Merge branch 'master' of https://github.com/chris9408/tutorials into feature/selenium-cookies

algorithms-miscellaneous-5/pom.xml

@@ -34,6 +34,11 @@
             <artifactId>tradukisto</artifactId>
             <version>${tradukisto.version}</version>
         </dependency>
+        <dependency>
+            <groupId>com.google.guava</groupId>
+            <artifactId>guava</artifactId>
+            <version>28.1-jre</version>
+        </dependency>
 
         <dependency>
             <groupId>org.assertj</groupId>

algorithms-miscellaneous-5/src/main/java/com/baeldung/algorithms/kruskal/CycleDetector.java

@@ -0,0 +1,72 @@
+package com.baeldung.algorithms.kruskal;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class CycleDetector {
+
+    List<DisjointSetInfo> nodes;
+
+    public CycleDetector(int totalNodes) {
+        initDisjointSets(totalNodes);
+    }
+
+    public boolean detectCycle(Integer u, Integer v) {
+        Integer rootU = pathCompressionFind(u);
+        Integer rootV = pathCompressionFind(v);
+        if (rootU.equals(rootV)) {
+            return true;
+        }
+        unionByRank(rootU, rootV);
+        return false;
+    }
+
+    private void initDisjointSets(int totalNodes) {
+        nodes = new ArrayList<>(totalNodes);
+        for (int i = 0; i < totalNodes; i++) {
+            nodes.add(new DisjointSetInfo(i));
+        }
+    }
+
+    private Integer find(Integer node) {
+        Integer parent = nodes.get(node).getParentNode();
+        if (parent.equals(node)) {
+            return node;
+        } else {
+            return find(parent);
+        }
+    }
+
+    private Integer pathCompressionFind(Integer node) {
+        DisjointSetInfo setInfo = nodes.get(node);
+        Integer parent = setInfo.getParentNode();
+        if (parent.equals(node)) {
+            return node;
+        } else {
+            Integer parentNode = find(parent);
+            setInfo.setParentNode(parentNode);
+            return parentNode;
+        }
+    }
+
+    private void union(Integer rootU, Integer rootV) {
+        DisjointSetInfo setInfoU = nodes.get(rootU);
+        setInfoU.setParentNode(rootV);
+    }
+
+    private void unionByRank(int rootU, int rootV) {
+        DisjointSetInfo setInfoU = nodes.get(rootU);
+        DisjointSetInfo setInfoV = nodes.get(rootV);
+        int rankU = setInfoU.getRank();
+        int rankV = setInfoV.getRank();
+        if (rankU < rankV) {
+            setInfoU.setParentNode(rootV);
+        } else {
+            setInfoV.setParentNode(rootU);
+            if (rankU == rankV) {
+                setInfoU.setRank(rankU + 1);
+            }
+        }
+    }
+
+}

algorithms-miscellaneous-5/src/main/java/com/baeldung/algorithms/kruskal/DisjointSetInfo.java

@@ -0,0 +1,28 @@
+package com.baeldung.algorithms.kruskal;
+
+public class DisjointSetInfo {
+
+    private Integer parentNode;
+    private int rank;
+
+    DisjointSetInfo(Integer nodeNumber) {
+        setParentNode(nodeNumber);
+        setRank(1);
+    }
+
+    public Integer getParentNode() {
+        return parentNode;
+    }
+
+    public void setParentNode(Integer parentNode) {
+        this.parentNode = parentNode;
+    }
+
+    public int getRank() {
+        return rank;
+    }
+
+    public void setRank(int rank) {
+        this.rank = rank;
+    }
+}

algorithms-miscellaneous-5/src/main/java/com/baeldung/algorithms/kruskal/Kruskal.java

@@ -0,0 +1,53 @@
+package com.baeldung.algorithms.kruskal;
+
+import com.google.common.graph.EndpointPair;
+import com.google.common.graph.MutableValueGraph;
+import com.google.common.graph.ValueGraph;
+import com.google.common.graph.ValueGraphBuilder;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.List;
+import java.util.Set;
+
+public class Kruskal {
+
+    public ValueGraph<Integer, Double> minSpanningTree(ValueGraph<Integer, Double> graph) {
+
+        return spanningTree(graph, true);
+    }
+
+    public ValueGraph<Integer, Double> maxSpanningTree(ValueGraph<Integer, Double> graph) {
+        return spanningTree(graph, false);
+    }
+
+    private ValueGraph<Integer, Double> spanningTree(ValueGraph<Integer, Double> graph, boolean minSpanningTree) {
+        Set<EndpointPair<Integer>> edges = graph.edges();
+        List<EndpointPair<Integer>> edgeList = new ArrayList<>(edges);
+
+        if (minSpanningTree) {
+            edgeList.sort(Comparator.comparing(e -> graph.edgeValue(e).get()));
+        } else {
+            edgeList.sort(Collections.reverseOrder(Comparator.comparing(e -> graph.edgeValue(e).get())));
+        }
+
+        int totalNodes = graph.nodes().size();
+        CycleDetector cycleDetector = new CycleDetector(totalNodes);
+        int edgeCount = 0;
+
+        MutableValueGraph<Integer, Double> spanningTree = ValueGraphBuilder.undirected().build();
+        for (EndpointPair<Integer> edge : edgeList) {
+            if (cycleDetector.detectCycle(edge.nodeU(), edge.nodeV())) {
+                continue;
+            }
+            spanningTree.putEdgeValue(edge.nodeU(), edge.nodeV(), graph.edgeValue(edge).get());
+            edgeCount++;
+            if (edgeCount == totalNodes - 1) {
+                break;
+            }
+        }
+        return spanningTree;
+    }
+
+}

algorithms-miscellaneous-5/src/test/java/com/baeldung/algorithms/kruskal/KruskalUnitTest.java

@@ -0,0 +1,67 @@
+package com.baeldung.algorithms.kruskal;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Before;
+import org.junit.Test;
+import com.google.common.graph.MutableValueGraph;
+import com.google.common.graph.ValueGraph;
+import com.google.common.graph.ValueGraphBuilder;
+import com.baeldung.algorithms.kruskal.Kruskal;
+
+public class KruskalUnitTest {
+
+    private MutableValueGraph<Integer, Double> graph;
+
+    @Before
+    public void setup() {
+        graph = ValueGraphBuilder.undirected().build();
+        graph.putEdgeValue(0, 1, 8.0);
+        graph.putEdgeValue(0, 2, 5.0);
+        graph.putEdgeValue(1, 2, 9.0);
+        graph.putEdgeValue(1, 3, 11.0);
+        graph.putEdgeValue(2, 3, 15.0);
+        graph.putEdgeValue(2, 4, 10.0);
+        graph.putEdgeValue(3, 4, 7.0);
+    }
+
+    @Test
+    public void givenGraph_whenMinimumSpanningTree_thenOutputCorrectResult() {
+        final Kruskal kruskal = new Kruskal();
+        ValueGraph<Integer, Double> spanningTree = kruskal.minSpanningTree(graph);
+
+        assertTrue(spanningTree.hasEdgeConnecting(0, 1));
+        assertTrue(spanningTree.hasEdgeConnecting(0, 2));
+        assertTrue(spanningTree.hasEdgeConnecting(2, 4));
+        assertTrue(spanningTree.hasEdgeConnecting(3, 4));
+        assertEquals(graph.edgeValue(0, 1), spanningTree.edgeValue(0, 1));
+        assertEquals(graph.edgeValue(0, 2), spanningTree.edgeValue(0, 2));
+        assertEquals(graph.edgeValue(2, 4), spanningTree.edgeValue(2, 4));
+        assertEquals(graph.edgeValue(3, 4), spanningTree.edgeValue(3, 4));
+
+        assertFalse(spanningTree.hasEdgeConnecting(1, 2));
+        assertFalse(spanningTree.hasEdgeConnecting(1, 3));
+        assertFalse(spanningTree.hasEdgeConnecting(2, 3));
+    }
+
+    @Test
+    public void givenGraph_whenMaximumSpanningTree_thenOutputCorrectResult() {
+        final Kruskal kruskal = new Kruskal();
+        ValueGraph<Integer, Double> spanningTree = kruskal.maxSpanningTree(graph);
+
+        assertTrue(spanningTree.hasEdgeConnecting(0, 1));
+        assertTrue(spanningTree.hasEdgeConnecting(1, 3));
+        assertTrue(spanningTree.hasEdgeConnecting(2, 3));
+        assertTrue(spanningTree.hasEdgeConnecting(2, 4));
+        assertEquals(graph.edgeValue(0, 1), spanningTree.edgeValue(0, 1));
+        assertEquals(graph.edgeValue(1, 3), spanningTree.edgeValue(1, 3));
+        assertEquals(graph.edgeValue(2, 3), spanningTree.edgeValue(2, 3));
+        assertEquals(graph.edgeValue(2, 4), spanningTree.edgeValue(2, 4));
+
+        assertFalse(spanningTree.hasEdgeConnecting(0, 2));
+        assertFalse(spanningTree.hasEdgeConnecting(1, 2));
+        assertFalse(spanningTree.hasEdgeConnecting(3, 4));
+    }
+}

apache-fop/src/main/webapp/WEB-INF/web.xml

@@ -16,7 +16,7 @@
     </context-param>
     <context-param>
         <param-name>contextConfigLocation</param-name>
-        <param-value>org.baeldung.config</param-value>
+        <param-value>com.baeldung.config</param-value>
     </context-param>
 
     <listener>

apache-fop/src/test/java/com/baeldung/java/ApacheFOPConvertHTMLIntegrationTest.java

@@ -1,4 +1,4 @@
-package org.baeldung.java;
+package com.baeldung.java;
 
 import java.io.BufferedOutputStream;
 import java.io.File;

apache-fop/src/test/java/com/baeldung/java/ApacheFOPHeroldLiveTest.java

@@ -1,4 +1,4 @@
-package org.baeldung.java;
+package com.baeldung.java;
 
 import java.io.BufferedOutputStream;
 import java.io.BufferedReader;

apache-olingo/olingo2/pom.xml

@@ -3,7 +3,7 @@
          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>org.baeldung.examples.olingo2</groupId>
+    <groupId>com.baeldung.examples.olingo2</groupId>
     <artifactId>olingo2</artifactId>
     <name>olingo2</name>
     <description>Sample Olingo 2 Project</description>

apache-olingo/olingo2/src/main/java/com/baeldung/examples/olingo2/CarsODataJPAServiceFactory.java

@@ -1,4 +1,4 @@
-package org.baeldung.examples.olingo2;
+package com.baeldung.examples.olingo2;
 
 import java.util.List;
 import java.util.Map;
@@ -9,10 +9,8 @@ import javax.persistence.EntityManagerFactory;
 import javax.persistence.EntityTransaction;
 import javax.persistence.FlushModeType;
 import javax.persistence.LockModeType;
-import javax.persistence.Persistence;
 import javax.persistence.Query;
 import javax.persistence.StoredProcedureQuery;
-import javax.persistence.SynchronizationType;
 import javax.persistence.TypedQuery;
 import javax.persistence.criteria.CriteriaBuilder;
 import javax.persistence.criteria.CriteriaDelete;
@@ -25,11 +23,8 @@ import org.apache.olingo.odata2.api.processor.ODataContext;
 import org.apache.olingo.odata2.jpa.processor.api.ODataJPAContext;
 import org.apache.olingo.odata2.jpa.processor.api.ODataJPAServiceFactory;
 import org.apache.olingo.odata2.jpa.processor.api.exception.ODataJPARuntimeException;
-import org.baeldung.examples.olingo2.JerseyConfig.EntityManagerFilter;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-import org.springframework.orm.jpa.EntityManagerFactoryUtils;
-import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
 import org.springframework.stereotype.Component;
 
 /**
@@ -58,7 +53,7 @@ public class CarsODataJPAServiceFactory extends ODataJPAServiceFactory {
         ODataJPAContext ctx = getODataJPAContext();
         ODataContext octx = ctx.getODataContext();
         HttpServletRequest request = (HttpServletRequest)octx.getParameter(ODataContext.HTTP_SERVLET_REQUEST_OBJECT);
-        EntityManager em = (EntityManager)request.getAttribute(EntityManagerFilter.EM_REQUEST_ATTRIBUTE);
+        EntityManager em = (EntityManager)request.getAttribute(JerseyConfig.EntityManagerFilter.EM_REQUEST_ATTRIBUTE);
                 
         // Here we're passing the EM that was created by the EntityManagerFilter (see JerseyConfig)
         ctx.setEntityManager(new EntityManagerWrapper(em));

apache-olingo/olingo2/src/main/java/com/baeldung/examples/olingo2/JerseyConfig.java

@@ -1,11 +1,10 @@
-    package org.baeldung.examples.olingo2;
+    package com.baeldung.examples.olingo2;
 
 import java.io.IOException;
 
 import javax.persistence.EntityManager;
 import javax.persistence.EntityManagerFactory;
 import javax.persistence.EntityTransaction;
-import javax.servlet.ServletContext;
 import javax.servlet.http.HttpServletRequest;
 import javax.ws.rs.ApplicationPath;
 import javax.ws.rs.Path;

apache-olingo/olingo2/src/main/java/com/baeldung/examples/olingo2/Olingo2SampleApplication.java

@@ -1,8 +1,7 @@
-package org.baeldung.examples.olingo2;
+package com.baeldung.examples.olingo2;
 
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
-import org.springframework.boot.builder.SpringApplicationBuilder;
 import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;
 
 @SpringBootApplication

apache-olingo/olingo2/src/main/java/com/baeldung/examples/olingo2/domain/CarMaker.java

@@ -1,4 +1,4 @@
-package org.baeldung.examples.olingo2.domain;
+package com.baeldung.examples.olingo2.domain;
 
 import java.util.List;
 

apache-olingo/olingo2/src/main/java/com/baeldung/examples/olingo2/domain/CarModel.java

@@ -1,4 +1,4 @@
-package org.baeldung.examples.olingo2.domain;
+package com.baeldung.examples.olingo2.domain;
 
 import javax.persistence.Entity;
 import javax.persistence.FetchType;

apache-olingo/olingo2/src/test/java/com/baeldung/examples/olingo2/Olingo2SampleApplicationUnitTest.java

@@ -1,4 +1,4 @@
-package org.baeldung.examples.olingo2;
+package com.baeldung.examples.olingo2;
 
 import org.junit.Test;
 import org.junit.runner.RunWith;

core-java-modules/core-java-exceptions-2/src/main/java/com/baeldung/exceptions/CatchingThrowable.java

@@ -0,0 +1,38 @@
+package com.baeldung.exceptions;
+
+import java.util.Set;
+import java.util.UUID;
+
+public class CatchingThrowable  {
+
+    class CapacityException extends Exception {
+        CapacityException(String message) {
+            super(message);
+        }
+    }
+
+    class StorageAPI {
+
+        public void addIDsToStorage(int capacity, Set<String> storage) throws CapacityException {
+            if (capacity < 1) {
+                throw new CapacityException("Capacity of less than 1 is not allowed");
+            }
+            int count = 0;
+            while (count < capacity) {
+                storage.add(UUID.randomUUID().toString());
+                count++;
+            }
+        }
+
+        // other methods go here ...
+    }
+
+    public void add(StorageAPI api, int capacity, Set<String> storage) {
+        try {
+            api.addIDsToStorage(capacity, storage);
+        } catch (Throwable throwable) {
+            // do something here
+        }
+    }
+
+}

core-kotlin-2/README.md

@@ -4,9 +4,6 @@ This module contains articles about core Kotlin.
 
 ### Relevant articles:
 
-- [Void Type in Kotlin](https://www.baeldung.com/kotlin-void-type)
-- [How to use Kotlin Range Expressions](https://www.baeldung.com/kotlin-ranges)
-- [Creating a Kotlin Range Iterator on a Custom Object](https://www.baeldung.com/kotlin-custom-range-iterator)
 - [Kotlin Scope Functions](https://www.baeldung.com/kotlin-scope-functions)
 - [Kotlin Annotations](https://www.baeldung.com/kotlin-annotations)
 - [Split a List into Parts in Kotlin](https://www.baeldung.com/kotlin-split-list-into-parts)

core-kotlin-modules/core-kotlin-lang-2/README.md

@@ -0,0 +1,13 @@
+## Core Kotlin Lang
+
+This module contains articles about core features in the Kotlin language.
+
+### Relevant articles:
+- [Kotlin return, break, continue Keywords](https://www.baeldung.com/kotlin-return-break-continue)
+- [Infix Functions in Kotlin](https://www.baeldung.com/kotlin-infix-functions)
+- [Lambda Expressions in Kotlin](https://www.baeldung.com/kotlin-lambda-expressions)
+- [Creating Java static final Equivalents in Kotlin](https://www.baeldung.com/kotlin-java-static-final)
+- [Initializing Arrays in Kotlin](https://www.baeldung.com/kotlin-initialize-array)
+- [Lazy Initialization in Kotlin](https://www.baeldung.com/kotlin-lazy-initialization)
+- [Comprehensive Guide to Null Safety in Kotlin](https://www.baeldung.com/kotlin-null-safety)
+- [[<-- Prev]](/core-kotlin-modules/core-kotlin-lang)

core-kotlin-modules/core-kotlin-lang-2/pom.xml

@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>core-kotlin-lang-2</artifactId>
+    <name>core-kotlin-lang-2</name>
+    <packaging>jar</packaging>
+
+    <parent>
+        <groupId>com.baeldung.core-kotlin-modules</groupId>
+        <artifactId>core-kotlin-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+</project>

core-kotlin-modules/core-kotlin-lang-2/src/test/java/com/baeldung/lazy/LazyJavaUnitTest.java

@@ -1,7 +1,5 @@
-package com.baeldung.kotlin;
+package com.baeldung.lazy;
 
-
-import com.baeldung.lazy.ClassWithHeavyInitialization;
 import org.junit.Test;
 
 import static junit.framework.TestCase.assertTrue;

core-kotlin-modules/core-kotlin-lang-2/src/test/kotlin/com/baeldung/arrayinitialization/ArrayInitializationTest.kt

@@ -1,4 +1,4 @@
-package com.baeldung.kotlin
+package com.baeldung.arrayinitialization
 
 import org.junit.Test
 import kotlin.test.assertEquals

core-kotlin-modules/core-kotlin-lang-2/src/test/kotlin/com/baeldung/constant/ConstantUnitTest.kt

@@ -1,5 +1,5 @@
-import com.baeldung.kotlin.constant.TestKotlinConstantClass
-import com.baeldung.kotlin.constant.TestKotlinConstantObject
+package com.baeldung.constant
+
 import org.junit.jupiter.api.Test
 import kotlin.test.assertEquals
 

core-kotlin-modules/core-kotlin-lang-2/src/test/kotlin/com/baeldung/constant/TestKotlinConstantClass.kt

@@ -1,4 +1,4 @@
-package com.baeldung.kotlin.constant
+package com.baeldung.constant
 
 
 class TestKotlinConstantClass {

core-kotlin-modules/core-kotlin-lang-2/src/test/kotlin/com/baeldung/constant/TestKotlinConstantObject.kt

@@ -1,4 +1,4 @@
-package com.baeldung.kotlin.constant
+package com.baeldung.constant
 
 
 object TestKotlinConstantObject {

core-kotlin-modules/core-kotlin-lang-2/src/test/kotlin/com/baeldung/infixfunctions/InfixFunctionsTest.kt

@@ -1,4 +1,4 @@
-package com.baeldung.kotlin
+package com.baeldung.infixfunctions
 
 import org.junit.Assert
 import org.junit.Test

core-kotlin-modules/core-kotlin-lang-2/src/test/kotlin/com/baeldung/lambda/LambdaTest.kt

@@ -6,6 +6,7 @@ import org.junit.jupiter.api.Test
 import kotlin.test.assertEquals
 
 class LambdaTest {
+
     @Test
     fun whenCallingALambda_thenPerformTheAction() {
         assertEquals(9, inferredType(3))

core-kotlin-modules/core-kotlin-lang-2/src/test/kotlin/com/baeldung/lazy/LazyUnitTest.kt

@@ -1,4 +1,4 @@
-package com.baeldung.kotlin
+package com.baeldung.lazy
 
 import org.junit.Test
 import java.util.concurrent.CountDownLatch

core-kotlin-modules/core-kotlin-lang-2/src/test/kotlin/com/baeldung/nullsafety/NullSafetyTest.kt

@@ -1,4 +1,4 @@
-package com.baeldung.kotlin
+package com.baeldung.nullsafety
 
 import org.junit.Test
 import kotlin.test.assertEquals
@@ -8,6 +8,7 @@ import kotlin.test.assertTrue
 
 
 class NullSafetyTest {
+
     @Test
     fun givenNonNullableField_whenAssignValueToIt_thenNotNeedToCheckAgainstNull() {
         //given

core-kotlin-modules/core-kotlin-lang-2/src/test/kotlin/com/baeldung/structuraljump/StructuralJumpUnitTest.kt

@@ -1,4 +1,4 @@
-package com.baeldung.kotlin
+package com.baeldung.structuraljump
 
 import org.junit.Test
 import kotlin.test.assertEquals

core-kotlin-modules/core-kotlin-lang/README.md

@@ -0,0 +1,16 @@
+## Core Kotlin Lang
+
+This module contains articles about core features in the Kotlin language.
+
+### Relevant articles:
+- [Guide to the “when{}” Block in Kotlin](https://www.baeldung.com/kotlin-when)
+- [Difference Between “==” and “===” Operators in Kotlin](https://www.baeldung.com/kotlin-equality-operators)
+- [Nested forEach in Kotlin](https://www.baeldung.com/kotlin-nested-foreach)
+- [Destructuring Declarations in Kotlin](https://www.baeldung.com/kotlin-destructuring-declarations)
+- [Try-with-resources in Kotlin](https://www.baeldung.com/kotlin-try-with-resources)
+- [Operator Overloading in Kotlin](https://www.baeldung.com/kotlin-operator-overloading)
+- [Inline Functions in Kotlin](https://www.baeldung.com/kotlin-inline-functions)
+- [Void Type in Kotlin](https://www.baeldung.com/kotlin-void-type)
+- [How to use Kotlin Range Expressions](https://www.baeldung.com/kotlin-ranges)
+- [Creating a Kotlin Range Iterator on a Custom Object](https://www.baeldung.com/kotlin-custom-range-iterator)
+- [[More --> ]](/core-kotlin-modules/core-kotlin-lang-2)

core-kotlin-modules/core-kotlin-lang/pom.xml

@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>core-kotlin-lang</artifactId>
+    <name>core-kotlin-lang</name>
+    <packaging>jar</packaging>
+
+    <parent>
+        <groupId>com.baeldung.core-kotlin-modules</groupId>
+        <artifactId>core-kotlin-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+</project>

core-kotlin-modules/core-kotlin-lang/src/main/kotlin/com/baeldung/destructuringdeclarations/Sandbox.kt

@@ -1,7 +1,5 @@
 package com.baeldung.destructuringdeclarations
 
-import com.baeldung.destructuringdeclarations.Person
-
 fun main(args: Array<String>) {
 
         //2.1. Objects

core-kotlin-modules/core-kotlin-lang/src/main/kotlin/com/baeldung/equalityoperators/User.kt

@@ -1,3 +1,3 @@
-package com.baeldung.kotlin
+package com.baeldung.equalityoperators
 
 data class User(val name: String, val age: Int, val hobbies: List<String>)

core-kotlin-modules/core-kotlin-lang/src/main/kotlin/com/baeldung/inline/Inline.kt

@@ -1,4 +1,4 @@
-package com.baeldung.functions
+package com.baeldung.inline
 
 import kotlin.random.Random
 

core-kotlin-modules/core-kotlin-lang/src/main/kotlin/com/baeldung/rangeiterator/CustomColor.kt

@@ -1,4 +1,4 @@
-package com.baeldung.range
+package com.baeldung.rangeiterator
 
 import java.lang.IllegalStateException
 
@@ -8,7 +8,7 @@ class CustomColor(val rgb: Int): Comparable<CustomColor> {
         return this.rgb.compareTo(other.rgb)
     }
 
-    operator fun rangeTo(that: CustomColor) = ColorRange(this,that)
+    operator fun rangeTo(that: CustomColor) = ColorRange(this, that)
 
     operator fun inc(): CustomColor {
         return CustomColor(rgb + 1)
@@ -25,7 +25,7 @@ class CustomColor(val rgb: Int): Comparable<CustomColor> {
     }
 }
 class ColorRange(override val start: CustomColor,
-                override val endInclusive: CustomColor) : ClosedRange<CustomColor>, Iterable<CustomColor>{
+                 override val endInclusive: CustomColor) : ClosedRange<CustomColor>, Iterable<CustomColor>{
 
     override fun iterator(): Iterator<CustomColor> {
         return ColorIterator(start, endInclusive)

core-kotlin-modules/core-kotlin-lang/src/main/kotlin/com/baeldung/whenblock/WhenBlockTypes.kt

@@ -1,4 +1,4 @@
-package com.baeldung.kotlin
+package com.baeldung.whenblock
 
 enum class UnixFileType {
     D, HYPHEN_MINUS, L

core-kotlin-modules/core-kotlin-lang/src/test/kotlin/com/baeldung/equalityoperators/EqualityTest.kt

@@ -1,4 +1,4 @@
-package com.baeldung.kotlin
+package com.baeldung.equalityoperators
 
 import org.junit.Test
 import kotlin.test.assertFalse

core-kotlin-modules/core-kotlin-lang/src/test/kotlin/com/baeldung/rangeiterator/CustomColorTest.kt

@@ -1,4 +1,4 @@
-package com.baeldung.range
+package com.baeldung.rangeiterator
 
 import org.junit.Test
 import java.lang.IllegalStateException

core-kotlin-modules/core-kotlin-lang/src/test/kotlin/com/baeldung/trywithresource/UseTest.kt

@@ -1,4 +1,4 @@
-package com.baeldung.kotlin
+package com.baeldung.trywithresource
 
 import org.junit.Test
 import java.beans.ExceptionListener

core-kotlin-modules/core-kotlin-lang/src/test/kotlin/com/baeldung/whenblock/WhenBlockUnitTest.kt

@@ -1,4 +1,4 @@
-package com.baeldung.kotlin
+package com.baeldung.whenblock
 
 import org.junit.Assert.assertEquals
 import org.junit.Assert.assertTrue

core-kotlin-modules/pom.xml

@@ -17,6 +17,8 @@
     <modules>
         <module>core-kotlin-annotations</module>
         <module>core-kotlin-io</module>
+        <module>core-kotlin-lang</module>
+        <module>core-kotlin-lang-2</module>
         <module>core-kotlin-strings</module>
     </modules>
 

core-kotlin/README.md

@@ -5,14 +5,9 @@ This module contains articles about core Kotlin.
 ### Relevant articles:
 
 - [Introduction to the Kotlin Language](https://www.baeldung.com/kotlin)
-- [Guide to the “when{}” Block in Kotlin](https://www.baeldung.com/kotlin-when)
-- [Comprehensive Guide to Null Safety in Kotlin](https://www.baeldung.com/kotlin-null-safety)
 - [Kotlin Java Interoperability](https://www.baeldung.com/kotlin-java-interoperability)
-- [Difference Between “==” and “===” operators in Kotlin](https://www.baeldung.com/kotlin-equality-operators)
 - [Generics in Kotlin](https://www.baeldung.com/kotlin-generics)
 - [Introduction to Kotlin Coroutines](https://www.baeldung.com/kotlin-coroutines)
-- [Destructuring Declarations in Kotlin](https://www.baeldung.com/kotlin-destructuring-declarations)
-- [Lazy Initialization in Kotlin](https://www.baeldung.com/kotlin-lazy-initialization)
 - [Overview of Kotlin Collections API](https://www.baeldung.com/kotlin-collections-api)
 - [Converting a List to Map in Kotlin](https://www.baeldung.com/kotlin-list-to-map)
 - [Data Classes in Kotlin](https://www.baeldung.com/kotlin-data-classes)
@@ -20,12 +15,9 @@ This module contains articles about core Kotlin.
 - [Sealed Classes in Kotlin](https://www.baeldung.com/kotlin-sealed-classes)
 - [JUnit 5 for Kotlin Developers](https://www.baeldung.com/junit-5-kotlin)
 - [Extension Methods in Kotlin](https://www.baeldung.com/kotlin-extension-methods)
-- [Infix Functions in Kotlin](https://www.baeldung.com/kotlin-infix-functions)
-- [Try-with-resources in Kotlin](https://www.baeldung.com/kotlin-try-with-resources)
 - [Regular Expressions in Kotlin](https://www.baeldung.com/kotlin-regular-expressions)
 - [Objects in Kotlin](https://www.baeldung.com/kotlin-objects)
 - [Filtering Kotlin Collections](https://www.baeldung.com/kotlin-filter-collection)
-- [Lambda Expressions in Kotlin](https://www.baeldung.com/kotlin-lambda-expressions)
 - [Working with Enums in Kotlin](https://www.baeldung.com/kotlin-enum)
 - [Create a Java and Kotlin Project with Maven](https://www.baeldung.com/kotlin-maven-java-project)
 - [Reflection with Kotlin](https://www.baeldung.com/kotlin-reflection)
@@ -37,21 +29,15 @@ This module contains articles about core Kotlin.
 - [Fuel HTTP Library with Kotlin](https://www.baeldung.com/kotlin-fuel)
 - [Introduction to Kovenant Library for Kotlin](https://www.baeldung.com/kotlin-kovenant)
 - [Converting Kotlin Data Class from JSON using GSON](https://www.baeldung.com/kotlin-json-convert-data-class)
-- [Kotlin return, break, continue Keywords](https://www.baeldung.com/kotlin-return-break-continue)
 - [Mapping of Data Objects in Kotlin](https://www.baeldung.com/kotlin-data-objects)
-- [Initializing Arrays in Kotlin](https://www.baeldung.com/kotlin-initialize-array)
 - [Threads vs Coroutines in Kotlin](https://www.baeldung.com/kotlin-threads-coroutines)
 - [Guide to Kotlin Interfaces](https://www.baeldung.com/kotlin-interfaces)
 - [Guide to Sorting in Kotlin](https://www.baeldung.com/kotlin-sort)
 - [Dependency Injection for Kotlin with Injekt](https://www.baeldung.com/kotlin-dependency-injection-with-injekt)
 - [Implementing a Binary Tree in Kotlin](https://www.baeldung.com/kotlin-binary-tree)
 - [Kotlin Contracts](https://www.baeldung.com/kotlin-contracts)
-- [Operator Overloading in Kotlin](https://www.baeldung.com/kotlin-operator-overloading)
 - [Inline Classes in Kotlin](https://www.baeldung.com/kotlin-inline-classes)
-- [Creating Java static final Equivalents in Kotlin](https://www.baeldung.com/kotlin-java-static-final)
-- [Nested forEach in Kotlin](https://www.baeldung.com/kotlin-nested-foreach)
 - [Building DSLs in Kotlin](https://www.baeldung.com/kotlin-dsl)
 - [Static Methods Behavior in Kotlin](https://www.baeldung.com/kotlin-static-methods)
-- [Inline Functions in Kotlin](https://www.baeldung.com/kotlin-inline-functions)
 - [Delegation Pattern in Kotlin](https://www.baeldung.com/kotlin-delegation-pattern)
 - More articles: [[next -->]](/core-kotlin-2)

custom-pmd/pom.xml

@@ -2,7 +2,7 @@
 <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">
     <modelVersion>4.0.0</modelVersion>
-    <groupId>org.baeldung.pmd</groupId>
+    <groupId>com.baeldung.pmd</groupId>
     <artifactId>custom-pmd</artifactId>
     <version>0.0.1</version>
     <name>custom-pmd</name>

custom-pmd/src/main/java/com/baeldung/pmd/UnitTestNamingConventionRule.java

@@ -1,4 +1,4 @@
-package org.baeldung.pmd;
+package com.baeldung.pmd;
 
 import net.sourceforge.pmd.lang.java.ast.ASTClassOrInterfaceDeclaration;
 import net.sourceforge.pmd.lang.java.rule.AbstractJavaRule;

grpc/src/main/java/com/baeldung/grpc/client/GrpcClient.java

@@ -1,8 +1,8 @@
-package org.baeldung.grpc.client;
+package com.baeldung.grpc.client;
 
-import org.baeldung.grpc.HelloRequest;
-import org.baeldung.grpc.HelloResponse;
-import org.baeldung.grpc.HelloServiceGrpc;
+import com.baeldung.grpc.HelloRequest;
+import com.baeldung.grpc.HelloResponse;
+import com.baeldung.grpc.HelloServiceGrpc;
 
 import io.grpc.ManagedChannel;
 import io.grpc.ManagedChannelBuilder;

grpc/src/main/java/com/baeldung/grpc/server/GrpcServer.java

@@ -1,4 +1,4 @@
-package org.baeldung.grpc.server;
+package com.baeldung.grpc.server;
 
 import java.io.IOException;
 

grpc/src/main/java/com/baeldung/grpc/server/HelloServiceImpl.java

@@ -1,8 +1,8 @@
-package org.baeldung.grpc.server;
+package com.baeldung.grpc.server;
 
-import org.baeldung.grpc.HelloRequest;
-import org.baeldung.grpc.HelloResponse;
-import org.baeldung.grpc.HelloServiceGrpc.HelloServiceImplBase;
+import com.baeldung.grpc.HelloRequest;
+import com.baeldung.grpc.HelloResponse;
+import com.baeldung.grpc.HelloServiceGrpc.HelloServiceImplBase;
 
 import io.grpc.stub.StreamObserver;
 

grpc/src/main/proto/HelloService.proto

@@ -1,6 +1,6 @@
 syntax = "proto3";
 option java_multiple_files = true;
-package org.baeldung.grpc;
+package com.baeldung.grpc;
 
 message HelloRequest {
     string firstName = 1;

guava-collections-set/src/test/java/com/baeldung/guava/GuavaMapFromSet.java

@@ -1,4 +1,4 @@
-package org.baeldung.guava;
+package com.baeldung.guava;
 
 import com.google.common.base.Function;
 

guava-collections-set/src/test/java/com/baeldung/guava/GuavaMapFromSetUnitTest.java

@@ -1,4 +1,4 @@
-package org.baeldung.guava;
+package com.baeldung.guava;
 
 import com.google.common.base.Function;
 import org.junit.Test;

guava-collections-set/src/test/java/com/baeldung/guava/GuavaMultiSetUnitTest.java

@@ -1,4 +1,4 @@
-package org.baeldung.guava;
+package com.baeldung.guava;
 
 import com.google.common.collect.HashMultiset;
 import com.google.common.collect.Multiset;

guava-collections-set/src/test/java/com/baeldung/guava/GuavaRangeSetUnitTest.java

@@ -1,4 +1,4 @@
-package org.baeldung.guava;
+package com.baeldung.guava;
 
 import com.google.common.collect.ImmutableRangeSet;
 import com.google.common.collect.Range;

guava-collections-set/src/test/java/com/baeldung/guava/GuavaSetOperationsUnitTest.java

@@ -1,4 +1,4 @@
-package org.baeldung.guava;
+package com.baeldung.guava;
 
 import com.google.common.base.Function;
 import com.google.common.base.Joiner;

guava-io/src/main/test/java/com/baeldung/guava/GuavaCountingOutputStreamUnitTest.java

@@ -1,4 +1,4 @@
-package org.baeldung.guava;
+package com.baeldung.guava;
 
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;

guava-io/src/main/test/java/com/baeldung/guava/GuavaIOUnitTest.java

@@ -1,4 +1,4 @@
-package org.baeldung.guava;
+package com.baeldung.guava;
 
 import static org.hamcrest.Matchers.contains;
 import static org.junit.Assert.assertEquals;

libraries-io/src/test/java/com/baeldung/java/io/remote/SftpFileTransferLiveTest.java

@@ -1,4 +1,4 @@
-package org.baeldung.java.io.remote;
+package com.baeldung.java.io.remote;
 
 import java.io.IOException;
 

maven-all/maven/custom-rule/src/main/java/com/baeldung/enforcer/MyCustomRule.java

@@ -19,8 +19,8 @@ public class MyCustomRule implements EnforcerRule {
 
             String groupId = (String) enforcerRuleHelper.evaluate("${project.groupId}");
 
-            if (groupId == null || !groupId.startsWith("org.baeldung")) {
-                throw new EnforcerRuleException("Project group id does not start with org.baeldung");
+            if (groupId == null || !groupId.startsWith("com.baeldung")) {
+                throw new EnforcerRuleException("Project group id does not start with com.baeldung");
             }
 
         }

spring-boot-data/pom.xml

@@ -97,8 +97,8 @@
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-compiler-plugin</artifactId>
                 <configuration>
-                    <source>8</source>
-                    <target>8</target>
+                    <source>${source.version}</source>
+                    <target>${target.version}</target>
                 </configuration>
             </plugin>
         </plugins>
@@ -121,8 +121,8 @@
                         <groupId>org.apache.maven.plugins</groupId>
                         <artifactId>maven-compiler-plugin</artifactId>
                         <configuration>
-                            <source>8</source>
-                            <target>8</target>
+                            <source>${source.version}</source>
+                            <target>${target.version}</target>
                         </configuration>
                     </plugin>
                     <plugin>
@@ -156,8 +156,8 @@
                         <groupId>org.apache.maven.plugins</groupId>
                         <artifactId>maven-compiler-plugin</artifactId>
                         <configuration>
-                            <source>1.8</source>
-                            <target>1.8</target>
+                            <source>${source.version}</source>
+                            <target>${target.version}</target>
                         </configuration>
                     </plugin>
                 </plugins>
@@ -168,6 +168,8 @@
     <properties>
         <javers.version>5.6.3</javers.version>
         <git-commit-id-plugin.version>2.2.4</git-commit-id-plugin.version>
+        <source.version>1.8</source.version>
+        <target.version>1.8</target.version>
     </properties>
     
 </project>

spring-boot-parent/spring-boot-with-starter-parent/pom.xml

@@ -20,7 +20,7 @@
             <dependency>
                 <groupId>org.springframework.boot</groupId>
                 <artifactId>spring-boot-starter-data-jpa</artifactId>
-                <version>2.1.1.RELEASE</version>
+                <version>${spring-boot.version}</version>
             </dependency>
         </dependencies>
     </dependencyManagement>
@@ -38,6 +38,7 @@
 
     <properties>
         <java.version>1.8</java.version>
+        <spring-boot.version>2.1.1.RELEASE</spring-boot.version>
         <junit.version>4.11</junit.version>
     </properties>
 

spring-boot-property-exp/property-exp-custom-config/pom.xml

@@ -52,7 +52,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-resources-plugin</artifactId>
-                <version>2.7</version>
+                <version>${apache-maven.version}</version>
                 <configuration>
                     <delimiters>
                         <delimiter>@</delimiter>
@@ -63,7 +63,7 @@
             <plugin>
                 <groupId>org.codehaus.mojo</groupId>
                 <artifactId>exec-maven-plugin</artifactId>
-                <version>1.6.0</version>
+                <version>${exec-maven-plugin.version}</version>
                 <configuration>
                     <mainClass>com.baeldung.propertyexpansion.SpringBootPropertyExpansionApp</mainClass>
                 </configuration>
@@ -74,6 +74,8 @@
     <properties>
         <spring-boot.version>1.5.10.RELEASE</spring-boot.version>
         <custom.property>Custom Property Value</custom.property>
+        <apache-maven.version>2.7</apache-maven.version>
+        <exec-maven-plugin.version>1.6.0</exec-maven-plugin.version>
     </properties>
 
 </project>

spring-boot-testing/pom.xml

@@ -42,7 +42,7 @@
         <dependency>
             <groupId>it.ozimov</groupId>
             <artifactId>embedded-redis</artifactId>
-            <version>0.7.2</version>
+            <version>${redis.version}</version>
             <scope>test</scope>
         </dependency>
         <!-- Spock & Spring -->
@@ -131,6 +131,7 @@
         <git-commit-id-plugin.version>2.2.4</git-commit-id-plugin.version>
         <spock.version>1.2-groovy-2.4</spock.version>
         <gmavenplus-plugin.version>1.6</gmavenplus-plugin.version>
+        <redis.version>0.7.2</redis.version>
     </properties>
 
 </project>

spring-cloud/spring-cloud-aws/pom.xml

@@ -50,7 +50,7 @@
             <dependency>
                 <groupId>org.springframework.cloud</groupId>
                 <artifactId>spring-cloud-aws</artifactId>
-                <version>2.0.1.RELEASE</version>
+                <version>${spring-cloud}</version>
                 <type>pom</type>
                 <scope>import</scope>
             </dependency>
@@ -60,6 +60,7 @@
     <properties>
         <start-class>com.baeldung.spring.cloud.aws.SpringCloudAwsApplication</start-class>
         <spring-cloud.version>Dalston.SR4</spring-cloud.version>
+        <spring-cloud>2.0.1.RELEASE</spring-cloud>
     </properties>
     
 </project>

spring-cloud/spring-cloud-contract/spring-cloud-contract-producer/pom.xml

@@ -36,7 +36,7 @@
             <plugin>
                 <groupId>org.springframework.cloud</groupId>
                 <artifactId>spring-cloud-contract-maven-plugin</artifactId>
-                <version>2.1.1.RELEASE</version>
+                <version>${spring-cloud.version}</version>
                 <extensions>true</extensions>
                 <configuration>
                     <baseClassForTests>com.baeldung.spring.cloud.springcloudcontractproducer.BaseTestClass
@@ -45,4 +45,8 @@
             </plugin>
         </plugins>
     </build>
+
+    <properties>
+        <spring-cloud.version>2.1.1.RELEASE</spring-cloud.version>
+    </properties>
 </project>

spring-cloud/spring-cloud-functions/pom.xml

@@ -65,7 +65,7 @@
                     <dependency>
                         <groupId>org.springframework.boot.experimental</groupId>
                         <artifactId>spring-boot-thin-layout</artifactId>
-                        <version>1.0.10.RELEASE</version>
+                        <version>${spring-boot-thin.version}</version>
                     </dependency>
                 </dependencies>
             </plugin>
@@ -88,6 +88,7 @@
         <aws-lambda-events.version>2.0.2</aws-lambda-events.version>
         <aws-lambda-java-core.version>1.1.0</aws-lambda-java-core.version>
         <spring-boot.version>2.0.4.RELEASE</spring-boot.version>
+        <spring-boot-thin.version>1.0.10.RELEASE</spring-boot-thin.version>
     </properties>
 
 </project>

spring-cloud/spring-cloud-kubernetes/kubernetes-guide/travel-agency-service/pom.xml

@@ -24,7 +24,7 @@
             <dependency>
                 <groupId>ch.qos.logback</groupId>
                 <artifactId>logback-classic</artifactId>
-                <version>1.2.3</version>
+                <version>${logback.version}</version>
             </dependency>
         </dependencies>
     </dependencyManagement>
@@ -71,6 +71,7 @@
 
     <properties>
         <spring-cloud-dependencies.version>Finchley.SR2</spring-cloud-dependencies.version>
+        <logback.version>1.2.3</logback.version>
     </properties>
 
 </project>

spring-core-2/pom.xml

@@ -174,7 +174,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-war-plugin</artifactId>
-                <version>3.2.2</version>
+                <version>${maven.version}</version>
                 <configuration>
                     <failOnMissingWebXml>false</failOnMissingWebXml>
                 </configuration>
@@ -214,6 +214,7 @@
         <assertj.version>3.6.1</assertj.version>
         <shedlock.version>2.1.0</shedlock.version>
         <javassist.version>3.22.0-GA</javassist.version>
+        <maven.version>3.2.2</maven.version>
     </properties>
 
 </project>

spring-data-rest-querydsl/pom.xml

@@ -72,8 +72,8 @@
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-compiler-plugin</artifactId>
                 <configuration>
-                    <source>1.8</source>
-                    <target>1.8</target>
+                    <source>${maven.source}</source>
+                    <target>${maven.target}</target>
                     <compilerArgs>
                         <arg>-verbose</arg>
                         <arg>-parameters</arg>
@@ -83,7 +83,7 @@
             <plugin>
                 <groupId>com.mysema.maven</groupId>
                 <artifactId>apt-maven-plugin</artifactId>
-                <version>1.1.3</version>
+                <version>${mysema.version}</version>
                 <executions>
                     <execution>
                         <phase>generate-sources</phase>
@@ -99,5 +99,10 @@
             </plugin>
         </plugins>
     </build>
+    <properties>
+        <maven.source>1.8</maven.source>
+        <maven.target>1.8</maven.target>
+        <mysema.version>1.1.3</mysema.version>
+    </properties>
 
 </project>

spring-data-rest/pom.xml

@@ -66,7 +66,7 @@
             <plugin>
                 <groupId>com.mysema.maven</groupId>
                 <artifactId>maven-apt-plugin</artifactId>
-                <version>1.0</version>
+                <version>${maven.version}</version>
                 <executions>
                     <execution>
                         <phase>generate-sources</phase>
@@ -90,6 +90,7 @@
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <start-class>com.baeldung.books.SpringDataRestApplication</start-class>
+        <maven.version>1.0</maven.version>
     </properties>
 
 </project>