Merge branch 'eugenmaster'

2019-06-11 16:00:56 +02:00 · 2019-06-11 16:00:56 +02:00 · 130d0878e7
parent fa83a46f4b 44fb9946c7
commit 130d0878e7
575 changed files with 18748 additions and 3214 deletions
--- a/README.md
+++ b/README.md
@ -20,17 +20,22 @@ In additional to Spring, the following technologies are in focus: `core Java`, `

 Building the project
 ====================
-To do the full build, do: `mvn install -Pdefault -Dgib.enabled=false`
+To do the full build, do: `mvn clean install`


 Building a single module
 ====================
-To build a specific module run the command: `mvn clean install -Dgib.enabled=false` in the module directory
+To build a specific module run the command: `mvn clean install` in the module directory


 Running a Spring Boot module
 ====================
-To run a Spring Boot module run the command: `mvn spring-boot:run -Dgib.enabled=false` in the module directory
+To run a Spring Boot module run the command: `mvn spring-boot:run` in the module directory
+
+#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`



--- a/algorithms-miscellaneous-2/README.md
+++ b/algorithms-miscellaneous-2/README.md
@ -15,3 +15,5 @@
 - [Calculate Percentage in Java](https://www.baeldung.com/java-calculate-percentage)
 - [Converting Between Byte Arrays and Hexadecimal Strings in Java](https://www.baeldung.com/java-byte-arrays-hex-strings)
 - [Convert Latitude and Longitude to a 2D Point in Java](https://www.baeldung.com/java-convert-latitude-longitude)
+- [Reversing a Binary Tree in Java](https://www.baeldung.com/java-reversing-a-binary-tree)
+- [Find If Two Numbers Are Relatively Prime in Java](https://www.baeldung.com/java-two-relatively-prime-numbers)
--- a/algorithms-miscellaneous-3/README.md
+++ b/algorithms-miscellaneous-3/README.md
@ -4,4 +4,3 @@
 - [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)
--- a/algorithms-miscellaneous-3/src/main/java/com/baeldung/algorithms/graphcycledetection/domain/Graph.java
+++ b/algorithms-miscellaneous-3/src/main/java/com/baeldung/algorithms/graphcycledetection/domain/Graph.java
@ -0,0 +1,51 @@
+package com.baeldung.algorithms.graphcycledetection.domain;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class Graph {
+
+    private List<Vertex> vertices;
+
+    public Graph() {
+        this.vertices = new ArrayList<>();
+    }
+
+    public Graph(List<Vertex> vertices) {
+        this.vertices = vertices;
+    }
+
+    public void addVertex(Vertex vertex) {
+        this.vertices.add(vertex);
+    }
+
+    public void addEdge(Vertex from, Vertex to) {
+        from.addNeighbour(to);
+    }
+
+    public boolean hasCycle() {
+        for (Vertex vertex : vertices) {
+            if (!vertex.isVisited() && hasCycle(vertex)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    public boolean hasCycle(Vertex sourceVertex) {
+        sourceVertex.setBeingVisited(true);
+
+        for (Vertex neighbour : sourceVertex.getAdjacencyList()) {
+            if (neighbour.isBeingVisited()) {
+                // backward edge exists
+                return true;
+            } else if (!neighbour.isVisited() && hasCycle(neighbour)) {
+                return true;
+            }
+        }
+
+        sourceVertex.setBeingVisited(false);
+        sourceVertex.setVisited(true);
+        return false;
+    }
+}
--- a/algorithms-miscellaneous-3/src/main/java/com/baeldung/algorithms/graphcycledetection/domain/Vertex.java
+++ b/algorithms-miscellaneous-3/src/main/java/com/baeldung/algorithms/graphcycledetection/domain/Vertex.java
@ -0,0 +1,56 @@
+package com.baeldung.algorithms.graphcycledetection.domain;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class Vertex {
+
+    private String label;
+
+    private boolean visited;
+
+    private boolean beingVisited;
+
+    private List<Vertex> adjacencyList;
+
+    public Vertex(String label) {
+        this.label = label;
+        this.adjacencyList = new ArrayList<>();
+    }
+
+    public String getLabel() {
+        return label;
+    }
+
+    public void setLabel(String label) {
+        this.label = label;
+    }
+
+    public boolean isVisited() {
+        return visited;
+    }
+
+    public void setVisited(boolean visited) {
+        this.visited = visited;
+    }
+
+    public boolean isBeingVisited() {
+        return beingVisited;
+    }
+
+    public void setBeingVisited(boolean beingVisited) {
+        this.beingVisited = beingVisited;
+    }
+
+    public List<Vertex> getAdjacencyList() {
+        return adjacencyList;
+    }
+
+    public void setAdjacencyList(List<Vertex> adjacencyList) {
+        this.adjacencyList = adjacencyList;
+    }
+
+    public void addNeighbour(Vertex adjacent) {
+        this.adjacencyList.add(adjacent);
+    }
+}
--- a/algorithms-miscellaneous-3/src/test/java/com/baeldung/algorithms/graphcycledetection/GraphCycleDetectionUnitTest.java
+++ b/algorithms-miscellaneous-3/src/test/java/com/baeldung/algorithms/graphcycledetection/GraphCycleDetectionUnitTest.java
@ -0,0 +1,56 @@
+package com.baeldung.algorithms.graphcycledetection;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Test;
+
+import com.baeldung.algorithms.graphcycledetection.domain.Graph;
+import com.baeldung.algorithms.graphcycledetection.domain.Vertex;
+
+public class GraphCycleDetectionUnitTest {
+
+    @Test
+    public void givenGraph_whenCycleExists_thenReturnTrue() {
+
+        Vertex vertexA = new Vertex("A");
+        Vertex vertexB = new Vertex("B");
+        Vertex vertexC = new Vertex("C");
+        Vertex vertexD = new Vertex("D");
+
+        Graph graph = new Graph();
+        graph.addVertex(vertexA);
+        graph.addVertex(vertexB);
+        graph.addVertex(vertexC);
+        graph.addVertex(vertexD);
+
+        graph.addEdge(vertexA, vertexB);
+        graph.addEdge(vertexB, vertexC);
+        graph.addEdge(vertexC, vertexA);
+        graph.addEdge(vertexD, vertexC);
+
+        assertTrue(graph.hasCycle());
+    }
+
+    @Test
+    public void givenGraph_whenNoCycleExists_thenReturnFalse() {
+
+        Vertex vertexA = new Vertex("A");
+        Vertex vertexB = new Vertex("B");
+        Vertex vertexC = new Vertex("C");
+        Vertex vertexD = new Vertex("D");
+
+        Graph graph = new Graph();
+        graph.addVertex(vertexA);
+        graph.addVertex(vertexB);
+        graph.addVertex(vertexC);
+        graph.addVertex(vertexD);
+
+        graph.addEdge(vertexA, vertexB);
+        graph.addEdge(vertexB, vertexC);
+        graph.addEdge(vertexA, vertexC);
+        graph.addEdge(vertexD, vertexC);
+
+        assertFalse(graph.hasCycle());
+    }
+}
--- a/apache-geode/src/test/java/com/baeldung/geode/GeodeSamplesIntegrationTest.java
+++ b/apache-geode/src/test/java/com/baeldung/geode/GeodeSamplesIntegrationTest.java
@ -21,7 +21,7 @@ import java.util.stream.Stream;

 import static org.junit.Assert.assertEquals;

-public class GeodeSamplesIntegrationTest {
+public class GeodeSamplesLiveTest {

    ClientCache cache = null;
    Region<String, String> region = null;
--- a/apache-olingo/README.md
+++ b/apache-olingo/README.md
@ -0,0 +1,3 @@
+## Relevant articles:
+
+- [OData Protocol Guide](https://www.baeldung.com/odata)
--- a/apache-olingo/olingo2/pom.xml
+++ b/apache-olingo/olingo2/pom.xml
@ -44,11 +44,6 @@
 			<artifactId>spring-boot-configuration-processor</artifactId>
 			<optional>true</optional>
 		</dependency>
-		<dependency>
-			<groupId>org.projectlombok</groupId>
-			<artifactId>lombok</artifactId>
-			<optional>true</optional>
-		</dependency>
 		<dependency>
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-starter-test</artifactId>
@ -68,16 +63,6 @@
 				</exclusion>
 			</exclusions>
 		</dependency>
-		<dependency>
-			<groupId>org.apache.olingo</groupId>
-			<artifactId>olingo-odata2-api</artifactId>
-			<version>${olingo2.version}</version>
-		</dependency>
-		<dependency>
-			<groupId>org.apache.olingo</groupId>
-			<artifactId>olingo-odata2-jpa-processor-api</artifactId>
-			<version>${olingo2.version}</version>
-		</dependency>
 		<dependency>
 			<groupId>org.apache.olingo</groupId>
 			<artifactId>olingo-odata2-jpa-processor-core</artifactId>
--- a/apache-olingo/olingo2/src/main/java/org/baeldung/examples/olingo2/domain/CarMaker.java
+++ b/apache-olingo/olingo2/src/main/java/org/baeldung/examples/olingo2/domain/CarMaker.java
@ -12,25 +12,104 @@ import javax.persistence.OneToMany;
 import javax.persistence.Table;
 import javax.validation.constraints.NotNull;

-import lombok.Data;
-
@Entity
-@Data
-@Table(name="car_maker")
+@Table(name = "car_maker")
 public class CarMaker {
-    
+
    @Id
-    @GeneratedValue(strategy=GenerationType.IDENTITY)    
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
-    
+
    @NotNull
-    @Column(name="name")
+    @Column(name = "name")
    private String name;
-    
-    @OneToMany(mappedBy="maker",
-      orphanRemoval = true,
-      cascade=CascadeType.ALL)
+
+    @OneToMany(mappedBy = "maker", orphanRemoval = true, cascade = CascadeType.ALL)
    private List<CarModel> models;
-    
+
+    /**
+     * @return the id
+     */
+    public Long getId() {
+        return id;
+    }
+
+    /**
+     * @param id the id to set
+     */
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    /**
+     * @return the name
+     */
+    public String getName() {
+        return name;
+    }
+
+    /**
+     * @param name the name to set
+     */
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    /**
+     * @return the models
+     */
+    public List<CarModel> getModels() {
+        return models;
+    }
+
+    /**
+     * @param models the models to set
+     */
+    public void setModels(List<CarModel> models) {
+        this.models = models;
+    }
+
+    /* (non-Javadoc)
+     * @see java.lang.Object#hashCode()
+     */
+    @Override
+    public int hashCode() {
+        final int prime = 31;
+        int result = 1;
+        result = prime * result + ((id == null) ? 0 : id.hashCode());
+        result = prime * result + ((models == null) ? 0 : models.hashCode());
+        result = prime * result + ((name == null) ? 0 : name.hashCode());
+        return result;
+    }
+
+    /* (non-Javadoc)
+     * @see java.lang.Object#equals(java.lang.Object)
+     */
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj)
+            return true;
+        if (obj == null)
+            return false;
+        if (getClass() != obj.getClass())
+            return false;
+        CarMaker other = (CarMaker) obj;
+        if (id == null) {
+            if (other.id != null)
+                return false;
+        } else if (!id.equals(other.id))
+            return false;
+        if (models == null) {
+            if (other.models != null)
+                return false;
+        } else if (!models.equals(other.models))
+            return false;
+        if (name == null) {
+            if (other.name != null)
+                return false;
+        } else if (!name.equals(other.name))
+            return false;
+        return true;
+    }

 }
--- a/apache-olingo/olingo2/src/main/java/org/baeldung/examples/olingo2/domain/CarModel.java
+++ b/apache-olingo/olingo2/src/main/java/org/baeldung/examples/olingo2/domain/CarModel.java
@ -1,6 +1,5 @@
 package org.baeldung.examples.olingo2.domain;

-
 import javax.persistence.Entity;
 import javax.persistence.FetchType;
 import javax.persistence.GeneratedValue;
@ -11,28 +10,150 @@ import javax.persistence.ManyToOne;
 import javax.persistence.Table;
 import javax.validation.constraints.NotNull;

-import lombok.Data;
-
@Entity
-@Data
-@Table(name="car_model")
+@Table(name = "car_model")
 public class CarModel {

    @Id
-    @GeneratedValue(strategy=GenerationType.AUTO)
+    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;
-    
+
    @NotNull
    private String name;
-    
+
    @NotNull
    private Integer year;
-    
+
    @NotNull
    private String sku;
-    
-    @ManyToOne(optional=false, fetch= FetchType.LAZY)
-    @JoinColumn(name="maker_fk")
+
+    @ManyToOne(optional = false, fetch = FetchType.LAZY)
+    @JoinColumn(name = "maker_fk")
    private CarMaker maker;

+    /**
+     * @return the id
+     */
+    public Long getId() {
+        return id;
+    }
+
+    /**
+     * @param id the id to set
+     */
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    /**
+     * @return the name
+     */
+    public String getName() {
+        return name;
+    }
+
+    /**
+     * @param name the name to set
+     */
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    /**
+     * @return the year
+     */
+    public Integer getYear() {
+        return year;
+    }
+
+    /**
+     * @param year the year to set
+     */
+    public void setYear(Integer year) {
+        this.year = year;
+    }
+
+    /**
+     * @return the sku
+     */
+    public String getSku() {
+        return sku;
+    }
+
+    /**
+     * @param sku the sku to set
+     */
+    public void setSku(String sku) {
+        this.sku = sku;
+    }
+
+    /**
+     * @return the maker
+     */
+    public CarMaker getMaker() {
+        return maker;
+    }
+
+    /**
+     * @param maker the maker to set
+     */
+    public void setMaker(CarMaker maker) {
+        this.maker = maker;
+    }
+
+    /* (non-Javadoc)
+     * @see java.lang.Object#hashCode()
+     */
+    @Override
+    public int hashCode() {
+        final int prime = 31;
+        int result = 1;
+        result = prime * result + ((id == null) ? 0 : id.hashCode());
+        result = prime * result + ((maker == null) ? 0 : maker.hashCode());
+        result = prime * result + ((name == null) ? 0 : name.hashCode());
+        result = prime * result + ((sku == null) ? 0 : sku.hashCode());
+        result = prime * result + ((year == null) ? 0 : year.hashCode());
+        return result;
+    }
+
+    /* (non-Javadoc)
+     * @see java.lang.Object#equals(java.lang.Object)
+     */
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj)
+            return true;
+        if (obj == null)
+            return false;
+        if (getClass() != obj.getClass())
+            return false;
+        CarModel other = (CarModel) obj;
+        if (id == null) {
+            if (other.id != null)
+                return false;
+        } else if (!id.equals(other.id))
+            return false;
+        if (maker == null) {
+            if (other.maker != null)
+                return false;
+        } else if (!maker.equals(other.maker))
+            return false;
+        if (name == null) {
+            if (other.name != null)
+                return false;
+        } else if (!name.equals(other.name))
+            return false;
+        if (sku == null) {
+            if (other.sku != null)
+                return false;
+        } else if (!sku.equals(other.sku))
+            return false;
+        if (year == null) {
+            if (other.year != null)
+                return false;
+        } else if (!year.equals(other.year))
+            return false;
+        return true;
+    }
+
 }
--- a/apache-olingo/olingo2/src/main/resources/application.yml
+++ b/apache-olingo/olingo2/src/main/resources/application.yml
@ -1,5 +1,5 @@
 server:
-  port: 8180
+  port: 8080
  
 spring:
  jersey:
--- a/apache-olingo/olingo4/.gitignore
+++ b/apache-olingo/olingo4/.gitignore
@ -1,29 +0,0 @@
-HELP.md
-/target/
-!.mvn/wrapper/maven-wrapper.jar
-
-### STS ###
-.apt_generated
-.classpath
-.factorypath
-.project
-.settings
-.springBeans
-.sts4-cache
-
-### IntelliJ IDEA ###
-.idea
-*.iws
-*.iml
-*.ipr
-
-### NetBeans ###
-/nbproject/private/
-/nbbuild/
-/dist/
-/nbdist/
-/.nb-gradle/
-/build/
-
-### VS Code ###
-.vscode/
--- a/apache-olingo/olingo4/pom.xml
+++ b/apache-olingo/olingo4/pom.xml
@ -1,95 +0,0 @@
-<?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>
-	<parent>
-		<groupId>org.springframework.boot</groupId>
-		<artifactId>spring-boot-starter-parent</artifactId>
-		<version>2.1.3.RELEASE</version>
-		<relativePath /> <!-- lookup parent from repository -->
-	</parent>
-	<groupId>org.baeldung.examples.olingo4</groupId>
-	<artifactId>olingo4-sample</artifactId>
-	<version>0.0.1-SNAPSHOT</version>
-	<name>olingo4-sample</name>
-	<description>Sample Olingo 4 Project</description>
-
-	<properties>
-		<java.version>1.8</java.version>
-		<odata.version>4.5.0</odata.version>
-	</properties>
-
-	<dependencies>
-		<dependency>
-			<groupId>org.springframework.boot</groupId>
-			<artifactId>spring-boot-starter-data-jpa</artifactId>
-		</dependency>
-
-		<dependency>
-			<groupId>org.springframework.boot</groupId>
-			<artifactId>spring-boot-configuration-processor</artifactId>
-			<optional>true</optional>
-		</dependency>
-
-		<dependency>
-			<groupId>com.h2database</groupId>
-			<artifactId>h2</artifactId>
-			<scope>runtime</scope>
-		</dependency>
-
-		<dependency>
-			<groupId>org.projectlombok</groupId>
-			<artifactId>lombok</artifactId>
-			<optional>true</optional>
-		</dependency>
-		<dependency>
-			<groupId>org.springframework.boot</groupId>
-			<artifactId>spring-boot-starter-test</artifactId>
-			<scope>test</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.springframework.boot</groupId>
-			<artifactId>spring-boot-starter-web</artifactId>
-		</dependency>
-		
-		<dependency>
-			<groupId>org.apache.olingo</groupId>
-			<artifactId>odata-server-api</artifactId>
-			<version>${odata.version}</version>
-		</dependency>
-		<dependency>
-			<groupId>org.apache.olingo</groupId>
-			<artifactId>odata-server-core</artifactId>
-			<version>${odata.version}</version>
-			<scope>runtime</scope>
-		</dependency>
-
-		<dependency>
-			<groupId>org.apache.olingo</groupId>
-			<artifactId>odata-commons-api</artifactId>
-			<version>${odata.version}</version>
-		</dependency>
-		<dependency>
-			<groupId>org.apache.olingo</groupId>
-			<artifactId>odata-commons-core</artifactId>
-			<version>${odata.version}</version>
-		</dependency>
-		
-		<dependency>
-			<groupId>commons-beanutils</groupId>
-			<artifactId>commons-beanutils</artifactId>
-			<version>1.9.3</version>
-		</dependency>
-	</dependencies>
-
-	<build>
-		<plugins>
-			<plugin>
-				<groupId>org.springframework.boot</groupId>
-				<artifactId>spring-boot-maven-plugin</artifactId>
-			</plugin>
-		</plugins>
-	</build>
-
-</project>
--- a/apache-olingo/olingo4/src/main/java/org/baeldung/examples/olingo4/DefaultODataFactory.java
+++ b/apache-olingo/olingo4/src/main/java/org/baeldung/examples/olingo4/DefaultODataFactory.java
@ -1,20 +0,0 @@
-package org.baeldung.examples.olingo4;
-
-import org.apache.olingo.server.api.OData;
-import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
-import org.springframework.stereotype.Component;
-
-/**
- * Default implementation for ODataFactory 
- * @author Philippe
- *
- */
-@Component
-public class DefaultODataFactory implements ODataFactory {
-
-    @Override
-    public OData newInstance() {
-        return OData.newInstance();
-    }
-
-}
--- a/apache-olingo/olingo4/src/main/java/org/baeldung/examples/olingo4/ODataFactory.java
+++ b/apache-olingo/olingo4/src/main/java/org/baeldung/examples/olingo4/ODataFactory.java
@ -1,8 +0,0 @@
-package org.baeldung.examples.olingo4;
-
-import org.apache.olingo.server.api.OData;
-
-public interface ODataFactory {
-
-    public OData newInstance();
-}
--- a/apache-olingo/olingo4/src/main/java/org/baeldung/examples/olingo4/ODataHttpHandlerFactory.java
+++ b/apache-olingo/olingo4/src/main/java/org/baeldung/examples/olingo4/ODataHttpHandlerFactory.java
@ -1,8 +0,0 @@
-package org.baeldung.examples.olingo4;
-
-import org.apache.olingo.server.api.ODataHttpHandler;
-
-public interface ODataHttpHandlerFactory {
-
-    ODataHttpHandler newInstance();
-}
--- a/apache-olingo/olingo4/src/main/java/org/baeldung/examples/olingo4/ODataHttpHandlerFactoryImpl.java
+++ b/apache-olingo/olingo4/src/main/java/org/baeldung/examples/olingo4/ODataHttpHandlerFactoryImpl.java
@ -1,42 +0,0 @@
-package org.baeldung.examples.olingo4;
-
-import java.util.Collections;
-import java.util.List;
-
-import org.apache.olingo.commons.api.edm.provider.CsdlEdmProvider;
-import org.apache.olingo.server.api.OData;
-import org.apache.olingo.server.api.ODataHttpHandler;
-import org.apache.olingo.server.api.ServiceMetadata;
-import org.apache.olingo.server.api.processor.Processor;
-
-import lombok.Builder;
-
-@Builder
-public class ODataHttpHandlerFactoryImpl implements ODataHttpHandlerFactory {
-    
-    
-    private final ODataFactory odataFactory;
-    private final CsdlEdmProvider edmProvider;
-    private final List<Processor> processors;
-
-    public ODataHttpHandlerFactoryImpl(ODataFactory odataFactory,CsdlEdmProvider edmProvider, List<Processor> processors) {
-        this.odataFactory = odataFactory;
-        this.edmProvider = edmProvider;
-        this.processors = processors;
-    }
-
-    @Override
-    public ODataHttpHandler newInstance() {
-        
-        OData odata = odataFactory.newInstance();
-        ServiceMetadata metadata = odata.createServiceMetadata(edmProvider, Collections.emptyList());
-        ODataHttpHandler handler = odata.createHandler(metadata);
-        
-        // Register all available processors
-        processors.forEach(p -> handler.register(p));
-        
-        
-        return handler;
-    }
-
-}
--- a/apache-olingo/olingo4/src/main/java/org/baeldung/examples/olingo4/ODataServiceConfiguration.java
+++ b/apache-olingo/olingo4/src/main/java/org/baeldung/examples/olingo4/ODataServiceConfiguration.java
@ -1,35 +0,0 @@
-package org.baeldung.examples.olingo4;
-
-import java.util.List;
-
-import javax.persistence.EntityManagerFactory;
-import javax.servlet.http.HttpServlet;
-
-import org.apache.olingo.commons.api.edm.provider.CsdlEdmProvider;
-import org.apache.olingo.server.api.processor.Processor;
-import org.baeldung.examples.olingo4.ODataHttpHandlerFactoryImpl.ODataHttpHandlerFactoryImplBuilder;
-import org.springframework.boot.web.servlet.ServletRegistrationBean;
-import org.springframework.context.annotation.Bean;
-import org.springframework.context.annotation.Configuration;
-
-@Configuration
-public class ODataServiceConfiguration {
-
-    @Bean
-    public ServletRegistrationBean<HttpServlet> odataServletRegistration(ODataHttpHandlerFactory factory) {
-        ServletRegistrationBean<HttpServlet> srb = 
-          new ServletRegistrationBean<>(new ODataServlet(factory), "/odata/*");
-        srb.setLoadOnStartup(1);
-        return srb;
-    }
-
-    @Bean
-    public ODataHttpHandlerFactory httpHandlerFactory(CsdlEdmProvider edmProvider, ODataFactory odataFactory, List<Processor> processors) {
-        return new ODataHttpHandlerFactoryImplBuilder()
-          .edmProvider(edmProvider)
-          .odataFactory(odataFactory)
-          .processors(processors)
-          .build();
-    }
-
-}
--- a/apache-olingo/olingo4/src/main/java/org/baeldung/examples/olingo4/ODataServlet.java
+++ b/apache-olingo/olingo4/src/main/java/org/baeldung/examples/olingo4/ODataServlet.java
@ -1,38 +0,0 @@
-/**
- * 
- */
-package org.baeldung.examples.olingo4;
-
-import java.io.IOException;
-
-import javax.persistence.EntityManager;
-import javax.persistence.EntityManagerFactory;
-import javax.persistence.EntityTransaction;
-import javax.servlet.ServletException;
-import javax.servlet.http.HttpServlet;
-import javax.servlet.http.HttpServletRequest;
-import javax.servlet.http.HttpServletResponse;
-
-import org.apache.olingo.server.api.ODataHttpHandler;
-
-/**
- * @author Philippe
- *
- */
-public class ODataServlet extends HttpServlet {
-
-    private static final long serialVersionUID = 1L;
-    private final ODataHttpHandlerFactory odataHttpHandlerFactory;
-    
-    
-    public ODataServlet(ODataHttpHandlerFactory factory) {
-        this.odataHttpHandlerFactory = factory;
-    }
-
-    @Override
-    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
-
-        ODataHttpHandler handler = odataHttpHandlerFactory.newInstance();
-        handler.process(req, resp);
-    }
-}
--- a/apache-olingo/olingo4/src/main/java/org/baeldung/examples/olingo4/domain/CarMaker.java
+++ b/apache-olingo/olingo4/src/main/java/org/baeldung/examples/olingo4/domain/CarMaker.java
@ -1,36 +0,0 @@
-package org.baeldung.examples.olingo4.domain;
-
-import java.util.List;
-
-import javax.persistence.CascadeType;
-import javax.persistence.Column;
-import javax.persistence.Entity;
-import javax.persistence.GeneratedValue;
-import javax.persistence.GenerationType;
-import javax.persistence.Id;
-import javax.persistence.OneToMany;
-import javax.persistence.Table;
-import javax.validation.constraints.NotNull;
-
-import lombok.Data;
-
-@Entity
-@Data
-@Table(name="car_maker")
-public class CarMaker {
-    
-    @Id
-    @GeneratedValue(strategy=GenerationType.IDENTITY)    
-    private Long id;
-    
-    @NotNull
-    @Column(name="name")
-    private String name;
-    
-    @OneToMany(mappedBy="maker",
-      orphanRemoval = true,
-      cascade=CascadeType.ALL)
-    private List<CarModel> models;
-    
-
-}
--- a/apache-olingo/olingo4/src/main/java/org/baeldung/examples/olingo4/domain/CarModel.java
+++ b/apache-olingo/olingo4/src/main/java/org/baeldung/examples/olingo4/domain/CarModel.java
@ -1,38 +0,0 @@
-package org.baeldung.examples.olingo4.domain;
-
-
-import javax.persistence.Entity;
-import javax.persistence.FetchType;
-import javax.persistence.GeneratedValue;
-import javax.persistence.GenerationType;
-import javax.persistence.Id;
-import javax.persistence.JoinColumn;
-import javax.persistence.ManyToOne;
-import javax.persistence.Table;
-import javax.validation.constraints.NotNull;
-
-import lombok.Data;
-
-@Entity
-@Data
-@Table(name="car_model")
-public class CarModel {
-
-    @Id
-    @GeneratedValue(strategy=GenerationType.AUTO)
-    private Long id;
-    
-    @NotNull
-    private String name;
-    
-    @NotNull
-    private Integer year;
-    
-    @NotNull
-    private String sku;
-    
-    @ManyToOne(optional=false, fetch= FetchType.EAGER   )
-    @JoinColumn(name="maker_fk")
-    private CarMaker maker;
-
-}
--- a/apache-olingo/olingo4/src/main/java/org/baeldung/examples/olingo4/edm/EdmTypeMapper.java
+++ b/apache-olingo/olingo4/src/main/java/org/baeldung/examples/olingo4/edm/EdmTypeMapper.java
@ -1,46 +0,0 @@
-package org.baeldung.examples.olingo4.edm;
-
-import java.util.Collections;
-import java.util.Date;
-import java.util.Map;
-import java.util.UUID;
-import java.util.stream.Collectors;
-import java.util.stream.Stream;
-import java.sql.Time;
-import java.util.AbstractMap.SimpleEntry;
-
-import org.apache.olingo.commons.api.edm.EdmPrimitiveTypeKind;
-import org.springframework.stereotype.Component;
-
-@Component
-public class EdmTypeMapper {
-
-    public EdmPrimitiveTypeKind java2edm(Class<?> clazz) {
-        EdmPrimitiveTypeKind result = java2edm.get(clazz);
-        if ( result == null ) {
-            throw new IllegalArgumentException("[E19] Unsupported class mapping: class=" + clazz);
-        }
-        else {
-            return result;
-        }
-    }
-    
-    // Static map used generate attribute metadada based on Java types
-    static Map<Class<?>,EdmPrimitiveTypeKind> java2edm = Collections
-      .unmodifiableMap(Stream.of(
-        new SimpleEntry<>(Boolean.class,EdmPrimitiveTypeKind.Boolean),
-        new SimpleEntry<>(Byte.class,EdmPrimitiveTypeKind.SByte),
-        new SimpleEntry<>(Date.class,EdmPrimitiveTypeKind.Date),
-        new SimpleEntry<>(Time.class,EdmPrimitiveTypeKind.TimeOfDay),
-        new SimpleEntry<>(Number.class,EdmPrimitiveTypeKind.Decimal),
-        new SimpleEntry<>(Float.class,EdmPrimitiveTypeKind.Single),
-        new SimpleEntry<>(Double.class,EdmPrimitiveTypeKind.Double),
-        new SimpleEntry<>(UUID.class,EdmPrimitiveTypeKind.Guid),
-        new SimpleEntry<>(Short.class,EdmPrimitiveTypeKind.Int16),
-        new SimpleEntry<>(Integer.class,EdmPrimitiveTypeKind.Int32),
-        new SimpleEntry<>(Long.class,EdmPrimitiveTypeKind.Int64),
-        new SimpleEntry<>(String.class,EdmPrimitiveTypeKind.String)
-      
-      ).collect(Collectors.toMap((e)-> e.getKey(),(e)-> e.getValue())));
-
-}
--- a/apache-olingo/olingo4/src/main/java/org/baeldung/examples/olingo4/edm/JpaEdmProvider.java
+++ b/apache-olingo/olingo4/src/main/java/org/baeldung/examples/olingo4/edm/JpaEdmProvider.java
@ -1,269 +0,0 @@
-package org.baeldung.examples.olingo4.edm;
-
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.stream.Collectors;
-
-import javax.persistence.EntityManagerFactory;
-import javax.persistence.metamodel.Attribute.PersistentAttributeType;
-import javax.persistence.metamodel.EntityType;
-import javax.persistence.metamodel.Metamodel;
-import javax.persistence.metamodel.PluralAttribute;
-import javax.persistence.metamodel.SingularAttribute;
-
-import org.apache.olingo.commons.api.edm.FullQualifiedName;
-import org.apache.olingo.commons.api.edm.provider.CsdlAbstractEdmProvider;
-import org.apache.olingo.commons.api.edm.provider.CsdlEntityContainer;
-import org.apache.olingo.commons.api.edm.provider.CsdlEntityContainerInfo;
-import org.apache.olingo.commons.api.edm.provider.CsdlEntitySet;
-import org.apache.olingo.commons.api.edm.provider.CsdlEntityType;
-import org.apache.olingo.commons.api.edm.provider.CsdlNavigationProperty;
-import org.apache.olingo.commons.api.edm.provider.CsdlProperty;
-import org.apache.olingo.commons.api.edm.provider.CsdlPropertyRef;
-import org.apache.olingo.commons.api.edm.provider.CsdlSchema;
-import org.apache.olingo.commons.api.ex.ODataException;
-import org.springframework.stereotype.Component;
-
-@Component
-public class JpaEdmProvider extends CsdlAbstractEdmProvider {
-
-    EntityManagerFactory emf;
-
-    //
-    private EdmTypeMapper typeMapper;
-
-    // Service Namespace
-    public static final String NAMESPACE = "Baeldung.OData";
-
-    // EDM Container
-    public static final String CONTAINER_NAME = "Cars";
-    public static final FullQualifiedName CONTAINER = new FullQualifiedName(NAMESPACE, CONTAINER_NAME);
-    
-    // Caches of OData types by it fully qualified name
-    private Map<FullQualifiedName, CsdlEntityType> cdslName2Type = new HashMap<>();
-
-    public JpaEdmProvider(EntityManagerFactory emf, EdmTypeMapper mapper) {
-        this.emf = emf;
-        this.typeMapper = mapper;
-    }
-
-    /* (non-Javadoc)
-     * @see org.apache.olingo.commons.api.edm.provider.CsdlAbstractEdmProvider#getEntitySet(org.apache.olingo.commons.api.edm.FullQualifiedName, java.lang.String)
-     */
-    @Override
-    public CsdlEntitySet getEntitySet(FullQualifiedName entityContainer, String entitySetName) throws ODataException {
-
-        if (entityContainer.equals(CONTAINER)) {
-
-            EntityType<?> e = emf.getMetamodel()
-                .getEntities()
-                .stream()
-                .filter((ent) -> (ent.getName() + "s")
-                    .equals(entitySetName))
-                .findFirst()
-                .orElse(null);
-
-            if (e != null) {
-                CsdlEntitySet entitySet = new CsdlEntitySet();
-                entitySet
-                  .setName(entitySetName)
-                  .setType(new FullQualifiedName(NAMESPACE, e.getName()));
-                return entitySet;
-            }
-        }
-
-        return null;
-    }
-
-    /* (non-Javadoc)
-     * @see org.apache.olingo.commons.api.edm.provider.CsdlAbstractEdmProvider#getEntityContainerInfo(org.apache.olingo.commons.api.edm.FullQualifiedName)
-     */
-    @Override
-    public CsdlEntityContainerInfo getEntityContainerInfo(FullQualifiedName entityContainerName) throws ODataException {
-
-        // This method is invoked when displaying the Service Document at e.g. http://localhost:8080/DemoService/DemoService.svc
-        if (entityContainerName == null || entityContainerName.equals(CONTAINER)) {
-            CsdlEntityContainerInfo entityContainerInfo = new CsdlEntityContainerInfo();
-            entityContainerInfo.setContainerName(CONTAINER);
-            return entityContainerInfo;
-        }
-
-        return null;
-    }
-
-    /* (non-Javadoc)
-     * @see org.apache.olingo.commons.api.edm.provider.CsdlAbstractEdmProvider#getSchemas()
-     */
-    @Override
-    public List<CsdlSchema> getSchemas() throws ODataException {
-        // create Schema
-        CsdlSchema schema = new CsdlSchema();
-        schema.setNamespace(NAMESPACE);
-
-        // add EntityTypes
-        List<CsdlEntityType> entityTypes = emf.getMetamodel()
-            .getEntities()
-            .stream()
-            .map((e) -> {
-                try {
-                    return getEntityType(new FullQualifiedName(NAMESPACE, e.getName()));
-                } catch (ODataException oe) {
-                    throw new RuntimeException(oe);
-                }
-            })
-            .collect(Collectors.toList());
-
-        schema.setEntityTypes(entityTypes);
-
-        // add EntityContainer
-        schema.setEntityContainer(getEntityContainer());
-
-        // finally
-        List<CsdlSchema> schemas = new ArrayList<CsdlSchema>();
-        schemas.add(schema);
-
-        return schemas;
-    }
-
-    /* (non-Javadoc)
-     * @see org.apache.olingo.commons.api.edm.provider.CsdlAbstractEdmProvider#getEntityContainer()
-     */
-    @Override
-    public CsdlEntityContainer getEntityContainer() throws ODataException {
-        
-        
-        // add EntityTypes
-        List<CsdlEntitySet> entitySets = emf.getMetamodel()
-            .getEntities()
-            .stream()
-            .map((e) -> {
-                try {
-                    // Here we use a simple mapping strategy to map entity types to entity set names:
-                    return getEntitySet(CONTAINER, e.getName() + "s");
-                } catch (ODataException oe) {
-                    throw new RuntimeException(oe);
-                }
-            })
-            .collect(Collectors.toList());
-        
-        // create EntityContainer
-        CsdlEntityContainer entityContainer = new CsdlEntityContainer();
-        entityContainer.setName(CONTAINER_NAME);
-        entityContainer.setEntitySets(entitySets);
-
-        return entityContainer;
-    }
-
-    @Override
-    public CsdlEntityType getEntityType(FullQualifiedName entityTypeName) throws ODataException {
-        
-        CsdlEntityType result = cdslName2Type.get(entityTypeName);
-        if ( result != null ) {
-            return result;
-        }
-
-        Metamodel mm = emf.getMetamodel();
-        result = mm.getEntities()
-            .stream()
-            .filter(et -> entityTypeName.equals(new FullQualifiedName(NAMESPACE, et.getName())))
-            .map(et -> buildODataType(et))
-            .findFirst()
-            .orElse(null);
-
-        // save for future use
-        cdslName2Type.put(entityTypeName, result);
-        return result;
-        
-    }
-
-    /**
-     * Maps a JPA type to its OData counterpart.
-     * @param et
-     * @return
-     */
-    protected CsdlEntityType buildODataType(EntityType<?> et) {
-
-        CsdlEntityType result = new CsdlEntityType();
-        result.setName(et.getName());
-
-        // Process simple properties
-        List<CsdlProperty> properties = et.getDeclaredSingularAttributes()
-            .stream()
-            .filter(attr -> attr.getPersistentAttributeType() == PersistentAttributeType.BASIC)
-            .map(attr -> buildBasicAttribute(et, attr))
-            .collect(Collectors.toList());
-
-        result.setProperties(properties);
-
-        // Process Ids
-        List<CsdlPropertyRef> ids = et.getDeclaredSingularAttributes()
-            .stream()
-            .filter(attr -> attr.getPersistentAttributeType() == PersistentAttributeType.BASIC && attr.isId())
-            .map(attr -> buildRefAttribute(et, attr))
-            .collect(Collectors.toList());
-
-        result.setKey(ids);
-
-        // Process 1:N navs
-        List<CsdlNavigationProperty> navs = et.getDeclaredPluralAttributes()
-            .stream()
-            .map(attr -> buildNavAttribute(et, attr))
-            .collect(Collectors.toList());
-        result.setNavigationProperties(navs);
-        
-        // Process N:1 navs
-        List<CsdlNavigationProperty> navs2 = et.getDeclaredSingularAttributes()
-            .stream()
-            .filter(attr -> attr.getPersistentAttributeType() == PersistentAttributeType.MANY_TO_ONE)
-            .map(attr -> buildNavAttribute(et, attr))
-            .collect(Collectors.toList());
-
-        result.getNavigationProperties().addAll(navs2);
-        
-
-        return result;
-    }
-
-    private CsdlProperty buildBasicAttribute(EntityType<?> et, SingularAttribute<?, ?> attr) {
-
-        CsdlProperty p = new CsdlProperty().setName(attr.getName())
-            .setType(typeMapper.java2edm(attr.getJavaType())
-                .getFullQualifiedName())
-            .setNullable(et.getDeclaredSingularAttribute(attr.getName())
-                .isOptional());
-
-        return p;
-    }
-
-    private CsdlPropertyRef buildRefAttribute(EntityType<?> et, SingularAttribute<?, ?> attr) {
-
-        CsdlPropertyRef p = new CsdlPropertyRef().setName(attr.getName());
-
-        return p;
-    }
-
-    // Build NavProperty for 1:N or M:N associations
-    private CsdlNavigationProperty buildNavAttribute(EntityType<?> et, PluralAttribute<?, ?, ?> attr) {
-
-        CsdlNavigationProperty p = new CsdlNavigationProperty().setName(attr.getName())
-            .setType(new FullQualifiedName(NAMESPACE, attr.getBindableJavaType().getSimpleName()))
-            .setCollection(true)
-            .setNullable(false); 
-
-        return p;
-    }
-
-    // Build NavProperty for N:1 associations
-    private CsdlNavigationProperty buildNavAttribute(EntityType<?> et, SingularAttribute<?, ?> attr) {
-
-        CsdlNavigationProperty p = new CsdlNavigationProperty().setName(attr.getName())
-            .setType(new FullQualifiedName(NAMESPACE, attr.getBindableJavaType().getSimpleName()))
-            .setCollection(false)
-            .setNullable(attr.isOptional());
-
-        return p;
-    }
-    
-}
--- a/apache-olingo/olingo4/src/main/java/org/baeldung/examples/olingo4/processor/JpaEntityCollectionProcessor.java
+++ b/apache-olingo/olingo4/src/main/java/org/baeldung/examples/olingo4/processor/JpaEntityCollectionProcessor.java
@ -1,161 +0,0 @@
-package org.baeldung.examples.olingo4.processor;
-
-import java.io.ByteArrayInputStream;
-import java.io.InputStream;
-import java.lang.reflect.InvocationTargetException;
-import java.net.URI;
-import java.net.URISyntaxException;
-import java.util.Collection;
-import java.util.List;
-
-import javax.persistence.EntityManagerFactory;
-import javax.persistence.metamodel.EntityType;
-import javax.persistence.metamodel.SingularAttribute;
-
-import org.apache.commons.beanutils.PropertyUtils;
-import org.apache.olingo.commons.api.data.ContextURL;
-import org.apache.olingo.commons.api.data.Entity;
-import org.apache.olingo.commons.api.data.EntityCollection;
-import org.apache.olingo.commons.api.data.Property;
-import org.apache.olingo.commons.api.data.ValueType;
-import org.apache.olingo.commons.api.edm.EdmEntitySet;
-import org.apache.olingo.commons.api.edm.EdmEntityType;
-import org.apache.olingo.commons.api.edm.EdmNavigationProperty;
-import org.apache.olingo.commons.api.ex.ODataRuntimeException;
-import org.apache.olingo.commons.api.format.ContentType;
-import org.apache.olingo.commons.api.http.HttpHeader;
-import org.apache.olingo.commons.api.http.HttpStatusCode;
-import org.apache.olingo.server.api.OData;
-import org.apache.olingo.server.api.ODataApplicationException;
-import org.apache.olingo.server.api.ODataLibraryException;
-import org.apache.olingo.server.api.ODataRequest;
-import org.apache.olingo.server.api.ODataResponse;
-import org.apache.olingo.server.api.ServiceMetadata;
-import org.apache.olingo.server.api.processor.CountEntityCollectionProcessor;
-import org.apache.olingo.server.api.processor.EntityCollectionProcessor;
-import org.apache.olingo.server.api.serializer.EntityCollectionSerializerOptions;
-import org.apache.olingo.server.api.serializer.ODataSerializer;
-import org.apache.olingo.server.api.serializer.SerializerResult;
-import org.apache.olingo.server.api.uri.UriInfo;
-import org.apache.olingo.server.api.uri.UriParameter;
-import org.apache.olingo.server.api.uri.UriResource;
-import org.apache.olingo.server.api.uri.UriResourceEntitySet;
-import org.baeldung.examples.olingo4.repository.RepositoryRegistry;
-import org.springframework.data.jpa.repository.JpaRepository;
-import org.springframework.stereotype.Component;
-
-@Component
-public class JpaEntityCollectionProcessor implements CountEntityCollectionProcessor {
-
-    private OData odata;
-    private ServiceMetadata serviceMetadata;
-    private EntityManagerFactory emf;
-    private RepositoryRegistry repositoryRegistry;
-    private JpaEntityMapper entityMapper;
-
-    public JpaEntityCollectionProcessor(EntityManagerFactory emf, RepositoryRegistry repositoryRegistry, JpaEntityMapper entityMapper) {
-        this.emf = emf;
-        this.repositoryRegistry = repositoryRegistry;
-        this.entityMapper = entityMapper;
-    }
-
-    @Override
-    public void init(OData odata, ServiceMetadata serviceMetadata) {
-        this.odata = odata;
-        this.serviceMetadata = serviceMetadata;
-    }
-
-    @Override
-    public void readEntityCollection(ODataRequest request, ODataResponse response, UriInfo uriInfo, ContentType responseFormat) throws ODataApplicationException, ODataLibraryException {
-
-        // 1st we have retrieve the requested EntitySet from the uriInfo object (representation of the parsed service URI)
-        List<UriResource> resourcePaths = uriInfo.getUriResourceParts();
-        UriResourceEntitySet uriResourceEntitySet = (UriResourceEntitySet) resourcePaths.get(0); // in our example, the first segment is the EntitySet
-        EdmEntitySet edmEntitySet = uriResourceEntitySet.getEntitySet();
-
-        // 2nd: fetch the data from backend for this requested EntitySetName
-        // it has to be delivered as EntitySet object
-        EntityCollection entitySet = getData(edmEntitySet, uriInfo);
-
-        // 3rd: create a serializer based on the requested format (json)
-        ODataSerializer serializer = odata.createSerializer(responseFormat);
-
-        // 4th: Now serialize the content: transform from the EntitySet object to InputStream
-        EdmEntityType edmEntityType = edmEntitySet.getEntityType();
-        ContextURL contextUrl = ContextURL.with()
-            .entitySet(edmEntitySet)
-            .build();
-
-        final String id = request.getRawBaseUri() + "/" + edmEntitySet.getName();
-        EntityCollectionSerializerOptions opts = EntityCollectionSerializerOptions.with()
-            .id(id)
-            .contextURL(contextUrl)
-            .build();
-        SerializerResult serializerResult = serializer.entityCollection(serviceMetadata, edmEntityType, entitySet, opts);
-        InputStream serializedContent = serializerResult.getContent();
-
-        // Finally: configure the response object: set the body, headers and status code
-        response.setContent(serializedContent);
-        response.setStatusCode(HttpStatusCode.OK.getStatusCode());
-        response.setHeader(HttpHeader.CONTENT_TYPE, responseFormat.toContentTypeString());
-
-    }
-
-    @Override
-    public void countEntityCollection(ODataRequest request, ODataResponse response, UriInfo uriInfo) throws ODataApplicationException, ODataLibraryException {
-
-        // 1st we have retrieve the requested EntitySet from the uriInfo object (representation of the parsed service URI)
-        List<UriResource> resourcePaths = uriInfo.getUriResourceParts();
-        UriResourceEntitySet uriResourceEntitySet = (UriResourceEntitySet) resourcePaths.get(0); // in our example, the first segment is the EntitySet
-        EdmEntitySet edmEntitySet = uriResourceEntitySet.getEntitySet();
-
-        // 2nd: fetch the data from backend for this requested EntitySetName
-        Long count = getCount(edmEntitySet, uriInfo);
-
-        // Finally: configure the response object: set the body, headers and status code
-        response.setContent(new ByteArrayInputStream(count.toString().getBytes()));
-        response.setStatusCode(HttpStatusCode.OK.getStatusCode());
-        response.setHeader(HttpHeader.CONTENT_TYPE, "text/plain");
-
-    }
-
-    /**
-     * Helper method to retrieve all entities of an entity set from an the backend database
-     * @param edmEntitySet
-     * @param uriInfo
-     * @return
-     */
-    protected EntityCollection getData(EdmEntitySet edmEntitySet, UriInfo uriInfo) {
-
-        EdmEntityType type = edmEntitySet.getEntityType();
-        JpaRepository<?, ?> repo = (JpaRepository<?, ?>)repositoryRegistry.getRepositoryForEntity(type);
-        EntityCollection result = new EntityCollection();
-
-        repo.findAll()
-          .stream()
-          .forEach((it) -> result.getEntities()
-          .add(entityMapper.map2entity(edmEntitySet, it)));
-
-        return result;
-    }
-
-
-    /**
-     * Helper method to get the total size of an entity set
-     * @param edmEntitySet
-     * @param uriInfo
-     * @return
-     */
-    protected Long getCount(EdmEntitySet edmEntitySet, UriInfo uriInfo) {
-        
-        EdmEntityType type = edmEntitySet.getEntityType();
-        JpaRepository<?, ?> repo = (JpaRepository<?, ?>)repositoryRegistry.getRepositoryForEntity(type);
-        EntityCollection result = new EntityCollection();
-
-        return repo.count();
-    }
-    
-    
-
-
-}
--- a/apache-olingo/olingo4/src/main/java/org/baeldung/examples/olingo4/processor/JpaEntityMapper.java
+++ b/apache-olingo/olingo4/src/main/java/org/baeldung/examples/olingo4/processor/JpaEntityMapper.java
@ -1,93 +0,0 @@
-/**
- * 
- */
-package org.baeldung.examples.olingo4.processor;
-
-import java.lang.reflect.InvocationTargetException;
-import java.net.URI;
-import java.net.URISyntaxException;
-
-import javax.persistence.EntityManagerFactory;
-import javax.persistence.metamodel.EntityType;
-
-import org.apache.commons.beanutils.PropertyUtils;
-import org.apache.olingo.commons.api.data.Entity;
-import org.apache.olingo.commons.api.data.Property;
-import org.apache.olingo.commons.api.data.ValueType;
-import org.apache.olingo.commons.api.edm.EdmEntitySet;
-import org.apache.olingo.commons.api.ex.ODataRuntimeException;
-import org.springframework.stereotype.Component;
-
-/**
- * <p>Helper class that converts a JPA entity into an OData entity using
- * available metadata from the JPA's EntityManagerFactory.</p>
- * 
- * @author Philippe
- *
- */
-@Component
-public class JpaEntityMapper {
-    
-    private EntityManagerFactory emf;
-
-    public JpaEntityMapper(EntityManagerFactory emf) {
-        this.emf = emf;
-    }
-    
-    
-    public Entity map2entity(EdmEntitySet edmEntitySet, Object entry) {
-
-        EntityType<?> et = emf.getMetamodel()
-            .entity(entry.getClass());
-
-
-        Entity e = new Entity();
-        try {
-            et.getDeclaredSingularAttributes().stream()
-              .forEach( (attr) -> {
-                 if ( !attr.isAssociation()) {
-                     Object v = getPropertyValue(entry,attr.getName());
-                     Property p = new Property(null, attr.getName(),ValueType.PRIMITIVE,v);
-                     e.addProperty(p);
-
-                     if ( attr.isId()) {
-                         e.setId(createId(edmEntitySet.getName(),v));                     
-                     }                     
-                 }                 
-              });
-        } catch (Exception ex) {
-            throw new ODataRuntimeException("[E141] Unable to create OData entity", ex);
-        }
-
-        return e;
-    }
-    
-    
-    public Object getPropertyValue(Object entry, String name) {
-        try {
-            return PropertyUtils.getProperty(entry,name);
-        } catch (IllegalAccessException | InvocationTargetException | NoSuchMethodException e) {
-            throw new ODataRuntimeException("[E141] Unable to read property from entity, property=" + name, e);
-        }
-    }
-    
-    public void setPropertyValue(Object entry, String name,Object value) {
-        try {
-            PropertyUtils.setProperty(entry,name,value);
-        } catch (IllegalAccessException | InvocationTargetException | NoSuchMethodException e) {
-            throw new ODataRuntimeException("[E141] Unable to read property from entity, property=" + name, e);
-        }
-    }
-    
-
-    private URI createId(String entitySetName, Object id)  {
-        try {
-            return new URI(entitySetName + "(" + String.valueOf(id) + ")");
-        } catch (URISyntaxException e) {
-            throw new ODataRuntimeException("[E177] Unable to create URI", e);
-        }
-    }
-    
-
-
-}
--- a/apache-olingo/olingo4/src/main/java/org/baeldung/examples/olingo4/processor/JpaEntityProcessor.java
+++ b/apache-olingo/olingo4/src/main/java/org/baeldung/examples/olingo4/processor/JpaEntityProcessor.java
@ -1,304 +0,0 @@
-/**
- * 
- */
-package org.baeldung.examples.olingo4.processor;
-
-import java.io.InputStream;
-import java.util.List;
-import java.util.Locale;
-import java.util.Optional;
-
-import javax.persistence.EntityManager;
-import javax.persistence.EntityManagerFactory;
-import javax.persistence.metamodel.SingularAttribute;
-
-import org.apache.olingo.commons.api.data.ContextURL;
-import org.apache.olingo.commons.api.data.Entity;
-import org.apache.olingo.commons.api.edm.EdmEntitySet;
-import org.apache.olingo.commons.api.edm.EdmEntityType;
-import org.apache.olingo.commons.api.edm.EdmNavigationProperty;
-import org.apache.olingo.commons.api.ex.ODataRuntimeException;
-import org.apache.olingo.commons.api.format.ContentType;
-import org.apache.olingo.commons.api.http.HttpHeader;
-import org.apache.olingo.commons.api.http.HttpStatusCode;
-import org.apache.olingo.server.api.OData;
-import org.apache.olingo.server.api.ODataApplicationException;
-import org.apache.olingo.server.api.ODataLibraryException;
-import org.apache.olingo.server.api.ODataRequest;
-import org.apache.olingo.server.api.ODataResponse;
-import org.apache.olingo.server.api.ServiceMetadata;
-import org.apache.olingo.server.api.processor.EntityProcessor;
-import org.apache.olingo.server.api.serializer.EntitySerializerOptions;
-import org.apache.olingo.server.api.serializer.ODataSerializer;
-import org.apache.olingo.server.api.serializer.SerializerResult;
-import org.apache.olingo.server.api.uri.UriInfo;
-import org.apache.olingo.server.api.uri.UriParameter;
-import org.apache.olingo.server.api.uri.UriResource;
-import org.apache.olingo.server.api.uri.UriResourceEntitySet;
-import org.apache.olingo.server.api.uri.UriResourceNavigation;
-import org.baeldung.examples.olingo4.repository.EdmEntityRepository;
-import org.baeldung.examples.olingo4.repository.RepositoryRegistry;
-import org.springframework.data.jpa.repository.JpaRepository;
-import org.springframework.stereotype.Component;
-
-/**
- * JpaEntityProcessor adapter. 
- * <p>This implementation is heavily based on the Tutorial available
- * at Olingo's site. It is meant to be an starting point for an actual implementation.</p>
- * <p>Please note that many features from a full-fledged are missing
- * @author Philippe
- *
- */
-@Component
-public class JpaEntityProcessor implements EntityProcessor {
-    
-    private EntityManagerFactory emf;
-    private OData odata;
-    private ServiceMetadata serviceMetadata;
-    private RepositoryRegistry registry;
-    private JpaEntityMapper entityMapper;
-
-    public JpaEntityProcessor(EntityManagerFactory emf, RepositoryRegistry registry, JpaEntityMapper entityMapper) {
-        this.emf = emf;
-        this.registry = registry;
-        this.entityMapper = entityMapper;
-    }
-
-    /* (non-Javadoc)
-     * @see org.apache.olingo.server.api.processor.Processor#init(org.apache.olingo.server.api.OData, org.apache.olingo.server.api.ServiceMetadata)
-     */
-    @Override
-    public void init(OData odata, ServiceMetadata serviceMetadata) {
-        this.odata = odata;
-        this.serviceMetadata = serviceMetadata;
-        
-    }
-
-    /* (non-Javadoc)
-     * @see org.apache.olingo.server.api.processor.EntityProcessor#readEntity(org.apache.olingo.server.api.ODataRequest, org.apache.olingo.server.api.ODataResponse, org.apache.olingo.server.api.uri.UriInfo, org.apache.olingo.commons.api.format.ContentType)
-     */
-    @Override
-    public void readEntity(ODataRequest request, ODataResponse response, UriInfo uriInfo, ContentType responseFormat) throws ODataApplicationException, ODataLibraryException {
-
-        // First, we have to figure out which entity is requested
-        List<UriResource> resourceParts = uriInfo.getUriResourceParts();
-        InputStream entityStream;
-        
-        UriResourceEntitySet rootResourceEntitySet = (UriResourceEntitySet) resourceParts.get(0);
-        EdmEntitySet rootEntitySet = rootResourceEntitySet.getEntitySet();        
-        List<UriParameter> rootPredicates = rootResourceEntitySet.getKeyPredicates();
-        
-        if ( resourceParts.size() == 1 ) {
-            entityStream = readRootEntity(rootEntitySet,rootPredicates,responseFormat);
-        }
-        else if ( resourceParts.size() == 2 ) {
-            UriResource part = resourceParts.get(1);
-            if ( !(part instanceof UriResourceNavigation)) {
-                throw new ODataRuntimeException("[E103] part type not supported: class=" + part.getClass().getName());
-            }
-
-            UriResourceNavigation navSegment = (UriResourceNavigation)part;
-            entityStream = readRelatedEntity(request, rootEntitySet,rootPredicates,navSegment.getProperty(),navSegment.getKeyPredicates(),responseFormat);                       
-        }
-        else {
-            // For now, we'll only allow navigation just to directly linked navs
-            throw new ODataApplicationException("[E109] Multi-level navigation not supported", HttpStatusCode.NOT_IMPLEMENTED.getStatusCode(), Locale.ROOT);
-        }
-
-        //4. configure the response object
-        response.setContent(entityStream);
-        response.setStatusCode(HttpStatusCode.OK.getStatusCode());
-        response.setHeader(HttpHeader.CONTENT_TYPE, responseFormat.toContentTypeString());       
-        
-    }
-    
-
-    // Lookup the EntitySet associated with an EntityType
-    // In our example, we assume we have only one entityset for each entity type
-    private EdmEntitySet entitySetFromType(EdmEntityType type) {
-        return serviceMetadata
-          .getEdm()
-          .getEntityContainer()
-          .getEntitySets()
-          .stream()
-          .filter((s) -> s.getEntityType().getName().equals(type.getName()))
-          .findFirst()
-          .orElseThrow(() -> new ODataRuntimeException("[E144] No entity set found for type " + type.getFullQualifiedName()));
-    }
-
-    // 
-   // private boolean isOne2ManyProperty(EdmEntityType entityType, EdmNavigationProperty property) {        
-    //    return entityType.getProperty(property.getName()) != null && property.isCollection();
-    //}
-
-    @SuppressWarnings({ "rawtypes", "unchecked" })
-    private InputStream readRootEntity(EdmEntitySet entitySet, List<UriParameter> keyPredicates,ContentType responseFormat) throws ODataApplicationException, ODataLibraryException {        
-        EdmEntityType type = entitySet.getEntityType();        
-        JpaRepository repo =  registry.getRepositoryForEntity(type);
-        
-        // Get key value
-        Long keyValue =  getEntityKey(keyPredicates);
-        Optional<Object> entry  = repo.findById(keyValue);
-        if ( !entry.isPresent()) {
-            throw new ODataApplicationException(
-              "[E116] NO entity found for the given key",
-              HttpStatusCode.NOT_FOUND.getStatusCode(), 
-              Locale.ENGLISH);
-        }
-      
-        Entity e = entityMapper.map2entity(entitySet, entry.get());        
-        return serializeEntity(entitySet,e,responseFormat);        
-    }
-    
-    private InputStream serializeEntity(EdmEntitySet entitySet, Entity entity,ContentType responseFormat) throws ODataApplicationException, ODataLibraryException {
-        ContextURL contextUrl = ContextURL.with().entitySet(entitySet).build();
-        // expand and select currently not supported
-        EntitySerializerOptions options = EntitySerializerOptions
-          .with()
-          .contextURL(contextUrl)
-          .build();
-
-        ODataSerializer serializer = odata.createSerializer(responseFormat);
-        
-        SerializerResult serializerResult = serializer.entity(serviceMetadata, entitySet.getEntityType(), entity, options);
-        return serializerResult.getContent();
-        
-    }
-    
-//    @SuppressWarnings("unchecked")
-//    protected InputStream readRelatedEntities(EdmEntitySet rootEntitySet, List<UriParameter> rootPredicates, EdmNavigationProperty property, ContentType responseFormat) throws ODataApplicationException {
-//
-//        Object jpaEntity = readJPAEntity(rootEntitySet, rootPredicates);
-//        try {
-//            Collection<Object> set = (Collection<Object>)PropertyUtils.getProperty(jpaEntity, property.getName());
-//            EdmEntitySet entitySet = entitySetFromType(property.getType());
-//            ContextURL contextUrl = ContextURL
-//              .with()
-//              .entitySet(entitySet)
-//              .build();
-//            
-//            EntityCollectionSerializerOptions options = EntityCollectionSerializerOptions
-//              .with()
-//              .contextURL(contextUrl)
-//              .build();
-//            
-//            EntityCollection result = new EntityCollection();
-//            
-//            set.stream()
-//              .map((o) -> this.entityMapper.map2entity(entitySet, o))
-//              .forEach((e) -> result.getEntities().add(e));
-//
-//            ODataSerializer serializer = odata.createSerializer(responseFormat);            
-//            SerializerResult serializerResult = serializer.entityCollection(serviceMetadata, property.getType(), result, options);
-//            return serializerResult.getContent();
-//        }
-//        catch(Exception ex) {
-//            throw new ODataRuntimeException("[E181] Error accessing database", ex);
-//        }
-//    }
-    
-    @SuppressWarnings({ "rawtypes", "unchecked" })
-    private InputStream readRelatedEntity(ODataRequest request, EdmEntitySet entitySet, List<UriParameter> rootPredicates, EdmNavigationProperty property, List<UriParameter> parentPredicates, ContentType responseFormat) throws ODataApplicationException, ODataLibraryException {
-
-
-        JpaRepository<Object,Object> repo =  (JpaRepository<Object,Object>)registry.getRepositoryForEntity(entitySet.getEntityType());
-        EdmEntityRepository<Object> relatedRepo =  (EdmEntityRepository<Object>)registry.getRepositoryForEntity(property.getType());
-
-        // We assume here that we have a bi-directional 1:N relationship, so we'll
-        // always have a property in the child entity that points to the parent
-        Class<?> rootClass = ((EdmEntityRepository)repo).getEntityClass();        
-        Class<?> relatedClass = ((EdmEntityRepository)relatedRepo).getEntityClass();
-        
-        SingularAttribute fk = emf.getMetamodel()
-          .entity(rootClass)
-          .getSingularAttributes()
-          .stream()
-          .filter((attr) -> {
-              boolean b = attr.isAssociation() && attr.getJavaType().isAssignableFrom(relatedClass);
-              return b;
-          })
-          .findFirst()
-          .orElse(null);
-        
-        if ( fk == null ) {
-            throw new ODataRuntimeException("[E230] No singular attribute of child class '" + relatedClass.getName() + "' found" );
-        }
-        
-        Long pkValue = getEntityKey(rootPredicates);  
-        EntityManager em = this.emf.createEntityManager();
-        try {
-            // Read data from DB 
-            Object root = em.find(rootClass, pkValue);            
-            Object related = this.entityMapper.getPropertyValue(root, fk.getName());
-                
-            EdmEntitySet relatedEntitySet = entitySetFromType(property.getType());        
-            Entity e = entityMapper.map2entity(relatedEntitySet, related);               
-            return serializeEntity(relatedEntitySet,e,responseFormat);
-        }
-        finally {
-            em.close();
-        }
-    }
-
-//    @SuppressWarnings("unchecked")
-//    private Object readJPAEntity(EdmEntitySet edmEntitySet, List<UriParameter> keyPredicates) throws ODataApplicationException {
-//        EdmEntityType type = edmEntitySet.getEntityType();        
-//        JpaRepository<Object,Object> repo =  (JpaRepository<Object,Object>)registry.getRepositoryForEntity(type);
-//        
-//        // Get key value
-//        Object keyValue =  getEntityKey(type,keyPredicates);
-//        Object entry = repo
-//          .findById(keyValue)
-//          .orElseThrow(
-//             () -> new ODataApplicationException("[E116] NO entity found for the given key",
-//                                       HttpStatusCode.NOT_FOUND.getStatusCode(), Locale.ENGLISH));
-//       
-//        return entry;
-//    }
-
-    private Long getEntityKey(List<UriParameter> keyPredicates) {
-        
-        if ( keyPredicates.size() > 1 ) {
-            throw new ODataRuntimeException("[E131] Composite keys are not supported");
-        }
-        
-        // For now, we'll assume we only have numeric keys.
-        UriParameter keyParam = keyPredicates.get(0);
-        try {
-            return Long.parseLong(keyParam.getText());
-        }
-        catch(NumberFormatException nfe) {
-            throw new ODataRuntimeException("[E140] Invalid key value. Only numeric keys are supported by this service");
-        }
-        
-        
-    }
-
-    /* (non-Javadoc)
-     * @see org.apache.olingo.server.api.processor.EntityProcessor#createEntity(org.apache.olingo.server.api.ODataRequest, org.apache.olingo.server.api.ODataResponse, org.apache.olingo.server.api.uri.UriInfo, org.apache.olingo.commons.api.format.ContentType, org.apache.olingo.commons.api.format.ContentType)
-     */
-    @Override
-    public void createEntity(ODataRequest request, ODataResponse response, UriInfo uriInfo, ContentType requestFormat, ContentType responseFormat) throws ODataApplicationException, ODataLibraryException {
-        // TODO Auto-generated method stub
-
-    }
-
-    /* (non-Javadoc)
-     * @see org.apache.olingo.server.api.processor.EntityProcessor#updateEntity(org.apache.olingo.server.api.ODataRequest, org.apache.olingo.server.api.ODataResponse, org.apache.olingo.server.api.uri.UriInfo, org.apache.olingo.commons.api.format.ContentType, org.apache.olingo.commons.api.format.ContentType)
-     */
-    @Override
-    public void updateEntity(ODataRequest request, ODataResponse response, UriInfo uriInfo, ContentType requestFormat, ContentType responseFormat) throws ODataApplicationException, ODataLibraryException {
-        // TODO Auto-generated method stub
-
-    }
-
-    /* (non-Javadoc)
-     * @see org.apache.olingo.server.api.processor.EntityProcessor#deleteEntity(org.apache.olingo.server.api.ODataRequest, org.apache.olingo.server.api.ODataResponse, org.apache.olingo.server.api.uri.UriInfo)
-     */
-    @Override
-    public void deleteEntity(ODataRequest request, ODataResponse response, UriInfo uriInfo) throws ODataApplicationException, ODataLibraryException {
-        // TODO Auto-generated method stub
-
-    }
-
-}
--- a/apache-olingo/olingo4/src/main/java/org/baeldung/examples/olingo4/repository/CarMakerRepository.java
+++ b/apache-olingo/olingo4/src/main/java/org/baeldung/examples/olingo4/repository/CarMakerRepository.java
@ -1,16 +0,0 @@
-package org.baeldung.examples.olingo4.repository;
-
-import org.baeldung.examples.olingo4.domain.CarMaker;
-import org.springframework.data.jpa.repository.JpaRepository;
-import org.springframework.data.jpa.repository.JpaSpecificationExecutor;
-import org.springframework.stereotype.Repository;
-
-@Repository
-public interface CarMakerRepository extends EdmEntityRepository<CarMaker>, JpaRepository<CarMaker, Long>, JpaSpecificationExecutor<CarMaker> {
-
-    public default String getEdmEntityName() { return CarMaker.class.getSimpleName();}
-    @Override
-    default Class<CarMaker> getEntityClass() {
-        return CarMaker.class;
-    }
-}
--- a/apache-olingo/olingo4/src/main/java/org/baeldung/examples/olingo4/repository/CarModelRepository.java
+++ b/apache-olingo/olingo4/src/main/java/org/baeldung/examples/olingo4/repository/CarModelRepository.java
@ -1,22 +0,0 @@
-package org.baeldung.examples.olingo4.repository;
-
-import java.util.List;
-
-import org.baeldung.examples.olingo4.domain.CarModel;
-import org.springframework.data.jpa.repository.JpaRepository;
-import org.springframework.data.jpa.repository.JpaSpecificationExecutor;
-import org.springframework.stereotype.Repository;
-
-@Repository
-public interface CarModelRepository extends EdmEntityRepository<CarModel>, JpaRepository<CarModel, Long>, JpaSpecificationExecutor<CarModel> {
-
-    public List<CarModel> findByMakerId(Long makerId);
-    
-    public default String getEdmEntityName() { return CarModel.class.getSimpleName();}
-    
-    @Override
-    default Class<CarModel> getEntityClass() {
-        return CarModel.class;
-    }
-
-}
--- a/apache-olingo/olingo4/src/main/java/org/baeldung/examples/olingo4/repository/EdmEntityRepository.java
+++ b/apache-olingo/olingo4/src/main/java/org/baeldung/examples/olingo4/repository/EdmEntityRepository.java
@ -1,17 +0,0 @@
-/**
- * 
- */
-package org.baeldung.examples.olingo4.repository;
-
-
-/**
- * @author Philippe
- *
- */
-public interface EdmEntityRepository<E>  {
-    
-    public String getEdmEntityName();
-    public Class<E> getEntityClass();
-
-
-}
--- a/apache-olingo/olingo4/src/main/java/org/baeldung/examples/olingo4/repository/RepositoryRegistry.java
+++ b/apache-olingo/olingo4/src/main/java/org/baeldung/examples/olingo4/repository/RepositoryRegistry.java
@ -1,29 +0,0 @@
-package org.baeldung.examples.olingo4.repository;
-
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-
-import org.apache.olingo.commons.api.edm.EdmEntityType;
-import org.springframework.data.jpa.repository.JpaRepository;
-import org.springframework.stereotype.Component;
-
-@Component
-public class RepositoryRegistry {
-    
-    private Map<String,JpaRepository<?,?>> repositoriesByClassName = new HashMap<>();
-
-    public RepositoryRegistry(List<EdmEntityRepository<?>> allRepositories) {
-        
-        allRepositories.stream()
-          .forEach((r) ->  
-            repositoriesByClassName.put(r.getEdmEntityName(),(JpaRepository<?,?>)r));
-        
-    }
-    
-    
-    public JpaRepository<?,?> getRepositoryForEntity(EdmEntityType entityType) {        
-        JpaRepository<?,?> repo = repositoriesByClassName.get(entityType.getName());
-        return repo;
-    }
-}
--- a/apache-olingo/olingo4/src/main/resources/application.properties
+++ b/apache-olingo/olingo4/src/main/resources/application.properties
@ -1,9 +0,0 @@
-server:
-	port: 8080
-	
-spring:    
-  jpa:
-    show-sql: true
-    open-in-view: true
-    hibernate:
-      ddl-auto: update
--- a/apache-olingo/olingo4/src/main/resources/data.sql
+++ b/apache-olingo/olingo4/src/main/resources/data.sql
@ -1,12 +0,0 @@
-insert into car_maker(id,name) values (1,'Special Motors');
-insert into car_maker(id,name) values (2,'BWM');
-insert into car_maker(id,name) values (3,'Dolores');
-
-insert into car_model(id,maker_fk,name,sku,year) values(1,1,'Muze','SM001',2018);
-insert into car_model(id,maker_fk,name,sku,year) values(2,1,'Empada','SM002',2008);
-
-insert into car_model(id,maker_fk,name,sku,year) values(4,2,'BWM-100','BWM100',2008);
-insert into car_model(id,maker_fk,name,sku,year) values(5,2,'BWM-200','BWM200',2009);
-insert into car_model(id,maker_fk,name,sku,year) values(6,2,'BWM-300','BWM300',2008);
-
-alter sequence hibernate_sequence restart with 100;
--- a/apache-olingo/olingo4/src/test/java/org/baeldung/examples/olingo4/Olingo4SampleApplicationTests.java
+++ b/apache-olingo/olingo4/src/test/java/org/baeldung/examples/olingo4/Olingo4SampleApplicationTests.java
@ -1,16 +0,0 @@
-package org.baeldung.examples.olingo4;
-
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.springframework.boot.test.context.SpringBootTest;
-import org.springframework.test.context.junit4.SpringRunner;
-
-@RunWith(SpringRunner.class)
-@SpringBootTest
-public class Olingo4SampleApplicationTests {
-
-	@Test
-	public void contextLoads() {
-	}
-
-}
--- a/clojure/ring/.gitignore
+++ b/clojure/ring/.gitignore
@ -0,0 +1,12 @@
+/target
+/classes
+/checkouts
+profiles.clj
+pom.xml
+pom.xml.asc
+*.jar
+*.class
+/.lein-*
+/.nrepl-port
+.hgignore
+.hg/
--- a/clojure/ring/README.md
+++ b/clojure/ring/README.md
@ -0,0 +1,19 @@
+# Clojure Ring Examples
+
+This project acts as a set of examples for the Clojure Ring library.
+
+## Runing the examples
+
+The examples can all be run from the Leiningen REPL.
+
+Firstly, start the REPL with `lein repl`. Then the examples can be executed with:
+
+* `(run simple-handler)` - A simple handler that just echos a constant string to the client
+* `(run check-ip-handler)` - A handler that echos the clients IP Address back to them
+* `(run echo-handler)` - A handler that echos the value of the "input" parameter back
+* `(run request-count-handler)` - A handler with a session that tracks how many times this session has requested this handler
+
+In all cases, the handlers can be accessed on http://localhost:3000.
+
+## Relevant Articles
+- [Writing Clojure Webapps with Ring](https://www.baeldung.com/clojure-ring)
--- a/clojure/ring/project.clj
+++ b/clojure/ring/project.clj
@ -0,0 +1,8 @@
+(defproject baeldung-ring "0.1.0-SNAPSHOT"
+  :dependencies [[org.clojure/clojure "1.10.0"]
+                 [ring/ring-core "1.7.1"]
+                 [ring/ring-jetty-adapter "1.7.1"]
+                 [ring/ring-devel "1.7.1"]]
+  :plugins [[lein-ring "0.12.5"]]
+  :ring {:handler ring.core/simple-handler}
+  :repl-options {:init-ns ring.core})
--- a/clojure/ring/src/ring/core.clj
+++ b/clojure/ring/src/ring/core.clj
@ -0,0 +1,48 @@
+(ns ring.core
+  (:use ring.adapter.jetty
+        [ring.middleware.content-type]
+        [ring.middleware.cookies]
+        [ring.middleware.params]
+        [ring.middleware.session]
+        [ring.middleware.session.cookie]
+        [ring.util.response]))
+
+;; Handler that just echos back the string "Hello World"
+(defn simple-handler [request]
+  {:status 200
+   :headers {"Content-Type" "text/plain"}
+   :body "Hello World"})
+
+;; Handler that echos back the clients IP Address
+;; This demonstrates building responses properly, and extracting values from the request
+(defn check-ip-handler [request]
+    (content-type
+        (response (:remote-addr request))
+        "text/plain"))
+
+;; Handler that echos back the incoming parameter "input"
+;; This demonstrates middleware chaining and accessing parameters
+(def echo-handler
+  (-> (fn [{params :params}]
+        (content-type
+          (response (get params "input"))
+          "text/plain"))
+      (wrap-params {:encoding "UTF-8"})
+  ))
+
+;; Handler that keeps track of how many times each session has accessed the service
+;; This demonstrates cookies and sessions
+(def request-count-handler
+  (-> (fn [{session :session}]
+        (let [count (:count session 0)
+              session (assoc session :count (inc count))]
+          (-> (response (str "You accessed this page " count " times."))
+              (assoc :session session))))
+      wrap-cookies
+      (wrap-session {:cookie-attrs {:max-age 3600}})
+  ))
+
+;; Run the provided handler on port 3000
+(defn run
+  [h]
+  (run-jetty h {:port 3000}))
--- a/core-groovy-2/README.md
+++ b/core-groovy-2/README.md
@ -3,5 +3,6 @@
 ## Relevant articles:

 - [String Matching in Groovy](http://www.baeldung.com/)
- [Groovy def Keyword]
-
+- [Template Engines in Groovy](https://www.baeldung.com/groovy-template-engines)
+- [Groovy def Keyword](https://www.baeldung.com/groovy-def-keyword)
+- [Pattern Matching in Strings in Groovy](https://www.baeldung.com/groovy-pattern-matching)
--- a/core-groovy-2/gmavenplus-pom.xml
+++ b/core-groovy-2/gmavenplus-pom.xml
@ -0,0 +1,178 @@
+<?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.apache.commons</groupId>
+            <artifactId>commons-lang3</artifactId>
+            <version>${commons-lang3.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>ch.qos.logback</groupId>
+            <artifactId>logback-classic</artifactId>
+            <version>${logback.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.codehaus.groovy</groupId>
+            <artifactId>groovy-all</artifactId>
+            <version>${groovy.version}</version>
+            <type>pom</type>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.platform</groupId>
+            <artifactId>junit-platform-runner</artifactId>
+            <version>${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>
+        <scriptSourceDirectory>src/main/groovy</scriptSourceDirectory>
+        <sourceDirectory>src/main/java</sourceDirectory>
+        <plugins>
+            <plugin>
+                <groupId>org.codehaus.gmavenplus</groupId>
+                <artifactId>gmavenplus-plugin</artifactId>
+                <version>1.7.0</version>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>execute</goal>
+                            <goal>addSources</goal>
+                            <goal>addTestSources</goal>
+                            <goal>generateStubs</goal>
+                            <goal>compile</goal>
+                            <goal>generateTestStubs</goal>
+                            <goal>compileTests</goal>
+                            <goal>removeStubs</goal>
+                            <goal>removeTestStubs</goal>
+                        </goals>
+                    </execution>
+                </executions>
+                <dependencies>
+                    <dependency>
+                        <groupId>org.codehaus.groovy</groupId>
+                        <artifactId>groovy-all</artifactId>
+                        <!-- any version of Groovy \>= 1.5.0 should work here -->
+                        <version>${groovy.version}</version>
+                        <scope>runtime</scope>
+                        <type>pom</type>
+                    </dependency>
+                </dependencies>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+            </plugin>
+            <plugin>
+                <artifactId>maven-failsafe-plugin</artifactId>
+                <version>${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>
+            <!-- Maven Assembly Plugin: needed to run the jar through command line -->
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-assembly-plugin</artifactId>
+                <version>3.1.0</version>
+                <configuration>
+                    <!-- get all project dependencies -->
+                    <descriptorRefs>
+                        <descriptorRef>jar-with-dependencies</descriptorRef>
+                    </descriptorRefs>
+                    <!-- MainClass in mainfest make a executable jar -->
+                    <archive>
+                        <manifest>
+                            <mainClass>com.baeldung.MyJointCompilationApp</mainClass>
+                        </manifest>
+                    </archive>
+
+                </configuration>
+                <executions>
+                    <execution>
+                        <id>make-assembly</id>
+                        <!-- bind to the packaging phase -->
+                        <phase>package</phase>
+                        <goals>
+                            <goal>single</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+    </build>
+
+    <repositories>
+        <repository>
+            <id>central</id>
+            <url>http://jcenter.bintray.com</url>
+        </repository>
+    </repositories>
+
+    <properties>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <junit.platform.version>1.0.0</junit.platform.version>
+        <hsqldb.version>2.4.0</hsqldb.version>
+        <spock-core.version>1.1-groovy-2.4</spock-core.version>
+        <commons-lang3.version>3.9</commons-lang3.version>
+        <java.version>1.8</java.version>
+        <logback.version>1.2.3</logback.version>
+        <groovy.version>2.5.7</groovy.version>
+        <gmavenplus-plugin.version>1.6</gmavenplus-plugin.version>
+    </properties>
+</project>
+
--- a/core-groovy-2/pom.xml
+++ b/core-groovy-2/pom.xml
@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <artifactId>core-groovy-2</artifactId>
    <version>1.0-SNAPSHOT</version>
@ -15,25 +15,20 @@

    <dependencies>
        <dependency>
-            <groupId>org.codehaus.groovy</groupId>
-            <artifactId>groovy</artifactId>
-            <version>${groovy.version}</version>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-lang3</artifactId>
+            <version>${commons-lang3.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>ch.qos.logback</groupId>
+            <artifactId>logback-classic</artifactId>
+            <version>${logback.version}</version>
        </dependency>
        <dependency>
            <groupId>org.codehaus.groovy</groupId>
            <artifactId>groovy-all</artifactId>
-            <version>${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>
+            <type>pom</type>
        </dependency>
        <dependency>
            <groupId>org.junit.platform</groupId>
@ -56,21 +51,35 @@
    </dependencies>

    <build>
+        <scriptSourceDirectory>src/main/groovy</scriptSourceDirectory>
+        <sourceDirectory>src/main/java</sourceDirectory>
        <plugins>
            <plugin>
-                <groupId>org.codehaus.gmavenplus</groupId>
-                <artifactId>gmavenplus-plugin</artifactId>
-                <version>${gmavenplus-plugin.version}</version>
-                <executions>
-                    <execution>
-                        <goals>
-                            <goal>addSources</goal>
-                            <goal>addTestSources</goal>
-                            <goal>compile</goal>
-                            <goal>compileTests</goal>
-                        </goals>
-                    </execution>
-                </executions>
+                <groupId>org.codehaus.groovy</groupId>
+                <artifactId>groovy-eclipse-compiler</artifactId>
+                <version>3.3.0-01</version>
+                <extensions>true</extensions>
+            </plugin>
+            <plugin>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>3.8.0</version>
+                <configuration>
+                    <compilerId>groovy-eclipse-compiler</compilerId>
+                    <source>${java.version}</source>
+                    <target>${java.version}</target>
+                </configuration>
+                <dependencies>
+                    <dependency>
+                        <groupId>org.codehaus.groovy</groupId>
+                        <artifactId>groovy-eclipse-compiler</artifactId>
+                        <version>3.3.0-01</version>
+                    </dependency>
+                    <dependency>
+                        <groupId>org.codehaus.groovy</groupId>
+                        <artifactId>groovy-eclipse-batch</artifactId>
+                        <version>${groovy.version}-01</version>
+                    </dependency>
+                </dependencies>
            </plugin>
            <plugin>
                <artifactId>maven-failsafe-plugin</artifactId>
@ -101,13 +110,42 @@
                <artifactId>maven-surefire-plugin</artifactId>
                <version>2.20.1</version>
                <configuration>
-                <useFile>false</useFile>
-                <includes>
-                    <include>**/*Test.java</include>
-                    <include>**/*Spec.java</include>
-                </includes>
+                    <useFile>false</useFile>
+                    <includes>
+                        <include>**/*Test.java</include>
+                        <include>**/*Spec.java</include>
+                    </includes>
                </configuration>
            </plugin>
+            <!-- Maven Assembly Plugin: needed to run the jar through command line -->
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-assembly-plugin</artifactId>
+                <version>3.1.0</version>
+                <configuration>
+                    <!-- get all project dependencies -->
+                    <descriptorRefs>
+                        <descriptorRef>jar-with-dependencies</descriptorRef>
+                    </descriptorRefs>
+                    <!-- MainClass in mainfest make a executable jar -->
+                    <archive>
+                        <manifest>
+                            <mainClass>com.baeldung.MyJointCompilationApp</mainClass>
+                        </manifest>
+                    </archive>
+
+                </configuration>
+                <executions>
+                    <execution>
+                        <id>make-assembly</id>
+                        <!-- bind to the packaging phase -->
+                        <phase>package</phase>
+                        <goals>
+                            <goal>single</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
        </plugins>
    </build>

@ -118,14 +156,32 @@
        </repository>
    </repositories>

+    <pluginRepositories>
+                <pluginRepository>
+                    <id>bintray</id>
+                    <name>Groovy Bintray</name>
+                    <url>https://dl.bintray.com/groovy/maven</url>
+                    <releases>
+                        <!-- avoid automatic updates -->
+                        <updatePolicy>never</updatePolicy>
+                    </releases>
+                    <snapshots>
+                        <enabled>false</enabled>
+                    </snapshots>
+                </pluginRepository>
+            </pluginRepositories>
+
+
    <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>
+        <commons-lang3.version>3.9</commons-lang3.version>
+        <java.version>1.8</java.version>
+        <maven-compiler-plugin.version>3.8.1</maven-compiler-plugin.version>
+        <logback.version>1.2.3</logback.version>
+        <groovy.version>2.5.7</groovy.version>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>
 </project>

--- a/core-groovy-2/src/main/groovy/com/baeldung/CalcMath.groovy
+++ b/core-groovy-2/src/main/groovy/com/baeldung/CalcMath.groovy
@ -0,0 +1,25 @@
+package com.baeldung
+
+import org.slf4j.LoggerFactory
+
+class CalcMath {
+    def log = LoggerFactory.getLogger(this.getClass())
+
+    def calcSum(x, y) {
+        log.info "Executing $x + $y"
+        x + y
+    }
+
+    /**
+     * example of method that in java would throw error at compile time
+     * @param x
+     * @param y
+     * @return
+     */
+    def calcSum2(x, y) {
+        log.info "Executing $x + $y"
+        // DANGER! This won't throw a compilation issue and fail only at runtime!!!
+        calcSum3()
+        log.info("Logging an undefined variable: $z")
+    }
+}
--- a/core-groovy-2/src/main/groovy/com/baeldung/CalcScript.groovy
+++ b/core-groovy-2/src/main/groovy/com/baeldung/CalcScript.groovy
@ -0,0 +1,16 @@
+package com.baeldung
+
+def calcSum(x, y) {
+    x + y
+}
+
+def calcSum2(x, y) {
+    // DANGER! The variable "log" may be undefined
+    log.info "Executing $x + $y"
+    // DANGER! This method doesn't exist!
+    calcSum3()
+    // DANGER! The logged variable "z" is undefined!
+    log.info("Logging an undefined variable: $z")
+}
+
+calcSum(1,5)
--- a/core-groovy-2/src/main/java/com/baeldung/MyJointCompilationApp.java
+++ b/core-groovy-2/src/main/java/com/baeldung/MyJointCompilationApp.java
@ -0,0 +1,120 @@
+package com.baeldung;
+
+import groovy.lang.*;
+import groovy.util.GroovyScriptEngine;
+import groovy.util.ResourceException;
+import groovy.util.ScriptException;
+import org.codehaus.groovy.jsr223.GroovyScriptEngineFactory;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import javax.script.ScriptEngine;
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.FileReader;
+import java.io.IOException;
+import java.net.MalformedURLException;
+import java.net.URL;
+
+/**
+ * Hello world!
+ *
+ */
+public class MyJointCompilationApp {
+    private final static Logger LOG = LoggerFactory.getLogger(MyJointCompilationApp.class);
+    private final GroovyClassLoader loader;
+    private final GroovyShell shell;
+    private final GroovyScriptEngine engine;
+    private final ScriptEngine engineFromFactory;
+
+    public MyJointCompilationApp() {
+        loader = new GroovyClassLoader(this.getClass().getClassLoader());
+        shell = new GroovyShell(loader, new Binding());
+
+        URL url = null;
+        try {
+            url = new File("src/main/groovy/com/baeldung/").toURI().toURL();
+        } catch (MalformedURLException e) {
+            LOG.error("Exception while creating url", e);
+        }
+        engine = new GroovyScriptEngine(new URL[] {url}, this.getClass().getClassLoader());
+        engineFromFactory = new GroovyScriptEngineFactory().getScriptEngine();
+    }
+
+    private void addWithCompiledClasses(int x, int y) {
+        LOG.info("Executing {} + {}", x, y);
+        Object result1 = new CalcScript().calcSum(x, y);
+        LOG.info("Result of CalcScript.calcSum() method is {}", result1);
+
+        Object result2 = new CalcMath().calcSum(x, y);
+        LOG.info("Result of CalcMath.calcSum() method is {}", result2);
+    }
+
+    private void addWithGroovyShell(int x, int y) throws IOException {
+        Script script = shell.parse(new File("src/main/groovy/com/baeldung/", "CalcScript.groovy"));
+        LOG.info("Executing {} + {}", x, y);
+        Object result = script.invokeMethod("calcSum", new Object[] { x, y });
+        LOG.info("Result of CalcScript.calcSum() method is {}", result);
+    }
+
+    private void addWithGroovyShellRun() throws IOException {
+        Script script = shell.parse(new File("src/main/groovy/com/baeldung/", "CalcScript.groovy"));
+        LOG.info("Executing script run method");
+        Object result = script.run();
+        LOG.info("Result of CalcScript.run() method is {}", result);
+    }
+
+    private void addWithGroovyClassLoader(int x, int y) throws IllegalAccessException, InstantiationException, IOException {
+        Class calcClass = loader.parseClass(
+          new File("src/main/groovy/com/baeldung/", "CalcMath.groovy"));
+        GroovyObject calc = (GroovyObject) calcClass.newInstance();
+        Object result = calc.invokeMethod("calcSum", new Object[] { x + 14, y + 14 });
+        LOG.info("Result of CalcMath.calcSum() method is {}", result);
+    }
+
+    private void addWithGroovyScriptEngine(int x, int y) throws IllegalAccessException,
+      InstantiationException, ResourceException, ScriptException {
+        Class<GroovyObject> calcClass = engine.loadScriptByName("CalcMath.groovy");
+        GroovyObject calc = calcClass.newInstance();
+        //WARNING the following will throw a ClassCastException
+        //((CalcMath)calc).calcSum(1,2);
+        Object result = calc.invokeMethod("calcSum", new Object[] { x, y });
+        LOG.info("Result of CalcMath.calcSum() method is {}", result);
+    }
+
+    private void addWithEngineFactory(int x, int y) throws IllegalAccessException,
+      InstantiationException, javax.script.ScriptException, FileNotFoundException {
+        Class calcClass = (Class) engineFromFactory.eval(
+          new FileReader(new File("src/main/groovy/com/baeldung/", "CalcMath.groovy")));
+        GroovyObject calc = (GroovyObject) calcClass.newInstance();
+        Object result = calc.invokeMethod("calcSum", new Object[] { x, y });
+        LOG.info("Result of CalcMath.calcSum() method is {}", result);
+    }
+
+    private void addWithStaticCompiledClasses() {
+        LOG.info("Running the Groovy classes compiled statically...");
+        addWithCompiledClasses(5, 10);
+
+    }
+
+    private void addWithDynamicCompiledClasses() throws IOException, IllegalAccessException, InstantiationException,
+      ResourceException, ScriptException, javax.script.ScriptException {
+        LOG.info("Invocation of a dynamic groovy script...");
+        addWithGroovyShell(5, 10);
+        LOG.info("Invocation of the run method of a dynamic groovy script...");
+        addWithGroovyShellRun();
+        LOG.info("Invocation of a dynamic groovy class loaded with GroovyClassLoader...");
+        addWithGroovyClassLoader(10, 30);
+        LOG.info("Invocation of a dynamic groovy class loaded with GroovyScriptEngine...");
+        addWithGroovyScriptEngine(15, 0);
+        LOG.info("Invocation of a dynamic groovy class loaded with GroovyScriptEngine JSR223...");
+        addWithEngineFactory(5, 6);
+    }
+
+    public static void main(String[] args) throws InstantiationException, IllegalAccessException,
+      ResourceException, ScriptException, IOException, javax.script.ScriptException {
+        MyJointCompilationApp myJointCompilationApp = new MyJointCompilationApp();
+        LOG.info("Example of addition operation via Groovy scripts integration with Java.");
+        myJointCompilationApp.addWithStaticCompiledClasses();
+        myJointCompilationApp.addWithDynamicCompiledClasses();
+    }
+}
--- a/core-groovy-2/src/main/resources/articleEmail.template
+++ b/core-groovy-2/src/main/resources/articleEmail.template
@ -0,0 +1,5 @@
+Dear <% out << (user) %>,
+Please read the requested article below.
+<% out << (articleText) %>
+From,
+<% out << (signature) %>
--- a/core-groovy-2/src/main/resources/email.template
+++ b/core-groovy-2/src/main/resources/email.template
@ -0,0 +1,3 @@
+Dear $user,
+Thanks for subscribing our services.
+${signature}
--- a/core-groovy-2/src/test/groovy/com/baeldung/templateengine/TemplateEnginesUnitTest.groovy
+++ b/core-groovy-2/src/test/groovy/com/baeldung/templateengine/TemplateEnginesUnitTest.groovy
@ -0,0 +1,96 @@
+package com.baeldung.templateengine
+
+import groovy.text.SimpleTemplateEngine
+import groovy.text.StreamingTemplateEngine
+import groovy.text.GStringTemplateEngine
+import groovy.text.XmlTemplateEngine
+import groovy.text.XmlTemplateEngine
+import groovy.text.markup.MarkupTemplateEngine
+import groovy.text.markup.TemplateConfiguration
+
+class TemplateEnginesUnitTest extends GroovyTestCase {
+    
+    def bindMap = [user: "Norman", signature: "Baeldung"]
+    
+    void testSimpleTemplateEngine() {
+        def smsTemplate = 'Dear <% print user %>, Thanks for reading our Article. ${signature}'
+        def smsText = new SimpleTemplateEngine().createTemplate(smsTemplate).make(bindMap)
+
+        assert smsText.toString() == "Dear Norman, Thanks for reading our Article. Baeldung"
+    }
+    
+    void testStreamingTemplateEngine() {
+        def articleEmailTemplate = new File('src/main/resources/articleEmail.template')
+        bindMap.articleText = """1. Overview
+This is a tutorial article on Template Engines""" //can be a string larger than 64k
+        
+        def articleEmailText = new StreamingTemplateEngine().createTemplate(articleEmailTemplate).make(bindMap)
+        
+        assert articleEmailText.toString() == """Dear Norman,
+Please read the requested article below.
+1. Overview
+This is a tutorial article on Template Engines
+From,
+Baeldung"""
+        
+    }
+    
+    void testGStringTemplateEngine() {
+        def emailTemplate = new File('src/main/resources/email.template')
+        def emailText = new GStringTemplateEngine().createTemplate(emailTemplate).make(bindMap)
+        
+        assert emailText.toString() == "Dear Norman,\nThanks for subscribing our services.\nBaeldung"
+    }
+    
+    void testXmlTemplateEngine() {
+        def emailXmlTemplate = '''<xs xmlns:gsp='groovy-server-pages'>
+                                      <gsp:scriptlet>def emailContent = "Thanks for subscribing our services."</gsp:scriptlet>
+                                      <email>
+                                          <greet>Dear ${user}</greet>
+                                          <content><gsp:expression>emailContent</gsp:expression></content>
+                                          <signature>${signature}</signature>
+                                      </email>
+                                  </xs>'''
+        def emailXml = new XmlTemplateEngine().createTemplate(emailXmlTemplate).make(bindMap)
+        println emailXml.toString()
+    }
+    
+    void testMarkupTemplateEngineHtml() {
+        def emailHtmlTemplate = """html {
+                                       head {
+                                           title('Service Subscription Email')
+                                       }
+                                       body {
+                                           p('Dear Norman')
+                                           p('Thanks for subscribing our services.')
+                                           p('Baeldung')
+                                       }
+                                   }"""
+        
+        
+        def emailHtml = new MarkupTemplateEngine().createTemplate(emailHtmlTemplate).make()
+        println emailHtml.toString()
+        
+    }
+    
+    void testMarkupTemplateEngineXml() {
+        def emailXmlTemplate = """xmlDeclaration()  
+                                      xs{
+                                          email {
+                                              greet('Dear Norman')
+                                              content('Thanks for subscribing our services.')
+                                              signature('Baeldung')
+                                          }  
+                                      }
+                               """
+        TemplateConfiguration config = new TemplateConfiguration()
+        config.autoIndent = true
+        config.autoEscape = true
+        config.autoNewLine = true
+
+        def emailXml = new MarkupTemplateEngine(config).createTemplate(emailXmlTemplate).make()
+        
+        println emailXml.toString()
+    }
+    
+}
--- a/core-groovy-2/src/test/groovy/com/baeldung/xml/MarkupBuilderUnitTest.groovy
+++ b/core-groovy-2/src/test/groovy/com/baeldung/xml/MarkupBuilderUnitTest.groovy
@ -0,0 +1,40 @@
+package com.baeldung.xml
+
+import groovy.xml.MarkupBuilder
+import groovy.xml.XmlUtil
+import spock.lang.Specification
+
+class MarkupBuilderUnitTest extends Specification {
+
+    def xmlFile = getClass().getResource("articles_short_formatted.xml")
+
+def "Should create XML properly"() {
+    given: "Node structures"
+
+    when: "Using MarkupBuilderUnitTest to create com.baeldung.xml structure"
+    def writer = new StringWriter()
+    new MarkupBuilder(writer).articles {
+        article {
+            title('First steps in Java')
+            author(id: '1') {
+                firstname('Siena')
+                lastname('Kerr')
+            }
+            'release-date'('2018-12-01')
+        }
+        article {
+            title('Dockerize your SpringBoot application')
+            author(id: '2') {
+                firstname('Jonas')
+                lastname('Lugo')
+            }
+            'release-date'('2018-12-01')
+        }
+    }
+
+    then: "Xml is created properly"
+    XmlUtil.serialize(writer.toString()) == XmlUtil.serialize(xmlFile.text)
+}
+
+
+}
--- a/core-groovy-2/src/test/groovy/com/baeldung/xml/XmlParserUnitTest.groovy
+++ b/core-groovy-2/src/test/groovy/com/baeldung/xml/XmlParserUnitTest.groovy
@ -0,0 +1,94 @@
+package com.baeldung.xml
+
+
+import spock.lang.Shared
+import spock.lang.Specification
+
+class XmlParserUnitTest extends Specification {
+
+    def xmlFile = getClass().getResourceAsStream("articles.xml")
+
+    @Shared
+    def parser = new XmlParser()
+
+    def "Should read XML file properly"() {
+        given: "XML file"
+
+        when: "Using XmlParser to read file"
+        def articles = parser.parse(xmlFile)
+
+        then: "Xml is loaded properly"
+        articles.'*'.size() == 4
+        articles.article[0].author.firstname.text() == "Siena"
+        articles.article[2].'release-date'.text() == "2018-06-12"
+        articles.article[3].title.text() == "Java 12 insights"
+        articles.article.find { it.author.'@id'.text() == "3" }.author.firstname.text() == "Daniele"
+    }
+
+
+    def "Should add node to existing com.baeldung.xml using NodeBuilder"() {
+        given: "XML object"
+        def articles = parser.parse(xmlFile)
+
+        when: "Adding node to com.baeldung.xml"
+        def articleNode = new NodeBuilder().article(id: '5') {
+            title('Traversing XML in the nutshell')
+            author {
+                firstname('Martin')
+                lastname('Schmidt')
+            }
+            'release-date'('2019-05-18')
+        }
+        articles.append(articleNode)
+
+        then: "Node is added to com.baeldung.xml properly"
+        articles.'*'.size() == 5
+        articles.article[4].title.text() == "Traversing XML in the nutshell"
+    }
+
+    def "Should replace node"() {
+        given: "XML object"
+        def articles = parser.parse(xmlFile)
+
+        when: "Adding node to com.baeldung.xml"
+        def articleNode = new NodeBuilder().article(id: '5') {
+            title('Traversing XML in the nutshell')
+            author {
+                firstname('Martin')
+                lastname('Schmidt')
+            }
+            'release-date'('2019-05-18')
+        }
+        articles.article[0].replaceNode(articleNode)
+
+        then: "Node is added to com.baeldung.xml properly"
+        articles.'*'.size() == 4
+        articles.article[0].title.text() == "Traversing XML in the nutshell"
+    }
+
+    def "Should modify node"() {
+        given: "XML object"
+        def articles = parser.parse(xmlFile)
+
+        when: "Changing value of one of the nodes"
+        articles.article.each { it.'release-date'[0].value = "2019-05-18" }
+
+        then: "XML is updated"
+        articles.article.findAll { it.'release-date'.text() != "2019-05-18" }.isEmpty()
+    }
+
+    def "Should remove article from com.baeldung.xml"() {
+        given: "XML object"
+        def articles = parser.parse(xmlFile)
+
+        when: "Removing all articles but with id==3"
+        articles.article
+          .findAll { it.author.'@id'.text() != "3" }
+          .each { articles.remove(it) }
+
+        then: "There is only one article left"
+        articles.children().size() == 1
+        articles.article[0].author.'@id'.text() == "3"
+    }
+
+}
--- a/core-groovy-2/src/test/groovy/com/baeldung/xml/XmlSlurperUnitTest.groovy
+++ b/core-groovy-2/src/test/groovy/com/baeldung/xml/XmlSlurperUnitTest.groovy
@ -0,0 +1,102 @@
+package com.baeldung.xml
+
+
+import groovy.xml.XmlUtil
+import spock.lang.Shared
+import spock.lang.Specification
+
+class XmlSlurperUnitTest extends Specification {
+
+    def xmlFile = getClass().getResourceAsStream("articles.xml")
+
+    @Shared
+    def parser = new XmlSlurper()
+
+    def "Should read XML file properly"() {
+        given: "XML file"
+
+        when: "Using XmlSlurper to read file"
+        def articles = parser.parse(xmlFile)
+
+        then: "Xml is loaded properly"
+        articles.'*'.size() == 4
+        articles.article[0].author.firstname == "Siena"
+        articles.article[2].'release-date' == "2018-06-12"
+        articles.article[3].title == "Java 12 insights"
+        articles.article.find { it.author.'@id' == "3" }.author.firstname == "Daniele"
+    }
+
+    def "Should add node to existing com.baeldung.xml"() {
+        given: "XML object"
+        def articles = parser.parse(xmlFile)
+
+        when: "Adding node to com.baeldung.xml"
+        articles.appendNode {
+            article(id: '5') {
+                title('Traversing XML in the nutshell')
+                author {
+                    firstname('Martin')
+                    lastname('Schmidt')
+                }
+                'release-date'('2019-05-18')
+            }
+        }
+
+        articles = parser.parseText(XmlUtil.serialize(articles))
+
+        then: "Node is added to com.baeldung.xml properly"
+        articles.'*'.size() == 5
+        articles.article[4].title == "Traversing XML in the nutshell"
+    }
+
+    def "Should modify node"() {
+        given: "XML object"
+        def articles = parser.parse(xmlFile)
+
+        when: "Changing value of one of the nodes"
+        articles.article.each { it.'release-date' = "2019-05-18" }
+
+        then: "XML is updated"
+        articles.article.findAll { it.'release-date' != "2019-05-18" }.isEmpty()
+    }
+
+    def "Should replace node"() {
+        given: "XML object"
+        def articles = parser.parse(xmlFile)
+
+        when: "Replacing node"
+        articles.article[0].replaceNode {
+            article(id: '5') {
+                title('Traversing XML in the nutshell')
+                author {
+                    firstname('Martin')
+                    lastname('Schmidt')
+                }
+                'release-date'('2019-05-18')
+            }
+        }
+
+        articles = parser.parseText(XmlUtil.serialize(articles))
+
+        then: "Node is replaced properly"
+        articles.'*'.size() == 4
+        articles.article[0].title == "Traversing XML in the nutshell"
+    }
+
+    def "Should remove article from com.baeldung.xml"() {
+        given: "XML object"
+        def articles = parser.parse(xmlFile)
+
+        when: "Removing all articles but with id==3"
+        articles.article
+          .findAll { it.author.'@id' != "3" }
+          .replaceNode {}
+
+        articles = parser.parseText(XmlUtil.serialize(articles))
+
+        then: "There is only one article left"
+        articles.children().size() == 1
+        articles.article[0].author.'@id' == "3"
+    }
+
+}
--- a/core-groovy-2/src/test/resources/com/baeldung/xml/articles.xml
+++ b/core-groovy-2/src/test/resources/com/baeldung/xml/articles.xml
@ -0,0 +1,34 @@
+<articles>
+    <article>
+        <title>First steps in Java</title>
+        <author id='1'>
+            <firstname>Siena</firstname>
+            <lastname>Kerr</lastname>
+        </author>
+        <release-date>2018-12-01</release-date>
+    </article>
+    <article>
+        <title>Dockerize your SpringBoot application</title>
+        <author id='2'>
+            <firstname>Jonas</firstname>
+            <lastname>Lugo</lastname>
+        </author>
+        <release-date>2018-12-01</release-date>
+    </article>
+    <article>
+        <title>SpringBoot tutorial</title>
+        <author id='3'>
+            <firstname>Daniele</firstname>
+            <lastname>Ferguson</lastname>
+        </author>
+        <release-date>2018-06-12</release-date>
+    </article>
+    <article>
+        <title>Java 12 insights</title>
+        <author id='1'>
+            <firstname>Siena</firstname>
+            <lastname>Kerr</lastname>
+        </author>
+        <release-date>2018-07-22</release-date>
+    </article>
+</articles>
--- a/core-groovy-2/src/test/resources/com/baeldung/xml/articles_short_formatted.xml
+++ b/core-groovy-2/src/test/resources/com/baeldung/xml/articles_short_formatted.xml
@ -0,0 +1,18 @@
+<articles>
+  <article>
+    <title>First steps in Java</title>
+    <author id='1'>
+      <firstname>Siena</firstname>
+      <lastname>Kerr</lastname>
+    </author>
+    <release-date>2018-12-01</release-date>
+  </article>
+  <article>
+    <title>Dockerize your SpringBoot application</title>
+    <author id='2'>
+      <firstname>Jonas</firstname>
+      <lastname>Lugo</lastname>
+    </author>
+    <release-date>2018-12-01</release-date>
+  </article>
+</articles>
--- a/core-groovy-collections/README.md
+++ b/core-groovy-collections/README.md
@ -2,5 +2,5 @@

 ## Relevant articles:

- [Maps in Groovy](http://www.baeldung.com/)
+- [Maps in Groovy](https://www.baeldung.com/groovy-maps)

--- a/core-java-arrays/README.MD
+++ b/core-java-arrays/README.MD
@ -0,0 +1,3 @@
+## Relevant Articles
+
+- [Extending an Array’s Length](https://www.baeldung.com/java-array-add-element-at-the-end)
--- a/core-java-arrays/src/main/java/com/baeldung/array/conversions/StreamArrayConversion.java
+++ b/core-java-arrays/src/main/java/com/baeldung/array/conversions/StreamArrayConversion.java
@ -0,0 +1,52 @@
+package com.baeldung.array.conversions;
+
+import java.util.Arrays;
+import java.util.function.IntFunction;
+import java.util.stream.IntStream;
+import java.util.stream.Stream;
+
+public class StreamArrayConversion {
+
+    public static String[] stringStreamToStringArrayUsingFunctionalInterface(Stream<String> stringStream) {
+        IntFunction<String[]> intFunction = new IntFunction<String[]>() {
+            @Override
+            public String[] apply(int value) {
+                return new String[value];
+            }
+        };
+
+        return stringStream.toArray(intFunction);
+    }
+
+    public static String[] stringStreamToStringArrayUsingMethodReference(Stream<String> stringStream) {
+        return stringStream.toArray(String[]::new);
+    }
+
+    public static String[] stringStreamToStringArrayUsingLambda(Stream<String> stringStream) {
+        return stringStream.toArray(value -> new String[value]);
+    }
+
+    public static Integer[] integerStreamToIntegerArray(Stream<Integer> integerStream) {
+        return integerStream.toArray(Integer[]::new);
+    }
+
+    public static int[] intStreamToPrimitiveIntArray(Stream<Integer> integerStream) {
+        return integerStream.mapToInt(i -> i).toArray();
+    }
+
+    public static Stream<String> stringArrayToStreamUsingArraysStream(String[] stringArray) {
+        return Arrays.stream(stringArray);
+    }
+
+    public static Stream<String> stringArrayToStreamUsingStreamOf(String[] stringArray) {
+        return Stream.of(stringArray);
+    }
+
+    public static IntStream primitiveIntArrayToStreamUsingArraysStream(int[] intArray) {
+        return Arrays.stream(intArray);
+    }
+
+    public static Stream<int[]> primitiveIntArrayToStreamUsingStreamOf(int[] intArray) {
+        return Stream.of(intArray);
+    }
+}
--- a/core-java-arrays/src/test/java/com/baeldung/array/conversions/StreamArrayConversionUnitTest.java
+++ b/core-java-arrays/src/test/java/com/baeldung/array/conversions/StreamArrayConversionUnitTest.java
@ -0,0 +1,70 @@
+package com.baeldung.array.conversions;
+
+import static com.baeldung.array.conversions.StreamArrayConversion.intStreamToPrimitiveIntArray;
+import static com.baeldung.array.conversions.StreamArrayConversion.integerStreamToIntegerArray;
+import static com.baeldung.array.conversions.StreamArrayConversion.stringStreamToStringArrayUsingFunctionalInterface;
+import static com.baeldung.array.conversions.StreamArrayConversion.stringStreamToStringArrayUsingLambda;
+import static com.baeldung.array.conversions.StreamArrayConversion.stringStreamToStringArrayUsingMethodReference;
+import static com.baeldung.array.conversions.StreamArrayConversion.stringArrayToStreamUsingArraysStream;
+import static com.baeldung.array.conversions.StreamArrayConversion.stringArrayToStreamUsingStreamOf;
+import static com.baeldung.array.conversions.StreamArrayConversion.primitiveIntArrayToStreamUsingArraysStream;
+import static com.baeldung.array.conversions.StreamArrayConversion.primitiveIntArrayToStreamUsingStreamOf;
+import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import com.google.common.collect.Iterators;
+import java.util.stream.IntStream;
+import java.util.stream.Stream;
+import org.junit.Test;
+
+public class StreamArrayConversionUnitTest {
+
+    private String[] stringArray = new String[]{"baeldung", "convert", "to", "string", "array"};
+    private Integer[] integerArray = new Integer[]{1, 2, 3, 4, 5, 6, 7};
+    private int[] intPrimitiveArray = new int[]{1, 2, 3, 4, 5, 6, 7};
+
+    @Test
+    public void givenStringStream_thenConvertToStringArrayUsingFunctionalInterface() {
+        Stream<String> stringStream = Stream.of("baeldung", "convert", "to", "string", "array");
+        assertArrayEquals(stringArray, stringStreamToStringArrayUsingFunctionalInterface(stringStream));
+    }
+
+    @Test
+    public void givenStringStream_thenConvertToStringArrayUsingMethodReference() {
+        Stream<String> stringStream = Stream.of("baeldung", "convert", "to", "string", "array");
+        assertArrayEquals(stringArray, stringStreamToStringArrayUsingMethodReference(stringStream));
+    }
+
+    @Test
+    public void givenStringStream_thenConvertToStringArrayUsingLambda() {
+        Stream<String> stringStream = Stream.of("baeldung", "convert", "to", "string", "array");
+        assertArrayEquals(stringArray, stringStreamToStringArrayUsingLambda(stringStream));
+    }
+
+    @Test
+    public void givenIntegerStream_thenConvertToIntegerArray() {
+        Stream<Integer> integerStream = Stream.of(1, 2, 3, 4, 5, 6, 7);
+        assertArrayEquals(integerArray, integerStreamToIntegerArray(integerStream));
+    }
+
+    @Test
+    public void givenIntStream_thenConvertToIntegerArray() {
+        Stream<Integer> integerStream = IntStream.rangeClosed(1, 7).boxed();
+        assertArrayEquals(intPrimitiveArray, intStreamToPrimitiveIntArray(integerStream));
+    }
+
+    @Test
+    public void givenStringArray_whenConvertedTwoWays_thenConvertedStreamsAreEqual() {
+        assertTrue(Iterators
+            .elementsEqual(stringArrayToStreamUsingArraysStream(stringArray).iterator(),
+                stringArrayToStreamUsingStreamOf(stringArray).iterator()));
+    }
+
+    @Test
+    public void givenPrimitiveArray_whenConvertedTwoWays_thenConvertedStreamsAreNotEqual() {
+        assertFalse(Iterators.elementsEqual(
+            primitiveIntArrayToStreamUsingArraysStream(intPrimitiveArray).iterator(),
+            primitiveIntArrayToStreamUsingStreamOf(intPrimitiveArray).iterator()));
+    }
+}
--- a/core-java-lambdas/README.md
+++ b/core-java-lambdas/README.md
@ -0,0 +1,2 @@
+### Relevant Articles:
+- [Java 9 java.lang.Module API](https://www.baeldung.com/java-lambda-effectively-final-local-variables)
--- a/core-java-modules/README.md
+++ b/core-java-modules/README.md
@ -1,3 +1,5 @@
 ## Relevant articles:

 - [Multi-Module Maven Application with Java Modules](https://www.baeldung.com/maven-multi-module-project-java-jpms)
+- [Guide to Java FileChannel](https://www.baeldung.com/java-filechannel)
+- [Understanding the NumberFormatException in Java](https://www.baeldung.com/java-number-format-exception)
--- a/core-java-modules/core-java-10/src/main/java/com/baeldung/set/CopySets.java
+++ b/core-java-modules/core-java-10/src/main/java/com/baeldung/set/CopySets.java
@ -0,0 +1,13 @@
+package com.baeldung.set;
+
+import java.util.Set;
+
+public class CopySets {
+
+    // Using Java 10
+    public static <T> Set<T> copyBySetCopyOf(Set<T> original) {
+        Set<T> copy = Set.copyOf(original);
+        return copy;
+    }
+
+}
--- a/core-java-modules/core-java-11/README.md
+++ b/core-java-modules/core-java-11/README.md
@ -7,3 +7,5 @@
 - [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)
+- [Negate a Predicate Method Reference with Java 11](https://www.baeldung.com/java-negate-predicate-method-reference)
+- [Transforming an Empty String into an Empty Optional](https://www.baeldung.com/java-empty-string-to-empty-optional)
--- a/core-java-modules/core-java-11/pom.xml
+++ b/core-java-modules/core-java-11/pom.xml
@ -1,5 +1,7 @@
-<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</groupId>
    <artifactId>core-java-11</artifactId>
@ -12,7 +14,7 @@
        <groupId>com.baeldung</groupId>
        <artifactId>parent-modules</artifactId>
        <version>1.0.0-SNAPSHOT</version>
-        <relativePath>../../</relativePath>
+        <relativePath>../..</relativePath>
    </parent>

    <dependencies>
@ -21,6 +23,12 @@
            <artifactId>guava</artifactId>
            <version>${guava.version}</version>
        </dependency>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${assertj.version}</version>
+            <scope>test</scope>
+        </dependency>
    </dependencies>

    <build>
@ -41,6 +49,7 @@
        <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>
+        <assertj.version>3.11.1</assertj.version>
    </properties>

 </project>
--- a/core-java-modules/core-java-11/src/main/java/com/baeldung/predicate/not/Person.java
+++ b/core-java-modules/core-java-11/src/main/java/com/baeldung/predicate/not/Person.java
@ -0,0 +1,19 @@
+package com.baeldung.predicate.not;
+
+public class Person {
+    private static final int ADULT_AGE = 18;
+
+    private int age;
+
+    public Person(int age) {
+        this.age = age;
+    }
+
+    public boolean isAdult() {
+        return age >= ADULT_AGE;
+    }
+
+    public boolean isNotAdult() {
+        return !isAdult();
+    }
+}
--- a/core-java-modules/core-java-11/src/test/java/com/baeldung/AppUnitTest.java
+++ b/core-java-modules/core-java-11/src/test/java/com/baeldung/AppUnitTest.java
@ -7,7 +7,7 @@ import junit.framework.TestSuite;
 /**
 * Unit test for simple App.
 */
-public class AppTest 
+public class AppUnitTest
    extends TestCase
 {
    /**
@ -15,7 +15,7 @@ public class AppTest
     *
     * @param testName name of the test case
     */
-    public AppTest( String testName )
+    public AppUnitTest(String testName )
    {
        super( testName );
    }
@ -25,7 +25,7 @@ public class AppTest
     */
    public static Test suite()
    {
-        return new TestSuite( AppTest.class );
+        return new TestSuite( AppUnitTest.class );
    }

    /**
--- a/core-java-modules/core-java-11/src/test/java/com/baeldung/java11/httpclient/test/HttpClientUnitTest.java
+++ b/core-java-modules/core-java-11/src/test/java/com/baeldung/java11/httpclient/test/HttpClientUnitTest.java
@ -32,7 +32,7 @@ import java.util.stream.Collectors;

 import org.junit.jupiter.api.Test;

-public class HttpClientTest {
+public class HttpClientUnitTest {

    @Test
    public void shouldReturnSampleDataContentWhenConnectViaSystemProxy() throws IOException, InterruptedException, URISyntaxException {
--- a/core-java-modules/core-java-11/src/test/java/com/baeldung/java11/httpclient/test/HttpRequestUnitTest.java
+++ b/core-java-modules/core-java-11/src/test/java/com/baeldung/java11/httpclient/test/HttpRequestUnitTest.java
@ -19,7 +19,7 @@ import java.time.Duration;

 import org.junit.Test;

-public class HttpRequestTest {
+public class HttpRequestUnitTest {

    @Test
    public void shouldReturnStatusOKWhenSendGetRequest() throws IOException, InterruptedException, URISyntaxException {
--- a/core-java-modules/core-java-11/src/test/java/com/baeldung/java11/httpclient/test/HttpResponseUnitTest.java
+++ b/core-java-modules/core-java-11/src/test/java/com/baeldung/java11/httpclient/test/HttpResponseUnitTest.java
@ -14,7 +14,7 @@ import java.net.http.HttpResponse;

 import org.junit.Test;

-public class HttpResponseTest {
+public class HttpResponseUnitTest {

    @Test
    public void shouldReturnStatusOKWhenSendGetRequest() throws IOException, InterruptedException, URISyntaxException {
--- a/core-java-modules/core-java-11/src/test/java/com/baeldung/predicate/not/PersonUnitTest.java
+++ b/core-java-modules/core-java-11/src/test/java/com/baeldung/predicate/not/PersonUnitTest.java
@ -0,0 +1,61 @@
+package com.baeldung.predicate.not;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import static java.util.function.Predicate.not;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class PersonUnitTest {
+    private List<Person> people;
+
+    @BeforeEach
+    void preparePeople() {
+        people = Arrays.asList(
+          new Person(1),
+          new Person(18),
+          new Person(2)
+        );
+    }
+
+    @Test
+    void givenPeople_whenFilterIsAdult_thenOneResult() {
+        List<Person> adults = people.stream()
+          .filter(Person::isAdult)
+          .collect(Collectors.toList());
+
+        assertThat(adults).size().isEqualTo(1);
+    }
+
+    @Test
+    void givenPeople_whenFilterIsAdultNegated_thenTwoResults() {
+        List<Person> nonAdults = people.stream()
+          .filter(person -> !person.isAdult())
+          .collect(Collectors.toList());
+
+        assertThat(nonAdults).size().isEqualTo(2);
+    }
+
+    @Test
+    void givenPeople_whenFilterIsNotAdult_thenTwoResults() {
+        List<Person> nonAdults = people.stream()
+          .filter(Person::isNotAdult)
+          .collect(Collectors.toList());
+
+        assertThat(nonAdults).size().isEqualTo(2);
+    }
+
+    @Test
+    void givenPeople_whenFilterNotIsAdult_thenTwoResults() {
+        List<Person> nonAdults = people.stream()
+          .filter(not(Person::isAdult))
+          .collect(Collectors.toList());
+
+        assertThat(nonAdults).size().isEqualTo(2);
+    }
+}
--- a/core-java-modules/core-java-12/src/test/java/com/baeldung/string/StringAPITest.java
+++ b/core-java-modules/core-java-12/src/test/java/com/baeldung/string/StringAPITest.java
@ -0,0 +1,43 @@
+package com.baeldung.string;
+
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.hamcrest.MatcherAssert.assertThat;
+
+import org.junit.Test;
+
+public class StringAPITest {
+
+    @Test
+    public void whenPositiveArgument_thenReturnIndentedString() {
+        String multilineStr = "This is\na multiline\nstring.";
+        String outputStr = "   This is\n   a multiline\n   string.\n";
+
+        String postIndent = multilineStr.indent(3);
+
+        assertThat(postIndent, equalTo(outputStr));
+    }
+
+    @Test
+    public void whenNegativeArgument_thenReturnReducedIndentedString() {
+        String multilineStr = "   This is\n   a multiline\n   string.";
+        String outputStr = " This is\n a multiline\n string.\n";
+
+        String postIndent = multilineStr.indent(-2);
+
+        assertThat(postIndent, equalTo(outputStr));
+    }
+
+    @Test
+    public void whenTransformUsingLamda_thenReturnTransformedString() {
+        String result = "hello".transform(input -> input + " world!");
+
+        assertThat(result, equalTo("hello world!"));
+    }
+
+    @Test
+    public void whenTransformUsingParseInt_thenReturnInt() {
+        int result = "42".transform(Integer::parseInt);
+
+        assertThat(result, equalTo(42));
+    }
+}
--- a/core-java-modules/core-java-8-2/README.md
+++ b/core-java-modules/core-java-8-2/README.md
@ -4,3 +4,5 @@

 ### Relevant Articles: 
 - [Anonymous Classes in Java](http://www.baeldung.com/)
+- [How to Delay Code Execution in Java](https://www.baeldung.com/java-delay-code-execution)
+- [Run JAR Application With Command Line Arguments](https://www.baeldung.com/java-run-jar-with-arguments)
--- a/core-java-modules/core-java-8-2/pom.xml
+++ b/core-java-modules/core-java-8-2/pom.xml
@ -30,7 +30,6 @@
            <artifactId>icu4j</artifactId>
            <version>${icu.version}</version>
        </dependency>
-
    </dependencies>

    <build>
--- a/core-java-modules/core-java-8-2/src/main/java/com/baeldung/delay/Delay.java
+++ b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/delay/Delay.java
@ -0,0 +1,91 @@
+package com.baeldung.delay;
+
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.ScheduledFuture;
+import java.util.concurrent.TimeUnit;
+
+public class Delay {
+
+    public static void main(String args[]) throws InterruptedException {
+        
+        threadSleep(4, 1);
+
+        timeunitSleep(4, 1);
+
+        delayedServiceTask(5);
+
+        fixedRateServiceTask(5);
+
+        System.out.println("Done.");
+
+        return;
+
+    }
+
+    private static void threadSleep(Integer iterations, Integer secondsToSleep) {
+
+        for (Integer i = 0; i < iterations; i++) {
+
+            System.out.println("This is loop iteration number " + i.toString());
+
+            try {
+                Thread.sleep(secondsToSleep * 1000);
+            } catch (InterruptedException ie) {
+                Thread.currentThread().interrupt();
+            }
+
+        }
+
+    }
+
+    private static void timeunitSleep(Integer iterations, Integer secondsToSleep) {
+
+        for (Integer i = 0; i < iterations; i++) {
+
+            System.out.println("This is loop iteration number " + i.toString());
+
+            try {
+                TimeUnit.SECONDS.sleep(secondsToSleep);
+            } catch (InterruptedException ie) {
+                Thread.currentThread().interrupt();
+            }
+
+        }
+
+    }
+
+    private static void delayedServiceTask(Integer delayInSeconds) {
+
+        ScheduledExecutorService executorService = Executors.newSingleThreadScheduledExecutor();
+
+        executorService.schedule(Delay::someTask1, delayInSeconds, TimeUnit.SECONDS);
+
+    }
+
+    private static void fixedRateServiceTask(Integer delayInSeconds) {
+
+        ScheduledExecutorService executorService = Executors.newSingleThreadScheduledExecutor();
+
+        ScheduledFuture<?> sf = executorService.scheduleAtFixedRate(Delay::someTask2, 0, delayInSeconds,
+                TimeUnit.SECONDS);
+
+        try {
+            TimeUnit.SECONDS.sleep(20);
+        } catch (InterruptedException ie) {
+            Thread.currentThread().interrupt();
+        }
+
+        sf.cancel(true);
+
+    }
+
+    private static void someTask1() {
+        System.out.println("Task 1 completed.");
+    }
+
+    private static void someTask2() {
+        System.out.println("Task 2 completed.");
+    }
+
+}
--- a/core-java-modules/core-java-8-2/src/main/resources/META-INF/persistence.xml
+++ b/core-java-modules/core-java-8-2/src/main/resources/META-INF/persistence.xml
@ -0,0 +1,34 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<persistence xmlns="http://java.sun.com/xml/ns/persistence"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"
+	version="2.0">
+
+	<persistence-unit
+		name="com.baeldung.optionalReturnType"
+		transaction-type="RESOURCE_LOCAL">
+		<description>Persist Optional Return Type Demo</description>
+		<provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
+		<class>com.baeldung.optionalReturnType.User</class>
+		<class>com.baeldung.optionalReturnType.UserOptional</class>
+		<!-- 
+		<class>com.baeldung.optionalReturnType.UserOptionalField</class>
+		-->
+		<exclude-unlisted-classes>true</exclude-unlisted-classes>
+
+		<properties>
+			<property name="javax.persistence.jdbc.driver"
+				value="org.h2.Driver" />
+			<property name="javax.persistence.jdbc.url"
+				value="jdbc:h2:mem:test" />
+			<property name="javax.persistence.jdbc.user" value="sa" />
+			<property name="javax.persistence.jdbc.password" value="" />
+			<property name="hibernate.dialect"
+				value="org.hibernate.dialect.H2Dialect" />
+			<property name="hibernate.hbm2ddl.auto" value="create-drop" />
+			<property name="show_sql" value="true" />
+			<property name="hibernate.temp.use_jdbc_metadata_defaults"
+				value="false" />
+		</properties>
+	</persistence-unit>
+</persistence>
--- a/core-java-modules/core-java-8/src/test/java/com/baeldung/java8/optional/OptionalChainingUnitTest.java
+++ b/core-java-modules/core-java-8/src/test/java/com/baeldung/java8/optional/OptionalChainingUnitTest.java
@ -101,7 +101,7 @@ public class OptionalChainingUnitTest {
    }

    private Optional<String> createOptional(String input) {
-        if (input == null || input == "" || input == "empty") {
+        if (input == null || "".equals(input) || "empty".equals(input)) {
            return Optional.empty();
        }

--- a/core-java-modules/core-java-9/README.md
+++ b/core-java-modules/core-java-9/README.md
@ -20,6 +20,14 @@
 - [Multi-Release Jar Files](https://www.baeldung.com/java-multi-release-jar)
 - [Ahead of Time Compilation (AoT)](https://www.baeldung.com/ahead-of-time-compilation)
 - [Java 9 Process API Improvements](https://www.baeldung.com/java-9-process-api)
- [Guide to java.lang.Process API](https://www.baeldung.com/java-process-api)
-
-
+- [Java 9 java.util.Objects Additions](https://www.baeldung.com/java-9-objects-new)
+- [Java 9 Reactive Streams](https://www.baeldung.com/java-9-reactive-streams)
+- [Java 9 Optional API Additions](https://www.baeldung.com/java-9-optional)
+- [Java 9 CompletableFuture API Improvements](https://www.baeldung.com/java-9-completablefuture)
+- [Introduction to Java 9 StackWalking API](https://www.baeldung.com/java-9-stackwalking-api)
+- [Java 9 Convenience Factory Methods for Collections](https://www.baeldung.com/java-9-collections-factory-methods)
+- [Java 9 Stream API Improvements](https://www.baeldung.com/java-9-stream-api)
+- [A Guide to Java 9 Modularity](https://www.baeldung.com/java-9-modularity)
+- [Java 9 java.lang.Module API](https://www.baeldung.com/java-9-module-api)
+- [Java 9 Platform Logging API](https://www.baeldung.com/java-9-logging-api)
+- [Filtering a Stream of Optionals in Java](https://www.baeldung.com/java-filter-stream-of-optional)
--- a/core-java-modules/core-java-9/src/modules/com.baeldung.logging.slf4j/com/baeldung/logging/slf4j/Slf4jLogger.java
+++ b/core-java-modules/core-java-9/src/modules/com.baeldung.logging.slf4j/com/baeldung/logging/slf4j/Slf4jLogger.java
@ -4,6 +4,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;

 import java.util.ResourceBundle;
+import java.text.MessageFormat;

 public class Slf4jLogger implements System.Logger {

@ -74,26 +75,27 @@ public class Slf4jLogger implements System.Logger {
        if (!isLoggable(level)) {
            return;
        }
+        String message = MessageFormat.format(format, params);

        switch (level) {
        case TRACE:
-            logger.trace(format, params);
+            logger.trace(message);
            break;
        case DEBUG:
-            logger.debug(format, params);
+            logger.debug(message);
            break;
        case INFO:
-            logger.info(format, params);
+            logger.info(message);
            break;
        case WARNING:
-            logger.warn(format, params);
+            logger.warn(message);
            break;
        case ERROR:
-            logger.error(format, params);
+            logger.error(message);
            break;
        case ALL:
        default:
-            logger.info(format, params);
+            logger.info(message);
        }
    }
 }
--- a/core-java-modules/core-java-arrays/README.md
+++ b/core-java-modules/core-java-arrays/README.md
@ -15,3 +15,4 @@
 - [Intersection Between two Integer Arrays](https://www.baeldung.com/java-array-intersection)
 - [Sorting Arrays in Java](https://www.baeldung.com/java-sorting-arrays)
 - [Convert a Float to a Byte Array in Java](https://www.baeldung.com/java-convert-float-to-byte-array)
+- [Converting Between Stream and Array in Java](https://www.baeldung.com/java-stream-to-array)
--- a/core-java-modules/core-java-collections-array-list/README.md
+++ b/core-java-modules/core-java-collections-array-list/README.md
@ -0,0 +1,10 @@
+=========
+
+## Core Java Collections Array List Cookbooks and Examples
+
+### Relevant Articles: 
+- [Immutable ArrayList in Java](http://www.baeldung.com/java-immutable-list)
+- [Guide to the Java ArrayList](http://www.baeldung.com/java-arraylist)
+- [Add Multiple Items to an Java ArrayList](http://www.baeldung.com/java-add-items-array-list)
+- [ClassCastException: Arrays$ArrayList cannot be cast to ArrayList](https://www.baeldung.com/java-classcastexception-arrays-arraylist)
+- [Multi Dimensional ArrayList in Java](https://www.baeldung.com/java-multi-dimensional-arraylist)
--- a/core-java-modules/core-java-collections-array-list/pom.xml
+++ b/core-java-modules/core-java-collections-array-list/pom.xml
@ -0,0 +1,46 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>core-java-collections-array-list</artifactId>
+    <version>0.1.0-SNAPSHOT</version>
+    <name>core-java-collections-array-list</name>
+    <packaging>jar</packaging>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-java</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../../parent-java</relativePath>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-collections4</artifactId>
+            <version>${commons-collections4.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-lang3</artifactId>
+            <version>${commons-lang3.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${assertj.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <version>${lombok.version}</version>
+            <scope>provided</scope>
+        </dependency>
+    </dependencies>
+
+    <properties>
+        <commons-collections4.version>4.1</commons-collections4.version>
+        <commons-lang3.version>3.8.1</commons-lang3.version>
+        <assertj.version>3.11.1</assertj.version>
+    </properties>
+</project>
--- a/core-java-modules/core-java-collections-array-list/src/main/java/com/baeldung/classcastexception/ClassCastException.java
+++ b/core-java-modules/core-java-collections-array-list/src/main/java/com/baeldung/classcastexception/ClassCastException.java
--- a/core-java-modules/core-java-collections-array-list/src/main/java/com/baeldung/java/list/Flower.java
+++ b/core-java-modules/core-java-collections-array-list/src/main/java/com/baeldung/java/list/Flower.java
@ -0,0 +1,28 @@
+package com.baeldung.java.list;
+
+public class Flower {
+
+    private String name;
+    private int petals;
+
+    public Flower(String name, int petals) {
+        this.name = name;
+        this.petals = petals;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public int getPetals() {
+        return petals;
+    }
+
+    public void setPetals(int petals) {
+        this.petals = petals;
+    }
+}
--- a/core-java-modules/core-java-collections-array-list/src/main/java/com/baeldung/list/multidimensional/ArrayListOfArrayList.java
+++ b/core-java-modules/core-java-collections-array-list/src/main/java/com/baeldung/list/multidimensional/ArrayListOfArrayList.java
--- a/core-java-modules/core-java-collections-array-list/src/main/java/com/baeldung/list/multidimensional/ThreeDimensionalArrayList.java
+++ b/core-java-modules/core-java-collections-array-list/src/main/java/com/baeldung/list/multidimensional/ThreeDimensionalArrayList.java
--- a/core-java-modules/core-java-collections-array-list/src/main/resources/logback.xml
+++ b/core-java-modules/core-java-collections-array-list/src/main/resources/logback.xml
@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
+            </pattern>
+        </encoder>
+    </appender>
+
+    <root level="INFO">
+        <appender-ref ref="STDOUT" />
+    </root>
+</configuration>
--- a/core-java-modules/core-java-collections-array-list/src/test/java/com/baeldung/list/listoflist/AddElementsToListUnitTest.java
+++ b/core-java-modules/core-java-collections-array-list/src/test/java/com/baeldung/list/listoflist/AddElementsToListUnitTest.java
--- a/core-java-modules/core-java-collections-array-list/src/test/java/org/baeldung/java/collections/ArrayListUnitTest.java
+++ b/core-java-modules/core-java-collections-array-list/src/test/java/org/baeldung/java/collections/ArrayListUnitTest.java
--- a/core-java-modules/core-java-collections-array-list/src/test/java/org/baeldung/java/collections/CoreJavaCollectionsUnitTest.java
+++ b/core-java-modules/core-java-collections-array-list/src/test/java/org/baeldung/java/collections/CoreJavaCollectionsUnitTest.java
--- a/core-java-modules/core-java-collections-list-2/README.md
+++ b/core-java-modules/core-java-collections-list-2/README.md
@ -0,0 +1,17 @@
+=========
+
+## Core Java Collections List Cookbooks and Examples
+
+### Relevant Articles: 
+- [Check If Two Lists are Equal in Java](http://www.baeldung.com/java-test-a-list-for-ordinality-and-equality)
+- [Java 8 Streams: Find Items From One List Based On Values From Another List](https://www.baeldung.com/java-streams-find-list-items)
+- [A Guide to the Java LinkedList](http://www.baeldung.com/java-linkedlist)
+- [Java List UnsupportedOperationException](http://www.baeldung.com/java-list-unsupported-operation-exception)
+- [Java List Initialization in One Line](https://www.baeldung.com/java-init-list-one-line)
+- [Ways to Iterate Over a List in Java](https://www.baeldung.com/java-iterate-list)
+- [Flattening Nested Collections in Java](http://www.baeldung.com/java-flatten-nested-collections)
+- [Intersection of Two Lists in Java](https://www.baeldung.com/java-lists-intersection)
+- [Determine If All Elements Are the Same in a Java List](https://www.baeldung.com/java-list-all-equal)
+- [List of Primitive Integer Values in Java](https://www.baeldung.com/java-list-primitive-int)
+- [Performance Comparison of Primitive Lists in Java](https://www.baeldung.com/java-list-primitive-performance)
+- [Filtering a Java Collection by a List](https://www.baeldung.com/java-filter-collection-by-list)
--- a/core-java-modules/core-java-collections-list-2/pom.xml
+++ b/core-java-modules/core-java-collections-list-2/pom.xml
@ -0,0 +1,76 @@
+<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-java-collections-list-2</artifactId>
+    <version>0.1.0-SNAPSHOT</version>
+    <name>core-java-collections-list-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>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-collections4</artifactId>
+            <version>${commons-collections4.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-lang3</artifactId>
+            <version>${commons-lang3.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${assertj.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <version>${lombok.version}</version>
+            <scope>provided</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>net.sf.trove4j</groupId>
+            <artifactId>trove4j</artifactId>
+            <version>${trove4j.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>it.unimi.dsi</groupId>
+            <artifactId>fastutil</artifactId>
+            <version>${fastutil.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>colt</groupId>
+            <artifactId>colt</artifactId>
+            <version>${colt.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.openjdk.jmh</groupId>
+            <artifactId>jmh-core</artifactId>
+            <version>${jmh-core.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.openjdk.jmh</groupId>
+            <artifactId>jmh-generator-annprocess</artifactId>
+            <version>${jmh-core.version}</version>
+        </dependency>
+    </dependencies>
+
+    <properties>
+        <commons-collections4.version>4.1</commons-collections4.version>
+        <commons-lang3.version>3.8.1</commons-lang3.version>
+        <assertj.version>3.11.1</assertj.version>
+		<trove4j.version>3.0.2</trove4j.version>
+		<fastutil.version>8.1.0</fastutil.version>
+		<colt.version>1.2.0</colt.version>
+    </properties>
+</project>
--- a/core-java-modules/core-java-collections-list-2/src/main/java/com/baeldung/allequalelements/VerifyAllEqualListElements.java
+++ b/core-java-modules/core-java-collections-list-2/src/main/java/com/baeldung/allequalelements/VerifyAllEqualListElements.java
--- a/core-java-modules/core-java-collections-list-2/src/main/java/com/baeldung/collection/filtering/Employee.java
+++ b/core-java-modules/core-java-collections-list-2/src/main/java/com/baeldung/collection/filtering/Employee.java
--- a/core-java-modules/core-java-collections-list-2/src/main/java/com/baeldung/java/list/WaysToIterate.java
+++ b/core-java-modules/core-java-collections-list-2/src/main/java/com/baeldung/java/list/WaysToIterate.java
--- a/core-java-modules/core-java-collections-list-2/src/main/java/com/baeldung/list/primitive/PrimitiveCollections.java
+++ b/core-java-modules/core-java-collections-list-2/src/main/java/com/baeldung/list/primitive/PrimitiveCollections.java
--- a/core-java-modules/core-java-collections-list-2/src/main/java/com/baeldung/list/primitive/PrimitivesListPerformance.java
+++ b/core-java-modules/core-java-collections-list-2/src/main/java/com/baeldung/list/primitive/PrimitivesListPerformance.java
--- a/core-java-modules/core-java-collections-list-2/src/main/resources/logback.xml
+++ b/core-java-modules/core-java-collections-list-2/src/main/resources/logback.xml
@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
+            </pattern>
+        </encoder>
+    </appender>
+
+    <root level="INFO">
+        <appender-ref ref="STDOUT" />
+    </root>
+</configuration>
--- a/core-java-modules/core-java-collections-list-2/src/test/java/com/baeldung/allequalelements/VerifyAllEqualListElementsUnitTest.java
+++ b/core-java-modules/core-java-collections-list-2/src/test/java/com/baeldung/allequalelements/VerifyAllEqualListElementsUnitTest.java
--- a/core-java-modules/core-java-collections-list-2/src/test/java/com/baeldung/array/converter/ArrayConvertToListUnitTest.java
+++ b/core-java-modules/core-java-collections-list-2/src/test/java/com/baeldung/array/converter/ArrayConvertToListUnitTest.java
--- a/core-java-modules/core-java-collections-list-2/src/test/java/com/baeldung/collection/filtering/CollectionFilteringUnitTest.java
+++ b/core-java-modules/core-java-collections-list-2/src/test/java/com/baeldung/collection/filtering/CollectionFilteringUnitTest.java
--- a/core-java-modules/core-java-collections-list-2/src/test/java/com/baeldung/findItems/FindItemsBasedOnOtherStreamUnitTest.java
+++ b/core-java-modules/core-java-collections-list-2/src/test/java/com/baeldung/findItems/FindItemsBasedOnOtherStreamUnitTest.java
--- a/core-java-modules/core-java-collections-list-2/src/test/java/com/baeldung/java/list/WaysToIterateUnitTest.java
+++ b/core-java-modules/core-java-collections-list-2/src/test/java/com/baeldung/java/list/WaysToIterateUnitTest.java
--- a/core-java-modules/core-java-collections-list-2/src/test/java/com/baeldung/java/listInitialization/ListInitializationUnitTest.java
+++ b/core-java-modules/core-java-collections-list-2/src/test/java/com/baeldung/java/listInitialization/ListInitializationUnitTest.java
--- a/Show More
+++ b/Show More