Merge branch 'master' of https://github.com/eugenp/tutorials

algorithms-miscellaneous-5/README.md

@@ -11,4 +11,5 @@ This module contains articles about algorithms. Some classes of algorithms, e.g.
 - [Knapsack Problem Implementation in Java](https://www.baeldung.com/java-knapsack)
 - [How to Determine if a Binary Tree is Balanced](https://www.baeldung.com/java-balanced-binary-tree)
 - [The Caesar Cipher in Java](https://www.baeldung.com/java-caesar-cipher)
+- [Overview of Combinatorial Problems in Java](https://www.baeldung.com/java-combinatorial-algorithms)
 - More articles: [[<-- prev]](/../algorithms-miscellaneous-4)

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));
+    }
+}

core-java-modules/core-java-11/src/test/java/com/baeldung/patternreuse/PatternJava11UnitTest.java

@@ -14,7 +14,7 @@ import static org.junit.Assert.assertTrue;
 public class PatternJava11UnitTest {
 
     @Test
-    public void givenPreCompiledPattern_whenCallAsMatchPredicate_thenReturnMatchPredicateToMatchesThePatternInTheListElements() {
+    public void givenPreCompiledPattern_whenCallAsMatchPredicate_thenReturnMatchPredicateToMatchesPattern() {
         List<String> namesToValidate = Arrays.asList("Fabio Silva", "Fabio Luis Silva");
         Pattern firstLastNamePreCompiledPattern = Pattern.compile("[a-zA-Z]{3,} [a-zA-Z]{3,}");
 

core-java-modules/core-java-date-operations/src/test/java/com/baeldung/jvmtimezone/ModifyDefaultTimezoneUnitTest.java

@@ -1,9 +1,8 @@
-package com.baeldung.timezone;
+package com.baeldung.jvmtimezone;
 
 import org.junit.Test;
 
 import java.util.Calendar;
-import java.util.Date;
 import java.util.TimeZone;
 
 import static org.junit.Assert.assertEquals;
@@ -13,9 +12,7 @@ public class ModifyDefaultTimezoneUnitTest {
     @Test
     public void givenDefaultTimezoneSet_thenDateTimezoneIsCorrect() {
         TimeZone.setDefault(TimeZone.getTimeZone("Portugal"));
-        Date date = new Date();
         Calendar calendar = Calendar.getInstance();
-        calendar.setTime(date);
         assertEquals(calendar.getTimeZone(), TimeZone.getTimeZone("Portugal"));
     }
 

core-java-modules/core-java-date-operations/src/test/java/com/baeldung/jvmtimezone/ModifyTimezonePropertyUnitTest.java

@@ -1,4 +1,4 @@
-package com.baeldung.timezone;
+package com.baeldung.jvmtimezone;
 
 import org.junit.After;
 import org.junit.Before;
@@ -14,7 +14,7 @@ public class ModifyTimezonePropertyUnitTest {
 
     @Before
     public void setup() {
-        System.setProperty("user.timezone", "IST");
+        System.setProperty("user.timezone", "Asia/Kolkata");
         TimeZone.setDefault(null);
     }
 
@@ -25,10 +25,8 @@ public class ModifyTimezonePropertyUnitTest {
 
     @Test
     public void givenTimezonePropertySet_thenDateTimezoneIsCorrect() {
-        Date date = new Date();
         Calendar calendar = Calendar.getInstance();
-        calendar.setTime(date);
-        assertEquals(calendar.getTimeZone(), TimeZone.getTimeZone("IST"));
+        assertEquals(calendar.getTimeZone(), TimeZone.getTimeZone("Asia/Kolkata"));
     }
 
 }

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-java-modules/core-java-lang-operators/README.md

@@ -11,4 +11,5 @@ This module contains articles about Java operators
 - [Java Compound Operators](https://www.baeldung.com/java-compound-operators)
 - [The XOR Operator in Java](https://www.baeldung.com/java-xor-operator)
 - [Java Bitwise Operators](https://www.baeldung.com/java-bitwise-operators)
+- [Bitwise & vs Logical && Operators](https://www.baeldung.com/bitwise-vs-logical-operators/)
 

core-java-modules/core-java-lang-operators/src/test/java/com/baeldung/andoperators/BitwiseAndLogicalANDOperatorsUnitTest.java

@@ -0,0 +1,71 @@
+package com.baeldung.andoperators;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.Assert.*;
+
+public class BitwiseAndLogicalANDOperatorsUnitTest {
+
+    @Test
+    public void givenTwoTrueBooleans_whenBitwiseAndOperator_thenTrue() {
+        boolean trueBool = true;
+        boolean anotherTrueBool = true;
+        boolean trueANDTrue = trueBool & anotherTrueBool;
+        assertTrue(trueANDTrue);
+    }
+
+    @Test
+    public void givenOneFalseAndOneTrueBooleans_whenBitwiseAndOperator_thenFalse() {
+        boolean trueBool = true;
+        boolean falseBool = false;
+        boolean trueANDFalse = trueBool & falseBool;
+        assertFalse(trueANDFalse);
+    }
+
+    @Test
+    public void givenTwoFalseBooleans_whenBitwiseAndOperator_thenFalse() {
+        boolean falseBool = false;
+        boolean anotherFalseBool = false;
+        boolean falseANDFalse = falseBool & anotherFalseBool;
+        assertFalse(falseANDFalse);
+    }
+
+    @Test
+    public void givenTwoIntegers_whenBitwiseAndOperator_thenNewDecimalNumber() {
+        int six = 6;
+        int five = 5;
+        int shouldBeFour = six & five;
+        assertEquals(4, shouldBeFour);
+    }
+
+    @Test
+    public void givenTwoTrueBooleans_whenLogicalAndOperator_thenTrue() {
+        boolean trueBool = true;
+        boolean anotherTrueBool = true;
+        boolean trueANDTrue = trueBool && anotherTrueBool;
+        assertTrue(trueANDTrue);
+    }
+
+    @Test
+    public void givenOneFalseAndOneTrueBooleans_whenLogicalAndOperator_thenFalse() {
+        boolean trueBool = true;
+        boolean falseBool = false;
+        boolean trueANDFalse = trueBool && falseBool;
+        assertFalse(trueANDFalse);
+    }
+
+    @Test
+    public void givenTwoFalseBooleans_whenLogicalAndOperator_thenFalse() {
+        boolean falseBool = false;
+        boolean anotherFalseBool = false;
+        boolean falseANDFalse = falseBool && anotherFalseBool;
+        assertFalse(falseANDFalse);
+    }
+
+    @Test
+    public void givenTwoFalseExpressions_whenLogicalAndOperator_thenShortCircuitFalse() {
+        boolean shortCircuitResult = (2<1) && (4<5);
+        assertFalse(shortCircuitResult);
+    }
+
+}

core-java-modules/core-java-lang-syntax-2/src/main/java/com/baeldung/core/operators/notoperator/NotOperator.java

@@ -0,0 +1,99 @@
+package com.baeldung.core.operators.notoperator;
+
+/**
+ * Examples used in the article `Using the Not Operator in If Conditions in Java`.
+ */
+public class NotOperator {
+
+    public static void ifElseStatementExample() {
+        boolean isValid = true;
+
+        if (isValid) {
+            System.out.println("Valid");
+        } else {
+            System.out.println("Invalid");
+        }
+    }
+
+    public static void checkIsValidIsFalseWithEmptyIfBlock() {
+        boolean isValid = true;
+
+        if (isValid) {
+
+        } else {
+            System.out.println("Invalid");
+        }
+    }
+
+    public static void checkIsValidIsFalseWithJustTheIfBlock() {
+        boolean isValid = true;
+
+        if (isValid == false) {
+            System.out.println("Invalid");
+        }
+    }
+
+    public static void checkIsValidIsFalseWithTheNotOperator() {
+        boolean isValid = true;
+
+        if (!isValid) {
+            System.out.println("Invalid");
+        }
+    }
+
+    public static void notOperatorWithBooleanValueAsOperand() {
+        System.out.println(!true);   // prints false
+        System.out.println(!false);  // prints true
+        System.out.println(!!false); // prints false
+    }
+
+    public static void applyNotOperatorToAnExpression_example1() {
+        int count = 2;
+
+        System.out.println(!(count > 2));  // prints true
+        System.out.println(!(count <= 2)); // prints false
+    }
+
+    public static void applyNotOperatorToAnExpression_LogicalOperators() {
+        boolean x = true;
+        boolean y = false;
+
+        System.out.println(!(x && y));  // prints true
+        System.out.println(!(x || y));  // prints false
+    }
+
+    public static void precedence_example() {
+        boolean x = true;
+        boolean y = false;
+
+        System.out.println(!x && y);   // prints false
+        System.out.println(!(x && y)); // prints true
+    }
+
+    public static void pitfalls_ComplexConditionsExample() {
+        int count = 9;
+        int total = 100;
+
+        if (!(count >= 10 || total >= 1000)) {
+            System.out.println("Some more work to do");
+        }
+    }
+
+    public static void pitfalls_simplifyComplexConditionsByReversingLogicExample() {
+        int count = 9;
+        int total = 100;
+
+        if (count < 10 && total < 1000) {
+            System.out.println("Some more work to do");
+        }
+    }
+
+    public static void exitEarlyExample() {
+        boolean isValid = false;
+
+        if(!isValid) {
+            throw new IllegalArgumentException("Invalid input");
+        }
+        // Code to execute when isValid == true goes here
+    }
+}

core-java-modules/core-java-strings/src/test/java/com/baeldung/randomstrings/RandomStringsUnitTest.java

@@ -1,72 +1,103 @@
-package com.baeldung.randomstrings;
-
-import org.apache.commons.lang3.RandomStringUtils;
-import org.junit.Test;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-import java.nio.charset.Charset;
-import java.util.Random;
-
-public class RandomStringsUnitTest {
-
-    private static final Logger LOG = LoggerFactory.getLogger(RandomStringsUnitTest.class);
-
-    @Test
-    public void givenUsingPlainJava_whenGeneratingRandomStringUnbounded_thenCorrect() {
-        final byte[] array = new byte[7]; // length is bounded by 7
-        new Random().nextBytes(array);
-        final String generatedString = new String(array, Charset.forName("UTF-8"));
-
-        LOG.debug(generatedString);
-    }
-
-    @Test
-    public void givenUsingPlainJava_whenGeneratingRandomStringBounded_thenCorrect() {
-        final int leftLimit = 97; // letter 'a'
-        final int rightLimit = 122; // letter 'z'
-        final int targetStringLength = 10;
-        final Random random = new Random();
-        final StringBuilder buffer = new StringBuilder(targetStringLength);
-
-        for (int i = 0; i < targetStringLength; i++) {
-            final int randomLimitedInt = leftLimit + (int) (random.nextFloat() * (rightLimit - leftLimit + 1));
-            buffer.append((char) randomLimitedInt);
-        }
-        final String generatedString = buffer.toString();
-
-        LOG.debug(generatedString);
-    }
-
-    @Test
-    public void givenUsingApache_whenGeneratingRandomString_thenCorrect() {
-        final String generatedString = RandomStringUtils.random(10);
-
-        LOG.debug(generatedString);
-    }
-
-    @Test
-    public void givenUsingApache_whenGeneratingRandomAlphabeticString_thenCorrect() {
-        final String generatedString = RandomStringUtils.randomAlphabetic(10);
-
-        LOG.debug(generatedString);
-    }
-
-    @Test
-    public void givenUsingApache_whenGeneratingRandomAlphanumericString_thenCorrect() {
-        final String generatedString = RandomStringUtils.randomAlphanumeric(10);
-
-        LOG.debug(generatedString);
-    }
-
-    @Test
-    public void givenUsingApache_whenGeneratingRandomStringBounded_thenCorrect() {
-        final int length = 10;
-        final boolean useLetters = true;
-        final boolean useNumbers = false;
-        final String generatedString = RandomStringUtils.random(length, useLetters, useNumbers);
-
-        LOG.debug(generatedString);
-    }
-
-}
+package com.baeldung.randomstrings;
+
+import org.apache.commons.lang3.RandomStringUtils;
+import org.junit.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.nio.charset.Charset;
+import java.util.Random;
+
+public class RandomStringsUnitTest {
+
+    private static final Logger LOG = LoggerFactory.getLogger(RandomStringsUnitTest.class);
+
+    @Test
+    public void givenUsingPlainJava_whenGeneratingRandomStringUnbounded_thenCorrect() {
+        byte[] array = new byte[7]; // length is bounded by 7
+        new Random().nextBytes(array);
+        String generatedString = new String(array, Charset.forName("UTF-8"));
+
+        LOG.debug(generatedString);
+    }
+
+    @Test
+    public void givenUsingPlainJava_whenGeneratingRandomStringBounded_thenCorrect() {
+        int leftLimit = 97; // letter 'a'
+        int rightLimit = 122; // letter 'z'
+        int targetStringLength = 10;
+        Random random = new Random();
+        StringBuilder buffer = new StringBuilder(targetStringLength);
+
+        for (int i = 0; i < targetStringLength; i++) {
+            int randomLimitedInt = leftLimit + (int) (random.nextFloat() * (rightLimit - leftLimit + 1));
+            buffer.append((char) randomLimitedInt);
+        }
+        String generatedString = buffer.toString();
+
+        LOG.debug(generatedString);
+    }
+
+    @Test
+    public void givenUsingJava8_whenGeneratingRandomAlphabeticString_thenCorrect() {
+        int leftLimit = 97; // letter 'a'
+        int rightLimit = 122; // letter 'z'
+        int targetStringLength = 10;
+        Random random = new Random();
+
+        String generatedString = random.ints(leftLimit, rightLimit + 1)
+            .limit(targetStringLength)
+            .collect(StringBuilder::new, StringBuilder::appendCodePoint, StringBuilder::append)
+            .toString();
+
+        LOG.debug(generatedString);
+    }
+
+    @Test
+    public void givenUsingJava8_whenGeneratingRandomAlphanumericString_thenCorrect() {
+        int leftLimit = 48; // numeral '0'
+        int rightLimit = 122; // letter 'z'
+        int targetStringLength = 10;
+        Random random = new Random();
+
+        String generatedString = random.ints(leftLimit, rightLimit + 1)
+            .filter(i -> (i <= 57 || i >= 65) && (i <= 90 || i >= 97))
+            .limit(targetStringLength)
+            .collect(StringBuilder::new, StringBuilder::appendCodePoint, StringBuilder::append)
+            .toString();
+
+        LOG.debug(generatedString);
+    }
+
+    @Test
+    public void givenUsingApache_whenGeneratingRandomString_thenCorrect() {
+        String generatedString = RandomStringUtils.random(10);
+
+        LOG.debug(generatedString);
+    }
+
+    @Test
+    public void givenUsingApache_whenGeneratingRandomAlphabeticString_thenCorrect() {
+        String generatedString = RandomStringUtils.randomAlphabetic(10);
+
+        LOG.debug(generatedString);
+    }
+
+    @Test
+    public void givenUsingApache_whenGeneratingRandomAlphanumericString_thenCorrect() {
+        String generatedString = RandomStringUtils.randomAlphanumeric(10);
+
+        LOG.debug(generatedString);
+    }
+
+    @Test
+    public void givenUsingApache_whenGeneratingRandomStringBounded_thenCorrect() {
+        int length = 10;
+        boolean useLetters = true;
+        boolean useNumbers = false;
+        String generatedString = RandomStringUtils.random(length, useLetters, useNumbers);
+
+        LOG.debug(generatedString);
+    }
+
+}

core-java-modules/core-java-text/src/test/java/com/baeldung/patternreuse/PatternUnitTest.java

@@ -30,7 +30,7 @@ public class PatternUnitTest {
     }
 
     @Test
-    public void givenPreCompiledPattern_whenCallAsPredicate_thenReturnPredicateToFindThePatternInTheListElements() {
+    public void givenPreCompiledPattern_whenCallAsPredicate_thenReturnPredicateToFindPatternInTheList() {
         List<String> namesToValidate = Arrays.asList("Fabio Silva", "Mr. Silva");
         Predicate<String> patternsAsPredicate = FIRST_LAST_NAME_PRE_COMPILED_PATTERN.asPredicate();
 
@@ -52,7 +52,7 @@ public class PatternUnitTest {
     }
 
     @Test
-    public void givenPreCompiledPattern_whenCallSplitAsStream_thenReturnArrayWithValuesSplitByThePattern() {
+    public void givenPreCompiledPattern_whenCallSplitAsStream_thenReturnArraySplitByThePattern() {
         Stream<String> textSplitAsStream = SPLIT_PRE_COMPILED_PATTERN.splitAsStream("My_Name__is__Fabio_Silva");
         String[] textSplit = textSplitAsStream.toArray(String[]::new);
 

jackson-modules/jackson-annotations/pom.xml

@@ -8,22 +8,11 @@
 
     <parent>
         <groupId>com.baeldung</groupId>
-        <artifactId>parent-java</artifactId>
+        <artifactId>jackson-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../parent-java</relativePath>
     </parent>
 
     <dependencies>
-        <dependency>
-            <groupId>com.fasterxml.jackson.core</groupId>
-            <artifactId>jackson-databind</artifactId>
-            <version>${jackson.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>com.fasterxml.jackson.dataformat</groupId>
-            <artifactId>jackson-dataformat-xml</artifactId>
-            <version>${jackson.version}</version>
-        </dependency>
         <dependency>
             <groupId>com.fasterxml.jackson.module</groupId>
             <artifactId>jackson-module-jsonSchema</artifactId>

jackson-modules/jackson-conversions-2/pom.xml

@@ -8,23 +8,11 @@
 
     <parent>
         <groupId>com.baeldung</groupId>
-        <artifactId>parent-java</artifactId>
+        <artifactId>jackson-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../parent-java</relativePath>
     </parent>
 
     <dependencies>
-        <dependency>
-            <groupId>com.fasterxml.jackson.core</groupId>
-            <artifactId>jackson-databind</artifactId>
-            <version>${jackson.version}</version>
-        </dependency>
-        <!--jackson for xml -->
-        <dependency>
-            <groupId>com.fasterxml.jackson.dataformat</groupId>
-            <artifactId>jackson-dataformat-xml</artifactId>
-            <version>${jackson.version}</version>
-        </dependency>
         <!-- YAML -->
         <dependency>
             <groupId>com.fasterxml.jackson.dataformat</groupId>

jackson-modules/jackson-conversions/pom.xml

@@ -8,17 +8,11 @@
 
     <parent>
         <groupId>com.baeldung</groupId>
-        <artifactId>parent-java</artifactId>
+        <artifactId>jackson-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../parent-java</relativePath>
     </parent>
 
     <dependencies>
-        <dependency>
-            <groupId>com.fasterxml.jackson.core</groupId>
-            <artifactId>jackson-databind</artifactId>
-            <version>${jackson.version}</version>
-        </dependency>
         <dependency>
             <groupId>com.fasterxml.jackson.datatype</groupId>
             <artifactId>jackson-datatype-joda</artifactId>
@@ -29,12 +23,6 @@
             <artifactId>jackson-datatype-jsr310</artifactId>
             <version>${jackson.version}</version>
         </dependency>
-        <!--jackson for xml -->
-        <dependency>
-            <groupId>com.fasterxml.jackson.dataformat</groupId>
-            <artifactId>jackson-dataformat-xml</artifactId>
-            <version>${jackson.version}</version>
-        </dependency>
     </dependencies>
 
     <build>