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

core-java-modules/core-java-io/src/main/java/com/baeldung/files/Main.java

@@ -0,0 +1,24 @@
+package com.baeldung.files;
+
+import static com.baeldung.files.NumberOfLineFinder.getTotalNumberOfLinesUsingApacheCommonsIO;
+import static com.baeldung.files.NumberOfLineFinder.getTotalNumberOfLinesUsingBufferedReader;
+import static com.baeldung.files.NumberOfLineFinder.getTotalNumberOfLinesUsingGoogleGuava;
+import static com.baeldung.files.NumberOfLineFinder.getTotalNumberOfLinesUsingLineNumberReader;
+import static com.baeldung.files.NumberOfLineFinder.getTotalNumberOfLinesUsingNIOFileChannel;
+import static com.baeldung.files.NumberOfLineFinder.getTotalNumberOfLinesUsingNIOFiles;
+import static com.baeldung.files.NumberOfLineFinder.getTotalNumberOfLinesUsingScanner;
+
+public class Main {
+
+    private static final String INPUT_FILE_NAME = "src/main/resources/input.txt";
+
+    public static void main(String... args) throws Exception {
+        System.out.printf("Total Number of Lines Using BufferedReader: %s%n", getTotalNumberOfLinesUsingBufferedReader(INPUT_FILE_NAME));
+        System.out.printf("Total Number of Lines Using LineNumberReader: %s%n", getTotalNumberOfLinesUsingLineNumberReader(INPUT_FILE_NAME));
+        System.out.printf("Total Number of Lines Using Scanner: %s%n", getTotalNumberOfLinesUsingScanner(INPUT_FILE_NAME));
+        System.out.printf("Total Number of Lines Using NIO Files: %s%n", getTotalNumberOfLinesUsingNIOFiles(INPUT_FILE_NAME));
+        System.out.printf("Total Number of Lines Using NIO FileChannel: %s%n", getTotalNumberOfLinesUsingNIOFileChannel(INPUT_FILE_NAME));
+        System.out.printf("Total Number of Lines Using Apache Commons IO: %s%n", getTotalNumberOfLinesUsingApacheCommonsIO(INPUT_FILE_NAME));
+        System.out.printf("Total Number of Lines Using NIO Google Guava: %s%n", getTotalNumberOfLinesUsingGoogleGuava(INPUT_FILE_NAME));
+    }
+}

core-java-modules/core-java-io/src/main/java/com/baeldung/files/NumberOfLineFinder.java

@@ -0,0 +1,112 @@
+package com.baeldung.files;
+
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.FileReader;
+import java.io.IOException;
+import java.io.LineNumberReader;
+import java.nio.ByteBuffer;
+import java.nio.channels.FileChannel;
+import java.nio.channels.FileChannel.MapMode;
+import java.nio.charset.Charset;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.nio.file.StandardOpenOption;
+import java.util.List;
+import java.util.Scanner;
+import java.util.stream.Stream;
+
+import org.apache.commons.io.FileUtils;
+import org.apache.commons.io.LineIterator;
+
+public class NumberOfLineFinder {
+
+    public static int getTotalNumberOfLinesUsingBufferedReader(String fileName) {
+        int lines = 0;
+        try (BufferedReader reader = new BufferedReader(new FileReader(fileName))) {
+            while (reader.readLine() != null) {
+                lines++;
+            }
+        } catch (IOException ioe) {
+            ioe.printStackTrace();
+        }
+        return lines;
+    }
+
+    public static int getTotalNumberOfLinesUsingLineNumberReader(String fileName) {
+        int lines = 0;
+        try (LineNumberReader reader = new LineNumberReader(new FileReader(fileName))) {
+            reader.skip(Integer.MAX_VALUE);
+            lines = reader.getLineNumber() + 1;
+        } catch (IOException ioe) {
+            ioe.printStackTrace();
+        }
+        return lines;
+    }
+
+    public static int getTotalNumberOfLinesUsingScanner(String fileName) {
+        int lines = 0;
+        try (Scanner scanner = new Scanner(new FileReader(fileName))) {
+            while (scanner.hasNextLine()) {
+                scanner.nextLine();
+                lines++;
+            }
+        } catch (IOException ioe) {
+            ioe.printStackTrace();
+        }
+        return lines;
+    }
+
+    public static int getTotalNumberOfLinesUsingNIOFiles(String fileName) {
+        int lines = 0;
+        try (Stream<String> fileStream = Files.lines(Paths.get(fileName))) {
+            lines = (int) fileStream.count();
+        } catch (IOException ioe) {
+            ioe.printStackTrace();
+        }
+        return lines;
+    }
+
+    public static int getTotalNumberOfLinesUsingNIOFileChannel(String fileName) {
+        int lines = 1;
+        try (FileChannel channel = FileChannel.open(Paths.get(fileName), StandardOpenOption.READ)) {
+            ByteBuffer byteBuffer = channel.map(MapMode.READ_ONLY, 0, channel.size());
+            while (byteBuffer.hasRemaining()) {
+                byte currentChar = byteBuffer.get();
+                if (currentChar == '\n') {
+                    lines++;
+                }
+            }
+        } catch (IOException ioe) {
+            ioe.printStackTrace();
+        }
+        return lines;
+    }
+
+    public static int getTotalNumberOfLinesUsingApacheCommonsIO(String fileName) {
+        int lines = 0;
+        try {
+            LineIterator lineIterator = FileUtils.lineIterator(new File(fileName));
+            while (lineIterator.hasNext()) {
+                lineIterator.nextLine();
+                lines++;
+            }
+        } catch (IOException ioe) {
+            ioe.printStackTrace();
+        }
+        return lines;
+    }
+
+    public static int getTotalNumberOfLinesUsingGoogleGuava(String fileName) {
+        int lines = 0;
+        try {
+            List<String> lineItems = com.google.common.io.Files.readLines(Paths.get(fileName)
+                .toFile(), Charset.defaultCharset());
+            lines = lineItems.size();
+        } catch (IOException ioe) {
+            ioe.printStackTrace();
+        }
+        return lines;
+    }
+
+}

core-java-modules/core-java-io/src/test/java/com/baeldung/file/NumberOfLineFinderUnitTest.java

@@ -0,0 +1,60 @@
+package com.baeldung.file;
+
+import static com.baeldung.files.NumberOfLineFinder.getTotalNumberOfLinesUsingApacheCommonsIO;
+import static com.baeldung.files.NumberOfLineFinder.getTotalNumberOfLinesUsingBufferedReader;
+import static com.baeldung.files.NumberOfLineFinder.getTotalNumberOfLinesUsingGoogleGuava;
+import static com.baeldung.files.NumberOfLineFinder.getTotalNumberOfLinesUsingLineNumberReader;
+import static com.baeldung.files.NumberOfLineFinder.getTotalNumberOfLinesUsingNIOFileChannel;
+import static com.baeldung.files.NumberOfLineFinder.getTotalNumberOfLinesUsingNIOFiles;
+import static com.baeldung.files.NumberOfLineFinder.getTotalNumberOfLinesUsingScanner;
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+public class NumberOfLineFinderUnitTest {
+    private static final String INPUT_FILE_NAME = "src/main/resources/input.txt";
+    private static final int ACTUAL_LINE_COUNT = 45;
+
+    @Test
+    public void whenUsingBufferedReader_thenReturnTotalNumberOfLines() {
+        int lines = getTotalNumberOfLinesUsingBufferedReader(INPUT_FILE_NAME);
+        assertEquals(ACTUAL_LINE_COUNT, lines);
+    }
+
+    @Test
+    public void whenUsingLineNumberReader_thenReturnTotalNumberOfLines() {
+        int lines = getTotalNumberOfLinesUsingLineNumberReader(INPUT_FILE_NAME);
+        assertEquals(ACTUAL_LINE_COUNT, lines);
+    }
+
+    @Test
+    public void whenUsingScanner_thenReturnTotalNumberOfLines() {
+        int lines = getTotalNumberOfLinesUsingScanner(INPUT_FILE_NAME);
+        assertEquals(ACTUAL_LINE_COUNT, lines);
+    }
+
+    @Test
+    public void whenUsingNIOFiles_thenReturnTotalNumberOfLines() {
+        int lines = getTotalNumberOfLinesUsingNIOFiles(INPUT_FILE_NAME);
+        assertEquals(ACTUAL_LINE_COUNT, lines);
+    }
+
+    @Test
+    public void whenUsingNIOFileChannel_thenReturnTotalNumberOfLines() {
+        int lines = getTotalNumberOfLinesUsingNIOFileChannel(INPUT_FILE_NAME);
+        assertEquals(ACTUAL_LINE_COUNT, lines);
+    }
+
+    @Test
+    public void whenUsingApacheCommonsIO_thenReturnTotalNumberOfLines() {
+        int lines = getTotalNumberOfLinesUsingApacheCommonsIO(INPUT_FILE_NAME);
+        assertEquals(ACTUAL_LINE_COUNT, lines);
+    }
+
+    @Test
+    public void whenUsingGoogleGuava_thenReturnTotalNumberOfLines() {
+        int lines = getTotalNumberOfLinesUsingGoogleGuava(INPUT_FILE_NAME);
+        assertEquals(ACTUAL_LINE_COUNT, lines);
+    }
+
+}

core-java-modules/core-java-lang-oop-2/src/main/java/com/baeldung/relationships/aggregation/Car.java

@@ -0,0 +1,9 @@
+package com.baeldung.relationships.aggregation;
+
+import java.util.List;
+
+public class Car {
+
+    private List<Wheel> wheels;
+    
+}

core-java-modules/core-java-lang-oop-2/src/main/java/com/baeldung/relationships/aggregation/CarWithStaticInnerWheel.java

@@ -0,0 +1,13 @@
+package com.baeldung.relationships.aggregation;
+
+import java.util.List;
+
+public class CarWithStaticInnerWheel {
+
+    private List<Wheel> wheels;
+
+    public static class Wheel {
+
+    }
+
+}

core-java-modules/core-java-lang-oop-2/src/main/java/com/baeldung/relationships/aggregation/Wheel.java

@@ -0,0 +1,7 @@
+package com.baeldung.relationships.aggregation;
+
+public class Wheel {
+
+    private Car car;
+    
+}

core-java-modules/core-java-lang-oop-2/src/main/java/com/baeldung/relationships/association/Child.java

@@ -0,0 +1,7 @@
+package com.baeldung.relationships.association;
+
+public class Child {
+
+    private Mother mother;
+
+}

core-java-modules/core-java-lang-oop-2/src/main/java/com/baeldung/relationships/association/Mother.java

@@ -0,0 +1,9 @@
+package com.baeldung.relationships.association;
+
+import java.util.List;
+
+public class Mother {
+
+    private List<Child> children;
+
+}

core-java-modules/core-java-lang-oop-2/src/main/java/com/baeldung/relationships/composition/Building.java

@@ -0,0 +1,18 @@
+package com.baeldung.relationships.composition;
+
+import java.util.List;
+
+public class Building {
+
+    private String address;
+    private List<Room> rooms;
+    
+    public class Room {
+        
+        public String getBuildingAddress() {
+            return Building.this.address;
+        }
+        
+    }
+    
+}

core-java-modules/core-java-lang-oop-2/src/main/java/com/baeldung/relationships/composition/BuildingWithDefinitionRoomInMethod.java

@@ -0,0 +1,28 @@
+package com.baeldung.relationships.composition;
+
+public class BuildingWithDefinitionRoomInMethod {
+
+    public Room createAnonymousRoom() {
+        return new Room() {
+            @Override
+            public void doInRoom() {}
+        };
+    }
+
+    public Room createInlineRoom() {
+        class InlineRoom implements Room {
+            @Override
+            public void doInRoom() {}
+        }
+        return new InlineRoom();
+    }
+    
+    public Room createLambdaRoom() {
+        return () -> {};
+    }
+
+    public interface Room {
+        void doInRoom();
+    }
+
+}

core-java-modules/core-java-lang-oop-2/src/main/java/com/baeldung/relationships/university/Department.java

@@ -0,0 +1,9 @@
+package com.baeldung.relationships.university;
+
+import java.util.List;
+
+public class Department {
+
+    private List<Professor> professors;
+
+}

core-java-modules/core-java-lang-oop-2/src/main/java/com/baeldung/relationships/university/Professor.java

@@ -0,0 +1,10 @@
+package com.baeldung.relationships.university;
+
+import java.util.List;
+
+public class Professor {
+
+    private List<Department> department;
+    private List<Professor> friends;
+    
+}

core-java-modules/core-java-lang-oop-2/src/main/java/com/baeldung/relationships/university/University.java

@@ -0,0 +1,9 @@
+package com.baeldung.relationships.university;
+
+import java.util.List;
+
+public class University {
+
+    private List<Department> department;
+    
+}

core-java-modules/core-java-lang-syntax/src/test/java/com/baeldung/incrementdecrementunaryoperator/IncrementDecrementUnaryOperatorUnitTest.java

@@ -0,0 +1,63 @@
+package com.baeldung.incrementdecrementunaryoperator;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import org.junit.Test;
+
+public class IncrementDecrementUnaryOperatorUnitTest {
+
+    @Test
+    public void givenAnOperand_whenUsingPreIncrementUnaryOperator_thenOperandIsIncrementedByOne() {
+        int operand = 1;
+        ++operand;
+        assertThat(operand).isEqualTo(2);
+    }
+
+    @Test
+    public void givenANumber_whenUsingPreIncrementUnaryOperatorInEvaluation_thenNumberIsIncrementedByOne() {
+        int operand = 1;
+        int number = ++operand;
+        assertThat(number).isEqualTo(2);
+    }
+
+    @Test
+    public void givenAnOperand_whenUsingPreDecrementUnaryOperator_thenOperandIsDecrementedByOne() {
+        int operand = 1;
+        --operand;
+        assertThat(operand).isEqualTo(0);
+    }
+
+    @Test
+    public void givenANumber_whenUsingPreDecrementUnaryOperatorInEvaluation_thenNumberIsDecrementedByOne() {
+        int operand = 1;
+        int number = --operand;
+        assertThat(number).isEqualTo(0);
+    }
+
+    @Test
+    public void givenAnOperand_whenUsingPostIncrementUnaryOperator_thenOperandIsIncrementedByOne() {
+        int operand = 1;
+        operand++;
+        assertThat(operand).isEqualTo(2);
+    }
+
+    @Test
+    public void givenANumber_whenUsingPostIncrementUnaryOperatorInEvaluation_thenNumberIsSameAsOldValue() {
+        int operand = 1;
+        int number = operand++;
+        assertThat(number).isEqualTo(1);
+    }
+
+    @Test
+    public void givenAnOperand_whenUsingPostDecrementUnaryOperator_thenOperandIsDecrementedByOne() {
+        int operand = 1;
+        operand--;
+        assertThat(operand).isEqualTo(0);
+    }
+
+    @Test
+    public void givenANumber_whenUsingPostDecrementUnaryOperatorInEvaluation_thenNumberIsSameAsOldValue() {
+        int operand = 1;
+        int number = operand--;
+        assertThat(number).isEqualTo(1);
+    }
+}

core-java-modules/core-java-networking-2/.gitignore

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

core-java-modules/core-java-security/src/main/java/com/baeldung/sasl/ClientCallbackHandler.java

@@ -0,0 +1,29 @@
+package com.baeldung.sasl;
+
+import java.io.IOException;
+
+import javax.security.auth.callback.Callback;
+import javax.security.auth.callback.CallbackHandler;
+import javax.security.auth.callback.NameCallback;
+import javax.security.auth.callback.PasswordCallback;
+import javax.security.auth.callback.UnsupportedCallbackException;
+import javax.security.sasl.RealmCallback;
+
+public class ClientCallbackHandler implements CallbackHandler {
+
+    @Override
+    public void handle(Callback[] cbs) throws IOException, UnsupportedCallbackException {
+        for (Callback cb : cbs) {
+            if (cb instanceof NameCallback) {
+                NameCallback nc = (NameCallback) cb;
+                nc.setName("username");
+            } else if (cb instanceof PasswordCallback) {
+                PasswordCallback pc = (PasswordCallback) cb;
+                pc.setPassword("password".toCharArray());
+            } else if (cb instanceof RealmCallback) {
+                RealmCallback rc = (RealmCallback) cb;
+                rc.setText("myServer");
+            }
+        }
+    }
+}

core-java-modules/core-java-security/src/main/java/com/baeldung/sasl/ServerCallbackHandler.java

@@ -0,0 +1,34 @@
+package com.baeldung.sasl;
+
+import java.io.IOException;
+
+import javax.security.auth.callback.Callback;
+import javax.security.auth.callback.CallbackHandler;
+import javax.security.auth.callback.NameCallback;
+import javax.security.auth.callback.PasswordCallback;
+import javax.security.auth.callback.UnsupportedCallbackException;
+import javax.security.sasl.AuthorizeCallback;
+import javax.security.sasl.RealmCallback;
+
+public class ServerCallbackHandler implements CallbackHandler {
+
+    @Override
+    public void handle(Callback[] cbs) throws IOException, UnsupportedCallbackException {
+        for (Callback cb : cbs) {
+            if (cb instanceof AuthorizeCallback) {
+                AuthorizeCallback ac = (AuthorizeCallback) cb;
+                ac.setAuthorized(true);
+            } else if (cb instanceof NameCallback) {
+                NameCallback nc = (NameCallback) cb;
+                nc.setName("username");
+
+            } else if (cb instanceof PasswordCallback) {
+                PasswordCallback pc = (PasswordCallback) cb;
+                pc.setPassword("password".toCharArray());
+            } else if (cb instanceof RealmCallback) {
+                RealmCallback rc = (RealmCallback) cb;
+                rc.setText("myServer");
+            }
+        }
+    }
+}

core-java-modules/core-java-security/src/test/java/com/baeldung/sasl/SaslUnitTest.java

@@ -0,0 +1,76 @@
+package com.baeldung.sasl;
+
+import static org.junit.Assert.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.nio.charset.StandardCharsets;
+import java.util.HashMap;
+import java.util.Map;
+
+import javax.security.sasl.Sasl;
+import javax.security.sasl.SaslClient;
+import javax.security.sasl.SaslException;
+import javax.security.sasl.SaslServer;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+public class SaslUnitTest {
+
+    private static final String MECHANISM = "DIGEST-MD5";
+    private static final String SERVER_NAME = "myServer";
+    private static final String PROTOCOL = "myProtocol";
+    private static final String AUTHORIZATION_ID = null;
+    private static final String QOP_LEVEL = "auth-conf";
+
+    private SaslServer saslServer;
+    private SaslClient saslClient;
+
+    @Before
+    public void setUp() throws SaslException {
+
+        ServerCallbackHandler serverHandler = new ServerCallbackHandler();
+        ClientCallbackHandler clientHandler = new ClientCallbackHandler();
+
+        Map<String, String> props = new HashMap<>();
+        props.put(Sasl.QOP, QOP_LEVEL);
+
+        saslServer = Sasl.createSaslServer(MECHANISM, PROTOCOL, SERVER_NAME, props, serverHandler);
+        saslClient = Sasl.createSaslClient(new String[] { MECHANISM }, AUTHORIZATION_ID, PROTOCOL, SERVER_NAME, props, clientHandler);
+
+    }
+
+    @Test
+    public void givenHandlers_whenStarted_thenAutenticationWorks() throws SaslException {
+
+        byte[] challenge;
+        byte[] response;
+
+        challenge = saslServer.evaluateResponse(new byte[0]);
+        response = saslClient.evaluateChallenge(challenge);
+
+        challenge = saslServer.evaluateResponse(response);
+        response = saslClient.evaluateChallenge(challenge);
+
+        assertTrue(saslServer.isComplete());
+        assertTrue(saslClient.isComplete());
+
+        String qop = (String) saslClient.getNegotiatedProperty(Sasl.QOP);
+        assertEquals("auth-conf", qop);
+
+        byte[] outgoing = "Baeldung".getBytes();
+        byte[] secureOutgoing = saslClient.wrap(outgoing, 0, outgoing.length);
+
+        byte[] secureIncoming = secureOutgoing;
+        byte[] incoming = saslServer.unwrap(secureIncoming, 0, secureIncoming.length);
+        assertEquals("Baeldung", new String(incoming, StandardCharsets.UTF_8));
+    }
+
+    @After
+    public void tearDown() throws SaslException {
+        saslClient.dispose();
+        saslServer.dispose();
+    }
+
+}

data-structures/src/main/java/com/baeldung/graph/Graph.java

@@ -2,6 +2,7 @@ package com.baeldung.graph;
 
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.Stack;
@@ -29,7 +30,7 @@ public class Graph {
         while (!stack.isEmpty()) {
             int current = stack.pop();
             isVisited[current] = true;
-            System.out.print(" " + current);
+            visit(current);
             for (int dest : adjVertices.get(current)) {
                 if (!isVisited[dest])
                     stack.push(dest);
@@ -44,29 +45,30 @@ public class Graph {
 
     private void dfsRecursive(int current, boolean[] isVisited) {
         isVisited[current] = true;
-        System.out.print(" " + current);
+        visit(current);
         for (int dest : adjVertices.get(current)) {
             if (!isVisited[dest])
                 dfsRecursive(dest, isVisited);
         }
     }
 
-    public void topologicalSort(int start) {
-        Stack<Integer> result = new Stack<Integer>();
+    public List<Integer> topologicalSort(int start) {
+        LinkedList<Integer> result = new LinkedList<Integer>();
         boolean[] isVisited = new boolean[adjVertices.size()];
         topologicalSortRecursive(start, isVisited, result);
-        while (!result.isEmpty()) {
-            System.out.print(" " + result.pop());
-        }
+        return result;
     }
 
-    private void topologicalSortRecursive(int current, boolean[] isVisited, Stack<Integer> result) {
+    private void topologicalSortRecursive(int current, boolean[] isVisited, LinkedList<Integer> result) {
         isVisited[current] = true;
         for (int dest : adjVertices.get(current)) {
             if (!isVisited[dest])
                 topologicalSortRecursive(dest, isVisited, result);
         }
-        result.push(current);
+        result.addFirst(current);
     }
 
+    private void visit(int value) {
+        System.out.print(" " + value);        
+    }
 }

data-structures/src/main/java/com/baeldung/tree/BinaryTree.java

@@ -103,14 +103,14 @@ public class BinaryTree {
     public void traverseInOrder(Node node) {
         if (node != null) {
             traverseInOrder(node.left);
-            System.out.print(" " + node.value);
+            visit(node.value);
             traverseInOrder(node.right);
         }
     }
 
     public void traversePreOrder(Node node) {
         if (node != null) {
-            System.out.print(" " + node.value);
+            visit(node.value);
             traversePreOrder(node.left);
             traversePreOrder(node.right);
         }
@@ -120,7 +120,7 @@ public class BinaryTree {
         if (node != null) {
             traversePostOrder(node.left);
             traversePostOrder(node.right);
-            System.out.print(" " + node.value);
+            visit(node.value);
         }
     }
 
@@ -159,7 +159,7 @@ public class BinaryTree {
                 stack.push(current);                
             }
             current = stack.pop();
-            System.out.print(" " + current.value);
+            visit(current.value);
             if(current.right != null) {
                 current = current.right;                
                 stack.push(current);
@@ -173,7 +173,7 @@ public class BinaryTree {
         stack.push(root);
         while(! stack.isEmpty()) {
             current = stack.pop();
-            System.out.print(" " + current.value);
+            visit(current.value);
             
             if(current.right != null)
                 stack.push(current.right);
@@ -196,7 +196,7 @@ public class BinaryTree {
 
             if (!hasChild || isPrevLastChild) {
                 current = stack.pop();
-                System.out.print(" " + current.value);
+                visit(current.value);
                 prev = current;
             } else {
                 if (current.right != null) {
@@ -209,6 +209,9 @@ public class BinaryTree {
         }   
     }    
     
+    private void visit(int value) {
+        System.out.print(" " + value);        
+    }
     
     class Node {
         int value;

data-structures/src/test/java/com/baeldung/graph/GraphUnitTest.java

@@ -1,5 +1,7 @@
 package com.baeldung.graph;
 
+import java.util.List;
+
 import org.junit.Test;
 
 public class GraphUnitTest {
@@ -15,7 +17,8 @@ public class GraphUnitTest {
     @Test
     public void givenDirectedGraph_whenGetTopologicalSort_thenPrintValuesSorted() {
         Graph graph = createDirectedGraph();
-        graph.topologicalSort(0);
+        List<Integer> list = graph.topologicalSort(0);
+        System.out.println(list);
     }
 
     private Graph createDirectedGraph() {

java-numbers-2/.gitignore

@@ -1,26 +0,0 @@
-*.class
-
-0.*
-
-#folders#
-/target
-/neoDb*
-/data
-/src/main/webapp/WEB-INF/classes
-*/META-INF/*
-.resourceCache
-
-# Packaged files #
-*.jar
-*.war
-*.ear
-
-# Files generated by integration tests
-*.txt
-backup-pom.xml
-/bin/
-/temp
-
-#IntelliJ specific
-.idea/
-*.iml

java-numbers-2/src/main/java/com/baeldung/binarynumbers/BinaryNumbers.java

@@ -0,0 +1,148 @@
+package com.baeldung.binarynumbers;
+
+public class BinaryNumbers {
+
+    /**
+     * This method takes a decimal number and convert it into a binary number.
+     * example:- input:10, output:1010
+     *
+     * @param decimalNumber
+     * @return binary number
+     */
+    public Integer convertDecimalToBinary(Integer decimalNumber) {
+
+        if (decimalNumber == 0) {
+            return decimalNumber;
+        }
+
+        StringBuilder binaryNumber = new StringBuilder();
+
+        while (decimalNumber > 0) {
+
+            int remainder = decimalNumber % 2;
+            int result = decimalNumber / 2;
+
+            binaryNumber.append(remainder);
+            decimalNumber = result;
+        }
+
+        binaryNumber = binaryNumber.reverse();
+
+        return Integer.valueOf(binaryNumber.toString());
+    }
+
+    /**
+     * This method takes a binary number and convert it into a decimal number.
+     * example:- input:101, output:5
+     *
+     * @param binary number
+     * @return decimal Number
+     */
+    public Integer convertBinaryToDecimal(Integer binaryNumber) {
+
+        Integer result = 0;
+        Integer base = 1;
+
+        while (binaryNumber > 0) {
+
+            int lastDigit = binaryNumber % 10;
+            binaryNumber = binaryNumber / 10;
+
+            result += lastDigit * base;
+
+            base = base * 2;
+        }
+        return result;
+    }
+
+    /**
+     * This method accepts two binary numbers and returns sum of input numbers.
+     * Example:- firstNum: 101, secondNum: 100, output: 1001
+     *
+     * @param firstNum
+     * @param secondNum
+     * @return addition of input numbers
+     */
+    public Integer addBinaryNumber(Integer firstNum, Integer secondNum) {
+
+        StringBuilder output = new StringBuilder();
+
+        int carry = 0;
+        int temp;
+
+        while (firstNum != 0 || secondNum != 0) {
+
+            temp = (firstNum % 10 + secondNum % 10 + carry) % 2;
+            output.append(temp);
+
+            carry = (firstNum % 10 + secondNum % 10 + carry) / 2;
+
+            firstNum = firstNum / 10;
+            secondNum = secondNum / 10;
+        }
+
+        if (carry != 0) {
+            output.append(carry);
+        }
+
+        return Integer.valueOf(output.reverse()
+            .toString());
+    }
+
+    /**
+    * This method takes two binary number as input and subtract second number from the first number.
+    * example:- firstNum: 1000, secondNum: 11, output: 101
+    * @param firstNum
+    * @param secondNum
+    * @return Result of subtraction of secondNum from first
+    */
+    public Integer substractBinaryNumber(Integer firstNum, Integer secondNum) {
+
+        int onesComplement = Integer.valueOf(getOnesComplement(secondNum));
+
+        StringBuilder output = new StringBuilder();
+
+        int carry = 0;
+        int temp;
+
+        while (firstNum != 0 || onesComplement != 0) {
+
+            temp = (firstNum % 10 + onesComplement % 10 + carry) % 2;
+            output.append(temp);
+
+            carry = (firstNum % 10 + onesComplement % 10 + carry) / 2;
+
+            firstNum = firstNum / 10;
+            onesComplement = onesComplement / 10;
+        }
+
+        String additionOfFirstNumAndOnesComplement = output.reverse()
+            .toString();
+
+        if (carry == 1) {
+            return addBinaryNumber(Integer.valueOf(additionOfFirstNumAndOnesComplement), carry);
+        } else {
+            return getOnesComplement(Integer.valueOf(additionOfFirstNumAndOnesComplement));
+        }
+
+    }
+
+    public Integer getOnesComplement(Integer num) {
+
+        StringBuilder onesComplement = new StringBuilder();
+
+        while (num > 0) {
+            int lastDigit = num % 10;
+            if (lastDigit == 0) {
+                onesComplement.append(1);
+            } else {
+                onesComplement.append(0);
+            }
+            num = num / 10;
+        }
+
+        return Integer.valueOf(onesComplement.reverse()
+            .toString());
+    }
+
+}

java-numbers-2/src/test/java/com/baeldung/binarynumbers/BinaryNumbersUnitTest.java

@@ -0,0 +1,73 @@
+package com.baeldung.binarynumbers;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+public class BinaryNumbersUnitTest {
+
+    private BinaryNumbers binaryNumbers = new BinaryNumbers();
+
+    @Test
+    public void given_decimalNumber_then_returnBinaryNumber() {
+        assertEquals(Integer.valueOf(1000), binaryNumbers.convertDecimalToBinary(8));
+        assertEquals(Integer.valueOf(10100), binaryNumbers.convertDecimalToBinary(20));
+    }
+
+    @Test
+    public void given_decimalNumber_then_convertToBinaryNumber() {
+        assertEquals("1000", Integer.toBinaryString(8));
+        assertEquals("10100", Integer.toBinaryString(20));
+    }
+
+    @Test
+    public void given_binaryNumber_then_ConvertToDecimalNumber() {
+        assertEquals(8, Integer.parseInt("1000", 2));
+        assertEquals(20, Integer.parseInt("10100", 2));
+    }
+
+    @Test
+    public void given_binaryNumber_then_returnDecimalNumber() {
+        assertEquals(Integer.valueOf(8), binaryNumbers.convertBinaryToDecimal(1000));
+        assertEquals(Integer.valueOf(20), binaryNumbers.convertBinaryToDecimal(10100));
+    }
+
+    @Test
+    public void given_twoBinaryNumber_then_returnAddition() {
+        // adding 4 and 10
+        assertEquals(Integer.valueOf(1110), binaryNumbers.addBinaryNumber(100, 1010));
+
+        // adding 26 and 14
+        assertEquals(Integer.valueOf(101000), binaryNumbers.addBinaryNumber(11010, 1110));
+    }
+
+    @Test
+    public void given_twoBinaryNumber_then_returnSubtraction() {
+        // subtracting 16 from 25
+        assertEquals(Integer.valueOf(1001), binaryNumbers.substractBinaryNumber(11001, 10000));
+
+        // subtracting 29 from 16, the output here is negative
+        assertEquals(Integer.valueOf(1101), binaryNumbers.substractBinaryNumber(10000, 11101));
+    }
+
+    @Test
+    public void given_binaryLiteral_thenReturnDecimalValue() {
+
+        byte five = 0b101;
+        assertEquals((byte) 5, five);
+
+        short three = 0b11;
+        assertEquals((short) 3, three);
+
+        int nine = 0B1001;
+        assertEquals(9, nine);
+
+        long twentyNine = 0B11101;
+        assertEquals(29, twentyNine);
+
+        int minusThirtySeven = -0B100101;
+        assertEquals(-37, minusThirtySeven);
+
+    }
+
+}

java-strings-2/README.MD

@@ -3,5 +3,20 @@
 - [Java Localization – Formatting Messages](https://www.baeldung.com/java-localization-messages-formatting)
 - [Check If a String Contains a Substring](https://www.baeldung.com/java-string-contains-substring)
 - [Removing Stopwords from a String in Java](https://www.baeldung.com/java-string-remove-stopwords)
+- [Java – Generate Random String](http://www.baeldung.com/java-random-string)
+- [Image to Base64 String Conversion](http://www.baeldung.com/java-base64-image-string)
+- [Java Base64 Encoding and Decoding](https://www.baeldung.com/java-base64-encode-and-decode)
+- [Generate a Secure Random Password in Java](https://www.baeldung.com/java-generate-secure-password)
+- [Removing Repeated Characters from a String](https://www.baeldung.com/java-remove-repeated-char)
+- [Join Array of Primitives with Separator in Java](https://www.baeldung.com/java-join-primitive-array)
+- [Pad a String with Zeros or Spaces in Java](https://www.baeldung.com/java-pad-string)
+- [Remove Emojis from a Java String](https://www.baeldung.com/java-string-remove-emojis)
+- [Convert a Comma Separated String to a List in Java](https://www.baeldung.com/java-string-with-separator-to-list)
+- [Guide to java.util.Formatter](http://www.baeldung.com/java-string-formatter)
+- [Remove Leading and Trailing Characters from a String](https://www.baeldung.com/java-remove-trailing-characters)
+- [Concatenating Strings In Java](https://www.baeldung.com/java-strings-concatenation)
+- [Java String Interview Questions and Answers](https://www.baeldung.com/java-string-interview-questions)
+- [Check if a String is a Pangram in Java](https://www.baeldung.com/java-string-pangram)
+- [Check If a String Contains Multiple Keywords](https://www.baeldung.com/string-contains-multiple-words)
 - [Blank and Empty Strings in Java](https://www.baeldung.com/java-blank-empty-strings)
 - [String Initialization in Java](https://www.baeldung.com/java-string-initialization)

java-strings-2/pom.xml

@@ -40,6 +40,16 @@
             <artifactId>commons-lang3</artifactId>
             <version>${commons-lang3.version}</version>
         </dependency>
+        <dependency>
+            <groupId>commons-io</groupId>
+            <artifactId>commons-io</artifactId>
+            <version>${commons-io.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>commons-codec</groupId>
+            <artifactId>commons-codec</artifactId>
+            <version>${commons-codec.version}</version>
+        </dependency>
         <dependency>
             <groupId>junit</groupId>
             <artifactId>junit</artifactId>
@@ -52,32 +62,54 @@
             <version>${org.hamcrest.version}</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${assertj.version}</version>
+            <scope>test</scope>
+        </dependency>
+
+        <!-- Added for password generation -->
+        <dependency>
+            <groupId>org.passay</groupId>
+            <artifactId>passay</artifactId>
+            <version>${passay.version}</version>
+        </dependency>
         <dependency>
             <groupId>org.apache.commons</groupId>
             <artifactId>commons-text</artifactId>
             <version>${commons-text.version}</version>
         </dependency>
+        <dependency>
+            <groupId>com.vdurmont</groupId>
+            <artifactId>emoji-java</artifactId>
+            <version>${emoji-java.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.ahocorasick</groupId>
+            <artifactId>ahocorasick</artifactId>
+            <version>${ahocorasick.version}</version>
+        </dependency>
         <dependency>
             <groupId>javax.validation</groupId>
             <artifactId>validation-api</artifactId>
-            <version>2.0.0.Final</version>
+            <version>${validation-api.version}</version>
         </dependency>
         <dependency>
             <groupId>org.hibernate.validator</groupId>
             <artifactId>hibernate-validator</artifactId>
-            <version>6.0.2.Final</version>
+            <version>${hibernate-validator.version}</version>
         </dependency>
         <dependency>
             <groupId>javax.el</groupId>
             <artifactId>javax.el-api</artifactId>
-            <version>3.0.0</version>
+            <version>${javax.el-api.version}</version>
         </dependency>
         <dependency>
             <groupId>org.glassfish.web</groupId>
             <artifactId>javax.el</artifactId>
-            <version>2.2.6</version>
+            <version>${javax.el.version}</version>
         </dependency>
-
     </dependencies>
 
     <build>
@@ -105,9 +137,19 @@
 
     <properties>
         <commons-lang3.version>3.8.1</commons-lang3.version>
+        <commons-codec.version>1.10</commons-codec.version>
+        <passay.version>1.3.1</passay.version>
+        <!-- testing -->
+        <assertj.version>3.6.1</assertj.version>
+        <emoji-java.version>4.0.0</emoji-java.version>
+        <ahocorasick.version>0.4.0</ahocorasick.version>
         <icu4j.version>61.1</icu4j.version>
         <guava.version>28.0-jre</guava.version>
         <commons-text.version>1.4</commons-text.version>
+        <validation-api.version>2.0.0.Final</validation-api.version>
+        <hibernate-validator.version>6.0.2.Final</hibernate-validator.version>
+        <javax.el-api.version>3.0.0</javax.el-api.version>
+        <javax.el.version>2.2.6</javax.el.version>
     </properties>
 
 </project>

java-strings-2/src/test/java/com/baeldung/string/todouble/StringToDoubleConversionUnitTest.java

@@ -0,0 +1,56 @@
+package com.baeldung.string.todouble;
+
+import static org.junit.Assert.assertEquals;
+
+import java.text.DecimalFormat;
+import java.text.ParseException;
+
+import org.junit.Test;
+
+public class StringToDoubleConversionUnitTest {
+
+    @Test
+    public void givenValidString_WhenParseDouble_ThenResultIsPrimitiveDouble() {
+        assertEquals(1.23, Double.parseDouble("1.23"), 0.000001);
+    }
+    
+    @Test(expected = NullPointerException.class)
+    public void givenNullString_WhenParseDouble_ThenNullPointerExceptionIsThrown() {
+        Double.parseDouble(null);
+    }
+    
+    @Test(expected = NumberFormatException.class)
+    public void givenInalidString_WhenParseDouble_ThenNumberFormatExceptionIsThrown() {
+        Double.parseDouble("&");
+    }
+    
+    @Test
+    public void givenValidString_WhenValueOf_ThenResultIsPrimitiveDouble() {
+        assertEquals(1.23, Double.valueOf("1.23"), 0.000001);
+    }
+    
+    @Test(expected = NullPointerException.class)
+    public void givenNullString_WhenValueOf_ThenNullPointerExceptionIsThrown() {
+        Double.valueOf(null);
+    }
+    
+    @Test(expected = NumberFormatException.class)
+    public void givenInalidString_WhenValueOf_ThenNumberFormatExceptionIsThrown() {
+        Double.valueOf("&");
+    }
+    
+    @Test
+    public void givenValidString_WhenDecimalFormat_ThenResultIsValidDouble() throws ParseException {
+        assertEquals(1.23, new DecimalFormat("#").parse("1.23").doubleValue(), 0.000001);
+    }
+    
+    @Test(expected = NullPointerException.class)
+    public void givenNullString_WhenDecimalFormat_ThenNullPointerExceptionIsThrown() throws ParseException {
+        new DecimalFormat("#").parse(null);
+    }
+    
+    @Test(expected = ParseException.class)
+    public void givenInvalidString_WhenDecimalFormat_ThenParseExceptionIsThrown() throws ParseException {
+        new DecimalFormat("#").parse("&");
+    }
+}

java-strings-ops/README.md

@@ -0,0 +1,22 @@
+=========
+
+## Java Strings Cookbooks and Examples
+
+### Relevant Articles:
+- [Convert char to String in Java](http://www.baeldung.com/java-convert-char-to-string)
+- [Convert String to int or Integer in Java](http://www.baeldung.com/java-convert-string-to-int-or-integer)
+- [Java String Conversions](https://www.baeldung.com/java-string-conversions)
+- [Check if a String is a Palindrome](http://www.baeldung.com/java-palindrome)
+- [Comparing Strings in Java](http://www.baeldung.com/java-compare-strings)
+- [Check If a String Is Numeric in Java](http://www.baeldung.com/java-check-string-number)
+- [Get Substring from String in Java](https://www.baeldung.com/java-substring)
+- [How to Remove the Last Character of a String?](http://www.baeldung.com/java-remove-last-character-of-string)
+- [Add a Character to a String at a Given Position](https://www.baeldung.com/java-add-character-to-string)
+- [Count Occurrences of a Char in a String](http://www.baeldung.com/java-count-chars)
+- [Guide to Java String Pool](http://www.baeldung.com/java-string-pool)
+- [Split a String in Java](http://www.baeldung.com/java-split-string)
+- [Common String Operations in Java](https://www.baeldung.com/java-string-operations)
+- [Convert String to Byte Array and Reverse in Java](https://www.baeldung.com/java-string-to-byte-array)
+- [Java toString() Method](https://www.baeldung.com/java-tostring)
+- [CharSequence vs. String in Java](http://www.baeldung.com/java-char-sequence-string)
+- [StringBuilder and StringBuffer in Java](http://www.baeldung.com/java-string-builder-string-buffer)

java-strings-ops/pom.xml

@@ -0,0 +1,99 @@
+<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>java-strings-ops</artifactId>
+    <version>0.1.0-SNAPSHOT</version>
+    <packaging>jar</packaging>
+    <name>java-strings-ops</name>
+
+    <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-lang3</artifactId>
+            <version>${commons-lang3.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>log4j</groupId>
+            <artifactId>log4j</artifactId>
+            <version>${log4j.version}</version>
+        </dependency>
+        <!-- test scoped -->
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${assertj.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.openjdk.jmh</groupId>
+            <artifactId>jmh-core</artifactId>
+            <version>${jmh-core.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.openjdk.jmh</groupId>
+            <artifactId>jmh-generator-annprocess</artifactId>
+            <version>${jmh-generator.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.google.guava</groupId>
+            <artifactId>guava</artifactId>
+            <version>${guava.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-api</artifactId>
+            <version>${junit-jupiter-api.version}</version>
+            <scope>test</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>org.hamcrest</groupId>
+            <artifactId>hamcrest-library</artifactId>
+            <version>${org.hamcrest.version}</version>
+            <scope>test</scope>
+        </dependency>
+
+    </dependencies>
+
+    <build>
+        <finalName>java-strings-ops</finalName>
+        <resources>
+            <resource>
+                <directory>src/main/resources</directory>
+                <filtering>true</filtering>
+            </resource>
+        </resources>
+
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>${maven-compiler-plugin.version}</version>
+                <configuration>
+                    <source>${java.version}</source>
+                    <target>${java.version}</target>
+                    <compilerArgument>-parameters</compilerArgument>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+    <properties>
+        <!-- util -->
+        <commons-lang3.version>3.8.1</commons-lang3.version>
+        <!-- testing -->
+        <assertj.version>3.6.1</assertj.version>
+        <guava.version>27.0.1-jre</guava.version>
+		<junit-jupiter-api.version>5.3.1</junit-jupiter-api.version>
+    </properties>
+
+</project>

java-strings-ops/src/test/resources/.gitignore

@@ -10,8 +10,4 @@
 # Packaged files #
 *.jar
 *.war
-*.ear
-
-*.ipr
-*.iml
-*.iws
+*.ear

java-strings/README.md

@@ -6,51 +6,18 @@
 - [String Operations with Java Streams](http://www.baeldung.com/java-stream-operations-on-strings)
 - [Converting String to Stream of chars](http://www.baeldung.com/java-string-to-stream)
 - [Java 8 StringJoiner](http://www.baeldung.com/java-string-joiner)
-- [Image to Base64 String Conversion](http://www.baeldung.com/java-base64-image-string)
-- [Java – Generate Random String](http://www.baeldung.com/java-random-string)
-- [Convert char to String in Java](http://www.baeldung.com/java-convert-char-to-string)
-- [Convert String to int or Integer in Java](http://www.baeldung.com/java-convert-string-to-int-or-integer)
-- [Java String Conversions](https://www.baeldung.com/java-string-conversions)
 - [Converting Strings to Enums in Java](http://www.baeldung.com/java-string-to-enum)
 - [Quick Guide to the Java StringTokenizer](http://www.baeldung.com/java-stringtokenizer)
-- [Count Occurrences of a Char in a String](http://www.baeldung.com/java-count-chars)
-- [Split a String in Java](http://www.baeldung.com/java-split-string)
-- [How to Remove the Last Character of a String?](http://www.baeldung.com/java-remove-last-character-of-string)
-- [CharSequence vs. String in Java](http://www.baeldung.com/java-char-sequence-string)
-- [StringBuilder and StringBuffer in Java](http://www.baeldung.com/java-string-builder-string-buffer)
-- [Guide to Java String Pool](http://www.baeldung.com/java-string-pool)
-- [Check if a String is a Palindrome](http://www.baeldung.com/java-palindrome)
-- [Comparing Strings in Java](http://www.baeldung.com/java-compare-strings)
-- [Check If a String Is Numeric in Java](http://www.baeldung.com/java-check-string-number)
 - [Use char[] Array Over a String for Manipulating Passwords in Java?](http://www.baeldung.com/java-storing-passwords)
 - [Convert a String to Title Case](http://www.baeldung.com/java-string-title-case)
 - [Compact Strings in Java 9](http://www.baeldung.com/java-9-compact-string)
 - [Java Check a String for Lowercase/Uppercase Letter, Special Character and Digit](https://www.baeldung.com/java-lowercase-uppercase-special-character-digit-regex)
 - [Convert java.util.Date to String](https://www.baeldung.com/java-util-date-to-string)
-- [Get Substring from String in Java](https://www.baeldung.com/java-substring)
 - [Converting a Stack Trace to a String in Java](https://www.baeldung.com/java-stacktrace-to-string)
 - [Sorting a String Alphabetically in Java](https://www.baeldung.com/java-sort-string-alphabetically)
-- [Remove Emojis from a Java String](https://www.baeldung.com/java-string-remove-emojis)
 - [String Not Empty Test Assertions in Java](https://www.baeldung.com/java-assert-string-not-empty)
 - [String Performance Hints](https://www.baeldung.com/java-string-performance)
 - [Using indexOf to Find All Occurrences of a Word in a String](https://www.baeldung.com/java-indexOf-find-string-occurrences)
-- [Convert String to Byte Array and Reverse in Java](https://www.baeldung.com/java-string-to-byte-array)
-- [Java Base64 Encoding and Decoding](https://www.baeldung.com/java-base64-encode-and-decode)
-- [Generate a Secure Random Password in Java](https://www.baeldung.com/java-generate-secure-password)
-- [Removing Repeated Characters from a String](https://www.baeldung.com/java-remove-repeated-char)
-- [Join Array of Primitives with Separator in Java](https://www.baeldung.com/java-join-primitive-array)
-- [Convert String to Byte Array and Reverse in Java](https://www.baeldung.com/java-string-to-byte-array)
-- [Pad a String with Zeros or Spaces in Java](https://www.baeldung.com/java-pad-string)
 - [Adding a Newline Character to a String in Java](https://www.baeldung.com/java-string-newline)
 - [Remove or Replace part of a String in Java](https://www.baeldung.com/java-remove-replace-string-part)
-- [Replace a Character at a Specific Index in a String in Java](https://www.baeldung.com/java-replace-character-at-index)
-- [Convert a Comma Separated String to a List in Java](https://www.baeldung.com/java-string-with-separator-to-list)
-- [Guide to java.util.Formatter](http://www.baeldung.com/java-string-formatter)
-- [Add a Character to a String at a Given Position](https://www.baeldung.com/java-add-character-to-string)
-- [Remove Leading and Trailing Characters from a String](https://www.baeldung.com/java-remove-trailing-characters)
-- [Concatenating Strings In Java](https://www.baeldung.com/java-strings-concatenation)
-- [Java toString() Method](https://www.baeldung.com/java-tostring)
-- [Java String Interview Questions and Answers](https://www.baeldung.com/java-string-interview-questions)
-- [Check if a String is a Pangram in Java](https://www.baeldung.com/java-string-pangram)
-- [Check If a String Contains Multiple Keywords](https://www.baeldung.com/string-contains-multiple-words)
-- [Common String Operations in Java](https://www.baeldung.com/java-string-operations)
+- [Replace a Character at a Specific Index in a String in Java](https://www.baeldung.com/java-replace-character-at-index)

java-strings/pom.xml

@@ -62,12 +62,6 @@
             <artifactId>guava</artifactId>
             <version>${guava.version}</version>
         </dependency>
-        
-        <dependency>
-            <groupId>com.vdurmont</groupId>
-            <artifactId>emoji-java</artifactId>
-            <version>${emoji-java.version}</version>
-        </dependency>
 
         <dependency>
             <groupId>org.junit.jupiter</groupId>
@@ -83,24 +77,6 @@
             <scope>test</scope>
         </dependency>
 
-        <!-- Added for password generation -->
-        <dependency>
-            <groupId>org.passay</groupId>
-            <artifactId>passay</artifactId>
-            <version>${passay.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>org.apache.commons</groupId>
-            <artifactId>commons-text</artifactId>
-            <version>${commons-text.version}</version>
-        </dependency>
-
-        <dependency>
-            <groupId>org.ahocorasick</groupId>
-            <artifactId>ahocorasick</artifactId>
-            <version>${ahocorasick.version}</version>
-        </dependency>
-
     </dependencies>
 
     <build>
@@ -134,11 +110,8 @@
         <assertj.version>3.6.1</assertj.version>
         <icu4j.version>61.1</icu4j.version>
         <guava.version>27.0.1-jre</guava.version>
-		<emoji-java.version>4.0.0</emoji-java.version>
 		<junit-jupiter-api.version>5.3.1</junit-jupiter-api.version>
-		<passay.version>1.3.1</passay.version>
 		<commons-text.version>1.4</commons-text.version>
-		<ahocorasick.version>0.4.0</ahocorasick.version>
     </properties>
 
 </project>