[BAEL-16824] - Added modules alphabatically

core-java-modules/core-java-concurrency-basic/src/main/java/com/baeldung/concurrent/mutex/SequenceGenerator.java

@@ -1,11 +1,12 @@
 package com.baeldung.concurrent.mutex;
 
 public class SequenceGenerator {
+
     private int currentValue = 0;
 
-    public int getNextSequence() throws InterruptedException {
+    public int getNextSequence() {
         currentValue = currentValue + 1;
-        Thread.sleep(500);
         return currentValue;
     }
+
 }

core-java-modules/core-java-concurrency-basic/src/main/java/com/baeldung/concurrent/mutex/SequenceGeneratorUsingMonitor.java

@@ -4,15 +4,16 @@ import com.google.common.util.concurrent.Monitor;
 
 public class SequenceGeneratorUsingMonitor extends SequenceGenerator {
 
-    private Monitor monitor = new Monitor();
+    private Monitor mutex = new Monitor();
 
     @Override
-    public int getNextSequence() throws InterruptedException {
-        monitor.enter();
+    public int getNextSequence() {
+        mutex.enter();
         try {
             return super.getNextSequence();
         } finally {
-            monitor.leave();
+            mutex.leave();
         }
     }
+
 }

core-java-modules/core-java-concurrency-basic/src/main/java/com/baeldung/concurrent/mutex/SequenceGeneratorUsingReentrantLock.java

@@ -7,7 +7,7 @@ public class SequenceGeneratorUsingReentrantLock extends SequenceGenerator {
     private ReentrantLock mutex = new ReentrantLock();
 
     @Override
-    public int getNextSequence() throws InterruptedException {
+    public int getNextSequence() {
         try {
             mutex.lock();
             return super.getNextSequence();
@@ -15,4 +15,5 @@ public class SequenceGeneratorUsingReentrantLock extends SequenceGenerator {
             mutex.unlock();
         }
     }
+
 }

core-java-modules/core-java-concurrency-basic/src/main/java/com/baeldung/concurrent/mutex/SequenceGeneratorUsingSemaphore.java

@@ -7,12 +7,15 @@ public class SequenceGeneratorUsingSemaphore extends SequenceGenerator {
     private Semaphore mutex = new Semaphore(1);
 
     @Override
-    public int getNextSequence() throws InterruptedException {
+    public int getNextSequence() {
         try {
             mutex.acquire();
             return super.getNextSequence();
+        } catch (InterruptedException e) {
+            throw new RuntimeException("Exception in critical section.", e);
         } finally {
             mutex.release();
         }
     }
+
 }

core-java-modules/core-java-concurrency-basic/src/main/java/com/baeldung/concurrent/mutex/SequenceGeneratorUsingSynchronizedBlock.java

@@ -2,9 +2,11 @@ package com.baeldung.concurrent.mutex;
 
 public class SequenceGeneratorUsingSynchronizedBlock extends SequenceGenerator {
 
+    private Object mutex = new Object();
+
     @Override
-    public int getNextSequence() throws InterruptedException {
-        synchronized (this) {
+    public int getNextSequence() {
+        synchronized (mutex) {
             return super.getNextSequence();
         }
     }

core-java-modules/core-java-concurrency-basic/src/main/java/com/baeldung/concurrent/mutex/SequenceGeneratorUsingSynchronizedMethod.java

@@ -3,7 +3,7 @@ package com.baeldung.concurrent.mutex;
 public class SequenceGeneratorUsingSynchronizedMethod extends SequenceGenerator {
 
     @Override
-    public synchronized int getNextSequence() throws InterruptedException {
+    public synchronized int getNextSequence() {
         return super.getNextSequence();
     }
 

core-java-modules/core-java-concurrency-basic/src/test/java/com/baeldung/concurrent/mutex/MutexUnitTest.java

@@ -1,7 +1,7 @@
 package com.baeldung.concurrent.mutex;
 
 import java.util.ArrayList;
-import java.util.HashSet;
+import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Set;
 import java.util.concurrent.ExecutorService;
@@ -12,59 +12,58 @@ import java.util.concurrent.TimeUnit;
 import org.junit.Assert;
 import org.junit.Test;
 
-import com.baeldung.concurrent.mutex.SequenceGenerator;
-import com.baeldung.concurrent.mutex.SequenceGeneratorUsingMonitor;
-import com.baeldung.concurrent.mutex.SequenceGeneratorUsingReentrantLock;
-import com.baeldung.concurrent.mutex.SequenceGeneratorUsingSemaphore;
-import com.baeldung.concurrent.mutex.SequenceGeneratorUsingSynchronizedBlock;
-import com.baeldung.concurrent.mutex.SequenceGeneratorUsingSynchronizedMethod;
-
 public class MutexUnitTest {
 
-    private final int RANGE = 30;
-
-    @Test
+    // @Test
+    // This test verifies the race condition use case, it may pass or fail based on execution environment
+    // Uncomment @Test to run it
     public void givenUnsafeSequenceGenerator_whenRaceCondition_thenUnexpectedBehavior() throws Exception {
-        Set<Integer> uniqueSequences = getASetOFUniqueSequences(new SequenceGenerator());
-        Assert.assertNotEquals(RANGE, uniqueSequences.size());
+        int count = 1000;
+        Set<Integer> uniqueSequences = getUniqueSequences(new SequenceGenerator(), count);
+        Assert.assertNotEquals(count, uniqueSequences.size());
     }
 
     @Test
     public void givenSequenceGeneratorUsingSynchronizedMethod_whenRaceCondition_thenSuccess() throws Exception {
-        Set<Integer> uniqueSequences = getASetOFUniqueSequences(new SequenceGeneratorUsingSynchronizedMethod());
-        Assert.assertEquals(RANGE, uniqueSequences.size());
+        int count = 1000;
+        Set<Integer> uniqueSequences = getUniqueSequences(new SequenceGeneratorUsingSynchronizedMethod(), count);
+        Assert.assertEquals(count, uniqueSequences.size());
     }
 
     @Test
     public void givenSequenceGeneratorUsingSynchronizedBlock_whenRaceCondition_thenSuccess() throws Exception {
-        Set<Integer> uniqueSequences = getASetOFUniqueSequences(new SequenceGeneratorUsingSynchronizedBlock());
-        Assert.assertEquals(RANGE, uniqueSequences.size());
+        int count = 1000;
+        Set<Integer> uniqueSequences = getUniqueSequences(new SequenceGeneratorUsingSynchronizedBlock(), count);
+        Assert.assertEquals(count, uniqueSequences.size());
     }
 
     @Test
     public void givenSequenceGeneratorUsingReentrantLock_whenRaceCondition_thenSuccess() throws Exception {
-        Set<Integer> uniqueSequences = getASetOFUniqueSequences(new SequenceGeneratorUsingReentrantLock());
-        Assert.assertEquals(RANGE, uniqueSequences.size());
+        int count = 1000;
+        Set<Integer> uniqueSequences = getUniqueSequences(new SequenceGeneratorUsingReentrantLock(), count);
+        Assert.assertEquals(count, uniqueSequences.size());
     }
 
     @Test
     public void givenSequenceGeneratorUsingSemaphore_whenRaceCondition_thenSuccess() throws Exception {
-        Set<Integer> uniqueSequences = getASetOFUniqueSequences(new SequenceGeneratorUsingSemaphore());
-        Assert.assertEquals(RANGE, uniqueSequences.size());
+        int count = 1000;
+        Set<Integer> uniqueSequences = getUniqueSequences(new SequenceGeneratorUsingSemaphore(), count);
+        Assert.assertEquals(count, uniqueSequences.size());
     }
 
     @Test
     public void givenSequenceGeneratorUsingMonitor_whenRaceCondition_thenSuccess() throws Exception {
-        Set<Integer> uniqueSequences = getASetOFUniqueSequences(new SequenceGeneratorUsingMonitor());
-        Assert.assertEquals(RANGE, uniqueSequences.size());
+        int count = 1000;
+        Set<Integer> uniqueSequences = getUniqueSequences(new SequenceGeneratorUsingMonitor(), count);
+        Assert.assertEquals(count, uniqueSequences.size());
     }
 
-    private Set<Integer> getASetOFUniqueSequences(SequenceGenerator generator) throws Exception {
+    private Set<Integer> getUniqueSequences(SequenceGenerator generator, int count) throws Exception {
         ExecutorService executor = Executors.newFixedThreadPool(3);
-        Set<Integer> uniqueSequences = new HashSet<>();
+        Set<Integer> uniqueSequences = new LinkedHashSet<>();
         List<Future<Integer>> futures = new ArrayList<>();
 
-        for (int i = 0; i < RANGE; i++) {
+        for (int i = 0; i < count; i++) {
             futures.add(executor.submit(generator::getNextSequence));
         }
 
@@ -72,7 +71,7 @@ public class MutexUnitTest {
             uniqueSequences.add(future.get());
         }
 
-        executor.awaitTermination(15, TimeUnit.SECONDS);
+        executor.awaitTermination(1, TimeUnit.SECONDS);
         executor.shutdown();
 
         return uniqueSequences;

core-java-modules/core-java-exceptions/src/main/java/com/baeldung/exceptions/CheckedUncheckedExceptions.java

@@ -0,0 +1,43 @@
+package com.baeldung.exceptions;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+
+public class CheckedUncheckedExceptions {
+    public static void checkedExceptionWithThrows() throws FileNotFoundException {
+        File file = new File("not_existing_file.txt");
+        FileInputStream stream = new FileInputStream(file);
+    }
+
+    public static void checkedExceptionWithTryCatch() {
+        File file = new File("not_existing_file.txt");
+        try {
+            FileInputStream stream = new FileInputStream(file);
+        } catch (FileNotFoundException e) {
+            e.printStackTrace();
+        }
+    }
+
+    public static int divideByZero() {
+        int numerator = 1;
+        int denominator = 0;
+        return numerator / denominator;
+    }
+
+    public static void checkFile(String fileName) throws IncorrectFileNameException {
+        if (fileName == null || fileName.isEmpty()) {
+            throw new NullOrEmptyException("The filename is null.");
+        }
+        if (!isCorrectFileName(fileName)) {
+            throw new IncorrectFileNameException("Incorrect filename : " + fileName);
+        }
+    }
+
+    private static boolean isCorrectFileName(String fileName) {
+        if (fileName.equals("wrongFileName.txt"))
+            return false;
+        else
+            return true;
+    }
+}

core-java-modules/core-java-exceptions/src/main/java/com/baeldung/exceptions/IncorrectFileNameException.java

@@ -0,0 +1,13 @@
+package com.baeldung.exceptions;
+
+public class IncorrectFileNameException extends Exception {
+    private static final long serialVersionUID = 1L;
+
+    public IncorrectFileNameException(String errorMessage) {
+        super(errorMessage);
+    }
+
+    public IncorrectFileNameException(String errorMessage, Throwable thr) {
+        super(errorMessage, thr);
+    }
+}

core-java-modules/core-java-exceptions/src/main/java/com/baeldung/exceptions/NullOrEmptyException.java

@@ -0,0 +1,14 @@
+package com.baeldung.exceptions;
+
+public class NullOrEmptyException extends RuntimeException {
+
+    private static final long serialVersionUID = 1L;
+
+    public NullOrEmptyException(String errorMessage) {
+        super(errorMessage);
+    }
+
+    public NullOrEmptyException(String errorMessage, Throwable thr) {
+        super(errorMessage, thr);
+    }
+}

core-java-modules/core-java-exceptions/src/test/java/com/baeldung/exceptions/CheckedUncheckedExceptionsUnitTest.java

@@ -0,0 +1,55 @@
+package com.baeldung.exceptions;
+
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import java.io.FileNotFoundException;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+/**
+ * Tests the {@link CheckedUncheckedExceptions}.
+ */
+public class CheckedUncheckedExceptionsUnitTest {
+
+    @Test
+    public void whenFileNotExist_thenThrowException() {
+        assertThrows(FileNotFoundException.class, () -> {
+            CheckedUncheckedExceptions.checkedExceptionWithThrows();
+        });
+    }
+
+    @Test
+    public void whenTryCatchExcetpion_thenSuccess() {
+        try {
+            CheckedUncheckedExceptions.checkedExceptionWithTryCatch();
+        } catch (Exception e) {
+            Assertions.fail(e.getMessage());
+        }
+    }
+
+    @Test
+    public void whenDivideByZero_thenThrowException() {
+        assertThrows(ArithmeticException.class, () -> {
+            CheckedUncheckedExceptions.divideByZero();
+        });
+    }
+
+    @Test
+    public void whenInvalidFile_thenThrowException() {
+
+        assertThrows(IncorrectFileNameException.class, () -> {
+            CheckedUncheckedExceptions.checkFile("wrongFileName.txt");
+        });
+    }
+
+    @Test
+    public void whenNullOrEmptyFile_thenThrowException() {
+        assertThrows(NullOrEmptyException.class, () -> {
+            CheckedUncheckedExceptions.checkFile(null);
+        });
+        assertThrows(NullOrEmptyException.class, () -> {
+            CheckedUncheckedExceptions.checkFile("");
+        });
+    }
+}

core-java-modules/core-java-lang-oop-2/src/main/java/com/baeldung/core/modifiers/Employee.java

@@ -0,0 +1,50 @@
+package com.baeldung.core.modifiers;
+
+public class Employee {
+
+    private String privateId;
+    public String name;
+    private boolean manager;
+
+    public Employee(String id, String name) {
+        changeId(id);
+        this.name = name;
+    }
+
+    private Employee(String id, String name, boolean managerAttribute) {
+        this.privateId = id;
+        this.name = name;
+        this.privateId = id + "_ID-MANAGER";
+    }
+
+    public void changeId(String customId) {
+        if (customId.endsWith("_ID")) {
+            this.privateId = customId;
+        } else {
+            this.privateId = customId + "_ID";
+        }
+    }
+
+    public String getId() {
+        return privateId;
+    }
+
+    public boolean isManager() {
+        return manager;
+    }
+
+    public void elevateToManager() {
+        if ("Carl".equals(this.name)) {
+            setManager(true);
+        }
+    }
+
+    private void setManager(boolean manager) {
+        this.manager = manager;
+    }
+
+    public static Employee buildManager(String id, String name) {
+        return new Employee(id, name, true);
+    }
+    
+}

core-java-modules/core-java-lang-oop-2/src/main/java/com/baeldung/core/modifiers/ExampleClass.java

@@ -0,0 +1,10 @@
+package com.baeldung.core.modifiers;
+
+public class ExampleClass {
+
+    public static void main(String[] args) {
+        Employee employee = new Employee("Bob","ABC123");
+        employee.changeId("BCD234");
+        System.out.println(employee.getId());
+    }
+}

core-java-modules/core-java-lang-oop-2/src/main/java/com/baeldung/core/modifiers/PublicOuterClass.java

@@ -0,0 +1,16 @@
+package com.baeldung.core.modifiers;
+
+public class PublicOuterClass {
+
+    public PrivateInnerClass getInnerClassInstance() {
+        PrivateInnerClass myPrivateClassInstance = this.new PrivateInnerClass();
+        myPrivateClassInstance.id = "ID1";
+        myPrivateClassInstance.name = "Bob";
+        return myPrivateClassInstance;
+    }
+
+    private class PrivateInnerClass {
+        public String name;
+        public String id;
+    }
+}

gradle-5/.gitignore

@@ -1,6 +0,0 @@
-/build/
-/bin/
-.settings
-.gradle
-.project
-.classpath

java-blockchain/.gitignore

@@ -0,0 +1,26 @@
+*.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-blockchain/README.md

@@ -0,0 +1,6 @@
+=========
+
+## Basic Implementation of Blockchian in Java
+
+### Relevant Articles: 
+- []()

java-blockchain/pom.xml

@@ -0,0 +1,40 @@
+<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.blockchain</groupId>
+    <artifactId>java-blockchain</artifactId>
+    <version>0.1.0-SNAPSHOT</version>
+    <name>java-blockchain</name>
+    <packaging>jar</packaging>
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-java</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../parent-java</relativePath>
+    </parent>
+    <build>
+        <finalName>java-blockchain</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>${maven-compiler-plugin.version}</version>
+                <configuration>
+                    <source>${maven.compiler.source}</source>
+                    <target>${maven.compiler.target}</target>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+    <properties>
+        <maven.compiler.source>1.8</maven.compiler.source>
+        <maven.compiler.target>1.8</maven.compiler.target>
+    </properties>
+</project>

java-blockchain/src/main/java/com/baeldung/blockchain/Block.java

@@ -0,0 +1,65 @@
+package com.baeldung.blockchain;
+
+import java.io.UnsupportedEncodingException;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.util.Date;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+public class Block {
+
+    private static Logger logger = Logger.getLogger(Block.class.getName());
+
+    private String hash;
+    private String previousHash;
+    private String data;
+    private long timeStamp;
+    private int nonce;
+
+    public Block(String data, String previousHash) {
+        this.data = data;
+        this.previousHash = previousHash;
+        this.timeStamp = new Date().getTime();
+        this.hash = calculateBlockHash();
+    }
+
+    public String mineBlock(int prefix) {
+        String prefixString = new String(new char[prefix]).replace('\0', '0');
+        while (!hash.substring(0, prefix)
+            .equals(prefixString)) {
+            nonce++;
+            hash = calculateBlockHash();
+        }
+        return hash;
+    }
+
+    public String calculateBlockHash() {
+        String dataToHash = previousHash + Long.toString(timeStamp) + Integer.toString(nonce) + data;
+        MessageDigest digest = null;
+        byte[] bytes = null;
+        try {
+            digest = MessageDigest.getInstance("SHA-256");
+            bytes = digest.digest(dataToHash.getBytes("UTF-8"));
+        } catch (NoSuchAlgorithmException | UnsupportedEncodingException ex) {
+            logger.log(Level.SEVERE, ex.getMessage());
+        }
+        StringBuffer buffer = new StringBuffer();
+        for (byte b : bytes) {
+            buffer.append(String.format("%02x", b));
+        }
+        return buffer.toString();
+    }
+
+    public String getHash() {
+        return this.hash;
+    }
+
+    public String getPreviousHash() {
+        return this.previousHash;
+    }
+
+    public void setData(String data) {
+        this.data = data;
+    }
+}

java-blockchain/src/main/resources/logback.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
+            </pattern>
+        </encoder>
+    </appender>
+
+    <root level="INFO">
+        <appender-ref ref="STDOUT" />
+    </root>
+</configuration>

java-blockchain/src/test/java/com/baeldung/blockchain/BlockchainUnitTest.java

@@ -0,0 +1,67 @@
+package com.baeldung.blockchain;
+
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+public class BlockchainUnitTest {
+
+    public static List<Block> blockchain = new ArrayList<Block>();
+    public static int prefix = 4;
+    public static String prefixString = new String(new char[prefix]).replace('\0', '0');
+
+    @BeforeClass
+    public static void setUp() {
+        Block genesisBlock = new Block("The is the Genesis Block.", "0");
+        genesisBlock.mineBlock(prefix);
+        blockchain.add(genesisBlock);
+        Block firstBlock = new Block("The is the First Block.", genesisBlock.getHash());
+        firstBlock.mineBlock(prefix);
+        blockchain.add(firstBlock);
+    }
+
+    @Test
+    public void givenBlockchain_whenNewBlockAdded_thenSuccess() {
+        Block newBlock = new Block("The is a New Block.", blockchain.get(blockchain.size() - 1)
+            .getHash());
+        newBlock.mineBlock(prefix);
+        assertTrue(newBlock.getHash()
+            .substring(0, prefix)
+            .equals(prefixString));
+        blockchain.add(newBlock);
+    }
+
+    @Test
+    public void givenBlockchain_whenValidated_thenSuccess() {
+        boolean flag = true;
+        for (int i = 0; i < blockchain.size(); i++) {
+            String previousHash = i == 0 ? "0"
+                : blockchain.get(i - 1)
+                    .getHash();
+            flag = blockchain.get(i)
+                .getHash()
+                .equals(blockchain.get(i)
+                    .calculateBlockHash())
+                && previousHash.equals(blockchain.get(i)
+                    .getPreviousHash())
+                && blockchain.get(i)
+                    .getHash()
+                    .substring(0, prefix)
+                    .equals(prefixString);
+            if (!flag)
+                break;
+        }
+        assertTrue(flag);
+    }
+
+    @AfterClass
+    public static void tearDown() {
+        blockchain.clear();
+    }
+
+}

java-blockchain/src/test/resources/.gitignore

@@ -0,0 +1,13 @@
+*.class
+
+#folders#
+/target
+/neoDb*
+/data
+/src/main/webapp/WEB-INF/classes
+*/META-INF/*
+
+# Packaged files #
+*.jar
+*.war
+*.ear

java-jdi/src/main/java/com/baeldung/jdi/JDIExampleDebuggee.java

@@ -1,6 +1,6 @@
 package com.baeldung.jdi;
 
-public class JDIExample {
+public class JDIExampleDebuggee {
 
     public static void main(String[] args) {
         String jpda = "Java Platform Debugger Architecture";

java-jdi/src/main/java/com/baeldung/jdi/JDIExampleDebugger.java

@@ -123,7 +123,7 @@ public class JDIExampleDebugger {
     public static void main(String[] args) throws Exception {
 
         JDIExampleDebugger debuggerInstance = new JDIExampleDebugger();
-        debuggerInstance.setDebugClass(JDIExample.class);
+        debuggerInstance.setDebugClass(JDIExampleDebuggee.class);
         int[] breakPoints = {6, 9};
         debuggerInstance.setBreakPointLines(breakPoints);
         VirtualMachine vm = null;

java-strings-2/src/main/java/com/baeldung/string/streamtokenizer/StreamTokenizerDemo.java

@@ -0,0 +1,76 @@
+package com.baeldung.string.streamtokenizer;
+
+import java.io.*;
+import java.util.ArrayList;
+import java.util.List;
+
+public class StreamTokenizerDemo {
+
+    private static final String INPUT_FILE = "/stream-tokenizer-example.txt";
+    private static final int QUOTE_CHARACTER = '\'';
+    private static final int DOUBLE_QUOTE_CHARACTER = '"';
+
+    public static List<Object> streamTokenizerWithDefaultConfiguration(Reader reader) throws IOException {
+        StreamTokenizer streamTokenizer = new StreamTokenizer(reader);
+        List<Object> tokens = new ArrayList<>();
+
+        int currentToken = streamTokenizer.nextToken();
+        while (currentToken != StreamTokenizer.TT_EOF) {
+
+            if (streamTokenizer.ttype == StreamTokenizer.TT_NUMBER) {
+                tokens.add(streamTokenizer.nval);
+            } else if (streamTokenizer.ttype == StreamTokenizer.TT_WORD
+                    || streamTokenizer.ttype == QUOTE_CHARACTER
+                    || streamTokenizer.ttype == DOUBLE_QUOTE_CHARACTER) {
+                tokens.add(streamTokenizer.sval);
+            } else {
+                tokens.add((char) currentToken);
+            }
+
+            currentToken = streamTokenizer.nextToken();
+        }
+
+        return tokens;
+    }
+
+    public static List<Object> streamTokenizerWithCustomConfiguration(Reader reader) throws IOException {
+        StreamTokenizer streamTokenizer = new StreamTokenizer(reader);
+        List<Object> tokens = new ArrayList<>();
+
+        streamTokenizer.wordChars('!', '-');
+        streamTokenizer.ordinaryChar('/');
+        streamTokenizer.commentChar('#');
+        streamTokenizer.eolIsSignificant(true);
+
+        int currentToken = streamTokenizer.nextToken();
+        while (currentToken != StreamTokenizer.TT_EOF) {
+
+            if (streamTokenizer.ttype == StreamTokenizer.TT_NUMBER) {
+                tokens.add(streamTokenizer.nval);
+            } else if (streamTokenizer.ttype == StreamTokenizer.TT_WORD
+                    || streamTokenizer.ttype == QUOTE_CHARACTER
+                    || streamTokenizer.ttype == DOUBLE_QUOTE_CHARACTER) {
+                tokens.add(streamTokenizer.sval);
+            } else {
+                tokens.add((char) currentToken);
+            }
+            currentToken = streamTokenizer.nextToken();
+        }
+
+        return tokens;
+    }
+
+    public static Reader createReaderFromFile() throws FileNotFoundException {
+        String inputFile = StreamTokenizerDemo.class.getResource(INPUT_FILE).getFile();
+        return new FileReader(inputFile);
+    }
+
+    public static void main(String[] args) throws IOException {
+        List<Object> tokens1 = streamTokenizerWithDefaultConfiguration(createReaderFromFile());
+        List<Object> tokens2 = streamTokenizerWithCustomConfiguration(createReaderFromFile());
+
+        System.out.println(tokens1);
+        System.out.println(tokens2);
+    }
+
+}

java-strings-2/src/main/resources/stream-tokenizer-example.txt

@@ -0,0 +1,3 @@
+3 quick brown foxes jump over the "lazy" dog!
+#test1
+//test2

java-strings-2/src/test/java/com/baeldung/string/streamtokenizer/StreamTokenizerDemoUnitTest.java

@@ -0,0 +1,34 @@
+package com.baeldung.string.streamtokenizer;
+
+import org.junit.Test;
+
+import java.io.IOException;
+import java.io.Reader;
+import java.util.Arrays;
+import java.util.List;
+
+import static org.junit.Assert.assertArrayEquals;
+
+public class StreamTokenizerDemoUnitTest {
+
+    @Test
+    public void whenStreamTokenizerWithDefaultConfigurationIsCalled_ThenCorrectTokensAreReturned() throws IOException {
+        Reader reader = StreamTokenizerDemo.createReaderFromFile();
+        List<Object> expectedTokens = Arrays.asList(3.0, "quick", "brown", "foxes", "jump", "over", "the", "lazy", "dog", '!', '#', "test1");
+
+        List<Object> actualTokens = StreamTokenizerDemo.streamTokenizerWithDefaultConfiguration(reader);
+
+        assertArrayEquals(expectedTokens.toArray(), actualTokens.toArray());
+    }
+
+    @Test
+    public void whenStreamTokenizerWithCustomConfigurationIsCalled_ThenCorrectTokensAreReturned() throws IOException {
+        Reader reader = StreamTokenizerDemo.createReaderFromFile();
+        List<Object> expectedTokens = Arrays.asList(3.0, "quick", "brown", "foxes", "jump", "over", "the", "\"lazy\"", "dog!", '\n', '\n', '/', '/', "test2");
+
+        List<Object> actualTokens = StreamTokenizerDemo.streamTokenizerWithCustomConfiguration(reader);
+
+        assertArrayEquals(expectedTokens.toArray(), actualTokens.toArray());
+    }
+
+}

jersey/pom.xml

@@ -32,7 +32,7 @@
         <dependency>
             <groupId>org.glassfish.jersey.containers</groupId>
             <artifactId>jersey-container-grizzly2-servlet</artifactId>
-             <version>${jersey.version}</version>
+            <version>${jersey.version}</version>
         </dependency>
         <dependency>
             <groupId>org.glassfish.jersey.ext</groupId>
@@ -44,6 +44,21 @@
             <artifactId>jersey-bean-validation</artifactId>
             <version>${jersey.version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.glassfish.jersey.security</groupId>
+            <artifactId>oauth1-client</artifactId>
+            <version>${jersey.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.glassfish.jersey.security</groupId>
+            <artifactId>oauth2-client</artifactId>
+            <version>${jersey.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.glassfish.jersey.media</groupId>
+            <artifactId>jersey-media-sse</artifactId>
+            <version>${jersey.version}</version>
+        </dependency>
         <dependency>
             <groupId>org.glassfish.jersey.test-framework</groupId>
             <artifactId>jersey-test-framework-core</artifactId>

jersey/src/main/java/com/baeldung/jersey/client/JerseyClientHeaders.java

@@ -0,0 +1,189 @@
+package com.baeldung.jersey.client;
+
+import com.baeldung.jersey.client.filter.AddHeaderOnRequestFilter;
+import org.glassfish.jersey.client.authentication.HttpAuthenticationFeature;
+import org.glassfish.jersey.client.oauth1.AccessToken;
+import org.glassfish.jersey.client.oauth1.ConsumerCredentials;
+import org.glassfish.jersey.client.oauth1.OAuth1ClientSupport;
+import org.glassfish.jersey.client.oauth2.OAuth2ClientSupport;
+
+import javax.ws.rs.client.Client;
+import javax.ws.rs.client.ClientBuilder;
+import javax.ws.rs.client.Invocation;
+import javax.ws.rs.client.WebTarget;
+import javax.ws.rs.core.Feature;
+import javax.ws.rs.core.Response;
+import javax.ws.rs.sse.InboundSseEvent;
+import javax.ws.rs.sse.SseEventSource;
+
+import static org.glassfish.jersey.client.authentication.HttpAuthenticationFeature.*;
+
+public class JerseyClientHeaders {
+
+    private static final String BEARER_CONSUMER_SECRET = "my-consumer-secret";
+    private static final String BEARER_ACCESS_TOKEN_SECRET = "my-access-token-secret";
+    private static final String TARGET = "http://localhost:9998/";
+    private static final String MAIN_RESOURCE = "echo-headers";
+    private static final String RESOURCE_AUTH_DIGEST = "digest";
+
+    private static String sseHeaderValue;
+
+    public static Response simpleHeader(String headerKey, String headerValue) {
+        Client client = ClientBuilder.newClient();
+        WebTarget webTarget = client.target(TARGET);
+        WebTarget resourceWebTarget = webTarget.path(MAIN_RESOURCE);
+        Invocation.Builder invocationBuilder = resourceWebTarget.request();
+        invocationBuilder.header(headerKey, headerValue);
+        return invocationBuilder.get();
+    }
+
+    public static Response simpleHeaderFluently(String headerKey, String headerValue) {
+        Client client = ClientBuilder.newClient();
+        return client.target(TARGET)
+                .path(MAIN_RESOURCE)
+                .request()
+                .header(headerKey, headerValue)
+                .get();
+    }
+
+    public static Response basicAuthenticationAtClientLevel(String username, String password) {
+        //To simplify we removed de SSL/TLS protection, but it's required to have an encryption
+        // when using basic authentication schema as it's send only on Base64 encoding
+        HttpAuthenticationFeature feature = HttpAuthenticationFeature.basic(username, password);
+        Client client = ClientBuilder.newBuilder().register(feature).build();
+        return client.target(TARGET)
+                .path(MAIN_RESOURCE)
+                .request()
+                .get();
+    }
+
+    public static Response basicAuthenticationAtRequestLevel(String username, String password) {
+        //To simplify we removed de SSL/TLS protection, but it's required to have an encryption
+        // when using basic authentication schema as it's send only on Base64 encoding
+        HttpAuthenticationFeature feature = HttpAuthenticationFeature.basicBuilder().build();
+        Client client = ClientBuilder.newBuilder().register(feature).build();
+        return client.target(TARGET)
+                .path(MAIN_RESOURCE)
+                .request()
+                .property(HTTP_AUTHENTICATION_BASIC_USERNAME, username)
+                .property(HTTP_AUTHENTICATION_BASIC_PASSWORD, password)
+                .get();
+    }
+
+    public static Response digestAuthenticationAtClientLevel(String username, String password) {
+        HttpAuthenticationFeature feature = HttpAuthenticationFeature.digest(username, password);
+        Client client = ClientBuilder.newBuilder().register(feature).build();
+        return client.target(TARGET)
+                .path(MAIN_RESOURCE)
+                .path(RESOURCE_AUTH_DIGEST)
+                .request()
+                .get();
+    }
+
+    public static Response digestAuthenticationAtRequestLevel(String username, String password) {
+        HttpAuthenticationFeature feature = HttpAuthenticationFeature.digest();
+
+        Client client = ClientBuilder.newBuilder().register(feature).build();
+        return client.target(TARGET)
+                .path(MAIN_RESOURCE)
+                .path(RESOURCE_AUTH_DIGEST)
+                .request()
+                .property(HTTP_AUTHENTICATION_DIGEST_USERNAME, username)
+                .property(HTTP_AUTHENTICATION_DIGEST_PASSWORD, password)
+                .get();
+    }
+
+    public static Response bearerAuthenticationWithOAuth1AtClientLevel(String token, String consumerKey) {
+        ConsumerCredentials consumerCredential = new ConsumerCredentials(consumerKey, BEARER_CONSUMER_SECRET);
+        AccessToken accessToken = new AccessToken(token, BEARER_ACCESS_TOKEN_SECRET);
+        Feature feature = OAuth1ClientSupport
+                .builder(consumerCredential)
+                .feature()
+                .accessToken(accessToken)
+                .build();
+
+        Client client = ClientBuilder.newBuilder().register(feature).build();
+        return client.target(TARGET)
+                .path(MAIN_RESOURCE)
+                .request()
+                .get();
+    }
+
+    public static Response bearerAuthenticationWithOAuth1AtRequestLevel(String token, String consumerKey) {
+        ConsumerCredentials consumerCredential = new ConsumerCredentials(consumerKey, BEARER_CONSUMER_SECRET);
+        AccessToken accessToken = new AccessToken(token, BEARER_ACCESS_TOKEN_SECRET);
+        Feature feature = OAuth1ClientSupport
+                .builder(consumerCredential)
+                .feature()
+                .build();
+
+        Client client = ClientBuilder.newBuilder().register(feature).build();
+        return client.target(TARGET)
+                .path(MAIN_RESOURCE)
+                .request()
+                .property(OAuth1ClientSupport.OAUTH_PROPERTY_ACCESS_TOKEN, accessToken)
+                .get();
+    }
+
+    public static Response bearerAuthenticationWithOAuth2AtClientLevel(String token) {
+        Feature feature = OAuth2ClientSupport.feature(token);
+
+        Client client = ClientBuilder.newBuilder().register(feature).build();
+        return client.target(TARGET)
+                .path(MAIN_RESOURCE)
+                .request()
+                .get();
+    }
+
+    public static Response bearerAuthenticationWithOAuth2AtRequestLevel(String token, String otherToken) {
+        Feature feature = OAuth2ClientSupport.feature(token);
+
+        Client client = ClientBuilder.newBuilder().register(feature).build();
+        return client.target(TARGET)
+                .path(MAIN_RESOURCE)
+                .request()
+                .property(OAuth2ClientSupport.OAUTH2_PROPERTY_ACCESS_TOKEN, otherToken)
+                .get();
+    }
+
+    public static Response filter() {
+        Client client = ClientBuilder.newBuilder().register(AddHeaderOnRequestFilter.class).build();
+        return client.target(TARGET)
+                .path(MAIN_RESOURCE)
+                .request()
+                .get();
+    }
+
+    public static Response sendRestrictedHeaderThroughDefaultTransportConnector(String headerKey, String headerValue) {
+        Client client = ClientBuilder.newClient();
+        System.setProperty("sun.net.http.allowRestrictedHeaders", "true");
+
+        return client.target(TARGET)
+                .path(MAIN_RESOURCE)
+                .request()
+                .header(headerKey, headerValue)
+                .get();
+    }
+
+    public static String simpleSSEHeader() throws InterruptedException {
+        Client client = ClientBuilder.newBuilder()
+                .register(AddHeaderOnRequestFilter.class)
+                .build();
+
+        WebTarget webTarget = client.target(TARGET)
+                .path(MAIN_RESOURCE)
+                .path("events");
+
+        SseEventSource sseEventSource = SseEventSource.target(webTarget).build();
+        sseEventSource.register(JerseyClientHeaders::receiveEvent);
+        sseEventSource.open();
+        Thread.sleep(3_000);
+        sseEventSource.close();
+
+        return sseHeaderValue;
+    }
+
+    private static void receiveEvent(InboundSseEvent event) {
+        sseHeaderValue = event.readData();
+    }
+}

jersey/src/main/java/com/baeldung/jersey/client/filter/AddHeaderOnRequestFilter.java

@@ -0,0 +1,16 @@
+package com.baeldung.jersey.client.filter;
+
+import javax.ws.rs.client.ClientRequestContext;
+import javax.ws.rs.client.ClientRequestFilter;
+import java.io.IOException;
+
+public class AddHeaderOnRequestFilter implements ClientRequestFilter {
+
+    public static final String FILTER_HEADER_VALUE = "filter-header-value";
+    public static final String FILTER_HEADER_KEY = "x-filter-header";
+
+    @Override
+    public void filter(ClientRequestContext requestContext) throws IOException {
+        requestContext.getHeaders().add(FILTER_HEADER_KEY, FILTER_HEADER_VALUE);
+    }
+}