        assertTrue([cb:11, ab:20, a:40, ba:93] == cloSortedMap)
+
+    }
+
+}

core-groovy/README.md

@@ -8,3 +8,8 @@
 - [Types of Strings in Groovy](https://www.baeldung.com/groovy-strings)
 - [A Quick Guide to Iterating a Map in Groovy](https://www.baeldung.com/groovy-map-iterating)
 - [An Introduction to Traits in Groovy](https://www.baeldung.com/groovy-traits)
+- [Closures in Groovy](https://www.baeldung.com/groovy-closures)
+- [Finding Elements in Collections in Groovy](https://www.baeldung.com/groovy-collections-find-elements)
+- [Lists in Groovy](https://www.baeldung.com/groovy-lists)
+- [Converting a String to a Date in Groovy](https://www.baeldung.com/groovy-string-to-date)
+- [Guide to I/O in Groovy](https://www.baeldung.com/groovy-io)

core-groovy/src/main/groovy/com/baeldung/Person.groovy

@@ -0,0 +1,37 @@
+package com.baeldung
+
+class Person {
+    private String firstname
+    private String lastname
+    private Integer age
+
+    Person(String firstname, String lastname, Integer age) {
+        this.firstname = firstname
+        this.lastname = lastname
+        this.age = age
+    }
+
+    String getFirstname() {
+        return firstname
+    }
+
+    void setFirstname(String firstname) {
+        this.firstname = firstname
+    }
+
+    String getLastname() {
+        return lastname
+    }
+
+    void setLastname(String lastname) {
+        this.lastname = lastname
+    }
+
+    Integer getAge() {
+        return age
+    }
+
+    void setAge(Integer age) {
+        this.age = age
+    }
+}

core-groovy/src/main/groovy/com/baeldung/closures/Closures.groovy

@@ -0,0 +1,87 @@
+package com.baeldung.closures
+
+class Closures {
+    
+    def printWelcome = {
+        println "Welcome to Closures!"
+    }
+    
+    def print = { name ->
+        println name
+    }
+    
+    def formatToLowerCase(name) {
+        return name.toLowerCase()
+    }
+    def formatToLowerCaseClosure = { name ->
+        return name.toLowerCase()
+    }
+    
+    def count=0
+    
+    def increaseCount = {
+        count++
+    }
+    
+    def greet = {
+        return "Hello! ${it}"
+    }
+   
+    def multiply = { x, y ->
+        return x*y
+    }
+    
+    def calculate = {int x, int y, String operation ->
+        
+        //log closure
+        def log = {
+            println "Performing $it"
+        }
+        
+        def result = 0    
+        switch(operation) {
+            case "ADD":
+                log("Addition")
+                result = x+y
+                break
+            case "SUB":
+                log("Subtraction")
+                result = x-y
+                break
+            case "MUL":
+                log("Multiplication")
+                result = x*y
+                break
+            case "DIV":
+                log("Division")
+                result = x/y
+                break
+        }
+        return result
+    }
+    
+    def addAll = { int... args ->
+        return args.sum()
+    }
+    
+    def volume(Closure areaCalculator, int... dimensions) {
+        if(dimensions.size() == 3) {
+            
+            //consider dimension[0] = length, dimension[1] = breadth, dimension[2] = height
+            //for cube and cuboid
+            return areaCalculator(dimensions[0], dimensions[1]) * dimensions[2]
+        } else if(dimensions.size() == 2) {
+            
+            //consider dimension[0] = radius, dimension[1] = height
+            //for cylinder and cone
+            return areaCalculator(dimensions[0]) * dimensions[1]
+        } else if(dimensions.size() == 1) {
+            
+            //consider dimension[0] = radius
+            //for sphere
+            return areaCalculator(dimensions[0]) * dimensions[0]
+        }
+        
+    }
+     
+}

core-groovy/src/main/groovy/com/baeldung/closures/Employee.groovy

@@ -0,0 +1,6 @@
+package com.baeldung.closures
+
+class Employee {
+    
+    String fullName
+}

core-groovy/src/test/groovy/com/baeldung/closures/ClosuresUnitTest.groovy

@@ -0,0 +1,80 @@
+package com.baeldung.closures
+
+import spock.lang.Specification
+
+class ClosuresUnitTest extends GroovyTestCase {
+
+    Closures closures = new Closures()
+    
+    void testDeclaration() {
+        
+        closures.print("Hello! Closure")
+        closures.formatToLowerCaseClosure("Hello! Closure")
+        
+        closures.print.call("Hello! Closure")
+        closures.formatToLowerCaseClosure.call("Hello! Closure")
+        
+    }
+    
+    void testClosureVsMethods() {   
+        assert closures.formatToLowerCase("TONY STARK") == closures.formatToLowerCaseClosure("Tony STark")
+    }
+    
+    void testParameters() {
+        //implicit parameter
+        assert closures.greet("Alex") == "Hello! Alex"
+        
+        //multiple parameters
+        assert closures.multiply(2, 4) == 8
+        
+        assert closures.calculate(12, 4, "ADD") == 16
+        assert closures.calculate(12, 4, "SUB") == 8
+        assert closures.calculate(43, 8, "DIV") == 5.375
+                
+        //varags
+        assert closures.addAll(12, 10, 14) == 36
+       
+    }
+    
+    void testClosureAsAnArgument() {
+        assert closures.volume({ l, b -> return l*b }, 12, 6, 10) == 720
+        
+        assert closures.volume({ radius -> return Math.PI*radius*radius/3 }, 5, 10) == Math.PI * 250/3
+    }
+    
+    void testGStringsLazyEvaluation() {
+        def name = "Samwell"
+        def welcomeMsg = "Welcome! $name"
+        
+        assert welcomeMsg == "Welcome! Samwell"
+        
+        // changing the name does not affect original interpolated value
+        name = "Tarly"
+        assert welcomeMsg != "Welcome! Tarly"
+        
+        def fullName = "Tarly Samson"
+        def greetStr = "Hello! ${-> fullName}"
+        
+        assert greetStr == "Hello! Tarly Samson"
+
+        // this time changing the variable affects the interpolated String's value
+        fullName = "Jon Smith"
+        assert greetStr == "Hello! Jon Smith"
+    }
+    
+    void testClosureInLists() {
+        def list = [10, 11, 12, 13, 14, true, false, "BUNTHER"]
+        list.each {
+            println it
+        }
+        
+        assert [13, 14] == list.findAll{ it instanceof Integer && it >= 13}
+    }
+    
+    void testClosureInMaps() {
+        def map = [1:10, 2:30, 4:5]
+        
+        assert [10, 60, 20] == map.collect{it.key * it.value}
+    }
+    
+}

core-groovy/src/test/groovy/com/baeldung/lists/ListTest.groovy

@@ -129,13 +129,13 @@ class ListTest{
         assertTrue(filterList.findAll{it > 3} == [4, 5, 6, 76])
 
         assertTrue(filterList.findAll{ it instanceof Number} == [2, 1, 3, 4, 5, 6, 76])
-        
+
         assertTrue(filterList.grep( Number )== [2, 1, 3, 4, 5, 6, 76])
-        
+
         assertTrue(filterList.grep{ it> 6 }== [76])
 
         def conditionList = [2, 1, 3, 4, 5, 6, 76]
-        
+
         assertFalse(conditionList.every{ it < 6})
 
         assertTrue(conditionList.any{ it%2 == 0})
@@ -165,7 +165,7 @@ class ListTest{
 
         def strList = ["na", "ppp", "as"]
         assertTrue(strList.max() == "ppp")
-        
+
         Comparator minc = {a,b -> a == b? 0: a < b? -1 : 1}
         def numberList = [3, 2, 0, 7]
         assertTrue(numberList.min(minc) == 0)

core-groovy/src/test/groovy/com/baeldung/lists/ListUnitTest.groovy

@@ -0,0 +1,58 @@
+package com.baeldung.lists
+
+import com.baeldung.Person
+import org.junit.Test
+
+import static org.junit.Assert.*
+
+class ListUnitTest {
+
+    private final personList = [
+      new Person("Regina", "Fitzpatrick", 25),
+      new Person("Abagail", "Ballard", 26),
+      new Person("Lucian", "Walter", 30),
+    ]
+
+    @Test
+    void whenListContainsElement_thenCheckReturnsTrue() {
+        def list = ['a', 'b', 'c']
+
+        assertTrue(list.indexOf('a') > -1)
+        assertTrue(list.contains('a'))
+    }
+
+    @Test
+    void whenListContainsElement_thenCheckWithMembershipOperatorReturnsTrue() {
+        def list = ['a', 'b', 'c']
+
+        assertTrue('a' in list)
+    }
+
+    @Test
+    void givenListOfPerson_whenUsingStreamMatching_thenShouldEvaluateList() {
+        assertTrue(personList.stream().anyMatch {it.age > 20})
+        assertFalse(personList.stream().allMatch {it.age < 30})
+    }
+
+    @Test
+    void givenListOfPerson_whenUsingCollectionMatching_thenShouldEvaluateList() {
+        assertTrue(personList.any {it.age > 20})
+        assertFalse(personList.every {it.age < 30})
+    }
+
+    @Test
+    void givenListOfPerson_whenUsingStreamFind_thenShouldReturnMatchingElements() {
+        assertTrue(personList.stream().filter {it.age > 20}.findAny().isPresent())
+        assertFalse(personList.stream().filter {it.age > 30}.findAny().isPresent())
+        assertTrue(personList.stream().filter {it.age > 20}.findAll().size() == 3)
+        assertTrue(personList.stream().filter {it.age > 30}.findAll().isEmpty())
+    }
+
+    @Test
+    void givenListOfPerson_whenUsingCollectionFind_thenShouldReturnMatchingElements() {
+        assertNotNull(personList.find {it.age > 20})
+        assertNull(personList.find {it.age > 30})
+        assertTrue(personList.findAll {it.age > 20}.size() == 3)
+        assertTrue(personList.findAll {it.age > 30}.isEmpty())
+    }
+}

core-groovy/src/test/groovy/com/baeldung/map/MapTest.groovy

@@ -0,0 +1,148 @@
+package com.baeldung.groovy.map;
+
+import static groovy.test.GroovyAssert.*
+import org.junit.Test
+
+class MapTest{
+
+    @Test
+    void createMap() {
+
+        def emptyMap = [:]
+        assertNotNull(emptyMap)
+
+        assertTrue(emptyMap instanceof java.util.LinkedHashMap)
+
+        def map = [name:"Jerry", age: 42, city: "New York"]
+        assertTrue(map.size() == 3)
+    }
+
+    @Test
+    void addItemsToMap() {
+
+        def map = [name:"Jerry"]
+
+        map["age"] = 42
+
+        map.city = "New York"
+
+        def hobbyLiteral = "hobby"
+        def hobbyMap = [(hobbyLiteral): "Singing"]
+        map.putAll(hobbyMap)
+
+        assertTrue(map == [name:"Jerry", age: 42, city: "New York", hobby:"Singing"])
+        assertTrue(hobbyMap.hobby == "Singing")
+        assertTrue(hobbyMap[hobbyLiteral] == "Singing")
+        
+        map.plus([1:20]) // returns new map
+
+        map << [2:30]
+
+    }
+
+    @Test
+    void getItemsFromMap() {
+
+        def map = [name:"Jerry", age: 42, city: "New York", hobby:"Singing"]
+
+        assertTrue(map["name"] == "Jerry")
+
+        assertTrue(map.name == "Jerry")
+
+        def propertyAge = "age"
+        assertTrue(map[propertyAge] == 42)
+    }
+
+    @Test
+    void removeItemsFromMap() {
+
+        def map = [1:20, a:30, 2:42, 4:34, ba:67, 6:39, 7:49]
+
+        def minusMap = map.minus([2:42, 4:34]);
+        assertTrue(minusMap == [1:20, a:30, ba:67, 6:39, 7:49])
+
+        minusMap.removeAll{it -> it.key instanceof String}
+        assertTrue( minusMap == [ 1:20, 6:39, 7:49])
+
+        minusMap.retainAll{it -> it.value %2 == 0}
+        assertTrue( minusMap == [1:20])
+    }
+
+    @Test
+    void iteratingOnMaps(){
+        def map = [name:"Jerry", age: 42, city: "New York", hobby:"Singing"]
+
+        map.each{ entry -> println "$entry.key: $entry.value" }
+
+        map.eachWithIndex{ entry, i -> println "$i $entry.key: $entry.value" }
+
+        map.eachWithIndex{ key, value, i -> println "$i $key: $value" }
+    }
+
+    @Test
+    void filteringAndSearchingMaps(){
+        def map = [name:"Jerry", age: 42, city: "New York", hobby:"Singing"]
+
+        assertTrue(map.find{ it.value == "New York"}.key == "city")
+
+        assertTrue(map.findAll{ it.value == "New York"} == [city : "New York"])
+
+        map.grep{it.value == "New York"}.each{ it -> assertTrue(it.key == "city" && it.value == "New York")}
+
+        assertTrue(map.every{it -> it.value instanceof String} == false)
+
+        assertTrue(map.any{it -> it.value instanceof String} == true)
+    }
+
+    @Test
+    void collect(){
+
+        def map = [1: [name:"Jerry", age: 42, city: "New York"],
+            2: [name:"Long", age: 25, city: "New York"],
+            3: [name:"Dustin", age: 29, city: "New York"],
+            4: [name:"Dustin", age: 34, city: "New York"]]
+
+        def names = map.collect{entry -> entry.value.name} // returns only list
+        assertTrue(names == ["Jerry", "Long", "Dustin", "Dustin"])
+
+        def uniqueNames = map.collect([] as HashSet){entry -> entry.value.name}
+        assertTrue(uniqueNames == ["Jerry", "Long", "Dustin"] as Set)
+
+        def idNames = map.collectEntries{key, value -> [key, value.name]}
+        assertTrue(idNames == [1:"Jerry", 2: "Long", 3:"Dustin", 4: "Dustin"])
+
+        def below30Names = map.findAll{it.value.age < 30}.collect{key, value -> value.name}
+        assertTrue(below30Names == ["Long", "Dustin"])
+
+
+    }
+
+    @Test
+    void group(){
+        def map = [1:20, 2: 40, 3: 11, 4: 93]
+
+        def subMap = map.groupBy{it.value % 2}
+        println subMap
+        assertTrue(subMap == [0:[1:20, 2:40 ], 1:[3:11, 4:93]])
+
+        def keySubMap = map.subMap([1, 2])
+        assertTrue(keySubMap == [1:20, 2:40])
+
+    }
+
+    @Test
+    void sorting(){
+        def map = [ab:20, a: 40, cb: 11, ba: 93]
+
+        def naturallyOrderedMap = map.sort()
+        assertTrue([a:40, ab:20, ba:93, cb:11] == naturallyOrderedMap)
+
+        def compSortedMap = map.sort({ k1, k2 -> k1 <=> k2 } as Comparator)
+        assertTrue([a:40, ab:20, ba:93, cb:11] == compSortedMap)
+
+        def cloSortedMap = map.sort({ it1, it2 -> it1.value <=> it1.value })
+        assertTrue([cb:11, ab:20, a:40, ba:93] == cloSortedMap)
+
+    }
+
+}

core-groovy/src/test/groovy/com/baeldung/map/MapUnitTest.groovy

@@ -1,10 +1,18 @@
 package com.baeldung.map
 
-import static org.junit.Assert.*
+import com.baeldung.Person
 import org.junit.Test
 
+import static org.junit.Assert.*
+
 class MapUnitTest {
 
+    private final personMap = [
+      Regina : new Person("Regina", "Fitzpatrick", 25),
+      Abagail: new Person("Abagail", "Ballard", 26),
+      Lucian : new Person("Lucian", "Walter", 30)
+    ]
+
     @Test
     void whenUsingEach_thenMapIsIterated() {
         def map = [
@@ -63,7 +71,7 @@ class MapUnitTest {
             'FF6347' : 'Tomato',
             'FF4500' : 'Orange Red'
         ]
-        
+
         map.eachWithIndex { key, val, index ->
             def indent = ((index == 0 || index % 2 == 0) ? "   " : "")
             println "$indent Hex Code: $key = Color Name: $val"
@@ -82,4 +90,65 @@ class MapUnitTest {
             println "Hex Code: $entry.key = Color Name: $entry.value"
         }
     }
+
+    @Test
+    void whenMapContainsKeyElement_thenCheckReturnsTrue() {
+        def map = [a: 'd', b: 'e', c: 'f']
+
+        assertTrue(map.containsKey('a'))
+        assertFalse(map.containsKey('e'))
+        assertTrue(map.containsValue('e'))
+    }
+
+    @Test
+    void whenMapContainsKeyElement_thenCheckByMembershipReturnsTrue() {
+        def map = [a: 'd', b: 'e', c: 'f']
+
+        assertTrue('a' in map)
+        assertFalse('f' in map)
+    }
+
+    @Test
+    void whenMapContainsFalseBooleanValues_thenCheckReturnsFalse() {
+        def map = [a: true, b: false, c: null]
+
+        assertTrue(map.containsKey('b'))
+        assertTrue('a' in map)
+        assertFalse('b' in map)
+        assertFalse('c' in map)
+    }
+
+    @Test
+    void givenMapOfPerson_whenUsingStreamMatching_thenShouldEvaluateMap() {
+        assertTrue(personMap.keySet().stream().anyMatch {it == "Regina"})
+        assertFalse(personMap.keySet().stream().allMatch {it == "Albert"})
+        assertFalse(personMap.values().stream().allMatch {it.age < 30})
+        assertTrue(personMap.entrySet().stream().anyMatch {it.key == "Abagail" && it.value.lastname == "Ballard"})
+    }
+
+    @Test
+    void givenMapOfPerson_whenUsingCollectionMatching_thenShouldEvaluateMap() {
+        assertTrue(personMap.keySet().any {it == "Regina"})
+        assertFalse(personMap.keySet().every {it == "Albert"})
+        assertFalse(personMap.values().every {it.age < 30})
+        assertTrue(personMap.any {firstname, person -> firstname == "Abagail" && person.lastname == "Ballard"})
+    }
+
+    @Test
+    void givenMapOfPerson_whenUsingCollectionFind_thenShouldReturnElements() {
+        assertNotNull(personMap.find {it.key == "Abagail" && it.value.lastname == "Ballard"})
+        assertTrue(personMap.findAll {it.value.age > 20}.size() == 3)
+    }
+
+    @Test
+    void givenMapOfPerson_whenUsingStreamFind_thenShouldReturnElements() {
+        assertTrue(
+          personMap.entrySet().stream()
+            .filter {it.key == "Abagail" && it.value.lastname == "Ballard"}
+            .findAny().isPresent())
+        assertTrue(
+          personMap.entrySet().stream()
+            .filter {it.value.age > 20}
+            .findAll().size() == 3)
+    }
 }

core-groovy/src/test/groovy/com/baeldung/set/SetUnitTest.groovy

@@ -0,0 +1,16 @@
+package com.baeldung.set
+
+import org.junit.Test
+
+import static org.junit.Assert.assertTrue
+
+class SetUnitTest {
+
+    @Test
+    void whenSetContainsElement_thenCheckReturnsTrue() {
+        def set = ['a', 'b', 'c'] as Set
+
+        assertTrue(set.contains('a'))
+        assertTrue('a' in set)
+    }
+}

core-groovy/src/test/groovy/com/baeldung/strings/StringMatchingSpec.groovy

@@ -0,0 +1,44 @@
+package com.baeldung.strings
+
+import spock.lang.Specification
+
+import java.util.regex.Pattern
+
+class StringMatchingSpec extends Specification {
+
+    def "pattern operator example"() {
+        given: "a pattern"
+        def p = ~'foo'
+
+        expect:
+        p instanceof Pattern
+
+        and: "you can use slash strings to avoid escaping of blackslash"
+        def digitPattern = ~/\d*/
+        digitPattern.matcher('4711').matches()
+    }
+
+    def "match operator example"() {
+        expect:
+        'foobar' ==~ /.*oba.*/
+
+        and: "matching is strict"
+        !('foobar' ==~ /foo/)
+    }
+
+    def "find operator example"() {
+        when: "using the find operator"
+        def matcher = 'foo and bar, baz and buz' =~ /(\w+) and (\w+)/
+
+        then: "will find groups"
+        matcher.size() == 2
+
+        and: "can access groups using array"
+        matcher[0][0] == 'foo and bar'
+        matcher[1][2] == 'buz'
+
+        and: "you can use it as a predicate"
+        'foobarbaz' =~ /bar/
+    }
+
+}

core-java-11/README.md

@@ -4,3 +4,6 @@
 - [Java 11 Local Variable Syntax for Lambda Parameters](https://www.baeldung.com/java-var-lambda-params)
 - [Java 11 String API Additions](https://www.baeldung.com/java-11-string-api)
 - [Java 11 Nest Based Access Control](https://www.baeldung.com/java-nest-based-access-control)
+- [Exploring the New HTTP Client in Java 9 and 11](https://www.baeldung.com/java-9-http-client)
+- [An Introduction to Epsilon GC: A No-Op Experimental Garbage Collector](https://www.baeldung.com/jvm-epsilon-gc-garbage-collector)
+- [Guide to jlink](https://www.baeldung.com/jlink)

core-java-11/pom.xml

@@ -14,6 +14,14 @@
         <version>1.0.0-SNAPSHOT</version>
     </parent>
 
+    <dependencies>
+        <dependency>
+            <groupId>com.google.guava</groupId>
+            <artifactId>guava</artifactId>
+            <version>${guava.version}</version>
+        </dependency>
+    </dependencies>
+
     <build>
         <plugins>
             <plugin>
@@ -31,6 +39,7 @@
     <properties>
         <maven.compiler.source.version>11</maven.compiler.source.version>
         <maven.compiler.target.version>11</maven.compiler.target.version>
+        <guava.version>27.1-jre</guava.version>
     </properties>
 
 </project>

core-java-11/src/modules/jlinkModule/com/baeldung/jlink/HelloWorld.java

@@ -0,0 +1,12 @@
+package com.baeldung.jlink;
+
+import java.util.logging.Logger;
+
+public class HelloWorld {
+
+    private static final Logger LOG = Logger.getLogger(HelloWorld.class.getName());
+
+    public static void main(String[] args) {
+        LOG.info("Hello World!");
+    }
+}

core-java-11/src/modules/jlinkModule/module-info.java

@@ -0,0 +1,3 @@
+module jlinkModule {
+    requires java.logging;
+}

core-java-11/src/test/java/com/baeldung/EmptyStringToEmptyOptionalUnitTest.java

@@ -0,0 +1,32 @@
+package com.baeldung;
+
+import com.google.common.base.Strings;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.util.Optional;
+import java.util.function.Predicate;
+
+public class EmptyStringToEmptyOptionalUnitTest {
+
+    @Test
+    public void givenEmptyString_whenFilteringOnOptional_thenEmptyOptionalIsReturned() {
+        String str = "";
+        Optional<String> opt = Optional.ofNullable(str).filter(s -> !s.isEmpty());
+        Assert.assertFalse(opt.isPresent());
+    }
+
+    @Test
+    public void givenEmptyString_whenFilteringOnOptionalInJava11_thenEmptyOptionalIsReturned() {
+        String str = "";
+        Optional<String> opt = Optional.ofNullable(str).filter(Predicate.not(String::isEmpty));
+        Assert.assertFalse(opt.isPresent());
+    }
+
+    @Test
+    public void givenEmptyString_whenPassingResultOfEmptyToNullToOfNullable_thenEmptyOptionalIsReturned() {
+        String str = "";
+        Optional<String> opt = Optional.ofNullable(Strings.emptyToNull(str));
+        Assert.assertFalse(opt.isPresent());
+    }
+}

core-java-12/pom.xml

@@ -0,0 +1,49 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <groupId>com.baeldung</groupId>
+    <artifactId>core-java-12</artifactId>
+    <version>0.1.0-SNAPSHOT</version>
+    <name>core-java-12</name>
+    <packaging>jar</packaging>
+    <url>http://maven.apache.org</url>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${assertj.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>${maven-compiler-plugin.version}</version>
+                <configuration>
+                    <source>${maven.compiler.source.version}</source>
+                    <target>${maven.compiler.target.version}</target>
+                    <compilerArgs>--enable-preview</compilerArgs>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+    <properties>
+        <maven.compiler.source.version>12</maven.compiler.source.version>
+        <maven.compiler.target.version>12</maven.compiler.target.version>
+        <assertj.version>3.6.1</assertj.version>
+    </properties>
+
+</project>

core-java-12/src/test/java/com/baeldung/collectors/CollectorsUnitTest.java

@@ -0,0 +1,71 @@
+package com.baeldung.collectors;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.Objects;
+
+import org.junit.Test;
+
+import static java.util.stream.Collectors.maxBy;
+import static java.util.stream.Collectors.minBy;
+import static java.util.stream.Collectors.teeing;
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Unit tests for collectors additions in Java 12.
+ */
+public class CollectorsUnitTest {
+
+    @Test
+    public void whenTeeing_ItShouldCombineTheResultsAsExpected() {
+        List<Integer> numbers = Arrays.asList(42, 4, 2, 24);
+        Range range = numbers.stream()
+            .collect(teeing(minBy(Integer::compareTo), maxBy(Integer::compareTo), (min, max) -> new Range(min.orElse(null), max.orElse(null))));
+
+        assertThat(range).isEqualTo(new Range(2, 42));
+    }
+
+    /**
+     * Represents a closed range of numbers between {@link #min} and
+     * {@link #max}, both inclusive.
+     */
+    private static class Range {
+
+        private final Integer min;
+
+        private final Integer max;
+
+        Range(Integer min, Integer max) {
+            this.min = min;
+            this.max = max;
+        }
+
+        Integer getMin() {
+            return min;
+        }
+
+        Integer getMax() {
+            return max;
+        }
+
+        @Override
+        public boolean equals(Object o) {
+            if (this == o)
+                return true;
+            if (o == null || getClass() != o.getClass())
+                return false;
+            Range range = (Range) o;
+            return Objects.equals(getMin(), range.getMin()) && Objects.equals(getMax(), range.getMax());
+        }
+
+        @Override
+        public int hashCode() {
+            return Objects.hash(getMin(), getMax());
+        }
+
+        @Override
+        public String toString() {
+            return "Range{" + "min=" + min + ", max=" + max + '}';
+        }
+    }
+}

core-java-12/src/test/java/com/baeldung/switchExpression/SwitchUnitTest.java

@@ -0,0 +1,37 @@
+package com.baeldung.switchExpression;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class SwitchUnitTest {
+
+    @Test
+    public void switchJava12(){
+
+        var month = Month.AUG;
+
+        var value = switch(month){
+            case JAN,JUN, JUL -> 3;
+            case FEB,SEP, OCT, NOV, DEC -> 1;
+            case MAR,MAY, APR, AUG -> 2;
+        };
+
+        Assert.assertEquals(value, 2);
+    }
+
+    @Test
+    public void switchLocalVariable(){
+        var month = Month.AUG;
+        int i = switch (month){
+            case JAN,JUN, JUL -> 3;
+            case FEB,SEP, OCT, NOV, DEC -> 1;
+            case MAR,MAY, APR, AUG -> {
+                int j = month.toString().length() * 4;
+                break j;
+            }
+        };
+        Assert.assertEquals(12, i);
+    }
+
+    enum Month {JAN, FEB, MAR, APR, MAY, JUN, JUL, AUG, SEP, OCT, NOV, DEC}
+}

core-java-8-2/.gitignore

@@ -0,0 +1,25 @@
+*.class
+
+0.*
+
+#folders#
+/target
+/neoDb*
+/data
+/src/main/webapp/WEB-INF/classes
+*/META-INF/*
+.resourceCache
+
+# Packaged files #
+*.jar
+*.war
+*.ear
+
+# Files generated by integration tests
+backup-pom.xml
+/bin/
+/temp
+
+#IntelliJ specific
+.idea/
+*.iml

core-java-8-2/README.md

@@ -0,0 +1,6 @@
+=========
+
+## Core Java 8 Cookbooks and Examples (part 2)
+
+### Relevant Articles: 
+- [Anonymous Classes in Java](http://www.baeldung.com/)

core-java-8-2/pom.xml

@@ -0,0 +1,50 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <groupId>com.baeldung</groupId>
+    <artifactId>core-java-8-2</artifactId>
+    <version>0.1.0-SNAPSHOT</version>
+    <name>core-java-8-2</name>
+    <packaging>jar</packaging>
+
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-java</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../parent-java</relativePath>
+    </parent>
+
+    <properties>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <maven.compiler.source>1.8</maven.compiler.source>
+        <maven.compiler.target>1.8</maven.compiler.target>
+        <icu.version>64.2</icu.version>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>com.ibm.icu</groupId>
+            <artifactId>icu4j</artifactId>
+            <version>${icu.version}</version>
+        </dependency>
+
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>${maven-compiler-plugin.version}</version>
+                <configuration>
+                    <source>${maven.compiler.source}</source>
+                    <target>${maven.compiler.target}</target>
+                </configuration>
+            </plugin>
+        </plugins>
+
+    </build>
+</project>

core-java-8-2/src/main/java/com/baeldung/jarArguments/JarExample.java

@@ -0,0 +1,18 @@
+package com.baeldung.jarArguments;
+
+public class JarExample {
+
+    public static void main(String[] args) {
+        System.out.println("Hello Baeldung Reader in JarExample!");
+        
+        if(args == null) {
+            System.out.println("You have not provided any arguments!");
+        }else {
+            System.out.println("There are "+args.length+" argument(s)!");
+            for(int i=0; i<args.length; i++) {
+                System.out.println("Argument("+(i+1)+"):" + args[i]);
+            }
+        }
+    }
+
+}

core-java-8-2/src/main/java/com/baeldung/localization/App.java

@@ -0,0 +1,21 @@
+package com.baeldung.localization;
+
+import java.text.ParseException;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Locale;
+
+public class App {
+
+    /**
+     * Runs all available formatter
+     * @throws ParseException 
+     */
+    public static void main(String[] args) {
+        List<Locale> locales = Arrays.asList(new Locale[] { Locale.UK, Locale.ITALY, Locale.FRANCE, Locale.forLanguageTag("pl-PL") });
+        Localization.run(locales);
+        JavaSEFormat.run(locales);
+        ICUFormat.run(locales);
+    }
+
+}

core-java-8-2/src/main/java/com/baeldung/localization/ICUFormat.java

@@ -0,0 +1,29 @@
+package com.baeldung.localization;
+
+import java.util.List;
+import java.util.Locale;
+import java.util.ResourceBundle;
+
+import com.ibm.icu.text.MessageFormat;
+
+public class ICUFormat {
+
+    public static String getLabel(Locale locale, Object[] data) {
+        ResourceBundle bundle = ResourceBundle.getBundle("formats", locale);
+        String format = bundle.getString("label-icu");
+        MessageFormat formatter = new MessageFormat(format, locale);
+        return formatter.format(data);
+    }
+
+    public static void run(List<Locale> locales) {
+        System.out.println("ICU formatter");
+        locales.forEach(locale -> System.out.println(getLabel(locale, new Object[] { "Alice", "female", 0 })));
+        locales.forEach(locale -> System.out.println(getLabel(locale, new Object[] { "Alice", "female", 1 })));
+        locales.forEach(locale -> System.out.println(getLabel(locale, new Object[] { "Alice", "female", 2 })));
+        locales.forEach(locale -> System.out.println(getLabel(locale, new Object[] { "Alice", "female", 3 })));
+        locales.forEach(locale -> System.out.println(getLabel(locale, new Object[] { "Bob", "male", 0 })));
+        locales.forEach(locale -> System.out.println(getLabel(locale, new Object[] { "Bob", "male", 1 })));
+        locales.forEach(locale -> System.out.println(getLabel(locale, new Object[] { "Bob", "male", 2 })));
+        locales.forEach(locale -> System.out.println(getLabel(locale, new Object[] { "Bob", "male", 3 })));
+    }
+}

core-java-8-2/src/main/java/com/baeldung/localization/JavaSEFormat.java

@@ -0,0 +1,24 @@
+package com.baeldung.localization;
+
+import java.text.MessageFormat;
+import java.util.Date;
+import java.util.List;
+import java.util.Locale;
+import java.util.ResourceBundle;
+
+public class JavaSEFormat {
+
+    public static String getLabel(Locale locale, Object[] data) {
+        ResourceBundle bundle = ResourceBundle.getBundle("formats", locale);
+        final String pattern = bundle.getString("label");
+        final MessageFormat formatter = new MessageFormat(pattern, locale);
+        return formatter.format(data);
+    }
+
+    public static void run(List<Locale> locales) {
+        System.out.println("Java formatter");
+        final Date date = new Date(System.currentTimeMillis());
+        locales.forEach(locale -> System.out.println(getLabel(locale, new Object[] { date, "Alice", 0 })));
+        locales.forEach(locale -> System.out.println(getLabel(locale, new Object[] { date, "Alice", 2 })));
+    }
+}

core-java-8-2/src/main/java/com/baeldung/localization/Localization.java

@@ -0,0 +1,18 @@
+package com.baeldung.localization;
+
+import java.util.List;
+import java.util.Locale;
+import java.util.ResourceBundle;
+
+public class Localization {
+
+    public static String getLabel(Locale locale) {
+        final ResourceBundle bundle = ResourceBundle.getBundle("messages", locale);
+        return bundle.getString("label");
+    }
+
+    public static void run(List<Locale> locales) {
+        locales.forEach(locale -> System.out.println(getLabel(locale)));
+    }
+
+}

core-java-8-2/src/main/resources/example_manifest.txt

@@ -0,0 +1 @@
+Main-Class: com.baeldung.jarArguments.JarExample

core-java-8-2/src/main/resources/formats_en.properties

@@ -0,0 +1,2 @@
+label=On {0, date, short} {1} has sent you {2, choice, 0#no messages|1#a message|2#two messages|2<{2,number,integer} messages}.
+label-icu={0} has sent you {2, plural, =0 {no messages} =1 {a message} other {{2, number, integer} messages}}.

core-java-8-2/src/main/resources/formats_fr.properties

@@ -0,0 +1,2 @@
+label={0, date, short}, {1}{2, choice, 0# ne|0<} vous a envoyé {2, choice, 0#aucun message|1#un message|2#deux messages|2<{2,number,integer} messages}.
+label-icu={0} {2, plural, =0 {ne } other {}}vous a envoyé {2, plural, =0 {aucun message} =1 {un message} other {{2, number, integer} messages}}.

core-java-8-2/src/main/resources/formats_it.properties

@@ -0,0 +1,2 @@
+label={0, date, short} {1} ti ha inviato {2, choice, 0#nessun messagio|1#un messaggio|2#due messaggi|2<{2, number, integer} messaggi}.
+label-icu={0} {2, plural, =0 {non } other {}}ti ha inviato {2, plural, =0 {nessun messaggio} =1 {un messaggio} other {{2, number, integer} messaggi}}.

core-java-8-2/src/main/resources/formats_pl.properties

@@ -0,0 +1,2 @@
+label=W {0, date, short} {1}{2, choice, 0# nie|0<} wys\u0142a\u0142a ci {2, choice, 0#\u017Cadnych wiadomo\u015Bci|1#wiadomo\u015B\u0107|2#dwie wiadomo\u015Bci|2<{2, number, integer} wiadomo\u015Bci}.
+label-icu={0} {2, plural, =0 {nie } other {}}{1, select, male {wys\u0142a\u0142} female {wys\u0142a\u0142a} other {wys\u0142a\u0142o}} ci {2, plural, =0 {\u017Cadnej wiadomo\u015Bci} =1 {wiadomo\u015B\u0107} other {{2, number, integer} wiadomo\u015Bci}}.

core-java-8-2/src/main/resources/messages_en.properties

@@ -0,0 +1 @@
+label=Alice has sent you a message.

core-java-8-2/src/main/resources/messages_fr.properties

@@ -0,0 +1 @@
+label=Alice vous a envoyé un message.

core-java-8-2/src/main/resources/messages_it.properties

@@ -0,0 +1 @@
+label=Alice ti ha inviato un messaggio.

core-java-8-2/src/main/resources/messages_pl.properties

@@ -0,0 +1 @@
+label=Alice wys\u0142a\u0142a ci wiadomo\u015B\u0107.

core-java-8-2/src/test/java/com/baeldung/localization/ICUFormatUnitTest.java

@@ -0,0 +1,74 @@
+package com.baeldung.localization;
+
+import static org.junit.Assert.assertEquals;
+
+import java.util.Locale;
+
+import org.junit.Test;
+
+import com.baeldung.localization.ICUFormat;
+
+public class ICUFormatUnitTest {
+
+    @Test
+    public void givenInUK_whenAliceSendsNothing_thenCorrectMessage() {
+        assertEquals("Alice has sent you no messages.", ICUFormat.getLabel(Locale.UK, new Object[] { "Alice", "female", 0 }));
+    }
+
+    @Test
+    public void givenInUK_whenAliceSendsOneMessage_thenCorrectMessage() {
+        assertEquals("Alice has sent you a message.", ICUFormat.getLabel(Locale.UK, new Object[] { "Alice", "female", 1 }));
+    }
+
+    @Test
+    public void givenInUK_whenBobSendsSixMessages_thenCorrectMessage() {
+        assertEquals("Bob has sent you 6 messages.", ICUFormat.getLabel(Locale.UK, new Object[] { "Bob", "male", 6 }));
+    }
+
+    @Test
+    public void givenInItaly_whenAliceSendsNothing_thenCorrectMessage() {
+        assertEquals("Alice non ti ha inviato nessun messaggio.", ICUFormat.getLabel(Locale.ITALY, new Object[] { "Alice", "female", 0 }));
+    }
+
+    @Test
+    public void givenInItaly_whenAliceSendsOneMessage_thenCorrectMessage() {
+        assertEquals("Alice ti ha inviato un messaggio.", ICUFormat.getLabel(Locale.ITALY, new Object[] { "Alice", "female", 1 }));
+    }
+
+    @Test
+    public void givenInItaly_whenBobSendsSixMessages_thenCorrectMessage() {
+        assertEquals("Bob ti ha inviato 6 messaggi.", ICUFormat.getLabel(Locale.ITALY, new Object[] { "Bob", "male", 6 }));
+    }
+
+    @Test
+    public void givenInFrance_whenAliceSendsNothing_thenCorrectMessage() {
+        assertEquals("Alice ne vous a envoyé aucun message.", ICUFormat.getLabel(Locale.FRANCE, new Object[] { "Alice", "female", 0 }));
+    }
+    
+    @Test
+    public void givenInFrance_whenAliceSendsOneMessage_thenCorrectMessage() {
+        assertEquals("Alice vous a envoyé un message.", ICUFormat.getLabel(Locale.FRANCE, new Object[] { "Alice", "female", 1 }));
+    }
+
+    @Test
+    public void givenInFrance_whenBobSendsSixMessages_thenCorrectMessage() {
+        assertEquals("Bob vous a envoyé 6 messages.", ICUFormat.getLabel(Locale.FRANCE, new Object[] { "Bob", "male", 6 }));
+    }
+
+
+    @Test
+    public void givenInPoland_whenAliceSendsNothing_thenCorrectMessage() {
+        assertEquals("Alice nie wysłała ci żadnej wiadomości.", ICUFormat.getLabel(Locale.forLanguageTag("pl-PL"), new Object[] { "Alice", "female", 0 }));
+    }
+    
+    @Test
+    public void givenInPoland_whenAliceSendsOneMessage_thenCorrectMessage() {
+        assertEquals("Alice wysłała ci wiadomość.", ICUFormat.getLabel(Locale.forLanguageTag("pl-PL"), new Object[] { "Alice", "female", 1 }));
+    }
+    
+    @Test
+    public void givenInPoland_whenBobSendsSixMessages_thenCorrectMessage() {
+        assertEquals("Bob wysłał ci 6 wiadomości.", ICUFormat.getLabel(Locale.forLanguageTag("pl-PL"), new Object[] { "Bob", "male", 6 }));
+    }
+
+}

core-java-8/README.md

@@ -3,7 +3,7 @@
 ## Core Java 8 Cookbooks and Examples
 
 ### Relevant Articles: 
-- [Java 8 Collectors](http://www.baeldung.com/java-8-collectors)
+- [Guide to Java 8’s Collectors](http://www.baeldung.com/java-8-collectors)
 - [Functional Interfaces in Java 8](http://www.baeldung.com/java-8-functional-interfaces)
 - [Java 8 – Powerful Comparison with Lambdas](http://www.baeldung.com/java-8-sort-lambda)
 - [New Features in Java 8](http://www.baeldung.com/java-8-new-features)

core-java-8/src/main/java/com/baeldung/Adder.java

@@ -1,12 +0,0 @@
-package com.baeldung;
-
-import java.util.function.Consumer;
-import java.util.function.Function;
-
-public interface Adder {
-
-    String addWithFunction(Function<String, String> f);
-
-    void addWithConsumer(Consumer<Integer> f);
-
-}

core-java-8/src/main/java/com/baeldung/AdderImpl.java

@@ -1,18 +0,0 @@
-package com.baeldung;
-
-
-import java.util.function.Consumer;
-import java.util.function.Function;
-
-public class AdderImpl implements Adder {
-
-    @Override
-    public String addWithFunction(final Function<String, String> f) {
-        return f.apply("Something ");
-    }
-
-    @Override
-    public void addWithConsumer(final Consumer<Integer> f) {
-    }
-
-}

core-java-8/src/main/java/com/baeldung/java8/lambda/tips/Bar.java

@@ -1,4 +1,4 @@
-package com.baeldung;
+package com.baeldung.java8.lambda.tips;
 
 
 @FunctionalInterface

core-java-8/src/main/java/com/baeldung/java8/lambda/tips/Baz.java

@@ -1,4 +1,4 @@
-package com.baeldung;
+package com.baeldung.java8.lambda.tips;
 
 
 @FunctionalInterface

core-java-8/src/main/java/com/baeldung/java8/lambda/tips/Foo.java

@@ -1,4 +1,4 @@
-package com.baeldung;
+package com.baeldung.java8.lambda.tips;
 
 
 @FunctionalInterface

core-java-8/src/main/java/com/baeldung/java8/lambda/tips/FooExtended.java

@@ -1,4 +1,4 @@
-package com.baeldung;
+package com.baeldung.java8.lambda.tips;
 
 
 @FunctionalInterface

core-java-8/src/main/java/com/baeldung/java8/lambda/tips/Processor.java

@@ -0,0 +1,12 @@
+package com.baeldung.java8.lambda.tips;
+
+import java.util.concurrent.Callable;
+import java.util.function.Supplier;
+
+public interface Processor {
+
+    String processWithCallable(Callable<String> c) throws Exception;
+
+    String processWithSupplier(Supplier<String> s);
+
+}

core-java-8/src/main/java/com/baeldung/java8/lambda/tips/ProcessorImpl.java

@@ -0,0 +1,20 @@
+package com.baeldung.java8.lambda.tips;
+
+
+import java.util.concurrent.Callable;
+import java.util.function.Consumer;
+import java.util.function.Function;
+import java.util.function.Supplier;
+
+public class ProcessorImpl implements Processor {
+
+    @Override
+    public String processWithCallable(Callable<String> c) throws Exception {
+        return c.call();
+    }
+
+    @Override
+    public String processWithSupplier(Supplier<String> s) {
+        return s.get();
+    }
+}