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