CODEBANK-5 更新 maven-javadoc-plugin 的插件版本为 3.6.0

2023-10-28 22:02:35 -04:00 · 2023-10-28 22:02:35 -04:00 · 29b5628dd7
commit 29b5628dd7
parent e31e6ba102
15 changed files with 653 additions and 0 deletions
--- a/core-java-modules/core-java-uuid/README.md
+++ b/core-java-modules/core-java-uuid/README.md
@ -0,0 +1,8 @@
+## Core Java UUID
+
+### Relevant Articles: 
+- [Generating Alphanumeric UUID String in Java](https://www.baeldung.com/java-generate-alphanumeric-uuid)
+- [Guide to UUID in Java](http://www.baeldung.com/java-uuid)
+- [Validate UUID String in Java](https://www.baeldung.com/java-validate-uuid-string)
+- [Generate the Same UUID From a String in Java](https://www.baeldung.com/java-generate-same-uuid-from-string)
+- [Generating Time Based UUIDs](https://www.baeldung.com/java-generating-time-based-uuids)
--- a/core-java-modules/core-java-uuid/pom.xml
+++ b/core-java-modules/core-java-uuid/pom.xml
@ -0,0 +1,149 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>core-java-uuid</artifactId>
+    <name>core-java-uuid</name>
+    <packaging>jar</packaging>
+
+    <parent>
+        <groupId>com.ossez.core-java-modules</groupId>
+        <artifactId>core-java-modules</artifactId>
+        <version>0.0.2-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>com.github.f4b6a3</groupId>
+            <artifactId>uuid-creator</artifactId>
+            <version>5.2.0</version>
+        </dependency>
+        <dependency>
+            <groupId>com.fasterxml.uuid</groupId>
+            <artifactId>java-uuid-generator</artifactId>
+            <version>4.1.0</version>
+        </dependency>
+        <dependency>
+            <groupId>com.github.f4b6a3</groupId>
+            <artifactId>tsid-creator</artifactId>
+            <version>5.2.3</version>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <finalName>core-java-uuid</finalName>
+        <resources>
+            <resource>
+                <directory>src/main/resources</directory>
+                <filtering>true</filtering>
+            </resource>
+        </resources>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-dependency-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <id>copy-dependencies</id>
+                        <phase>prepare-package</phase>
+                        <goals>
+                            <goal>copy-dependencies</goal>
+                        </goals>
+                        <configuration>
+                            <outputDirectory>${project.build.directory}/libs</outputDirectory>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+            <plugin>
+                <groupId>org.codehaus.mojo</groupId>
+                <artifactId>exec-maven-plugin</artifactId>
+                <configuration>
+                    <executable>java</executable>
+                    <mainClass>com.baeldung.outofmemoryerror.OutOfMemoryGCLimitExceed</mainClass>
+                    <arguments>
+                        <argument>-Xmx300m</argument>
+                        <argument>-XX:+UseParallelGC</argument>
+                        <argument>-classpath</argument>
+                        <classpath/>
+                        <argument>com.baeldung.outofmemoryerror.OutOfMemoryGCLimitExceed</argument>
+                    </arguments>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-javadoc-plugin</artifactId>
+                <version>${maven-javadoc-plugin.version}</version>
+                <configuration>
+                    <source>17</source>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+    <profiles>
+        <profile>
+            <id>integration</id>
+            <build>
+                <plugins>
+                    <plugin>
+                        <groupId>org.apache.maven.plugins</groupId>
+                        <artifactId>maven-surefire-plugin</artifactId>
+                        <executions>
+                            <execution>
+                                <phase>integration-test</phase>
+                                <goals>
+                                    <goal>test</goal>
+                                </goals>
+                                <configuration>
+                                    <excludes>
+                                        <exclude>**/*ManualTest.java</exclude>
+                                    </excludes>
+                                    <includes>
+                                        <include>**/*IntegrationTest.java</include>
+                                        <include>**/*IntTest.java</include>
+                                    </includes>
+                                </configuration>
+                            </execution>
+                        </executions>
+                        <configuration>
+                            <systemPropertyVariables>
+                                <test.mime>json</test.mime>
+                            </systemPropertyVariables>
+                        </configuration>
+                    </plugin>
+                    <plugin>
+                        <groupId>org.codehaus.mojo</groupId>
+                        <artifactId>exec-maven-plugin</artifactId>
+                        <executions>
+                            <execution>
+                                <id>run-benchmarks</id>
+                                <!-- <phase>integration-test</phase> -->
+                                <phase>none</phase>
+                                <goals>
+                                    <goal>exec</goal>
+                                </goals>
+                                <configuration>
+                                    <classpathScope>test</classpathScope>
+                                    <executable>java</executable>
+                                    <arguments>
+                                        <argument>-classpath</argument>
+                                        <classpath/>
+                                        <argument>org.openjdk.jmh.Main</argument>
+                                        <argument>.*</argument>
+                                    </arguments>
+                                </configuration>
+                            </execution>
+                        </executions>
+                    </plugin>
+                </plugins>
+            </build>
+        </profile>
+    </profiles>
+
+    <properties>
+        <maven-javadoc-plugin.version>3.6.0</maven-javadoc-plugin.version>
+    </properties>
+
+</project>
--- a/core-java-modules/core-java-uuid/src/main/java/com/baeldung/timebaseduuid/JavaUUIDCreatorBenchmark.java
+++ b/core-java-modules/core-java-uuid/src/main/java/com/baeldung/timebaseduuid/JavaUUIDCreatorBenchmark.java
@ -0,0 +1,42 @@
+package com.baeldung.timebaseduuid;
+
+import com.fasterxml.uuid.Generators;
+
+import java.util.Map;
+import java.util.UUID;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicLong;
+
+public class JavaUUIDCreatorBenchmark {
+
+public static void main(String[] args) throws InterruptedException {
+
+    int threadCount = 128;
+    int iterationCount = 100_000;
+    Map<UUID, Long> uuidMap = new ConcurrentHashMap<>();
+    AtomicLong collisionCount = new AtomicLong();
+    long startNanos = System.nanoTime();
+    CountDownLatch endLatch = new CountDownLatch(threadCount);
+
+    for (long i = 0; i < threadCount; i++) {
+        long threadId = i;
+        new Thread(() -> {
+            for (long j = 0; j < iterationCount; j++) {
+                UUID uuid = Generators.timeBasedGenerator().generate();
+                Long existingUUID = uuidMap.put(uuid, (threadId * iterationCount) + j);
+                if(existingUUID != null) {
+                    collisionCount.incrementAndGet();
+                }
+            }
+            endLatch.countDown();
+        }).start();
+    }
+
+    endLatch.await();
+    System.out.println(threadCount * iterationCount + " UUIDs generated, " + collisionCount + " collisions in "
+            + TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - startNanos) + "ms");
+}
+}
+
--- a/core-java-modules/core-java-uuid/src/main/java/com/baeldung/timebaseduuid/JavaUUIDCreatorExample.java
+++ b/core-java-modules/core-java-uuid/src/main/java/com/baeldung/timebaseduuid/JavaUUIDCreatorExample.java
@ -0,0 +1,13 @@
+package com.baeldung.timebaseduuid;
+
+import com.fasterxml.uuid.Generators;
+
+public class JavaUUIDCreatorExample {
+
+    public static void main(String[] args) {
+        System.out.println("UUID Version 1: " + Generators.timeBasedGenerator().generate());
+        System.out.println("UUID Version 6: " + Generators.timeBasedReorderedGenerator().generate());
+        System.out.println("UUID Version 7: " + Generators.timeBasedEpochGenerator().generate());
+
+    }
+}
--- a/core-java-modules/core-java-uuid/src/main/java/com/baeldung/timebaseduuid/UUIDCreatorBenchmark.java
+++ b/core-java-modules/core-java-uuid/src/main/java/com/baeldung/timebaseduuid/UUIDCreatorBenchmark.java
@ -0,0 +1,42 @@
+package com.baeldung.timebaseduuid;
+
+import com.github.f4b6a3.uuid.UuidCreator;
+
+import java.util.Map;
+import java.util.UUID;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicLong;
+
+public class UUIDCreatorBenchmark {
+
+    public static void main(String[] args) throws InterruptedException {
+
+        int threadCount = 128;
+        int iterationCount = 100_000;
+        Map<UUID, Long> uuidMap = new ConcurrentHashMap<>();
+        AtomicLong collisionCount = new AtomicLong();
+        long startNanos = System.nanoTime();
+        CountDownLatch endLatch = new CountDownLatch(threadCount);
+
+        for (long i = 0; i < threadCount; i++) {
+            long threadId = i;
+            new Thread(() -> {
+                for (long j = 0; j < iterationCount; j++) {
+                    UUID uuid = UuidCreator.getTimeBased();
+                    Long existingUUID = uuidMap.put(uuid, (threadId * iterationCount) + j);
+                    if(existingUUID != null) {
+                        collisionCount.incrementAndGet();
+                    }
+                }
+                endLatch.countDown();
+            }).start();
+        }
+
+        endLatch.await();
+        System.out.println(threadCount * iterationCount + " UUIDs generated, " + collisionCount + " collisions in "
+                + TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - startNanos) + "ms");
+    }
+}
--- a/core-java-modules/core-java-uuid/src/main/java/com/baeldung/timebaseduuid/UUIDCreatorExample.java
+++ b/core-java-modules/core-java-uuid/src/main/java/com/baeldung/timebaseduuid/UUIDCreatorExample.java
@ -0,0 +1,13 @@
+package com.baeldung.timebaseduuid;
+
+import com.github.f4b6a3.uuid.UuidCreator;
+
+public class UUIDCreatorExample {
+
+    public static void main(String[] args) {
+        System.out.println("UUID Version 1: " + UuidCreator.getTimeBased());
+        System.out.println("UUID Version 6: " + UuidCreator.getTimeOrdered());
+        System.out.println("UUID Version 7: " + UuidCreator.getTimeOrderedEpoch());
+    }
+}
+
--- a/core-java-modules/core-java-uuid/src/main/java/com/baeldung/uuid/UUIDGenerator.java
+++ b/core-java-modules/core-java-uuid/src/main/java/com/baeldung/uuid/UUIDGenerator.java
@ -0,0 +1,164 @@
+package com.baeldung.uuid;
+
+import java.nio.charset.StandardCharsets;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.util.Arrays;
+import java.util.Random;
+import java.util.UUID;
+
+public final class UUIDGenerator {
+
+    private static final char[] hexArray = "0123456789ABCDEF".toCharArray();
+
+    private UUIDGenerator() {
+    }
+
+    /**
+     * Type 1 UUID Generation
+     */
+    public static UUID generateType1UUID() {
+
+        final long most64SigBits = get64MostSignificantBitsForVersion1();
+        final long least64SigBits = get64LeastSignificantBitsForVersion1();
+
+        return new UUID(most64SigBits, least64SigBits);
+    }
+
+    private static long get64LeastSignificantBitsForVersion1() {
+        final long random63BitLong = new Random().nextLong() & 0x3FFFFFFFFFFFFFFFL;
+        long variant3BitFlag = 0x8000000000000000L;
+        return random63BitLong | variant3BitFlag;
+    }
+
+    private static long get64MostSignificantBitsForVersion1() {
+        final long currentTimeMillis = System.currentTimeMillis();
+        final long time_low = (currentTimeMillis & 0x0000_0000_FFFF_FFFFL) << 32;
+        final long time_mid = ((currentTimeMillis >> 32) & 0xFFFF) << 16;
+        final long version = 1 << 12;
+        final long time_high = ((currentTimeMillis >> 48) & 0x0FFF);
+        return time_low | time_mid | version | time_high;
+    }
+
+    /**
+     * Type 3 UUID Generation
+     */
+    public static UUID generateType3UUID(String namespace, String name) {
+
+        final byte[] nameSpaceBytes = bytesFromUUID(namespace);
+        final byte[] nameBytes = name.getBytes(StandardCharsets.UTF_8);
+        final byte[] result = joinBytes(nameSpaceBytes, nameBytes);
+
+        return UUID.nameUUIDFromBytes(result);
+    }
+
+    /**
+     * Type 4 UUID Generation
+     */
+    public static UUID generateType4UUID() {
+        return UUID.randomUUID();
+    }
+
+    /**
+     * Type 5 UUID Generation
+     */
+    public static UUID generateType5UUID(String namespace, String name) {
+
+        final byte[] nameSpaceBytes = bytesFromUUID(namespace);
+        final byte[] nameBytes = name.getBytes(StandardCharsets.UTF_8);
+        final byte[] result = joinBytes(nameSpaceBytes, nameBytes);
+
+        return type5UUIDFromBytes(result);
+    }
+
+    public static UUID type5UUIDFromBytes(byte[] name) {
+        final MessageDigest md;
+        try {
+            md = MessageDigest.getInstance("SHA-1");
+        } catch (NoSuchAlgorithmException exception) {
+            throw new InternalError("SHA-1 not supported", exception);
+        }
+        final byte[] bytes = Arrays.copyOfRange(md.digest(name), 0, 16);
+        bytes[6] &= 0x0f; /* clear version        */
+        bytes[6] |= 0x50; /* set to version 5     */
+        bytes[8] &= 0x3f; /* clear variant        */
+        bytes[8] |= 0x80; /* set to IETF variant  */
+        return constructType5UUID(bytes);
+    }
+
+    private static UUID constructType5UUID(byte[] data) {
+        long msb = 0;
+        long lsb = 0;
+        assert data.length == 16 : "data must be 16 bytes in length";
+
+        for (int i = 0; i < 8; i++) {
+            msb = (msb << 8) | (data[i] & 0xff);
+        }
+
+        for (int i = 8; i < 16; i++) {
+            lsb = (lsb << 8) | (data[i] & 0xff);
+        }
+        return new UUID(msb, lsb);
+    }
+
+    private static byte[] bytesFromUUID(String uuidHexString) {
+        final String normalizedUUIDHexString = uuidHexString.replace("-", "");
+
+        assert normalizedUUIDHexString.length() == 32;
+
+        final byte[] bytes = new byte[16];
+        for (int i = 0; i < 16; i++) {
+            final byte b = hexToByte(normalizedUUIDHexString.substring(i * 2, i * 2 + 2));
+            bytes[i] = b;
+        }
+        return bytes;
+    }
+
+    public static byte hexToByte(String hexString) {
+        final int firstDigit = Character.digit(hexString.charAt(0), 16);
+        final int secondDigit = Character.digit(hexString.charAt(1), 16);
+        return (byte) ((firstDigit << 4) + secondDigit);
+    }
+
+    public static byte[] joinBytes(byte[] byteArray1, byte[] byteArray2) {
+        final int finalLength = byteArray1.length + byteArray2.length;
+        final byte[] result = new byte[finalLength];
+
+        System.arraycopy(byteArray1, 0, result, 0, byteArray1.length);
+        System.arraycopy(byteArray2, 0, result, byteArray1.length, byteArray2.length);
+        return result;
+    }
+
+    public static UUID generateType5UUID(String name) {
+
+        try {
+
+            final byte[] bytes = name.getBytes(StandardCharsets.UTF_8);
+            final MessageDigest md = MessageDigest.getInstance("SHA-1");
+
+            final byte[] hash = md.digest(bytes);
+
+            long msb = getLeastAndMostSignificantBitsVersion5(hash, 0);
+            long lsb = getLeastAndMostSignificantBitsVersion5(hash, 8);
+            // Set the version field
+            msb &= ~(0xfL << 12);
+            msb |= 5L << 12;
+            // Set the variant field to 2
+            lsb &= ~(0x3L << 62);
+            lsb |= 2L << 62;
+            return new UUID(msb, lsb);
+
+        } catch (NoSuchAlgorithmException e) {
+            throw new AssertionError(e);
+        }
+    }
+
+    private static long getLeastAndMostSignificantBitsVersion5(final byte[] src, final int offset) {
+        long ans = 0;
+        for (int i = offset + 7; i >= offset; i -= 1) {
+            ans <<= 8;
+            ans |= src[i] & 0xffL;
+        }
+        return ans;
+    }
+}
--- a/core-java-modules/core-java-uuid/src/main/resources/log4j.properties
+++ b/core-java-modules/core-java-uuid/src/main/resources/log4j.properties
@ -0,0 +1,6 @@
+log4j.rootLogger=DEBUG, A1
+
+log4j.appender.A1=org.apache.log4j.ConsoleAppender
+
+log4j.appender.A1.layout=org.apache.log4j.PatternLayout
+log4j.appender.A1.layout.ConversionPattern=%-4r [%t] %-5p %c %x - %m%n
--- a/core-java-modules/core-java-uuid/src/main/resources/log4j2.xml
+++ b/core-java-modules/core-java-uuid/src/main/resources/log4j2.xml
@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Configuration status="WARN">
+    <Appenders>
+        <Console name="Console" target="SYSTEM_OUT">
+            <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level - %msg%n"/>
+        </Console>
+    </Appenders>
+    <Loggers>
+        <Root level="debug">
+            <AppenderRef ref="Console"/>
+        </Root>
+    </Loggers>
+</Configuration>
--- a/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDFromStringUnitTest.java
+++ b/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDFromStringUnitTest.java
@ -0,0 +1,62 @@
+package com.baeldung.uuid;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.UUID;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+public class UUIDFromStringUnitTest {
+    @Test
+    void whenStringInUUIDFormat_thenFromStringWorks() {
+        String inputStr = "bbcc4621-d88f-4a94-ae2f-b38072bf5087";
+        
+        UUID uuid = UUID.fromString(inputStr);
+        UUID uuid2 = UUID.fromString(inputStr);
+        UUID uuid3 = UUID.fromString(inputStr);
+
+        assertEquals(inputStr, uuid.toString());
+
+        assertEquals(uuid, uuid2);
+        assertEquals(uuid, uuid3);
+
+    }
+
+    @Test
+    void whenStringNotInUUIDFormat_thenFromStringRaisesException() {
+        String inputStr = "I am not a standard UUID representation.";
+        assertThrows(IllegalArgumentException.class, () -> UUID.fromString(inputStr));
+    }
+
+    @Test
+    void whenStringInFreeFormat_thenNameUUIDFromBytesWorks() {
+        String inputStr = "I am not a standard UUID representation.";
+
+        UUID uuid = UUID.nameUUIDFromBytes(inputStr.getBytes());
+        UUID uuid2 = UUID.nameUUIDFromBytes(inputStr.getBytes());
+        UUID uuid3 = UUID.nameUUIDFromBytes(inputStr.getBytes());
+
+        assertTrue(uuid != null);
+
+        assertEquals(uuid, uuid2);
+        assertEquals(uuid, uuid3);
+
+        assertEquals(3, uuid.version());
+    }
+
+    @Test
+    void whenStringInFreeFormat_thenGenerateVer5UUIDWorks() {
+        String inputStr = "I am not a standard UUID representation.";
+
+        UUID uuid = UUIDGenerator.generateType5UUID(inputStr);
+        UUID uuid2 = UUIDGenerator.generateType5UUID(inputStr);
+        UUID uuid3 = UUIDGenerator.generateType5UUID(inputStr);
+
+        assertEquals(5, uuid.version());
+
+        assertTrue(uuid != null);
+
+        assertEquals(uuid, uuid2);
+        assertEquals(uuid, uuid3);
+    }
+}
--- a/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDGeneratorUnitTest.java
+++ b/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDGeneratorUnitTest.java
@ -0,0 +1,84 @@
+package com.baeldung.uuid;
+
+import org.junit.jupiter.api.Test;
+
+import java.io.UnsupportedEncodingException;
+import java.time.Instant;
+import java.time.LocalDate;
+import java.time.LocalDateTime;
+import java.time.ZoneId;
+import java.util.UUID;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class UUIDGeneratorUnitTest {
+
+    private static final String NAMESPACE_URL = "6ba7b811-9dad-11d1-80b4-00c04fd430c8";
+    private static final String NAMESPACE_DNS = "6ba7b810-9dad-11d1-80b4-00c04fd430c8";
+
+    @Test
+    void shouldGenerateType1UUIDWithCorrectVersionAndVariant() {
+        UUID uuid = UUIDGenerator.generateType1UUID();
+        assertEquals(36, uuid.toString().length());
+        assertEquals(1, uuid.version());
+        assertEquals(2, uuid.variant());
+    }
+
+    @Test
+    void shouldGenerateType1UUIDWithTheCurrentDate() {
+        UUID uuid = UUIDGenerator.generateType1UUID();
+        long time = uuid.timestamp();
+        LocalDateTime dateTime = LocalDateTime.ofInstant(Instant.ofEpochMilli(time), ZoneId.systemDefault());
+        assertEquals(LocalDate.now(), dateTime.toLocalDate());
+    }
+
+    @Test
+    void version_3_UUID_is_correctly_generated_for_domain_baeldung_com() {
+
+        UUID uuid = UUIDGenerator.generateType3UUID(NAMESPACE_DNS, "baeldung.com");
+
+        assertEquals("23785b78-0132-3ac6-aff6-cfd5be162139", uuid.toString());
+        assertEquals(3, uuid.version());
+        assertEquals(2, uuid.variant());
+    }
+
+    @Test
+    void version_3_UUID_is_correctly_generated_for_domain_d() {
+
+        UUID uuid = UUIDGenerator.generateType3UUID(NAMESPACE_DNS, "d");
+
+        assertEquals("dbd41ecb-f466-33de-b309-1468addfc63b", uuid.toString());
+        assertEquals(3, uuid.version());
+        assertEquals(2, uuid.variant());
+    }
+
+    @Test
+    public void version_4_UUID_is_generated_with_correct_length_version_and_variant() {
+
+        UUID uuid = UUIDGenerator.generateType4UUID();
+
+        assertEquals(36, uuid.toString().length());
+        assertEquals(4, uuid.version());
+        assertEquals(2, uuid.variant());
+    }
+
+    @Test
+    public void version_5_UUID_is_correctly_generated_for_domain_baeldung_com() throws UnsupportedEncodingException {
+
+        UUID uuid = UUIDGenerator.generateType5UUID(NAMESPACE_URL, "baeldung.com");
+
+        assertEquals("aeff44a5-8a61-52b6-bcbe-c8e5bd7d0300", uuid.toString());
+        assertEquals(5, uuid.version());
+        assertEquals(2, uuid.variant());
+    }
+
+    @Test
+    public void version_5_UUID_is_correctly_generated_for_domain_baeldung_name() {
+
+        UUID uuid = UUIDGenerator.generateType5UUID("baeldung.com");
+
+        assertEquals("efd5462b-b07a-52a3-94ea-bf575c0e0e75", uuid.toString());
+        assertEquals(5, uuid.version());
+        assertEquals(2, uuid.variant());
+    }
+}
--- a/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDValidatorUnitTest.java
+++ b/core-java-modules/core-java-uuid/src/test/java/com/baeldung/uuid/UUIDValidatorUnitTest.java
@ -0,0 +1,29 @@
+package com.baeldung.uuid;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+import java.util.UUID;
+import java.util.regex.Pattern;
+
+public class UUIDValidatorUnitTest {
+
+  @Test
+  public void whenValidUUIDStringIsValidated_thenValidationSucceeds() {
+    String validUUID = "26929514-237c-11ed-861d-0242ac120002";
+    Assertions.assertEquals(UUID.fromString(validUUID).toString(), validUUID);
+
+    String invalidUUID = "invalid-uuid";
+    Assertions.assertThrows(IllegalArgumentException.class, () -> UUID.fromString(invalidUUID));
+  }
+
+  @Test
+  public void whenUUIDIsValidatedUsingRegex_thenValidationSucceeds() {
+    Pattern UUID_REGEX =
+        Pattern.compile("^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}$");
+
+    Assertions.assertTrue(UUID_REGEX.matcher("26929514-237c-11ed-861d-0242ac120002").matches());
+
+    Assertions.assertFalse(UUID_REGEX.matcher("invalid-uuid").matches());
+  }
+}
--- a/core-java-modules/core-java-uuid/src/test/resources/log4j.properties
+++ b/core-java-modules/core-java-uuid/src/test/resources/log4j.properties
@ -0,0 +1,6 @@
+log4j.rootLogger=DEBUG, A1
+
+log4j.appender.A1=org.apache.log4j.ConsoleAppender
+
+log4j.appender.A1.layout=org.apache.log4j.PatternLayout
+log4j.appender.A1.layout.ConversionPattern=%-4r [%t] %-5p %c %x - %m%n
--- a/core-java-modules/core-java-uuid/src/test/resources/log4j2.xml
+++ b/core-java-modules/core-java-uuid/src/test/resources/log4j2.xml
@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Configuration status="WARN">
+    <Appenders>
+        <Console name="Console" target="SYSTEM_OUT">
+            <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level - %msg%n"/>
+        </Console>
+    </Appenders>
+    <Loggers>
+        <Root level="debug">
+            <AppenderRef ref="Console"/>
+        </Root>
+    </Loggers>
+</Configuration>
--- a/core-java-modules/core-java-uuid/src/test/resources/log4jstructuraldp.properties
+++ b/core-java-modules/core-java-uuid/src/test/resources/log4jstructuraldp.properties
@ -0,0 +1,9 @@
+
+# Root logger 
+log4j.rootLogger=INFO, file, stdout
+
+# Write to console
+log4j.appender.stdout=org.apache.log4j.ConsoleAppender
+log4j.appender.stdout.Target=System.out
+log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
+log4j.appender.stdout.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n