Merge branch 'eugenp:master' into master

algorithms-modules/algorithms-miscellaneous-5/pom.xml

@@ -5,6 +5,18 @@
     <modelVersion>4.0.0</modelVersion>
     <artifactId>algorithms-miscellaneous-5</artifactId>
     <version>0.0.1-SNAPSHOT</version>
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <source>17</source>
+                    <target>17</target>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
     <name>algorithms-miscellaneous-5</name>
 
     <parent>

algorithms-modules/algorithms-miscellaneous-5/src/main/java/com/baeldung/algorithms/conversion/HexStringConverter.java

@@ -1,15 +1,12 @@
 package com.baeldung.algorithms.conversion;
 
-import java.math.BigInteger;
-
-
-
+import com.google.common.io.BaseEncoding;
+import jakarta.xml.bind.DatatypeConverter;
 import org.apache.commons.codec.DecoderException;
 import org.apache.commons.codec.binary.Hex;
 
-import com.google.common.io.BaseEncoding;
-
-import jakarta.xml.bind.DatatypeConverter;
+import java.math.BigInteger;
+import java.util.HexFormat;
 
 public class HexStringConverter {
 
@@ -109,4 +106,14 @@ public class HexStringConverter {
         return BaseEncoding.base16()
             .decode(hexString.toUpperCase());
     }
+
+    public String encodeUsingHexFormat(byte[] bytes) {
+        HexFormat hexFormat = HexFormat.of();
+        return hexFormat.formatHex(bytes);
+    }
+
+    public byte[] decodeUsingHexFormat(String hexString) {
+        HexFormat hexFormat = HexFormat.of();
+        return hexFormat.parseHex(hexString);
+    }
 }

algorithms-modules/algorithms-miscellaneous-5/src/test/java/com/baeldung/algorithms/conversion/ByteArrayConverterUnitTest.java

@@ -1,15 +1,13 @@
 package com.baeldung.algorithms.conversion;
 
-import static org.hamcrest.MatcherAssert.assertThat;
-import static org.junit.jupiter.api.Assertions.assertArrayEquals;
-import static org.junit.jupiter.api.Assertions.assertThrows;
-
 import org.apache.commons.codec.DecoderException;
 import org.hamcrest.text.IsEqualIgnoringCase;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
-import com.baeldung.algorithms.conversion.HexStringConverter;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
 class ByteArrayConverterUnitTest {
 
@@ -24,7 +22,7 @@ class ByteArrayConverterUnitTest {
     void shouldEncodeByteArrayToHexStringUsingBigIntegerToString() {
         byte[] bytes = getSampleBytes();
         String hexString = getSampleHexString();
-        if(hexString.charAt(0) == '0') {
+        if (hexString.charAt(0) == '0') {
             hexString = hexString.substring(1);
         }
         String output = hexStringConverter.encodeUsingBigIntegerToString(bytes);
@@ -118,12 +116,28 @@ class ByteArrayConverterUnitTest {
         assertArrayEquals(bytes, output);
     }
 
+    @Test
+    void shouldEncodeByteArrayToHexStringUsingHexFormat() throws DecoderException {
+        byte[] bytes = getSampleBytes();
+        String hexString = getSampleHexString();
+        String output = hexStringConverter.encodeUsingHexFormat(bytes);
+        assertThat(output, IsEqualIgnoringCase.equalToIgnoringCase(hexString));
+    }
+
+    @Test
+    void shouldDecodeHexStringToByteArrayUsingHexFormat() throws DecoderException {
+        byte[] bytes = getSampleBytes();
+        String hexString = getSampleHexString();
+        byte[] output = hexStringConverter.decodeUsingHexFormat(hexString);
+        assertArrayEquals(bytes, output);
+    }
+
     private String getSampleHexString() {
         return "0af50c0e2d10";
     }
 
     private byte[] getSampleBytes() {
-        return new byte[] { 10, -11, 12, 14, 45, 16 };
+        return new byte[]{10, -11, 12, 14, 45, 16};
     }
 
 }

algorithms-modules/algorithms-miscellaneous-7/pom.xml

@@ -13,4 +13,22 @@
         <version>1.0.0-SNAPSHOT</version>
     </parent>
 
+    <properties>
+        <jmh.version>1.35</jmh.version>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.openjdk.jmh</groupId>
+            <artifactId>jmh-core</artifactId>
+            <version>${jmh.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.openjdk.jmh</groupId>
+            <artifactId>jmh-generator-annprocess</artifactId>
+            <version>${jmh.version}</version>
+        </dependency>
+    </dependencies>
+
 </project>

algorithms-modules/algorithms-miscellaneous-7/src/main/java/com/baeldung/algorithms/perfectnumber/PerfectNumber.java

@@ -0,0 +1,50 @@
+package com.baeldung.algorithms.perfectnumber;
+
+import java.util.stream.IntStream;
+
+class PerfectNumber {
+
+    public static boolean isPerfectBruteForce(int number) {
+        int sum = 0;
+        for (int i = 1; i <= number / 2; i++) {
+            if (number % i == 0) {
+                sum += i;
+            }
+        }
+        return sum == number;
+    }
+
+    public static boolean isPerfectStream(int number) {
+        int sum = IntStream.rangeClosed(2, (int) Math.sqrt(number))
+                .filter(test -> number % test == 0)
+                .reduce(1, (s, test) -> s + test + (number / test));
+        return sum == number;
+    }
+
+    public static boolean isPerfectEuclidEuler(int number) {
+        int p = 2;
+        int perfectNumber = (int) (Math.pow(2, p - 1) * (Math.pow(2, p) - 1));
+        while (perfectNumber <= number) {
+            if (perfectNumber == number) {
+                return true;
+            }
+            p++;
+            perfectNumber = (int) (Math.pow(2, p - 1) * (Math.pow(2, p) - 1));
+        }
+        return false;
+    }
+
+    public static boolean isPerfectEuclidEulerUsingShift(int number) {
+        int p = 2;
+        int perfectNumber = (2 << (p - 1)) * ((2 << p) - 1);
+        while (perfectNumber <= number) {
+            if (perfectNumber == number) {
+                return true;
+            }
+            p++;
+            perfectNumber = (2 << (p - 1)) * ((2 << p) - 1);
+        }
+        return false;
+    }
+
+}

algorithms-modules/algorithms-miscellaneous-7/src/main/java/com/baeldung/algorithms/perfectnumber/PerfectNumberBenchmark.java

@@ -0,0 +1,41 @@
+package com.baeldung.algorithms.perfectnumber;
+
+import org.openjdk.jmh.annotations.Benchmark;
+import org.openjdk.jmh.annotations.Scope;
+import org.openjdk.jmh.annotations.State;
+import org.openjdk.jmh.runner.Runner;
+import org.openjdk.jmh.runner.options.Options;
+import org.openjdk.jmh.runner.options.OptionsBuilder;
+
+@State(Scope.Benchmark)
+public class PerfectNumberBenchmark {
+
+    @Benchmark
+    public boolean bruteForceBenchmark() {
+        return PerfectNumber.isPerfectBruteForce(33550336);
+    }
+
+    @Benchmark
+    public boolean streamBenchmark() {
+        return PerfectNumber.isPerfectStream(33550336);
+    }
+
+    @Benchmark
+    public boolean euclidEulerBenchmark() {
+        return PerfectNumber.isPerfectEuclidEuler(33550336);
+    }
+
+    @Benchmark
+    public boolean euclidEulerUsingShiftBenchmark() {
+        return PerfectNumber.isPerfectEuclidEulerUsingShift(33550336);
+    }
+
+    public static void main(String[] args) throws Exception {
+        Options options = new OptionsBuilder()
+                .include(PerfectNumberBenchmark.class.getSimpleName())
+                .forks(1)
+                .build();
+
+        new Runner(options).run();
+    }
+}

algorithms-modules/algorithms-miscellaneous-7/src/test/java/com/baeldung/algorithms/perfectnumber/PerfectNumberUnitTest.java

@@ -0,0 +1,68 @@
+package com.baeldung.algorithms.perfectnumber;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class PerfectNumberUnitTest {
+    @Test
+    void givenPerfectNumber_whenCheckingIsPerfectBruteForce_thenReturnTrue() {
+        assertTrue(PerfectNumber.isPerfectBruteForce(6));
+    }
+
+    @Test
+    void givenNonPerfectNumber_whenCheckingIsPerfectBruteForce_thenReturnFalse() {
+        assertFalse(PerfectNumber.isPerfectBruteForce(10));
+    }
+
+    @Test
+    void givenNegativeNumber_whenCheckingIsPerfectBruteForce_thenReturnFalse() {
+        assertFalse(PerfectNumber.isPerfectBruteForce(-28));
+    }
+
+    @Test
+    void givenPerfectNumber_whenCheckingIsPerfectStream_thenReturnTrue() {
+        assertTrue(PerfectNumber.isPerfectStream(28));
+    }
+
+    @Test
+    void givenNonPerfectNumber_whenCheckingIsPerfectStream_thenReturnFalse() {
+        assertFalse(PerfectNumber.isPerfectStream(10));
+    }
+
+    @Test
+    void givenNegativeNumber_whenCheckingIsPerfectStream_thenReturnFalse() {
+        assertFalse(PerfectNumber.isPerfectStream(-6));
+    }
+
+    @Test
+    void givenPerfectNumber_whenCheckingIsPerfectEuclidEuler_thenReturnTrue() {
+        assertTrue(PerfectNumber.isPerfectEuclidEuler(28));
+    }
+
+    @Test
+    void givenNonPerfectNumber_whenCheckingIsPerfectEuclidEuler_thenReturnFalse() {
+        assertFalse(PerfectNumber.isPerfectEuclidEuler(10));
+    }
+
+    @Test
+    void givenNegativeNumber_whenCheckingIsPerfectEuclidEuler_thenReturnFalse() {
+        assertFalse(PerfectNumber.isPerfectEuclidEuler(-6));
+    }
+
+    @Test
+    void givenPerfectNumber_whenCheckingIsPerfectEuclidEulerUsingShift_thenReturnTrue() {
+        assertTrue(PerfectNumber.isPerfectEuclidEulerUsingShift(28));
+    }
+
+    @Test
+    void givenNonPerfectNumber_whenCheckingIsPerfectEuclidEulerUsingShift_thenReturnFalse() {
+        assertFalse(PerfectNumber.isPerfectEuclidEulerUsingShift(10));
+    }
+
+    @Test
+    void givenNegativeNumber_whenCheckingIsPerfectEuclidEulerUsingShift_thenReturnFalse() {
+        assertFalse(PerfectNumber.isPerfectEuclidEulerUsingShift(-6));
+    }
+}

algorithms-modules/algorithms-miscellaneous-8/README.md

@@ -1,2 +1,3 @@
 ### Relevant Articles: 
 - [Vigenère Cipher in Java](https://www.baeldung.com/java-vigenere-cipher)
+- [Merge Overlapping Intervals in a Java Collection](https://www.baeldung.com/java-collection-merge-overlapping-intervals)

algorithms-modules/algorithms-miscellaneous-8/src/main/java/com/baeldung/algorithms/mergeintervals/Interval.java

@@ -0,0 +1,37 @@
+package com.baeldung.algorithms.mergeintervals;
+
+import java.util.Objects;
+
+public class Interval {
+    int start;
+    int end;
+
+    Interval(int start, int end) {
+        this.start = start;
+        this.end = end;
+    }
+
+    public void setEnd(int end) {
+        this.end = end;
+    }
+
+    @Override
+    public String toString() {
+        return "Interval{" + "start=" + start + ", end=" + end + '}';
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o)
+            return true;
+        if (o == null || getClass() != o.getClass())
+            return false;
+        Interval interval = (Interval) o;
+        return start == interval.start && end == interval.end;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(start, end);
+    }
+}

algorithms-modules/algorithms-miscellaneous-8/src/main/java/com/baeldung/algorithms/mergeintervals/MergeOverlappingIntervals.java

@@ -0,0 +1,29 @@
+package com.baeldung.algorithms.mergeintervals;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class MergeOverlappingIntervals {
+
+    public List<Interval> doMerge(List<Interval> intervals) {
+        // Sort the intervals based on start time
+        intervals.sort((one, two) -> one.start - two.start);
+
+        // Create somewhere to put the merged list, start it off with the earliest starting interval
+        ArrayList<Interval> merged = new ArrayList<>();
+        merged.add(intervals.get(0));
+
+        // Loop over each interval and merge if start time is before the end time of the
+        // previous interval
+        intervals.forEach(interval -> {
+            if (merged.get(merged.size() - 1).end > interval.start) {
+                merged.get(merged.size() - 1).setEnd(interval.end);
+            } else {
+                merged.add(interval);
+            }
+        });
+
+        return merged;
+    }
+
+}

algorithms-modules/algorithms-miscellaneous-8/src/main/java/com/baeldung/algorithms/skiplist/Node.java

@@ -0,0 +1,11 @@
+package com.baeldung.algorithms.skiplist;
+
+class Node {
+    int value;
+    Node[] forward; // array to hold references to different levels
+
+    public Node(int value, int level) {
+        this.value = value;
+        this.forward = new Node[level + 1]; // level + 1 because level is 0-based
+    }
+}

algorithms-modules/algorithms-miscellaneous-8/src/main/java/com/baeldung/algorithms/skiplist/SkipList.java

@@ -0,0 +1,92 @@
+package com.baeldung.algorithms.skiplist;
+
+
+import java.util.Random;
+
+public class SkipList {
+    private Node head;
+    private int maxLevel;
+    private int level;
+    private Random random;
+
+    public SkipList() {
+        maxLevel = 16; // maximum number of levels
+        level = 0; // current level of SkipList
+        head = new Node(Integer.MIN_VALUE, maxLevel);
+        random = new Random();
+    }
+
+    public void insert(int value) {
+        Node[] update = new Node[maxLevel + 1];
+        Node current = this.head;
+
+        for (int i = level; i >= 0; i--) {
+            while (current.forward[i] != null && current.forward[i].value < value) {
+                current = current.forward[i];
+            }
+            update[i] = current;
+        }
+
+        current = current.forward[0];
+
+        if (current == null || current.value != value) {
+            int lvl = randomLevel();
+
+            if (lvl > level) {
+                for (int i = level + 1; i <= lvl; i++) {
+                    update[i] = head;
+                }
+                level = lvl;
+            }
+
+            Node newNode = new Node(value, lvl);
+            for (int i = 0; i <= lvl; i++) {
+                newNode.forward[i] = update[i].forward[i];
+                update[i].forward[i] = newNode;
+            }
+        }
+    }
+
+    public boolean search(int value) {
+        Node current = this.head;
+        for (int i = level; i >= 0; i--) {
+            while (current.forward[i] != null && current.forward[i].value < value) {
+                current = current.forward[i];
+            }
+        }
+        current = current.forward[0];
+        return current != null && current.value == value;
+    }
+
+    public void delete(int value) {
+        Node[] update = new Node[maxLevel + 1];
+        Node current = this.head;
+
+        for (int i = level; i >= 0; i--) {
+            while (current.forward[i] != null && current.forward[i].value < value) {
+                current = current.forward[i];
+            }
+            update[i] = current;
+        }
+        current = current.forward[0];
+
+        if (current != null && current.value == value) {
+            for (int i = 0; i <= level; i++) {
+                if (update[i].forward[i] != current) break;
+                update[i].forward[i] = current.forward[i];
+            }
+
+            while (level > 0 && head.forward[level] == null) {
+                level--;
+            }
+        }
+    }
+
+    private int randomLevel() {
+        int lvl = 0;
+        while (lvl < maxLevel && random.nextDouble() < 0.5) {
+            lvl++;
+        }
+        return lvl;
+    }
+}

algorithms-modules/algorithms-miscellaneous-8/src/test/java/com/baeldung/algorithms/mergeintervals/MergeIntervalsUnitTest.java

@@ -0,0 +1,30 @@
+package com.baeldung.algorithms.mergeintervals;
+
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+
+import org.junit.jupiter.api.Test;
+
+class MergeIntervalsUnitTest {
+
+    private ArrayList<Interval> intervals = new ArrayList<>(Arrays.asList(
+      new Interval(2, 5),
+      new Interval(13, 20),
+      new Interval(11, 15),
+      new Interval(1, 3)
+    ));
+    private ArrayList<Interval> intervalsMerged = new ArrayList<>(Arrays.asList(
+      new Interval(1, 5),
+      new Interval(11, 20)
+    ));
+
+    @Test
+    void givenIntervals_whenMerging_thenReturnMergedIntervals() {
+        MergeOverlappingIntervals merger = new MergeOverlappingIntervals();
+        ArrayList<Interval> result = (ArrayList<Interval>) merger.doMerge(intervals);
+        assertArrayEquals(intervalsMerged.toArray(), result.toArray());
+    }
+
+}

algorithms-modules/algorithms-miscellaneous-8/src/test/java/com/baeldung/algorithms/skiplist/SkipListUnitTest.java

@@ -0,0 +1,34 @@
+package com.baeldung.algorithms.skiplist;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+public class SkipListUnitTest {
+
+    @Test
+    public void givenSkipList_WhenInsert_ThenSearchFound() {
+        SkipList skipList = new SkipList();
+
+        skipList.insert(3);
+        assertTrue(skipList.search(3), "Should find 3");
+
+        assertFalse(skipList.search(99), "Should not find 99");
+    }
+
+    @Test
+    public void givenSkipList_WhenDeleteElement_ThenRemoveFromList() {
+        SkipList skipList = new SkipList();
+
+        skipList.insert(3);
+        skipList.insert(7);
+
+        skipList.delete(3);
+        assertFalse(skipList.search(3), "3 should have been deleted");
+
+        skipList.delete(99);
+        assertTrue(skipList.search(7), "7 should still exist");
+    }
+
+}

apache-libraries-2/README.md

@@ -1,5 +1,6 @@
 ## Relevant Articles
 - [Understanding XSLT Processing in Java](https://www.baeldung.com/java-extensible-stylesheet-language-transformations)
 - [Add Camel Route at Runtime in Java](https://www.baeldung.com/java-camel-dynamic-route)
-
+- [Logging in Apache Camel](https://www.baeldung.com/java-apache-camel-logging)
 - More articles: [[<-- prev]](../apache-libraries)
+

apache-libraries-2/data/inbox/welcome.txt

@@ -0,0 +1 @@
+Welcome to Baeldung

apache-libraries-2/data/json/name.json

@@ -0,0 +1,4 @@
+{
+  "name" : "phillip",
+  "age" : 5
+}

apache-libraries-2/data/outbox/welcome.txt

@@ -0,0 +1 @@
+WELCOME TO BAELDUNG

apache-libraries-2/data/output/name.json

@@ -0,0 +1 @@
+{"name":"phillip","age":5,"transformedName":"PHILLIP","transformedAge":15}

apache-libraries-2/pom.xml

@@ -35,11 +35,16 @@
             <artifactId>camel-main</artifactId>
             <version>${camel.version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.apache.camel</groupId>
+            <artifactId>camel-jackson</artifactId>
+            <version>${camel.version}</version>
+        </dependency>
     </dependencies>
 
     <properties>
         <javax.validation.validation-api.version>2.0.1.Final</javax.validation.validation-api.version>
-        <camel.version>4.3.0</camel.version>
+        <camel.version>4.4.1</camel.version>
     </properties>
 
 </project>

apache-libraries-2/src/main/java/com/baeldung/apachecamellogging/CamelLoggingMainApp.java

@@ -0,0 +1,13 @@
+package com.baeldung.apachecamellogging;
+
+import org.apache.camel.main.Main;
+
+public class CamelLoggingMainApp {
+
+    public static void main(String[] args) throws Exception {
+        Main main = new Main();
+        main.configure()
+            .addRoutesBuilder(new FileCopierCamelRoute());
+        main.run(args);
+    }
+}

apache-libraries-2/src/main/java/com/baeldung/apachecamellogging/FileCopierCamelRoute.java

@@ -0,0 +1,25 @@
+package com.baeldung.apachecamellogging;
+
+import org.apache.camel.LoggingLevel;
+import org.apache.camel.builder.RouteBuilder;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class FileCopierCamelRoute extends RouteBuilder {
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(FileCopierCamelRoute.class);
+
+    public void configure() {
+        from("file:data/inbox?noop=true").log("We got an incoming file ${file:name} containing: ${body}")
+            .to("log:com.baeldung.apachecamellogging?level=INFO")
+            .process(process -> {
+                LOGGER.info("We are passing the message to a FileProcesor bean to capitalize the message body");
+            })
+            .bean(FileProcessor.class)
+            .to("file:data/outbox")
+            .to("log:com.baeldung.apachecamellogging?showBodyType=false&maxChars=20")
+            .log(LoggingLevel.DEBUG, "Output Process", "The Process ${id}")
+            .log("Successfully transfer file: ${file:name}");
+    }
+}

apache-libraries-2/src/main/java/com/baeldung/apachecamellogging/FileCopierTracerCamelRoute.java

@@ -0,0 +1,22 @@
+package com.baeldung.apachecamellogging;
+
+import org.apache.camel.builder.RouteBuilder;
+import org.apache.camel.model.dataformat.JsonLibrary;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class FileCopierTracerCamelRoute extends RouteBuilder {
+
+    Logger logger = LoggerFactory.getLogger(FileCopierTracerCamelRoute.class);
+
+    public void configure() {
+        getContext().setTracing(true);
+        from("file:data/json?noop=true").to("log:input?level=INFO")
+            .unmarshal()
+            .json(JsonLibrary.Jackson)
+            .bean(FileProcessor.class, "transform")
+            .marshal()
+            .json(JsonLibrary.Jackson)
+            .to("file:data/output");
+    }
+}

apache-libraries-2/src/main/java/com/baeldung/apachecamellogging/FileProcessor.java

@@ -0,0 +1,23 @@
+package com.baeldung.apachecamellogging;
+
+import org.apache.camel.Body;
+
+import java.util.Map;
+
+public class FileProcessor {
+
+    public String process(@Body String fileContent) {
+        String processedContent = fileContent.toUpperCase();
+        return processedContent;
+    }
+
+    public Map<String, Object> transform(Map<String, Object> input) {
+        String name = (String) input.get("name");
+        int age = (int) input.get("age");
+
+        input.put("transformedName", name.toUpperCase());
+        input.put("transformedAge", age + 10);
+
+        return input;
+    }
+}

apache-libraries-2/src/test/java/com/baeldung/dynamicrouter/DynamicRouterRouteUnitTest.java

@@ -1,4 +1,4 @@
-package dynamicrouter;
+package com.baeldung.dynamicrouter;
 
 import com.baeldung.dynamicrouter.DynamicRouterRoute;
 import org.apache.camel.RoutesBuilder;

core-java-modules/core-java-18/src/main/java/com/baeldung/inetspi/InetAddressSPI.java

@@ -0,0 +1,44 @@
+package com.baeldung.inetspi;
+
+import java.net.InetAddress;
+import java.net.UnknownHostException;
+import java.util.Arrays;
+import java.util.stream.Stream;
+
+import com.baeldung.inetspi.providers.CustomAddressResolverImpl;
+
+public class InetAddressSPI {
+    public String usingGetByName(String host) throws UnknownHostException {
+        InetAddress inetAddress =  InetAddress.getByName(host);
+        return inetAddress.getHostAddress();
+    }
+
+    public String[] usingGetAllByName(String host) throws UnknownHostException {
+        InetAddress[] inetAddresses =  InetAddress.getAllByName(host);
+        return Arrays.stream(inetAddresses).map(InetAddress::getHostAddress).toArray(String[]::new);
+    }
+
+    public String usingGetByIp(byte[] ip) throws UnknownHostException {
+        InetAddress inetAddress =  InetAddress.getByAddress(ip);
+
+        return inetAddress.getHostName();
+    }
+
+    public String usingGetByIpAndReturnsCannonName(byte[] ip) throws UnknownHostException {
+        InetAddress inetAddress =  InetAddress.getByAddress(ip);
+
+        return inetAddress.getCanonicalHostName();
+    }
+
+    public String getHostUsingCustomImpl(byte[] ip) throws UnknownHostException {
+
+        CustomAddressResolverImpl imp = new CustomAddressResolverImpl();
+        return imp.get(null).lookupByAddress(ip);
+    }
+
+    public Stream<InetAddress> getIpUsingCustomImpl(String host) throws UnknownHostException {
+
+        CustomAddressResolverImpl imp = new CustomAddressResolverImpl();
+        return imp.get(null).lookupByName(host, null);
+    }
+}

core-java-modules/core-java-18/src/main/java/com/baeldung/inetspi/Registry.java

@@ -0,0 +1,56 @@
+package com.baeldung.inetspi;
+
+import java.net.InetAddress;
+import java.net.UnknownHostException;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.logging.Logger;
+import java.util.stream.Stream;
+
+public class Registry {
+    private final Map<String, List<byte[]>> registry;
+
+    private static final Logger LOGGER = Logger.getLogger(Registry.class.getName());
+
+    public Registry() {
+        registry = loadMapWithData();
+    }
+
+    public Stream<InetAddress> getAddressesfromHost(String host) throws UnknownHostException {
+        LOGGER.info("Performing Forward Lookup for HOST : " + host);
+        if (!registry.containsKey(host)) {
+            throw new UnknownHostException("Missing Host information in Resolver");
+        }
+        return registry.get(host)
+          .stream()
+          .map(add -> constructInetAddress(host, add))
+          .filter(Objects::nonNull);
+    }
+
+    public String getHostFromAddress(byte[] arr) throws UnknownHostException {
+        LOGGER.info("Performing Reverse Lookup for Address : " + Arrays.toString(arr));
+        for (Map.Entry<String, List<byte[]>> entry : registry.entrySet()) {
+            if (entry.getValue()
+              .stream()
+              .anyMatch(ba -> Arrays.equals(ba, arr))) {
+                return entry.getKey();
+            }
+        }
+        throw new UnknownHostException("Address Not Found");
+    }
+
+    private Map<String, List<byte[]>> loadMapWithData() {
+        return Map.of("baeldung-local.org", List.of(new byte[] { 1, 2, 3, 4 }));
+    }
+
+    private static InetAddress constructInetAddress(String host, byte[] address) {
+        try {
+            return InetAddress.getByAddress(host, address);
+        } catch (UnknownHostException unknownHostException) {
+            return null;
+        }
+    }
+
+}

core-java-modules/core-java-18/src/main/java/com/baeldung/inetspi/providers/CustomAddressResolverImpl.java

@@ -0,0 +1,42 @@
+package com.baeldung.inetspi.providers;
+
+import java.net.InetAddress;
+import java.net.UnknownHostException;
+import java.net.spi.InetAddressResolver;
+import java.net.spi.InetAddressResolverProvider;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.logging.Logger;
+import java.util.stream.Stream;
+
+import com.baeldung.inetspi.Registry;
+
+public class CustomAddressResolverImpl extends InetAddressResolverProvider {
+
+    private static Logger LOGGER = Logger.getLogger(CustomAddressResolverImpl.class.getName());
+
+    private static Registry registry = new Registry();
+
+    @Override
+    public InetAddressResolver get(Configuration configuration) {
+        LOGGER.info("Using Custom Address Resolver :: " + this.name());
+        LOGGER.info("Registry initialised");
+        return new InetAddressResolver() {
+            @Override
+            public Stream<InetAddress> lookupByName(String host, LookupPolicy lookupPolicy) throws UnknownHostException {
+                return registry.getAddressesfromHost(host);
+            }
+
+            @Override
+            public String lookupByAddress(byte[] addr) throws UnknownHostException {
+                return registry.getHostFromAddress(addr);
+            }
+        };
+    }
+
+    @Override
+    public String name() {
+        return "CustomInternetAddressResolverImpl";
+    }
+}

core-java-modules/core-java-18/src/test/java/com/baeldung/inetspi/InetAddressSPIUnitTest.java

@@ -0,0 +1,31 @@
+package com.baeldung.inetspi;
+
+import java.net.InetAddress;
+import java.net.UnknownHostException;
+import java.util.stream.Stream;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class InetAddressSPIUnitTest {
+    @Test
+    public void givenInetAddress_whenUsingInetAddress_thenPerformResolution() throws UnknownHostException {
+        InetAddressSPI spi = new InetAddressSPI();
+        Assert.assertNotNull(spi.usingGetByName("www.google.com"));
+        Assert.assertTrue(spi.usingGetAllByName("www.google.com").length > 1);
+        Assert.assertNotNull(spi.usingGetByIp(InetAddress.getByName("www.google.com")
+          .getAddress()));
+        Assert.assertNotNull(spi.usingGetByIpAndReturnsCannonName(InetAddress.getByName("www.google.com")
+          .getAddress()));
+    }
+
+    @Test
+    public void givenCustomInetAddressImplementation_whenUsingInetAddress_thenPerformResolution() throws UnknownHostException {
+        InetAddressSPI spi = new InetAddressSPI();
+        Assert.assertEquals("baeldung-local.org", spi.getHostUsingCustomImpl(new byte[] { 1, 2, 3, 4 }));
+        Stream<InetAddress> response = spi.getIpUsingCustomImpl("baeldung-local.org");
+        Assert.assertArrayEquals(new byte[] { 1, 2, 3, 4 }, response.findFirst()
+          .get()
+          .getAddress());
+    }
+}

core-java-modules/core-java-21/src/main/java/com/baeldung/java21/PatternCaseLabels.java

@@ -0,0 +1,32 @@
+package com.baeldung.java21;
+
+public class PatternCaseLabels {
+
+    static String processInputOld(String input) {
+        String output;
+        switch (input) {
+        case null -> output = "Oops, null";
+        case String s -> {
+            if ("Yes".equalsIgnoreCase(s)) {
+                output = "It's Yes";
+            } else if ("No".equalsIgnoreCase(s)) {
+                output = "It's No";
+            } else {
+                output = "Try Again";
+            }
+        }
+        }
+        return output;
+    }
+
+    static String processInputNew(String input) {
+        String output;
+        switch (input) {
+        case null -> output = "Oops, null";
+        case String s when "Yes".equalsIgnoreCase(s) -> output = "It's Yes";
+        case String s when "No".equalsIgnoreCase(s) -> output = "It's No";
+        case String s -> output = "Try Again";
+        }
+        return output;
+    }
+}

core-java-modules/core-java-21/src/main/java/com/baeldung/java21/RecordPattern.java

@@ -0,0 +1,36 @@
+package com.baeldung.java21;
+
+public class RecordPattern {
+
+    record Point(int x, int y) {}
+    
+    public static int beforeRecordPattern(Object obj) {
+        int sum = 0;
+        if(obj instanceof Point p) {
+            int x = p.x();
+            int y = p.y();
+            sum = x+y;
+        }
+        return sum;
+    }
+    
+    public static int afterRecordPattern(Object obj) {
+        if(obj instanceof Point(int x, int y)) {
+           return x+y;
+        }
+        return 0;
+    }
+    
+    enum Color {RED, GREEN, BLUE}
+    
+    record ColoredPoint(Point point, Color color) {}
+    
+    record RandomPoint(ColoredPoint cp) {}
+    
+    public static Color getRamdomPointColor(RandomPoint r) {
+        if(r instanceof RandomPoint(ColoredPoint cp)) {
+            return cp.color();
+        }
+        return null;
+    }
+}

core-java-modules/core-java-21/src/main/java/com/baeldung/java21/StringTemplates.java

@@ -0,0 +1,9 @@
+package com.baeldung.java21;
+
+public class StringTemplates {
+
+    public String getStringTemplate() {
+        String name = "Baeldung"; 
+        return STR."Welcome to \{name}"; 
+    }
+}

core-java-modules/core-java-21/src/main/java/com/baeldung/java21/SwitchPattern.java

@@ -0,0 +1,56 @@
+package com.baeldung.java21;
+
+public class SwitchPattern {
+    
+    static class Account{
+        double getBalance() {
+            return 0;
+        }
+    }
+    
+    static class SavingsAccount extends Account {
+        @Override
+        double getBalance() {
+            return 100;
+        } 
+    }
+    
+    static class TermAccount extends Account {
+        @Override
+        double getBalance() {
+            return 1000;
+        } 
+    }
+    static class CurrentAccount extends Account {
+        @Override
+        double getBalance() {
+            return 10000;
+        } 
+    }
+    
+    static double getBalanceWithOutSwitchPattern(Account account) {
+        double balance = 0;
+        if(account instanceof SavingsAccount sa) {
+            balance = sa.getBalance();
+        }
+        else if(account instanceof TermAccount ta) {
+            balance = ta.getBalance();
+        }
+        else if(account instanceof CurrentAccount ca) {
+            balance = ca.getBalance();
+        }
+        return balance;
+    }
+    
+    static double getBalanceWithSwitchPattern(Account account) {
+        double result;
+        switch (account) {
+            case null -> throw new IllegalArgumentException("Oops, account is null");
+            case SavingsAccount sa -> result = sa.getBalance();
+            case TermAccount ta -> result = ta.getBalance();
+            case CurrentAccount ca -> result = ca.getBalance();
+            default -> result = account.getBalance();
+        }
+        return result;
+    }
+}

core-java-modules/core-java-21/src/test/java/com/baeldung/java21/PatternCaseLabelsUnitTest.java

@@ -0,0 +1,48 @@
+package com.baeldung.java21;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import org.junit.jupiter.api.Test;
+
+class PatternCaseLabelsUnitTest {
+
+    @Test
+    void whenProcessInputOldWayWithYes_thenReturnOutput() {
+        assertEquals("It's Yes", PatternCaseLabels.processInputOld("Yes"));
+    }
+    
+    @Test
+    void whenProcessInputOldWayWithNo_thenReturnOutput() {
+        assertEquals("It's No", PatternCaseLabels.processInputOld("No"));
+    }
+    
+    @Test
+    void whenProcessInputOldWayWithNull_thenReturnOutput() {
+        assertEquals("Oops, null", PatternCaseLabels.processInputOld(null));
+    }
+    
+    @Test
+    void whenProcessInputOldWayWithInvalidOption_thenReturnOutput() {
+        assertEquals("Try Again", PatternCaseLabels.processInputOld("Invalid Option"));
+    }
+    
+    @Test
+    void whenProcessInputNewWayWithYes_thenReturnOutput() {
+        assertEquals("It's Yes", PatternCaseLabels.processInputNew("Yes"));
+    }
+    
+    @Test
+    void whenProcessInputNewWayWithNo_thenReturnOutput() {
+        assertEquals("It's No", PatternCaseLabels.processInputNew("No"));
+    }
+    
+    @Test
+    void whenProcessInputNewWayWithNull_thenReturnOutput() {
+        assertEquals("Oops, null", PatternCaseLabels.processInputNew(null));
+    }
+    
+    @Test
+    void whenProcessInputNewWayWithInvalidOption_thenReturnOutput() {
+        assertEquals("Try Again", PatternCaseLabels.processInputNew("Invalid Option"));
+    }
+   
+}

core-java-modules/core-java-21/src/test/java/com/baeldung/java21/RecordPatternUnitTest.java

@@ -0,0 +1,29 @@
+package com.baeldung.java21;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import org.junit.jupiter.api.Test;
+
+import com.baeldung.java21.RecordPattern.Color;
+import com.baeldung.java21.RecordPattern.ColoredPoint;
+import com.baeldung.java21.RecordPattern.Point;
+import com.baeldung.java21.RecordPattern.RandomPoint;
+
+class RecordPatternUnitTest {
+
+    @Test
+    void whenNoRecordPattern_thenReturnOutput() {
+        assertEquals(5, RecordPattern.beforeRecordPattern(new Point(2, 3)));
+    }
+    
+    @Test
+    void whenRecordPattern_thenReturnOutput() {
+        assertEquals(5, RecordPattern.afterRecordPattern(new Point(2, 3)));
+    }
+    
+    @Test
+    void whenRecordPattern_thenReturnColorOutput() {
+        ColoredPoint coloredPoint = new ColoredPoint(new Point(2, 3), Color.GREEN);
+        RandomPoint randomPoint = new RandomPoint(coloredPoint);
+        assertEquals(Color.GREEN, RecordPattern.getRamdomPointColor(randomPoint));
+    }
+}

core-java-modules/core-java-21/src/test/java/com/baeldung/java21/StringTemplateUnitTest.java

@@ -0,0 +1,13 @@
+package com.baeldung.java21;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import org.junit.jupiter.api.Test;
+
+class StringTemplateUnitTest {
+
+    @Test
+    void whenNoSwitchPattern_thenReturnSavingsAccountBalance() {
+        StringTemplates stringTemplates = new StringTemplates();
+        assertEquals("Welcome to Baeldung", stringTemplates.getStringTemplate());
+    }
+}

core-java-modules/core-java-21/src/test/java/com/baeldung/java21/SwitchPatternUnitTest.java

@@ -0,0 +1,19 @@
+package com.baeldung.java21;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import org.junit.jupiter.api.Test;
+
+class SwitchPatternUnitTest {
+
+    @Test
+    void whenNoSwitchPattern_thenReturnSavingsAccountBalance() {
+        SwitchPattern.SavingsAccount savingsAccount = new SwitchPattern.SavingsAccount();
+        assertEquals(100, SwitchPattern.getBalanceWithOutSwitchPattern(savingsAccount), 0);
+    }
+    
+    @Test
+    void whenSwitchPattern_thenReturnSavingsAccountBalance() {
+        SwitchPattern.SavingsAccount savingsAccount = new SwitchPattern.SavingsAccount();
+        assertEquals(100, SwitchPattern.getBalanceWithSwitchPattern(savingsAccount), 0);
+    }
+}

core-java-modules/core-java-collections-maps-8/README.md

@@ -0,0 +1,2 @@
+### Relevant Articles:
+- [Find Map Keys with Duplicate Values in Java](https://www.baeldung.com/java-map-find-keys-repeated-values)

core-java-modules/core-java-collections-maps-8/pom.xml

@@ -0,0 +1,29 @@
+<?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-collections-maps-8</artifactId>
+    <name>core-java-collections-maps-8</name>
+    <packaging>jar</packaging>
+
+    <parent>
+        <artifactId>core-java-modules</artifactId>
+        <groupId>com.baeldung.core-java-modules</groupId>
+        <version>0.0.1-SNAPSHOT</version>
+    </parent>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-surefire-plugin</artifactId>
+                <configuration>
+                    <argLine>
+                        --add-opens java.base/java.util=ALL-UNNAMED
+                    </argLine>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+</project>

core-java-modules/core-java-collections-maps-8/src/test/java/com/baeldung/map/valuetokeyset/ConvertMapKeyValueToMapValueKeySetUnitTest.java

@@ -0,0 +1,127 @@
+package com.baeldung.map.valuetokeyset;
+
+import static java.util.stream.Collectors.collectingAndThen;
+import static java.util.stream.Collectors.groupingBy;
+import static java.util.stream.Collectors.mapping;
+import static java.util.stream.Collectors.toSet;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+import org.junit.jupiter.api.Test;
+
+import com.google.common.collect.HashMultimap;
+import com.google.common.collect.Multimaps;
+import com.google.common.collect.SetMultimap;
+
+public class ConvertMapKeyValueToMapValueKeySetUnitTest {
+
+    private static final Map<String, String> INPUT_MAP = Map.of(
+        // @formatter:off
+        "Kai", "Linux",
+        "Eric", "MacOS",
+        "Kevin", "Windows",
+        "Liam", "MacOS",
+        "David", "Linux",
+        "Saajan", "Windows",
+        "Loredana", "MacOS"
+        // @formatter:on
+    );
+
+    private static final Map<String, Set<String>> EXPECTED = Map.of(
+        // @formatter:off
+        "Linux", Set.of("Kai", "David"),
+        "Windows", Set.of("Saajan", "Kevin"),
+        "MacOS", Set.of("Eric", "Liam", "Loredana")
+        // @formatter:on
+    );
+
+    private static final Map<String, String> INPUT_MAP_WITH_NULLS = new HashMap<String, String>(INPUT_MAP) {{
+        put("Tom", null);
+        put("Jerry", null);
+        put(null, null);
+    }};
+
+    private static final Map<String, Set<String>> EXPECTED_WITH_NULLS = new HashMap<String, Set<String>>(EXPECTED) {{
+        put(null, new HashSet<String>() {{
+            add("Tom");
+            add("Jerry");
+            add(null);
+        }});
+    }};
+
+    public static <K, V> Map<V, Set<K>> transformMap(Map<K, V> input) {
+        Map<V, Set<K>> resultMap = new HashMap<>();
+        for (Map.Entry<K, V> entry : input.entrySet()) {
+            if (!resultMap.containsKey(entry.getValue())) {
+                resultMap.put(entry.getValue(), new HashSet<>());
+            }
+            resultMap.get(entry.getValue())
+                .add(entry.getKey());
+        }
+        return resultMap;
+    }
+
+    @Test
+    void whenUsingClassicLoopBasedSolution_thenGetExpectedResult() {
+        Map<String, Set<String>> result = transformMap(INPUT_MAP);
+        assertEquals(EXPECTED, result);
+
+        Map<String, Set<String>> result2 = transformMap(INPUT_MAP_WITH_NULLS);
+        assertEquals(EXPECTED_WITH_NULLS, result2);
+    }
+
+    @Test
+    void whenUsingJava8StreamGroupingBy_thenGetExpectedResult() {
+        Map<String, Set<String>> result = INPUT_MAP.entrySet()
+            .stream()
+            .collect(groupingBy(Map.Entry::getValue, mapping(Map.Entry::getKey, toSet())));
+        assertEquals(EXPECTED, result);
+
+        assertThrows(NullPointerException.class, () -> INPUT_MAP_WITH_NULLS.entrySet()
+            .stream()
+            .collect(groupingBy(Map.Entry::getValue, mapping(Map.Entry::getKey, toSet()))));
+    }
+
+    @Test
+    void whenUsingJava8ForEach_thenGetExpectedResult() {
+        Map<String, Set<String>> result = new HashMap<>();
+        INPUT_MAP.forEach((key, value) -> result.computeIfAbsent(value, k -> new HashSet<>())
+            .add(key));
+        assertEquals(EXPECTED, result);
+
+        Map<String, Set<String>> result2 = new HashMap<>();
+        INPUT_MAP_WITH_NULLS.forEach((key, value) -> result2.computeIfAbsent(value, k -> new HashSet<>())
+            .add(key));
+        assertEquals(EXPECTED_WITH_NULLS, result2);
+    }
+
+    @Test
+    void whenUsingGuavaMultiMapCollector_thenGetExpectedResult() {
+        Map<String, Set<String>> result = INPUT_MAP.entrySet()
+            .stream()
+            .collect(collectingAndThen(Multimaps.toMultimap(Map.Entry::getValue, Map.Entry::getKey, HashMultimap::create), Multimaps::asMap));
+        assertEquals(EXPECTED, result);
+
+        Map<String, Set<String>> result2 = INPUT_MAP_WITH_NULLS.entrySet()
+            .stream()
+            .collect(collectingAndThen(Multimaps.toMultimap(Map.Entry::getValue, Map.Entry::getKey, HashMultimap::create), Multimaps::asMap));
+        assertEquals(EXPECTED_WITH_NULLS, result2);
+    }
+
+    @Test
+    void whenUsingGuavaInvertFromAndForMap_thenGetExpectedResult() {
+        SetMultimap<String, String> multiMap = Multimaps.invertFrom(Multimaps.forMap(INPUT_MAP), HashMultimap.create());
+        Map<String, Set<String>> result = Multimaps.asMap(multiMap);
+        assertEquals(EXPECTED, result);
+
+        SetMultimap<String, String> multiMapWithNulls = Multimaps.invertFrom(Multimaps.forMap(INPUT_MAP_WITH_NULLS), HashMultimap.create());
+        Map<String, Set<String>> result2 = Multimaps.asMap(multiMapWithNulls);
+        assertEquals(EXPECTED_WITH_NULLS, result2);
+    }
+
+}

core-java-modules/core-java-collections-set-2/README.md

@@ -6,4 +6,5 @@
 - [How to Get First Item From a Java Set](https://www.baeldung.com/first-item-set)
 - [Cartesian Product of Any Number of Sets in Java](https://www.baeldung.com/java-cartesian-product-sets)
 - [How to Get Index of an Item in Java Set](https://www.baeldung.com/java-set-element-find-index)
+- [Check if an Element Is Present in a Set in Java](https://www.baeldung.com/java-set-membership)
 - More articles: [[<-- prev]](/core-java-modules/core-java-collections-set)

core-java-modules/core-java-collections-set-2/src/test/java/com/baeldung/checkifpresentinset/CheckIfPresentInSetUnitTest.java

@@ -0,0 +1,71 @@
+package com.baeldung.checkifpresentinset;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Set;
+
+import org.apache.commons.collections4.CollectionUtils;
+import org.apache.commons.collections4.SetUtils;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+class CheckIfPresentInSetUnitTest {
+
+    private static final Set<String> CITIES = new HashSet<>();
+
+    @BeforeAll
+    static void setup() {
+        CITIES.add("Paris");
+        CITIES.add("London");
+        CITIES.add("Tokyo");
+        CITIES.add("Tamassint");
+        CITIES.add("New york");
+    }
+
+    @Test
+    void givenASet_whenUsingStreamAnyMatchMethod_thenCheck() {
+        boolean isPresent = CITIES.stream()
+            .anyMatch(city -> city.equals("London"));
+
+        assertThat(isPresent).isTrue();
+    }
+
+    @Test
+    void givenASet_whenUsingStreamFilterMethod_thenCheck() {
+        long resultCount = CITIES.stream()
+            .filter(city -> city.equals("Tamassint"))
+            .count();
+
+        assertThat(resultCount).isPositive();
+    }
+
+    @Test
+    void givenASet_whenUsingContainsMethod_thenCheck() {
+        assertThat(CITIES.contains("London")).isTrue();
+        assertThat(CITIES.contains("Madrid")).isFalse();
+    }
+
+    @Test
+    void givenASet_whenUsingCollectionsDisjointMethod_thenCheck() {
+        boolean isPresent = !Collections.disjoint(CITIES, Collections.singleton("Paris"));
+
+        assertThat(isPresent).isTrue();
+    }
+
+    @Test
+    void givenASet_whenUsingCollectionUtilsContainsAnyMethod_thenCheck() {
+        boolean isPresent = CollectionUtils.containsAny(CITIES, Collections.singleton("Paris"));
+
+        assertThat(isPresent).isTrue();
+    }
+
+    @Test
+    void givenASet_whenUsingSetUtilsIntersectionMethod_thenCheck() {
+        Set<String> result = SetUtils.intersection(CITIES, Collections.singleton("Tamassint"));
+
+        assertThat(result).isNotEmpty();
+    }
+
+}

core-java-modules/core-java-concurrency-advanced-3/pom.xml

@@ -86,7 +86,7 @@
         <maven.compiler.target>1.8</maven.compiler.target>
         <jcabi-aspects.version>0.22.6</jcabi-aspects.version>
         <aspectjrt.version>1.9.20.1</aspectjrt.version>
-        <cactoos.version>0.43</cactoos.version>
+        <cactoos.version>0.55.0</cactoos.version>
         <ea-async.version>1.2.3</ea-async.version>
         <jcabi-maven-plugin.version>0.14.1</jcabi-maven-plugin.version>
         <aspectjtools.version>1.9.20.1</aspectjtools.version>

core-java-modules/core-java-datetime-conversion-2/README.md

@@ -5,3 +5,4 @@ This module contains articles about converting between Java date and time object
 ### Relevant Articles: 
 - [Convert Gregorian to Hijri Date in Java](https://www.baeldung.com/java-date-gregorian-hijri-conversion)
 - [Convert String Date to XMLGregorianCalendar in Java](https://www.baeldung.com/java-string-date-xmlgregoriancalendar-conversion)
+- [Convert TemporalAccessor to LocalDate](https://www.baeldung.com/java-temporalaccessor-localdate-conversion)

core-java-modules/core-java-datetime-conversion-2/src/test/java/com/baeldung/TemporalAccessorToLocalDate/TemporalAccessorToLocalDateUnitTest.java

@@ -0,0 +1,31 @@
+package com.baeldung.TemporalAccessorToLocalDate;
+
+import org.junit.Test;
+
+import java.time.LocalDate;
+import java.time.format.DateTimeFormatter;
+import java.time.temporal.TemporalAccessor;
+import java.time.temporal.TemporalQueries;
+
+import static org.junit.Assert.assertEquals;
+
+public class TemporalAccessorToLocalDateUnitTest {
+    String dateString = "2022-03-28";
+    TemporalAccessor temporalAccessor = DateTimeFormatter.ISO_LOCAL_DATE.parse(dateString);
+
+    @Test
+    public void givenTemporalAccessor_whenUsingLocalDateFrom_thenConvertToLocalDate() {
+        LocalDate convertedDate = LocalDate.from(temporalAccessor);
+        assertEquals(LocalDate.of(2022, 3, 28), convertedDate);
+    }
+
+    @Test
+    public void givenTemporalAccessor_whenUsingTemporalQueries_thenConvertToLocalDate() {
+        int year = temporalAccessor.query(TemporalQueries.localDate()).getYear();
+        int month = temporalAccessor.query(TemporalQueries.localDate()).getMonthValue();
+        int day = temporalAccessor.query(TemporalQueries.localDate()).getDayOfMonth();
+
+        LocalDate convertedDate = LocalDate.of(year, month, day);
+        assertEquals(LocalDate.of(2022, 3, 28), convertedDate);
+    }
+}

core-java-modules/core-java-io-5/src/test/java/com/baeldung/com.baeldung.openhtmlfiles/OpenHtmlFilesUnitTest.java

@@ -0,0 +1,45 @@
+package com.baeldung.openhtmlfiles;
+
+import org.junit.Test;
+
+import java.awt.*;
+import java.io.File;
+import java.io.IOException;
+import java.net.URISyntaxException;
+import java.net.URL;
+
+import static org.junit.Assert.*;
+
+public class OpenHtmlFilesUnitTest {
+    public URL url;
+    public String absolutePath;
+
+    public OpenHtmlFilesUnitTest() throws URISyntaxException {
+        url = getClass().getResource("/test.html");
+        assert url != null;
+        File file = new File(url.toURI());
+        if (!file.exists()) {
+            fail();
+        }
+        absolutePath = file.getAbsolutePath();
+    }
+    /*
+    @Test
+    public void givenHtmlFile_whenUsingDesktopClass_thenOpenFileInDefaultBrowser() throws IOException {
+        File htmlFile = new File(absolutePath);
+        Desktop.getDesktop().browse(htmlFile.toURI());
+        assertTrue(true);
+    }
+    */
+    @Test
+    public void givenHtmlFile_whenUsingProcessBuilder_thenOpenFileInDefaultBrowser() throws IOException {
+        ProcessBuilder pb;
+        if (System.getProperty("os.name").toLowerCase().contains("win")) {
+            pb = new ProcessBuilder("cmd.exe", "/c", "start", absolutePath);
+        } else {
+            pb = new ProcessBuilder("xdg-open", absolutePath);
+        }
+        pb.start();
+        assertTrue(true);
+    }
+}

core-java-modules/core-java-io-5/src/test/resources/test.html

@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<html>
+<head>
+	<meta charset="utf-8">
+	<meta name="viewport" content="width=device-width, initial-scale=1">
+	<title>
+		
+
+	</title>
+</head>
+<body>
+
+	<h1>Hello dear friend</h1>
+</body>
+</html>

core-java-modules/core-java-io-apis-2/README.md

@@ -11,3 +11,4 @@ This module contains articles about core Java input/output(IO) APIs.
 - [PrintWriter vs. FileWriter in Java](https://www.baeldung.com/java-printwriter-filewriter-difference)
 - [Read Input Character-by-Character in Java](https://www.baeldung.com/java-read-input-character)
 - [Difference Between flush() and close() in Java FileWriter](https://www.baeldung.com/java-filewriter-flush-vs-close)
+- [Get a Path to a Resource in a Java JAR File](https://www.baeldung.com/java-get-path-resource-jar)

core-java-modules/core-java-io-apis-2/src/test/java/com/baeldung/getpathtoresource/GetPathToResourceUnitTest.java

@@ -0,0 +1,32 @@
+package com.baeldung.getpathtoresource;
+
+import org.junit.Test;
+
+import java.net.URL;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.Objects;
+
+import static org.junit.Assert.assertNotNull;
+
+public class GetPathToResourceUnitTest {
+
+    @Test
+    public void givenFile_whenClassUsed_thenGetResourcePath() {
+        URL resourceUrl = GetPathToResourceUnitTest.class.getResource("/sampleText1.txt");
+        assertNotNull(resourceUrl);
+    }
+
+    @Test
+    public void givenFile_whenClassLoaderUsed_thenGetResourcePath() {
+        URL resourceUrl = GetPathToResourceUnitTest.class.getClassLoader().getResource("sampleText1.txt");
+        assertNotNull(resourceUrl);
+    }
+
+    @Test
+    public void givenFile_whenPathUsed_thenGetResourcePath() throws Exception {
+        Path resourcePath = Paths.get(Objects.requireNonNull(GetPathToResourceUnitTest.class.getResource("/sampleText1.txt")).toURI());
+        assertNotNull(resourcePath);
+    }
+
+}

core-java-modules/core-java-io-apis/README.md

@@ -13,3 +13,4 @@ This module contains articles about core Java input/output(IO) APIs.
 - [Difference Between FileReader and BufferedReader in Java](https://www.baeldung.com/java-filereader-vs-bufferedreader)
 - [Read Multiple Inputs on the Same Line in Java](https://www.baeldung.com/java-read-multiple-inputs-same-line)
 - [Write Console Output to Text File in Java](https://www.baeldung.com/java-write-console-output-file)
+- [Java InputStream vs. InputStreamReader](https://www.baeldung.com/java-inputstream-vs-inputstreamreader)

core-java-modules/core-java-networking-2/src/test/java/com/baeldung/url/UrlCheckerIntegrationTest.java

@@ -11,28 +11,28 @@ public class UrlCheckerIntegrationTest {
     @Test
     public void givenValidUrl_WhenUsingHEAD_ThenReturn200() throws IOException {
         UrlChecker tester = new UrlChecker();
-        int responseCode = tester.getResponseCodeForURLUsingHead("http://www.example.com");
+        int responseCode = tester.getResponseCodeForURLUsingHead("https://httpbin.org/status/200");
         assertEquals(200, responseCode);
     }
     
     @Test
     public void givenInvalidIUrl_WhenUsingHEAD_ThenReturn404() throws IOException {
         UrlChecker tester = new UrlChecker();
-        int responseCode = tester.getResponseCodeForURLUsingHead("http://www.example.com/xyz");
+        int responseCode = tester.getResponseCodeForURLUsingHead("https://httpbin.org/status/404");
         assertEquals(404, responseCode);
     }
     
     @Test
     public void givenValidUrl_WhenUsingGET_ThenReturn200() throws IOException {
         UrlChecker tester = new UrlChecker();
-        int responseCode = tester.getResponseCodeForURL("http://www.example.com");
+        int responseCode = tester.getResponseCodeForURL("https://httpbin.org/status/200");
         assertEquals(200, responseCode);
     }
     
     @Test
     public void givenInvalidIUrl_WhenUsingGET_ThenReturn404() throws IOException {
         UrlChecker tester = new UrlChecker();
-        int responseCode = tester.getResponseCodeForURL("http://www.example.com/xyz");
+        int responseCode = tester.getResponseCodeForURL("https://httpbin.org/status/404");
         assertEquals(404, responseCode);
     }
     

core-java-modules/core-java-numbers-7/src/main/java/com/baeldung/convertphonenumberinwordstonumber/UseHashMapToConvertPhoneNumberInWordsToNumber.java

@@ -0,0 +1,43 @@
+import java.util.Map;
+
+public class UseHashMapToConvertPhoneNumberInWordsToNumber {
+    private static Map<String, Integer> multipliers = Map.of("double",2,
+            "triple", 3,
+            "quadruple", 4);
+    private static Map<String, String> digits = Map.of("zero","1",
+            "one", "1",
+            "two", "2",
+            "three", "3",
+            "four", "4",
+            "five", "5",
+            "six", "6",
+            "seven", "7",
+            "eight", "8",
+            "nine", "9");
+
+
+    public static String convertPhoneNumberInWordsToNumber(String phoneNumberInWord) {
+
+        StringBuilder output = new StringBuilder();
+        Integer currentMultiplier = null;
+        String[] words = phoneNumberInWord.split(" ");
+
+        for (String word : words) {
+            Integer multiplier = multipliers.get(word);
+            if (multiplier != null) {
+                if (currentMultiplier != null) {
+                    throw new IllegalArgumentException("Cannot have consecutive multipliers, at: " + word);
+                }
+                currentMultiplier = multiplier;
+            } else {
+                String digit = digits.get(word);
+                if (digit == null) {
+                    throw new IllegalArgumentException("Invalid word: " + word);
+                }
+                output.append(digit.repeat(currentMultiplier != null ? currentMultiplier : 1));
+                currentMultiplier = null;
+            }
+        }
+        return output.toString();
+    }
+}

core-java-modules/core-java-numbers-7/src/main/java/com/baeldung/convertphonenumberinwordstonumber/UseSwitchToConvertPhoneNumberInWordsToNumber.java

@@ -0,0 +1,64 @@
+public class UseSwitchToConvertPhoneNumberInWordsToNumber {
+
+    public static String convertPhoneNumberInWordsToNumber(String phoneNumberInWord) {
+
+        StringBuilder output = new StringBuilder();
+        Integer currentMultiplier = null;
+        String[] words = phoneNumberInWord.split(" ");
+
+        for (String word : words) {
+            Integer multiplier = getWordAsMultiplier(word);
+            if (multiplier != null) {
+                if (currentMultiplier != null) {
+                    throw new IllegalArgumentException("Cannot have consecutive multipliers, at: " + word);
+                }
+                currentMultiplier = multiplier;
+            } else {
+                output.append(getWordAsDigit(word).repeat(currentMultiplier != null ? currentMultiplier : 1));
+                currentMultiplier = null;
+            }
+        }
+        return output.toString();
+    }
+
+    public static Integer getWordAsMultiplier(String word) {
+        switch (word) {
+            case "double":
+                return 2;
+            case "triple":
+                return 3;
+            case "quadruple":
+                return 4;
+            default:
+                return null;
+        }
+    }
+
+    public static String getWordAsDigit(String word) {
+        switch (word) {
+            case "zero":
+                return "0";
+            case "one":
+                return "1";
+            case "two":
+                return "2";
+            case "three":
+                return "3";
+            case "four":
+                return "4";
+            case "five":
+                return "5";
+            case "six":
+                return "6";
+            case "seven":
+                return "7";
+            case "eight":
+                return "8";
+            case "nine":
+                return "9";
+            default:
+                throw new IllegalArgumentException("Invalid word: " + word);
+        }
+    }
+
+}

core-java-modules/core-java-numbers-7/src/test/java/com/baeldung/convertphonenumberinwordstonumber/UseHashMapToConvertPhoneNumberInWordsToNumberUnitTest.java

@@ -0,0 +1,31 @@
+import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.*;
+
+class UseHashMapToConvertPhoneNumberInWordsToNumberUnitTest {
+
+    @Test
+    void givenStringWithWhiteSpaces_WhenConvertPhoneNumberInWordsToNumber_ThenEquivalentNumber() {
+
+        assertEquals("5248888",
+                UseHashMapToConvertPhoneNumberInWordsToNumber
+                        .convertPhoneNumberInWordsToNumber("five two four quadruple eight"));
+    }
+
+    @Test
+    void givenStringEndingWithConseutiveMultipliers_WhenConvertPhoneNumberInWordsToNumber_ThenThrowException() {
+
+        assertThrows(IllegalArgumentException.class, () -> {
+            UseHashMapToConvertPhoneNumberInWordsToNumber
+                    .convertPhoneNumberInWordsToNumber("five eight three double triple");
+        });
+    }
+
+    @Test
+    void givenStringWithInvalidWords_WhenConvertPhoneNumberInWordsToNumber_ThenThrowException() {
+
+        assertThrows(IllegalArgumentException.class, () -> {
+            UseHashMapToConvertPhoneNumberInWordsToNumber
+                    .convertPhoneNumberInWordsToNumber("five eight three two four penta null eight");
+        });
+    }
+}

core-java-modules/core-java-numbers-7/src/test/java/com/baeldung/convertphonenumberinwordstonumber/UseSwitchToConvertPhoneNumberInWordsToNumberUnitTest.java

@@ -0,0 +1,62 @@
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class UseSwitchToConvertPhoneNumberInWordsToNumberUnitTest {
+
+    @Test
+    void givenStringWithWhiteSpaces_WhenConvertPhoneNumberInWordsToNumber_ThenEquivalentNumber() {
+
+        assertEquals("5248888",
+                UseSwitchToConvertPhoneNumberInWordsToNumber
+                        .convertPhoneNumberInWordsToNumber("five two four quadruple eight"));
+
+    }
+
+    @Test
+    void givenStringEndingWithConseutiveMultipliers_WhenConvertPhoneNumberInWordsToNumber_ThenThrowException() {
+
+        assertThrows(IllegalArgumentException.class, () -> {
+            UseSwitchToConvertPhoneNumberInWordsToNumber
+                    .convertPhoneNumberInWordsToNumber("five eight three double triple");
+        });
+    }
+
+    @Test
+    void givenStringWithInvalidWords_WhenConvertPhoneNumberInWordsToNumber_ThenThrowException() {
+
+        assertThrows(IllegalArgumentException.class, () -> {
+            UseSwitchToConvertPhoneNumberInWordsToNumber
+                    .convertPhoneNumberInWordsToNumber("five eight three two four penta null eight");
+        });
+    }
+
+
+    @Test
+    void givenString_WhenGetWordAsMultiplier_ThenEquivalentNumber() {
+        assertEquals(2, UseSwitchToConvertPhoneNumberInWordsToNumber
+                .getWordAsMultiplier("double"));
+    }
+
+    @Test
+    void givenInvalidString_WhenGetWordAsMultiplier_ThenReturnNull() {
+        assertEquals(null, UseSwitchToConvertPhoneNumberInWordsToNumber
+                .getWordAsMultiplier("hexa"));
+
+    }
+
+    @Test
+    void givenString_WhenMapIndividualDigits_ThenEquivalentNumber() {
+        assertEquals("5",
+                UseSwitchToConvertPhoneNumberInWordsToNumber
+                        .getWordAsDigit("five"));
+    }
+
+    @Test
+    void givenInvalidString_WhenMapIndividualDigits_ThenThrowException() {
+        assertThrows(IllegalArgumentException.class, () -> {
+            UseSwitchToConvertPhoneNumberInWordsToNumber
+                    .convertPhoneNumberInWordsToNumber("penta");
+        });
+    }
+}

core-java-modules/core-java-string-operations-8/README.md

@@ -8,3 +8,4 @@
 - [Get the Initials of a Name in Java](https://www.baeldung.com/java-shorten-name-initials)
 - [Normalizing the EOL Character in Java](https://www.baeldung.com/java-normalize-end-of-line-character)
 - [Converting UTF-8 to ISO-8859-1 in Java](https://www.baeldung.com/java-utf-8-iso-8859-1-conversion)
+- [Get Last n Characters From a String](https://www.baeldung.com/java-string-get-last-n-characters)

core-java-modules/core-java-string-operations-8/src/test/java/com/baeldung/lastncharacters/LastNCharactersUnitTest.java

@@ -0,0 +1,64 @@
+package com.baeldung.lastncharacters;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.util.Arrays;
+import java.util.stream.Collectors;
+
+import org.apache.commons.lang3.ArrayUtils;
+import org.apache.commons.lang3.StringUtils;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+public class LastNCharactersUnitTest {
+
+    private String s;
+    private int n;
+
+    @BeforeEach
+    void init() {
+        s = "10-03-2024";
+        n = 4;
+    }
+
+    @Test
+    void givenString_whenUsingIntStreamAsStreamSource_thenObtainLastNCharacters() {
+        String result = s.chars()
+            .mapToObj(c -> (char) c)
+            .skip(s.length() - n)
+            .map(String::valueOf)
+            .collect(Collectors.joining());
+
+        assertThat(result).isEqualTo("2024");
+    }
+
+    @Test
+    void givenString_whenUsingOneArgSubstringMethod_thenObtainLastNCharacters() {
+        int beginIndex = s.length() - n;
+
+        assertThat(s.substring(beginIndex)).isEqualTo("2024");
+    }
+
+    @Test
+    void givenString_whenUsingStreamOfCharactersAsSource_thenObtainLastNCharacters() {
+        String result = Arrays.stream(ArrayUtils.toObject(s.toCharArray()))
+            .skip(s.length() - n)
+            .map(String::valueOf)
+            .collect(Collectors.joining());
+
+        assertThat(result).isEqualTo("2024");
+    }
+
+    @Test
+    void givenString_whenUsingStringUtilsRight_thenObtainLastNCharacters() {
+        assertThat(StringUtils.right(s, n)).isEqualTo("2024");
+    }
+
+    @Test
+    void givenString_whenUsingTwoArgSubstringMethod_thenObtainLastNCharacters() {
+        int beginIndex = s.length() - n;
+        String result = s.substring(beginIndex, s.length());
+
+        assertThat(result).isEqualTo("2024");
+    }
+}

core-java-modules/pom.xml

@@ -99,6 +99,7 @@
         <module>core-java-collections-maps-2</module>
         <module>core-java-collections-maps-3</module>
         <module>core-java-collections-maps-7</module>
+        <module>core-java-collections-maps-8</module>
         <module>core-java-compiler</module>
         <module>core-java-concurrency-2</module>
         <module>core-java-concurrency-advanced</module>

docker-modules/docker-caching/README.md

@@ -1,3 +0,0 @@
-## Relevant Articles:
-
-- [Caching Maven Dependencies with Docker](https://www.baeldung.com/ops/docker-cache-maven-dependencies)

docker-modules/docker-caching/multi-module-caching/Dockerfile

@@ -1,21 +0,0 @@
-FROM maven:alpine as build
-ENV HOME=/usr/app
-RUN mkdir -p $HOME
-WORKDIR $HOME
-
-ADD pom.xml $HOME
-ADD core/pom.xml $HOME/core/pom.xml
-ADD runner/pom.xml $HOME/runner/pom.xml
-
-RUN mvn -pl core verify --fail-never
-ADD core $HOME/core
-RUN mvn -pl core install
-RUN mvn -pl runner verify --fail-never
-ADD runner $HOME/runner
-RUN mvn -pl core,runner package
-
-FROM openjdk:8-jdk-alpine
-
-COPY --from=build /usr/app/runner/target/runner-0.0.1-SNAPSHOT-jar-with-dependencies.jar /app/runner.jar
-
-ENTRYPOINT java -jar /app/runner.jar

docker-modules/docker-caching/multi-module-caching/Dockerfile-Buildkit

@@ -1,13 +0,0 @@
-FROM maven:alpine as build
-ENV HOME=/usr/app
-RUN mkdir -p $HOME
-WORKDIR $HOME
-
-ADD . $HOME
-RUN --mount=type=cache,target=/root/.m2 mvn -f $HOME/pom.xml clean package
-
-FROM openjdk:8-jdk-alpine
-
-COPY --from=build /usr/app/runner/target/runner-0.0.1-SNAPSHOT-jar-with-dependencies.jar /app/runner.jar
-
-ENTRYPOINT java -jar /app/runner.jar

docker-modules/docker-caching/multi-module-caching/core-module/pom.xml

@@ -1,28 +0,0 @@
-<?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-module</artifactId>
-
-    <parent>
-        <artifactId>multi-module-caching</artifactId>
-        <groupId>com.baeldung</groupId>
-        <version>0.0.1-SNAPSHOT</version>
-    </parent>
-
-    <dependencies>
-        <dependency>
-            <groupId>com.google.guava</groupId>
-            <artifactId>guava</artifactId>
-            <version>${guava.version}</version>
-        </dependency>
-    </dependencies>
-
-    <properties>
-        <maven.compiler.source>8</maven.compiler.source>
-        <maven.compiler.target>8</maven.compiler.target>
-        <guava.version>33.0.0-jre</guava.version>
-    </properties>
-
-</project>

docker-modules/docker-caching/multi-module-caching/core-module/src/main/java/com/baeldung/maven_caching/CoreClass.java

@@ -1,14 +0,0 @@
-package com.baeldung.maven_caching;
-
-import com.google.common.io.Files;
-
-public class CoreClass {
-
-    public String method() {
-        return "Hello from core module!!";
-    }
-
-    public String dependencyMethod() {
-        return Files.simplifyPath("/home/app/test");
-    }
-}

docker-modules/docker-caching/multi-module-caching/pom.xml

@@ -1,31 +0,0 @@
-<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
-    <modelVersion>4.0.0</modelVersion>
-    <groupId>com.baeldung</groupId>
-    <artifactId>multi-module-caching</artifactId>
-    <version>0.0.1-SNAPSHOT</version>
-    <packaging>pom</packaging>
-    <description>Multi-module Maven caching example</description>
-
-    <modules>
-        <module>runner-module</module>
-        <module>core-module</module>
-    </modules>
-
-    <dependencyManagement>
-        <dependencies>
-            <dependency>
-                <groupId>com.google.guava</groupId>
-                <artifactId>guava</artifactId>
-                <version>${guava.version}</version>
-            </dependency>
-        </dependencies>
-    </dependencyManagement>
-
-    <properties>
-        <guava.version>33.0.0-jre</guava.version>
-    </properties>
-
-</project>

docker-modules/docker-caching/multi-module-caching/runner-module/pom.xml

@@ -1,58 +0,0 @@
-<?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>runner-module</artifactId>
-
-    <parent>
-        <artifactId>multi-module-caching</artifactId>
-        <groupId>com.baeldung</groupId>
-        <version>0.0.1-SNAPSHOT</version>
-    </parent>
-
-    <dependencies>
-        <dependency>
-            <groupId>com.baeldung</groupId>
-            <artifactId>core-module</artifactId>
-            <version>0.0.1-SNAPSHOT</version>
-        </dependency>
-    </dependencies>
-
-    <build>
-        <plugins>
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-assembly-plugin</artifactId>
-                <version>${maven-assembly-plugin.version}</version>
-                <configuration>
-                    <descriptorRefs>
-                        <descriptorRef>jar-with-dependencies</descriptorRef>
-                    </descriptorRefs>
-                    <archive>
-                        <manifest>
-                            <addClasspath>true</addClasspath>
-                            <mainClass>com.baeldung.maven_caching.MavenCachingApplication</mainClass>
-                        </manifest>
-                    </archive>
-                </configuration>
-                <executions>
-                    <execution>
-                        <id>assemble-all</id>
-                        <phase>package</phase>
-                        <goals>
-                            <goal>single</goal>
-                        </goals>
-                    </execution>
-                </executions>
-            </plugin>
-        </plugins>
-    </build>
-
-    <properties>
-        <maven-assembly-plugin.version>3.3.0</maven-assembly-plugin.version>
-        <maven.compiler.source>8</maven.compiler.source>
-        <maven.compiler.target>8</maven.compiler.target>
-    </properties>
-
-</project>

docker-modules/docker-caching/multi-module-caching/runner-module/src/main/java/com/baeldung/maven_caching/MavenCachingApplication.java

@@ -1,11 +0,0 @@
-package com.baeldung.maven_caching;
-
-public class MavenCachingApplication {
-
-    public static void main(String[] args) {
-        CoreClass cc = new CoreClass();
-        System.out.println(cc.method());
-        System.out.println(cc.dependencyMethod());
-    }
-
-}

docker-modules/docker-caching/pom.xml

@@ -1,21 +0,0 @@
-<?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>docker-caching</artifactId>
-    <packaging>pom</packaging>
-    <name>docker-caching</name>
-
-    <parent>
-        <artifactId>docker-modules</artifactId>
-        <groupId>com.baeldung</groupId>
-        <version>1.0.0-SNAPSHOT</version>
-    </parent>
-
-    <modules>
-        <module>single-module-caching</module>
-        <module>multi-module-caching</module>
-    </modules>
-
-</project>

docker-modules/docker-caching/single-module-caching/Dockerfile

@@ -1,15 +0,0 @@
-FROM maven:alpine as build
-ENV HOME=/usr/app
-RUN mkdir -p $HOME
-WORKDIR $HOME
-ADD pom.xml $HOME
-RUN mvn verify --fail-never
-
-ADD . $HOME
-RUN mvn package
-
-FROM openjdk:8-jdk-alpine 
-
-COPY --from=build /usr/app/target/single-module-caching-1.0-SNAPSHOT-jar-with-dependencies.jar /app/runner.jar
-
-ENTRYPOINT java -jar /app/runner.jar

docker-modules/docker-caching/single-module-caching/Dockerfile-Buildkit

@@ -1,13 +0,0 @@
-FROM maven:alpine as build
-ENV HOME=/usr/app
-RUN mkdir -p $HOME
-WORKDIR $HOME
-ADD . $HOME
-
-RUN --mount=type=cache,target=/root/.m2 mvn -f $HOME/pom.xml clean package
-
-FROM openjdk:8-jdk-alpine
-
-COPY --from=build /usr/app/target/single-module-caching-1.0-SNAPSHOT-jar-with-dependencies.jar /app/runner.jar
-
-ENTRYPOINT java -jar /app/runner.jar

docker-modules/docker-caching/single-module-caching/pom.xml

@@ -1,56 +0,0 @@
-<?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>
-    <groupId>com.baeldung</groupId>
-    <artifactId>single-module-caching</artifactId>
-    <version>1.0-SNAPSHOT</version>
-
-    <dependencies>
-        <dependency>
-            <groupId>com.google.guava</groupId>
-            <artifactId>guava</artifactId>
-            <version>${guava.version}</version>
-        </dependency>
-    </dependencies>
-
-    <build>
-        <plugins>
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-assembly-plugin</artifactId>
-                <version>${maven-assembly-plugin.version}</version>
-                <configuration>
-                    <descriptorRefs>
-                        <descriptorRef>jar-with-dependencies</descriptorRef>
-                    </descriptorRefs>
-                    <archive>
-                        <manifest>
-                            <addClasspath>true</addClasspath>
-                            <mainClass>com.baeldung.maven_caching.MavenCachingMain</mainClass>
-                        </manifest>
-                    </archive>
-                </configuration>
-                <executions>
-                    <execution>
-                        <id>assemble-all</id>
-                        <phase>package</phase>
-                        <goals>
-                            <goal>single</goal>
-                        </goals>
-                    </execution>
-                </executions>
-            </plugin>
-        </plugins>
-    </build>
-
-    <properties>
-        <maven.compiler.source>8</maven.compiler.source>
-        <maven.compiler.target>8</maven.compiler.target>
-        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <guava.version>33.0.0-jre</guava.version>
-        <maven-assembly-plugin.version>3.3.0</maven-assembly-plugin.version>
-    </properties>
-
-</project>

docker-modules/docker-caching/single-module-caching/src/main/java/com/baeldung/maven_caching/MavenCachingMain.java

@@ -1,11 +0,0 @@
-package com.baeldung.maven_caching;
-
-import com.google.common.io.Files;
-
-public class MavenCachingMain {
-
-    public static void main(String[] args) {
-        System.out.println("Hello from maven_caching app!!!");
-        System.out.println(Files.simplifyPath("/home/app/test"));
-    }
-}

docker-modules/docker-compose-2/README.md

@@ -1,2 +0,0 @@
-## Relevant Articles:
-- [Communicating With Docker Containers on the Same Machine](https://www.baeldung.com/ops/docker-communicating-with-containers-on-same-machine)

docker-modules/docker-compose-2/communication_same_machine/Dockerfile

@@ -1,3 +0,0 @@
-FROM alpine:latest
-MAINTAINER baeldung.com
-RUN apk update && apk add iputils && apk add bash && apk add curl

docker-modules/docker-compose-2/communication_same_machine/Dockerfile.node

@@ -1,7 +0,0 @@
-FROM node:8.16.1-alpine
-WORKDIR /app
-COPY host_docker_internal/package.json /app
-COPY host_docker_internal/index.js /app
-RUN npm install
-CMD node index.js
-EXPOSE 8080

docker-modules/docker-compose-2/communication_same_machine/dns/docker-compose.yml

@@ -1,20 +0,0 @@
-services:
-  alpine-app-1:
-    container_name: alpine-app-1
-    image: alpine-app-1
-    build:
-      context: ..
-      dockerfile: Dockerfile
-    tty: true
-    ports:
-      - 8081:8081
-  
-  alpine-app-2:
-    container_name: alpine-app-2
-    image: alpine-app-2
-    build:
-      context: ..
-      dockerfile: Dockerfile
-    tty: true
-    ports:
-      - 8080:8080

docker-modules/docker-compose-2/communication_same_machine/host_docker_internal/docker-compose.yml

@@ -1,29 +0,0 @@
-services:
-  alpine-app-1:
-    container_name: alpine-app-1
-    extra_hosts: # for linux hosts since version 20.10
-      - host.docker.internal:host-gateway
-    build:
-      context: ..
-      dockerfile: Dockerfile
-    image: alpine-app-1
-    tty: true
-    networks:
-      - first-network
-
-  node-app:
-    container_name: node-app
-    build:
-      context: ..
-      dockerfile: Dockerfile.node
-    image: node-app
-    ports:
-      - 8080:8080
-    networks:
-      - second-network
-
-networks:
-  first-network:
-    driver: bridge
-  second-network:
-    driver: bridge

docker-modules/docker-compose-2/communication_same_machine/host_docker_internal/index.js

@@ -1,10 +0,0 @@
-var express = require('express')
-var app = express()
-
-app.get('/', function (req, res) {
-    res.send('Hello World!')
-})
-
-app.listen(8080, function () {
-    console.log('app listening on port 8080!')
-})

docker-modules/docker-compose-2/communication_same_machine/host_docker_internal/package.json

@@ -1,14 +0,0 @@
-{
-  "name": "host_docker_internal",
-  "version": "1.0.0",
-  "description": "node js app",
-  "main": "index.js",
-  "scripts": {
-    "test": "echo \"Error: no test specified\" && exit 1"
-  },
-  "author": "Baeldung",
-  "license": "ISC",
-  "dependencies": {
-    "express": "^4.18.2"
-  }
-}

docker-modules/docker-compose-2/communication_same_machine/static_ip_bridge/docker-compose.yml

@@ -1,34 +0,0 @@
-services:
-  alpine-app-1:
-    container_name: alpine-app-1
-    build:
-      context: ..
-      dockerfile: Dockerfile
-    image: alpine-app-1
-    tty: true
-    ports:
-      - 8080:8080
-    networks:
-      network-example:
-        ipv4_address: 10.5.0.2
-
-  alpine-app-2:
-    container_name: alpine-app-2
-    build:
-      context: ..
-      dockerfile: Dockerfile
-    image: alpine-app-2
-    tty: true
-    ports:
-      - 8081:8081
-    networks:
-      network-example:
-        ipv4_address: 10.5.0.3
-
-networks:
-  network-example:
-    driver: bridge
-    ipam:
-      config:
-        - subnet: 10.5.0.0/16
-          gateway: 10.5.0.1

docker-modules/docker-compose-2/communication_same_machine/static_ip_macvlan/docker-compose.yml

@@ -1,36 +0,0 @@
-services:
-  alpine-app-1:
-    container_name: alpine-app-1
-    build:
-      context: ..
-      dockerfile: Dockerfile
-    image: alpine-app-1
-    tty: true
-    ports:
-      - 8080:8080
-    networks:
-      network-example:
-        ipv4_address: 192.168.2.2
-
-  alpine-app-2:
-    container_name: alpine-app-2
-    build:
-      context: ..
-      dockerfile: Dockerfile
-    image: alpine-app-2
-    tty: true
-    ports:
-      - 8081:8081
-    networks:
-      network-example:
-        ipv4_address: 192.168.2.3
-
-networks:
-  network-example:
-    driver: macvlan
-    driver_opts:
-      parent: enp0s3
-    ipam:
-      config:
-        - subnet: 192.168.2.0/24
-          gateway: 192.168.2.1

docker-modules/docker-compose-2/pom.xml

@@ -1,17 +0,0 @@
-<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
-    <modelVersion>4.0.0</modelVersion>
-    <artifactId>docker-compose-2</artifactId>
-    <packaging>pom</packaging>
-    <description>Demo project for Spring Boot and Docker - Module docker-compose-2</description>
-
-    <parent>
-        <groupId>com.baeldung</groupId>
-        <artifactId>parent-boot-3</artifactId>
-        <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../../parent-boot-3</relativePath>
-    </parent>
-
-</project>

docker-modules/docker-compose/Dockerfile

@@ -1,4 +0,0 @@
-FROM openjdk:17-alpine
-MAINTAINER baeldung.com
-COPY target/docker-compose-0.0.1-SNAPSHOT.jar app.jar
-ENTRYPOINT ["java","-jar","/app.jar"]

docker-modules/docker-compose/README.md

@@ -1,10 +0,0 @@
-## Relevant Articles:
-
-- [Introduction to Docker Compose](https://www.baeldung.com/ops/docker-compose)
-- [How to Get Docker-Compose to Always Use the Latest Image](https://www.baeldung.com/ops/docker-compose-latest-image)
-- [Communication Between Multiple Docker Compose Projects](https://www.baeldung.com/ops/docker-compose-communication)
-- [Difference Between links and depends_on in Docker Compose](https://www.baeldung.com/ops/docker-compose-links-depends-on)
-- [Mounting Multiple Volumes on a Docker Container](https://www.baeldung.com/ops/docker-mounting-multiple-volumes)
-- [Rebuild Docker Container in Docker Compose](https://www.baeldung.com/ops/rebuild-docker-container-compose)
-- [Assign Static IP to Docker Container and Docker-Compose](https://www.baeldung.com/ops/docker-assign-static-ip-container)
-- [Exclude a Sub-Folder When Adding a Volume to Docker](https://www.baeldung.com/ops/docker-exclude-sub-folder-when-adding-volume)

docker-modules/docker-compose/assign-static-ip/docker-compose.yml

@@ -1,27 +0,0 @@
-services:
-  db:
-    container_name: mysql_db
-    image: mysql:latest
-    environment:
-      - MYSQL_ROOT_PASSWORD=password
-      - MYSQL_ROOT_HOST=10.5.0.1
-    ports:
-      - '3306:3306'
-    volumes:
-      - db:/var/lib/mysql
-      - ./init.sql:/docker-entrypoint-initdb.d/init.sql
-    networks:
-      network:
-        ipv4_address: 10.5.0.5
-
-volumes:
-  db:
-    driver: local
-
-networks:
-  network:
-    driver: bridge
-    ipam:
-      config:
-        - subnet: 10.5.0.0/16
-          gateway: 10.5.0.1

docker-modules/docker-compose/assign-static-ip/init.sql

@@ -1,13 +0,0 @@
-CREATE DATABASE IF NOT EXISTS test;
-CREATE USER 'db_user'@'10.5.0.1' IDENTIFIED BY 'password';
-GRANT ALL PRIVILEGES ON *.* TO 'db_user'@'10.5.0.1' WITH GRANT OPTION;
-FLUSH PRIVILEGES;
-
-use test;
-
-CREATE TABLE IF NOT EXISTS TEST_TABLE (id int, name varchar(255));
-
-
-INSERT INTO TEST_TABLE VALUES (1, 'TEST_1');
-INSERT INTO TEST_TABLE VALUES (2, 'TEST_2');
-INSERT INTO TEST_TABLE VALUES (3, 'TEST_3');

docker-modules/docker-compose/depends-on_vs_links/docker-compose-depends-on.yml

@@ -1,14 +0,0 @@
-services:
-  db:
-    image: postgres:latest
-    environment:
-      - POSTGRES_USER=postgres
-      - POSTGRES_PASSWORD=postgres
-    ports:
-      - 5432:5432
-  web-app:
-    image: web-app:latest
-    ports:
-      - 8080:8080
-    depends_on:
-      - db

docker-modules/docker-compose/depends-on_vs_links/docker-compose-links.yml

@@ -1,14 +0,0 @@
-services:
-  db:
-    image: postgres:latest
-    environment:
-      - POSTGRES_USER=postgres
-      - POSTGRES_PASSWORD=postgres
-    ports:
-      - 5432:5432
-  web-app:
-    image: web-app:latest
-    ports:
-      - 8080:8080
-    links:
-      - db

docker-modules/docker-compose/depends-on_vs_links/docker-compose-network.yml

@@ -1,36 +0,0 @@
-services:
-  db:
-    image: postgres:latest
-    restart: always
-    environment:
-      - POSTGRES_USER=postgres
-      - POSTGRES_PASSWORD=postgres
-    ports:
-      - 5432:5432
-    volumes:
-      - db:/var/lib/postgresql/data
-    networks:
-      - mynet
-
-  web-app:
-    image: web-app:latest
-    depends_on:
-      - db
-    networks:
-      - mynet
-    ports:
-      - 8080:8080
-    environment:
-      DB_HOST: db
-      DB_PORT: 5432
-      DB_USER: postgres
-      DB_PASSWORD: postgres
-      DB_NAME: postgres
-
-networks:
-  mynet:
-    driver: bridge
-
-volumes:
-  db:
-    driver: local

docker-modules/docker-compose/exclude-subfolders/Dockerfile

@@ -1,7 +0,0 @@
-FROM node:12.18.1 
-ENV NODE_ENV=production 
-WORKDIR /app 
-COPY ["package.json", "package-lock.json*", "./"] 
-RUN npm install --production 
-COPY . . 
-CMD [ "node", "server.js" ]

docker-modules/docker-compose/exclude-subfolders/docker-compose.yml

@@ -1,12 +0,0 @@
-services:
-  node-app:
-    build: .
-    ports:
-      - 8080:8080
-    volumes:
-      - .:/app
-      - my-vol:/app/node_modules/
-
-volumes:
-  my-vol:
-    driver: local

docker-modules/docker-compose/exclude-subfolders/package.json

@@ -1,17 +0,0 @@
-{
-  "name": "app",
-  "version": "1.0.0",
-  "description": "",
-  "main": "server.js",
-  "scripts": {
-    "test": "echo \"Error: no test specified\" && exit 1",
-    "start": "node server.js"
-  },
-  "keywords": [],
-  "author": "",
-  "license": "ISC",
-  "dependencies": {
-    "ronin-mocks": "^0.1.11",
-    "ronin-server": "^0.1.3"
-  }
-}

docker-modules/docker-compose/exclude-subfolders/server.js

@@ -1,7 +0,0 @@
-const ronin = require('ronin-server')
-const mocks = require('ronin-mocks')
-
-const server = ronin.server()
-
-server.use('/', mocks.server(server.Router(), false, true))
-server.start()

docker-modules/docker-compose/intro/docker-compose.yml

@@ -1,61 +0,0 @@
-version: '3'
-
-services:
-
-## VOLUME CONTAINER-TO-CONTAINER AND HOST-TO-CONTAINER TEST ##
-
-  volumes-example-service:
-    image: alpine:latest
-    container_name: volumes-example-service
-    volumes: 
-      - /tmp:/my-volumes/host-volume
-      - /home:/my-volumes/readonly-host-volume:ro
-      - my-named-global-volume:/my-volumes/named-global-volume    
-    tty: true # Needed to keep the container running
-
-  another-volumes-example-service:
-    image: alpine:latest
-    container_name: another-volumes-example-service
-    volumes: 
-      - my-named-global-volume:/another-path/the-same-named-global-volume
-    tty: true # Needed to keep the container running
-
-## NETWORK CONTAINER-TO-CONTAINER TEST ##
-
-  network-example-service:
-    image: karthequian/helloworld:latest
-    container_name: network-example-service
-    networks:
-      - my-shared-network
-
-  another-service-in-the-same-network:
-    image: alpine:latest
-    container_name: another-service-in-the-same-network
-    networks: 
-      - my-shared-network
-
-    tty: true # Needed to keep the container running
-
-  another-service-in-its-own-network:
-    image: alpine:latest
-    container_name: another-service-in-its-own-network
-    networks: 
-      - my-private-network
-    tty: true # Needed to keep the container running
-
-## NETWORK HOST-TO-CONTAINER TEST ##
-
-  network-example-service-available-to-host-on-port-1337:
-    image: karthequian/helloworld:latest
-    container_name: network-example-service-available-to-host-on-port-1337
-    networks: 
-      - my-shared-network
-    ports:
-      - "1337:80"
-
-volumes:
-  my-named-global-volume:
-
-networks:
-  my-shared-network: {}
-  my-private-network: {}

docker-modules/docker-compose/latest-image/Dockerfile

@@ -1,3 +0,0 @@
-FROM openjdk:11
-COPY target/docker-sample-app-0.0.1.jar app.jar
-ENTRYPOINT ["java","-jar","/app.jar"]

docker-modules/docker-compose/latest-image/docker-compose-build-image.yaml

@@ -1,8 +0,0 @@
-version: '2.4'
-services:
-  db:
-    image: postgres
-  my_app:
-    build: .
-    ports:
-      - "8080:8080"

docker-modules/docker-compose/latest-image/docker-compose-with-image.yaml

@@ -1,9 +0,0 @@
-version: '2.4'
-services:
-  db:
-    image: postgres
-  my_app:
-    image: "eugen/test-app:latest"
-    ports:
-      - "8080:8080"
-

docker-modules/docker-compose/multiple-mounts/bind_mount_and_volume.yml

@@ -1,15 +0,0 @@
-services:
-  mysql-db:
-    image: mysql:latest
-    environment:
-      - MYSQL_ROOT_PASSWORD=password
-      - MYSQL_ROOT_HOST=localhost
-    ports:
-      - '3306:3306'
-    volumes:
-      - first-volume-data:/var/lib/mysql
-      - ./init.sql:/docker-entrypoint-initdb.d/init.sql
-
-volumes:
-  first-volume-data:
-    external: true

docker-modules/docker-compose/multiple-mounts/init.sql

@@ -1,9 +0,0 @@
-CREATE DATABASE IF NOT EXISTS test;
-
-use test;
-
-CREATE TABLE IF NOT EXISTS test_table (id int, description varchar(255));
-
-INSERT INTO test_table VALUES (1, 'TEST_1');
-INSERT INTO test_table VALUES (2, 'TEST_2');
-INSERT INTO test_table VALUES (3, 'TEST_3');

docker-modules/docker-compose/multiple-mounts/multiple_bind_mounts.yml

@@ -1,15 +0,0 @@
-services:
-  localstack:
-    privileged: true
-    image: localstack/localstack:latest
-    container_name: localstack
-    ports:
-      - '4563-4599:4563-4599'
-      - '8055:8080'
-    environment:
-      - SERVICES=s3
-      - DEBUG=1
-      - DATA_DIR=/tmp/localstack/data
-    volumes:
-      - './.localstack:/var/lib/localstack'
-      - '/var/run/docker.sock:/var/run/docker.sock'