Merge branch 'eugenp:master' into master

2024-02-01 14:47:22 +01:00
parent ab43a18bb0 59e33914a7
commit 36363a112e
169 changed files with 1631 additions and 344 deletions
@@ -46,7 +46,7 @@
        <maven.compiler.source.version>11</maven.compiler.source.version>
        <maven.compiler.target.version>11</maven.compiler.target.version>
        <jackson.version>2.16.0</jackson.version>
-        <gson.version>2.10</gson.version>
+        <gson.version>2.10.1</gson.version>
    </properties>

 </project>
@@ -3,3 +3,4 @@
 - [String Templates in Java 21](https://www.baeldung.com/java-21-string-templates)
 - [Unnamed Classes and Instance Main Methods in Java 21](https://www.baeldung.com/java-21-unnamed-class-instance-main)
 - [Unnamed Patterns and Variables in Java 21](https://www.baeldung.com/java-unnamed-patterns-variables)
+- [JFR View Command in Java 21](https://www.baeldung.com/java-flight-recorder-view)
@@ -11,4 +11,6 @@
 - [Retrieving Unix Time in Java](https://www.baeldung.com/java-retrieve-unix-time)
 - [Calculate Months Between Two Dates in Java](https://www.baeldung.com/java-months-difference-two-dates)
 - [Format LocalDate to ISO 8601 With T and Z](https://www.baeldung.com/java-format-localdate-iso-8601-t-z)
+- [Check if Two Date Ranges Overlap](https://www.baeldung.com/java-check-two-date-ranges-overlap)
+- [Difference between ZoneOffset.UTC and ZoneId.of(“UTC”)](https://www.baeldung.com/java-zoneoffset-utc-zoneid-of)
 - [[<-- Prev]](/core-java-modules/core-java-datetime-java8-1)
@@ -12,3 +12,4 @@ This module contains articles about arrays conversion in Java
 - [Convert an ArrayList of String to a String Array in Java](https://www.baeldung.com/java-convert-string-arraylist-array)
 - [Convert Char Array to Int Array in Java](https://www.baeldung.com/java-convert-char-int-array)
 - [How to Convert Byte Array to Char Array](https://www.baeldung.com/java-convert-byte-array-char)
+- [Convert byte[] to Byte[] and Vice Versa in Java](https://www.baeldung.com/java-byte-array-wrapper-primitive-type-convert)
@@ -7,10 +7,6 @@
    <name>core-java-arrays-guides</name>
    <packaging>jar</packaging>

-    <properties>
-        <system-stubs.jupiter.version>2.1.5</system-stubs.jupiter.version>
-    </properties>
-
    <parent>
        <artifactId>core-java-modules</artifactId>
        <groupId>com.baeldung.core-java-modules</groupId>
@@ -34,7 +30,10 @@
            <version>${system-stubs.jupiter.version}</version>
            <scope>test</scope>
        </dependency>
-
    </dependencies>

+    <properties>
+        <system-stubs.jupiter.version>2.1.5</system-stubs.jupiter.version>
+    </properties>
+
 </project>
@@ -13,4 +13,5 @@
 - [Time Complexity of Java Collections Sort in Java](https://www.baeldung.com/java-time-complexity-collections-sort)
 - [Check if List Contains at Least One Enum](https://www.baeldung.com/java-list-check-enum-presence)
 - [Comparison of for Loops and Iterators](https://www.baeldung.com/java-for-loops-vs-iterators)
+- [PriorityQueue iterator() Method in Java](https://www.baeldung.com/java-priorityqueue-iterator)
 - More articles: [[<-- prev]](/core-java-modules/core-java-collections-4)
@@ -5,18 +5,6 @@
    <modelVersion>4.0.0</modelVersion>
    <artifactId>core-java-collections-5</artifactId>
    <name>core-java-collections-5</name>
-    <build>
-        <plugins>
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-compiler-plugin</artifactId>
-                <configuration>
-                    <source>9</source>
-                    <target>9</target>
-                </configuration>
-            </plugin>
-        </plugins>
-    </build>
    <packaging>jar</packaging>

    <parent>
@@ -61,6 +49,19 @@
        </dependency>
    </dependencies>

+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <source>9</source>
+                    <target>9</target>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
    <properties>
        <junit.version>5.9.2</junit.version>
        <roaringbitmap.version>0.9.38</roaringbitmap.version>
@@ -55,7 +55,6 @@
            <version>${org.json.version}</version>
            <scope>test</scope>
        </dependency>
-
    </dependencies>

    <properties>
@@ -3,3 +3,4 @@
 - [Removing the Last Node in a Linked List](https://www.baeldung.com/java-linked-list-remove-last-element)
 - [Call a Method on Each Element of a List in Java](https://www.baeldung.com/java-call-method-each-list-item)
 - [Sorting One List Based on Another List in Java](https://www.baeldung.com/java-sorting-one-list-using-another)
+- [Reset ListIterator to First Element of the List in Java](https://www.baeldung.com/java-reset-listiterator)
@@ -27,7 +27,7 @@
        <dependency>
            <groupId>com.google.code.gson</groupId>
            <artifactId>gson</artifactId>
-            <version>2.8.9</version>
+            <version>2.10.1</version>
        </dependency>
        <dependency>
            <groupId>org.json</groupId>
@@ -41,7 +41,7 @@
    </build>

    <properties>
-        <gson.version>2.8.5</gson.version>
+        <gson.version>2.10.1</gson.version>
    </properties>

 </project>
@@ -0,0 +1,33 @@
+package com.baeldung.countdownlatchvssemaphore;
+
+import java.util.concurrent.CountDownLatch;
+
+public class CountDownLatchDemo {
+
+    public static void main(String[] args) throws InterruptedException {
+        // Create a CountDownLatch with an initial count equal to the number of tasks to be completed
+        int numberOfTasks = 3;
+        CountDownLatch latch = new CountDownLatch(numberOfTasks);
+
+        // Simulate completion of tasks by worker threads
+        for (int i = 1; i <= numberOfTasks; i++) {
+            new Thread(() -> {
+                System.out.println("Task completed by Thread " + Thread.currentThread()
+                    .getId());
+
+                // Decrement the latch count to signal completion of a task
+                latch.countDown();
+            }).start();
+        }
+
+        // Main thread waits until all tasks are completed
+        latch.await();
+        System.out.println("All tasks completed. Main thread proceeds.");
+
+        // Attempting to reset will have no effect
+        latch.countDown();
+        // Latch is already at zero, await() returns immediately
+        latch.await(); // This line won't block
+        System.out.println("Latch is already at zero and cannot be reset.");
+    }
+}
@@ -0,0 +1,42 @@
+package com.baeldung.countdownlatchvssemaphore;
+
+import java.util.concurrent.Semaphore;
+
+public class SemaphoreDemo {
+
+    public static void main(String[] args) {
+        // Create a Semaphore with a fixed number of permits
+        int NUM_PERMITS = 3;
+        Semaphore semaphore = new Semaphore(NUM_PERMITS);
+
+        // Simulate resource access by worker threads
+        for (int i = 1; i <= 5; i++) {
+            new Thread(() -> {
+                try {
+                    // Acquire a permit to access the resource
+                    semaphore.acquire();
+                    System.out.println("Thread " + Thread.currentThread().getId() + " accessing resource.");
+
+                    // Simulate resource usage
+                    Thread.sleep(2000);
+                } catch (InterruptedException e) {
+                    e.printStackTrace();
+                } finally {
+                    // Release the permit after resource access is complete
+                    semaphore.release();
+                }
+            }).start();
+        }
+
+        // Simulate resetting the Semaphore by releasing additional permits after a delay
+        try {
+            Thread.sleep(5000);
+
+            // Resetting the semaphore permits to the initial count
+            semaphore.release(NUM_PERMITS);
+            System.out.println("Semaphore permits reset to initial count.");
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+    }
+}
@@ -8,3 +8,4 @@
 - [System.console() vs. System.out](https://www.baeldung.com/java-system-console-vs-system-out)
 - [How to Log to the Console in Color](https://www.baeldung.com/java-log-console-in-color)
 - [Create Table Using ASCII in a Console in Java](https://www.baeldung.com/java-console-ascii-make-table)
+- [Printing Message on Console without Using main() Method in Java](https://www.baeldung.com/java-no-main-print-message-console)
@@ -2,4 +2,5 @@
 This module contains articles about date operations in Java.

 ### Relevant Articles:
+- [Calculate Number of Weekdays Between Two Dates in Java](https://www.baeldung.com/java-count-weekdays-between-two-dates)

@@ -0,0 +1,42 @@
+package com.baeldung.stringdatetoxmlgregoriancalendar;
+
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+import java.time.LocalDate;
+import java.util.Date;
+import java.util.GregorianCalendar;
+
+import javax.xml.datatype.DatatypeConfigurationException;
+import javax.xml.datatype.DatatypeFactory;
+import javax.xml.datatype.XMLGregorianCalendar;
+
+import org.joda.time.DateTime;
+import org.joda.time.format.DateTimeFormat;
+
+public class StringDateToXMLGregorianCalendarConverter {
+    public static XMLGregorianCalendar usingDatatypeFactoryForDate(String dateAsString) throws DatatypeConfigurationException {
+        return DatatypeFactory.newInstance().newXMLGregorianCalendar(dateAsString);
+    }
+
+    public static XMLGregorianCalendar usingLocalDate(String dateAsString) throws DatatypeConfigurationException {
+        LocalDate localDate = LocalDate.parse(dateAsString);
+        return DatatypeFactory.newInstance().newXMLGregorianCalendar(localDate.toString());
+    }
+
+    public static XMLGregorianCalendar usingSimpleDateFormat(String dateTimeAsString) throws DatatypeConfigurationException, ParseException {
+        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");
+        Date date = simpleDateFormat.parse(dateTimeAsString);
+        return DatatypeFactory.newInstance().newXMLGregorianCalendar(simpleDateFormat.format(date));
+    }
+
+    public static XMLGregorianCalendar usingGregorianCalendar(String dateTimeAsString) throws DatatypeConfigurationException, ParseException {
+        GregorianCalendar calendar = new GregorianCalendar();
+        calendar.setTime(new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss").parse(dateTimeAsString));
+        return DatatypeFactory.newInstance().newXMLGregorianCalendar(calendar);
+    }
+
+    public static XMLGregorianCalendar usingJodaTime(String dateTimeAsString) throws DatatypeConfigurationException {
+        DateTime dateTime = DateTime.parse(dateTimeAsString, DateTimeFormat.forPattern("yyyy-MM-dd'T'HH:mm:ss"));
+        return DatatypeFactory.newInstance().newXMLGregorianCalendar(dateTime.toGregorianCalendar());
+    }
+}
@@ -0,0 +1,63 @@
+package com.baeldung.stringdatetoxmlgregoriancalendar;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.text.ParseException;
+import javax.xml.datatype.DatatypeConfigurationException;
+import javax.xml.datatype.XMLGregorianCalendar;
+
+import org.junit.jupiter.api.Test;
+
+public class StringDateToXMLGregorianCalendarConverterUnitTest {
+    private static final String dateAsString = "2014-04-24";
+    private static final String dateTimeAsString = "2014-04-24T15:45:30";
+
+    @Test
+    void givenStringDate_whenUsingDatatypeFactory_thenConvertToXMLGregorianCalendar() throws DatatypeConfigurationException {
+        XMLGregorianCalendar xmlGregorianCalendar = StringDateToXMLGregorianCalendarConverter.usingDatatypeFactoryForDate(dateAsString);
+        assertEquals(24,xmlGregorianCalendar.getDay());
+        assertEquals(4,xmlGregorianCalendar.getMonth());
+        assertEquals(2014,xmlGregorianCalendar.getYear());
+    }
+
+    @Test
+    void givenStringDateTime_whenUsingApacheCommonsLang3_thenConvertToXMLGregorianCalendar() throws DatatypeConfigurationException {
+        XMLGregorianCalendar xmlGregorianCalendar = StringDateToXMLGregorianCalendarConverter.usingLocalDate(dateAsString);
+        assertEquals(24,xmlGregorianCalendar.getDay());
+        assertEquals(4,xmlGregorianCalendar.getMonth());
+        assertEquals(2014,xmlGregorianCalendar.getYear());
+    }
+
+    @Test
+    void givenStringDateTime_whenUsingSimpleDateFormat_thenConvertToXMLGregorianCalendar() throws DatatypeConfigurationException, ParseException {
+        XMLGregorianCalendar xmlGregorianCalendar = StringDateToXMLGregorianCalendarConverter.usingSimpleDateFormat(dateTimeAsString);
+        assertEquals(24,xmlGregorianCalendar.getDay());
+        assertEquals(4,xmlGregorianCalendar.getMonth());
+        assertEquals(2014,xmlGregorianCalendar.getYear());
+        assertEquals(15,xmlGregorianCalendar.getHour());
+        assertEquals(45,xmlGregorianCalendar.getMinute());
+        assertEquals(30,xmlGregorianCalendar.getSecond());
+    }
+
+    @Test
+    void givenStringDateTime_whenUsingGregorianCalendar_thenConvertToXMLGregorianCalendar() throws DatatypeConfigurationException, ParseException {
+        XMLGregorianCalendar xmlGregorianCalendar = StringDateToXMLGregorianCalendarConverter.usingGregorianCalendar(dateTimeAsString);
+        assertEquals(24,xmlGregorianCalendar.getDay());
+        assertEquals(4,xmlGregorianCalendar.getMonth());
+        assertEquals(2014,xmlGregorianCalendar.getYear());
+        assertEquals(15,xmlGregorianCalendar.getHour());
+        assertEquals(45,xmlGregorianCalendar.getMinute());
+        assertEquals(30,xmlGregorianCalendar.getSecond());
+    }
+
+    @Test
+     void givenStringDateTime_whenUsingJodaTime_thenConvertToXMLGregorianCalendar() throws DatatypeConfigurationException {
+        XMLGregorianCalendar xmlGregorianCalendar = StringDateToXMLGregorianCalendarConverter.usingJodaTime(dateTimeAsString);
+        assertEquals(24,xmlGregorianCalendar.getDay());
+        assertEquals(4,xmlGregorianCalendar.getMonth());
+        assertEquals(2014,xmlGregorianCalendar.getYear());
+        assertEquals(15,xmlGregorianCalendar.getHour());
+        assertEquals(45,xmlGregorianCalendar.getMinute());
+        assertEquals(30,xmlGregorianCalendar.getSecond());
+    }
+}
@@ -5,3 +5,4 @@ This module contains articles about parsing and formatting Java date and time ob
 ### Relevant Articles: 
 - [Convert String to Instant](https://www.baeldung.com/java-string-to-instant)
 - [Sort Date Strings in Java](https://www.baeldung.com/java-sort-date-strings)
+- [Using Current Time as Filename in Java](https://www.baeldung.com/java-current-time-filename)
@@ -0,0 +1 @@
+Hello, world!
@@ -0,0 +1,85 @@
+package com.baeldung.readwritethread;
+
+import java.io.BufferedReader;
+import java.io.BufferedWriter;
+import java.io.FileReader;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.LinkedBlockingQueue;
+
+public class ReadWriteBlockingQueue {
+
+    public static void main(String[] args) throws InterruptedException {
+
+        BlockingQueue<String> queue = new LinkedBlockingQueue<>();
+        String readFileName = "src/main/resources/read_file.txt";
+        String writeFileName = "src/main/resources/write_file.txt";
+
+        Thread producerThread = new Thread(new FileProducer(queue, readFileName));
+        Thread consumerThread1 = new Thread(new FileConsumer(queue, writeFileName));
+
+        producerThread.start();
+        Thread.sleep(100); // Give producer a head start
+        consumerThread1.start();
+        try {
+            producerThread.join();
+            consumerThread1.join();
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+
+    }
+}
+
+class FileProducer implements Runnable {
+
+    private final BlockingQueue<String> queue;
+    private final String inputFileName;
+
+    public FileProducer(BlockingQueue<String> queue, String inputFileName) {
+        this.queue = queue;
+        this.inputFileName = inputFileName;
+    }
+
+    @Override
+    public void run() {
+        try (BufferedReader reader = new BufferedReader(new FileReader(inputFileName))) {
+            String line;
+            while ((line = reader.readLine()) != null) {
+                queue.offer(line);
+                System.out.println("Producer added line: " + line);
+                System.out.println("Queue size: " + queue.size());
+            }
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+}
+
+class FileConsumer implements Runnable {
+
+    private final BlockingQueue<String> queue;
+    private final String outputFileName;
+
+    public FileConsumer(BlockingQueue queue, String outputFileName) {
+        this.queue = queue;
+        this.outputFileName = outputFileName;
+    }
+
+    @Override
+    public void run() {
+        try (BufferedWriter writer = new BufferedWriter(new FileWriter(outputFileName))) {
+            String line;
+            while ((line = queue.poll()) != null) {
+                writer.write(line);
+                writer.newLine();
+                System.out.println(Thread.currentThread()
+                    .getId() + " - Consumer processed line: " + line);
+                System.out.println("Queue size: " + queue.size());
+            }
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+}
@@ -0,0 +1,55 @@
+package com.baeldung.readwritethread;
+
+import java.io.BufferedReader;
+import java.io.FileReader;
+import java.io.FileWriter;
+import java.io.IOException;
+
+public class ReadWriteThread {
+
+    public static void readFile(String filePath) {
+        Thread thread = new Thread(new Runnable() {
+            @Override
+            public void run() {
+                try (BufferedReader bufferedReader = new BufferedReader(new FileReader(filePath))) {
+                    String line;
+                    while ((line = bufferedReader.readLine()) != null) {
+                        System.out.println(line);
+                    }
+                } catch (IOException e) {
+                    e.printStackTrace();
+                }
+            }
+        });
+        thread.start();
+    }
+
+    public static void writeFile(String filePath, String content) {
+        Thread thread = new Thread(new Runnable() {
+            @Override
+            public void run() {
+                try (FileWriter fileWriter = new FileWriter(filePath)) {
+                    fileWriter.write("Hello, world!");
+                } catch (IOException e) {
+                    e.printStackTrace();
+                }
+            }
+        });
+        thread.start();
+    }
+
+    public static void main(String[] args) {
+        String file = "src/main/resources/text.txt";
+
+        writeFile(file, "Hello, world!");
+
+        readFile(file);
+
+        // Sleep for a while to allow the threads to complete
+        try {
+            Thread.sleep(1000);
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+    }
+}
@@ -0,0 +1,5 @@
+Hello,
+Baeldung!
+Nice to meet you!
+My name is
+Wynn.
@@ -0,0 +1 @@
+Hello, world!
@@ -0,0 +1,5 @@
+Hello,
+Baeldung!
+Nice to meet you!
+My name is
+Wynn.
@@ -82,6 +82,7 @@
            <scope>test</scope>
        </dependency>
    </dependencies>
+
    <build>
        <finalName>core-java-io-apis-2</finalName>
        <resources>
@@ -91,6 +92,7 @@
            </resource>
        </resources>
    </build>
+
    <properties>
        <junit-jupiter-version>5.9.3</junit-jupiter-version>
    </properties>
@@ -3,14 +3,14 @@
    xmlns="http://maven.apache.org/POM/4.0.0"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
+    <artifactId>core-java-lang-6</artifactId>
+
    <parent>
        <groupId>com.baeldung.core-java-modules</groupId>
        <artifactId>core-java-modules</artifactId>
        <version>0.0.1-SNAPSHOT</version>
    </parent>

-    <artifactId>core-java-lang-6</artifactId>
-
    <dependencies>
        <!-- https://mvnrepository.com/artifact/org.mapstruct/mapstruct -->
        <dependency>
@@ -14,4 +14,7 @@
 - [Clamp Function in Java](https://www.baeldung.com/java-clamp-function)
 - [Creating a Magic Square in Java](https://www.baeldung.com/java-magic-square)
 - [Check if a Point Is Between Two Points Drawn on a Straight Line in Java](https://www.baeldung.com/java-check-point-straight-line)
+- [Validate if a String Is a Valid Geo Coordinate](https://www.baeldung.com/java-geo-coordinates-validation)
+- [Rotate a Vertex Around a Certain Point in Java](https://www.baeldung.com/java-rotate-vertex-around-point)
+- [Calculating the Power of Any Number in Java Without Using Math pow() Method](https://www.baeldung.com/java-calculating-the-power-without-math-pow)
 - More articles: [[<-- Prev]](/core-java-modules/core-java-lang-math-2)
@@ -5,6 +5,14 @@
    <modelVersion>4.0.0</modelVersion>
    <artifactId>core-java-lang-math</artifactId>
    <name>core-java-lang-math</name>
+    <packaging>jar</packaging>
+
+    <parent>
+        <groupId>com.baeldung.core-java-modules</groupId>
+        <artifactId>core-java-modules</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+    </parent>
+
    <dependencies>
        <dependency>
            <groupId>org.projectlombok</groupId>
@@ -13,13 +21,6 @@
            <scope>compile</scope>
        </dependency>
    </dependencies>
-    <packaging>jar</packaging>
-
-    <parent>
-        <groupId>com.baeldung.core-java-modules</groupId>
-        <artifactId>core-java-modules</artifactId>
-        <version>0.0.1-SNAPSHOT</version>
-    </parent>

    <build>
        <finalName>core-java-lang-math</finalName>
@@ -32,7 +32,7 @@
    </dependencies>

    <properties>
-        <gson.version>2.8.2</gson.version>
+        <gson.version>2.10.1</gson.version>
    </properties>

 </project>
@@ -22,7 +22,7 @@ public class URLNormalizationUnitTest {
            String normalizedUri = originalUrl.split("\\?")[0];
            assertEquals(expectedNormalizedUrl, normalizedUri);
        } else {
-            throw new IllegalArgumentException("Invalid URL: " + originalUrl);
+            fail(originalUrl);
        }
    }

@@ -35,7 +35,7 @@ public class URLNormalizationUnitTest {
    }

    @Test
-    public void givenOriginalUrl_whenUsingRegularExpression_thenNormalizedUrl() throws URISyntaxException, UnsupportedEncodingException {
+    public void givenOriginalUrl_whenUsingRegularExpression_thenNormalizedUrl() {
        String regex = "^(https?://[^/]+/[^?#]+)";
        Pattern pattern = Pattern.compile(regex);
        Matcher matcher = pattern.matcher(originalUrl);
@@ -44,7 +44,7 @@ public class URLNormalizationUnitTest {
            String normalizedUrl = matcher.group(1);
            assertEquals(expectedNormalizedUrl, normalizedUrl);
        } else {
-            throw new IllegalArgumentException("Invalid URL: " + originalUrl);
+            fail(originalUrl);
        }
    }
 }
@@ -31,6 +31,7 @@
            <version>${guava.version}</version>
        </dependency>
    </dependencies>
+
    <build>
        <finalName>core-java-numbers-6</finalName>
        <resources>
@@ -44,4 +45,5 @@
    <properties>
        <commons-codec>1.16.0</commons-codec>
    </properties>
+
 </project>
@@ -1,3 +1,4 @@
 ## Relevant Articles
 - [Check if a double Is an Integer in Java](https://www.baeldung.com/java-check-double-integer)
 - [Print a Double Value Without Scientific Notation in Java](https://www.baeldung.com/java-print-double-number-no-scientific-notation)
+- [Check if a Float Value is Equivalent to an Integer Value in Java](https://www.baeldung.com/java-float-integer-equal)
@@ -25,6 +25,7 @@
            <version>${guava.version}</version>
        </dependency>
    </dependencies>
+
    <build>
        <finalName>core-java-numbers-7</finalName>
        <resources>
@@ -34,4 +35,5 @@
            </resource>
        </resources>
    </build>
+
 </project>
@@ -2,14 +2,15 @@
 <project xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>core-java-records</artifactId>
+
    <parent>
        <artifactId>core-java-modules</artifactId>
        <groupId>com.baeldung.core-java-modules</groupId>
        <version>0.0.1-SNAPSHOT</version>
    </parent>
-    <modelVersion>4.0.0</modelVersion>

-    <artifactId>core-java-records</artifactId>
    <build>
        <plugins>
            <plugin>
@@ -7,4 +7,5 @@ This module contains articles about core Java Security
 - [Extract CN From X509 Certificate in Java](https://www.baeldung.com/java-extract-common-name-x509-certificate)
 - [Check Certificate Name and Alias in Keystore File](https://www.baeldung.com/java-keystore-check-certificate-name-alias)
 - [Using a Custom TrustStore in Java](https://www.baeldung.com/java-custom-truststore)
+- [Enable Java SSL Debug Logging](https://www.baeldung.com/java-ssl-debug-logging)
 - More articles: [[<-- prev]](/core-java-modules/core-java-security-3)
@@ -0,0 +1,93 @@
+package com.baeldung.string.runlength;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.Collections;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class RunLengthEncodingUnitTest {
+    private static final String INPUT = "WWWWWWWWWWWWBAAACCDEEEEE";
+    private static final String RLE = "12W1B3A2C1D5E";
+
+    String runLengthEncode(String input) {
+        StringBuilder result = new StringBuilder();
+        int count = 1;
+        char[] chars = input.toCharArray();
+        for (int i = 0; i < chars.length; i++) {
+            char c = chars[i];
+            if (i + 1 < chars.length && c == chars[i + 1]) {
+                count++;
+            } else {
+                result.append(count).append(c);
+                count = 1;
+            }
+        }
+        return result.toString();
+    }
+
+
+    String runLengthDecode(String rle) {
+        StringBuilder result = new StringBuilder();
+        char[] chars = rle.toCharArray();
+
+        int count = 0;
+        for (char c : chars) {
+            if (Character.isDigit(c)) {
+                count = 10 * count + Character.getNumericValue(c);
+            } else {
+                result.append(String.join("", Collections.nCopies(count, String.valueOf(c))));
+                count = 0;
+            }
+        }
+        return result.toString();
+    }
+
+    String runLengthEncodeByRegEx(String input) {
+        String[] arr = input.split("(?<=(\\D))(?!\\1)");
+        StringBuilder result = new StringBuilder();
+        for (String run : arr) {
+            result.append(run.length()).append(run.charAt(0));
+        }
+        return result.toString();
+    }
+
+    String runLengthDecodeByRegEx(String rle) {
+        if (rle.isEmpty()) {
+            return "";
+        }
+        String[] arr = rle.split("(?<=\\D)|(?=\\D+)");
+        if (arr.length % 2 != 0) {
+            throw new IllegalArgumentException("Not a RLE string");
+        }
+        StringBuilder result = new StringBuilder();
+
+        for (int i = 1; i <= arr.length; i += 2) {
+            int count = Integer.parseInt(arr[i - 1]);
+            String c = arr[i];
+
+            result.append(String.join("", Collections.nCopies(count, c)));
+        }
+        return result.toString();
+    }
+
+    @Test
+    void whenInvokingRunLengthEncode_thenGetExpectedResult() {
+        assertEquals(RLE, runLengthEncode(INPUT));
+    }
+
+    @Test
+    void whenInvokingRunLengthDecode_thenGetExpectedResult() {
+        assertEquals(INPUT, runLengthDecode(RLE));
+    }
+
+    @Test
+    void whenInvokingRunLengthEncodeByRegEx_thenGetExpectedResult() {
+        assertEquals(RLE, runLengthEncodeByRegEx(INPUT));
+    }
+
+    @Test
+    void whenInvokingRunLengthDecodeByRegEx_thenGetExpectedResult() {
+        assertEquals(INPUT, runLengthDecodeByRegEx(RLE));
+    }
+}
@@ -12,6 +12,7 @@
        <artifactId>core-java-modules</artifactId>
        <version>0.0.1-SNAPSHOT</version>
    </parent>
+
    <dependencies>
        <dependency>
            <groupId>org.apache.commons</groupId>
@@ -12,3 +12,5 @@
 - [Check If a Java StringBuilder Object Contains a Character](https://www.baeldung.com/java-check-stringbuilder-object-contains-character)
 - [Comparing One String With Multiple Values in One Expression in Java](https://www.baeldung.com/java-compare-string-multiple-values-one-expression)
 - [UTF-8 Validation in Java](https://www.baeldung.com/java-utf-8-validation)
+- [Simple Morse Code Translation in Java](https://www.baeldung.com/java-morse-code-english-translate)
+- [How to Determine if a String Contains Invalid Encoded Characters](https://www.baeldung.com/java-check-string-contains-invalid-encoded-characters)
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project xmlns="http://maven.apache.org/POM/4.0.0"
-         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <artifactId>core-java-swing</artifactId>
    <name>core-java-swing</name>
@@ -12,6 +12,7 @@
        <artifactId>core-java-modules</artifactId>
        <version>0.0.1-SNAPSHOT</version>
    </parent>
+
    <properties>
        <maven.compiler.source>20</maven.compiler.source>
        <maven.compiler.target>20</maven.compiler.target>