Merge branch 'eugenp:master' into master

2022-02-28 10:56:45 -03:00
parent b6db99e3a1 be0e55765c
commit 6a9b7f935f
122 changed files with 2580 additions and 562 deletions
@@ -1,7 +1,5 @@
 package com.baeldung.algorithms.dfs;

-import java.util.LinkedList;
-import java.util.Queue;
 import java.util.Stack;

 public class BinaryTree {
@@ -124,69 +122,43 @@ public class BinaryTree {
        }
    }

-    public void traverseLevelOrder() {
-        if (root == null) {
-            return;
-        }

-        Queue<Node> nodes = new LinkedList<>();
-        nodes.add(root);
-
-        while (!nodes.isEmpty()) {
-
-            Node node = nodes.remove();
-
-            System.out.print(" " + node.value);
-
-            if (node.left != null) {
-                nodes.add(node.left);
-            }
-
-            if (node.left != null) {
-                nodes.add(node.right);
-            }
-        }
-    }
-
-    
    public void traverseInOrderWithoutRecursion() {
-        Stack<Node> stack = new Stack<Node>();
+        Stack<Node> stack = new Stack<>();
        Node current = root;
-        stack.push(root);
-        while(! stack.isEmpty()) {
-            while(current.left != null) {
-                current = current.left;                
-                stack.push(current);                
-            }
-            current = stack.pop();
-            visit(current.value);
-            if(current.right != null) {
-                current = current.right;                
+
+        while (current != null || !stack.isEmpty()) {
+            while (current != null) {
                stack.push(current);
+                current = current.left;
            }
+
+            Node top = stack.pop();
+            visit(top.value);
+            current = top.right;
        }
    }
-    
+
    public void traversePreOrderWithoutRecursion() {
-        Stack<Node> stack = new Stack<Node>();
-        Node current = root;
+        Stack<Node> stack = new Stack<>();
+        Node current;
        stack.push(root);
        while(! stack.isEmpty()) {
            current = stack.pop();
            visit(current.value);
-            
+
            if(current.right != null)
                stack.push(current.right);
-                
+
            if(current.left != null)
                stack.push(current.left);
-        }        
+        }
    }
-    
+
    public void traversePostOrderWithoutRecursion() {
-        Stack<Node> stack = new Stack<Node>();
+        Stack<Node> stack = new Stack<>();
        Node prev = root;
-        Node current = root;
+        Node current;
        stack.push(root);

        while (!stack.isEmpty()) {
@@ -206,14 +178,14 @@ public class BinaryTree {
                    stack.push(current.left);
                }
            }
-        }   
-    }    
-    
-    private void visit(int value) {
-        System.out.print(" " + value);        
+        }
    }
-    
-    class Node {
+
+    private void visit(int value) {
+        System.out.print(" " + value);
+    }
+
+    static class Node {
        int value;
        Node left;
        Node right;
@@ -1,11 +1,11 @@
 package com.baeldung.algorithms.dfs;

+import org.junit.Test;
+
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;

-import org.junit.Test;
-
 public class BinaryTreeUnitTest {

    @Test
@@ -13,7 +13,7 @@ public class BinaryTreeUnitTest {

        BinaryTree bt = createBinaryTree();

-        assertTrue(!bt.isEmpty());
+        assertFalse(bt.isEmpty());
    }

    @Test
@@ -111,14 +111,6 @@ public class BinaryTreeUnitTest {
        bt.traversePostOrderWithoutRecursion();
    }

-    @Test
-    public void givenABinaryTree_WhenTraversingLevelOrder_ThenPrintValues() {
-
-        BinaryTree bt = createBinaryTree();
-
-        bt.traverseLevelOrder();
-    }
-
    private BinaryTree createBinaryTree() {
        BinaryTree bt = new BinaryTree();

@@ -8,4 +8,5 @@ This module contains articles about Java 8 core features
 - [Java 8 Stream skip() vs limit()](https://www.baeldung.com/java-stream-skip-vs-limit)
 - [Guide to Java BiFunction Interface](https://www.baeldung.com/java-bifunction-interface)
 - [Interface With Default Methods vs Abstract Class](https://www.baeldung.com/java-interface-default-method-vs-abstract-class)
+- [Convert Between Byte Array and UUID in Java](https://www.baeldung.com/java-byte-array-to-uuid)
 - [[<-- Prev]](/core-java-modules/core-java-8)
@@ -1,17 +1,24 @@
 package com.baeldung.game;

-import java.util.HashMap;
-import java.util.Map;
-import java.util.Random;
-import java.util.Scanner;
+import java.util.*;

 class RockPaperScissorsGame {

-    private static Map<Integer, String> movesMap = new HashMap<Integer, String>() {{
-        put(0, "rock");
-        put(1, "paper");
-        put(2, "scissors");
-    }};
+    enum Move {
+        ROCK("rock"),
+        PAPER("paper"),
+        SCISSORS("scissors");
+
+        private String value;
+
+        Move(String value) {
+            this.value = value;
+        }
+
+        public String getValue() {
+            return value;
+        }
+    }

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
@@ -31,7 +38,7 @@ class RockPaperScissorsGame {
                break;
            }

-            if (!movesMap.containsValue(playerMove)) {
+            if (Arrays.stream(Move.values()).noneMatch(x -> x.getValue().equals(playerMove))) {
                System.out.println("Your move isn't valid!");
                continue;
            }
@@ -51,15 +58,15 @@ class RockPaperScissorsGame {
    }

    private static boolean isPlayerWin(String playerMove, String computerMove) {
-        return playerMove.equals("rock") && computerMove.equals("scissors")
-                || (playerMove.equals("scissors") && computerMove.equals("paper"))
-                || (playerMove.equals("paper") && computerMove.equals("rock"));
+        return playerMove.equals(Move.ROCK.value) && computerMove.equals(Move.SCISSORS.value)
+                || (playerMove.equals(Move.SCISSORS.value) && computerMove.equals(Move.PAPER.value))
+                || (playerMove.equals(Move.PAPER.value) && computerMove.equals(Move.ROCK.value));
    }

    private static String getComputerMove() {
        Random random = new Random();
        int randomNumber = random.nextInt(3);
-        String computerMove = movesMap.get(randomNumber);
+        String computerMove = Move.values()[randomNumber].getValue();
        System.out.println("Computer move: " + computerMove);
        return computerMove;
    }
@@ -7,3 +7,4 @@
 - [ArrayList vs. LinkedList vs. HashMap in Java](https://www.baeldung.com/java-arraylist-vs-linkedlist-vs-hashmap)
 - [Java Deque vs. Stack](https://www.baeldung.com/java-deque-vs-stack)
 - [Collection.toArray(new T[0]) or .toArray(new T[size])](https://www.baeldung.com/java-collection-toarray-methods)
+- [Create an Empty Map in Java](https://www.baeldung.com/java-create-empty-map)
@@ -15,6 +15,16 @@
    </parent>

    <dependencies>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-collections4</artifactId>
+            <version>${commons-collections4.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.google.guava</groupId>
+            <artifactId>guava</artifactId>
+            <version>${guava.version}</version>
+        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
@@ -37,12 +47,23 @@
                </plugin>
            </plugins>
        </pluginManagement>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>${maven-compiler-plugin.version}</version>
+                <configuration>
+                    <source>${maven.compiler.source}</source>
+                    <target>${maven.compiler.target}</target>
+                </configuration>
+            </plugin>
+        </plugins>
    </build>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <maven.compiler.source>1.8</maven.compiler.source>
-        <maven.compiler.target>1.8</maven.compiler.target>
+        <maven.compiler.source>1.9</maven.compiler.source>
+        <maven.compiler.target>1.9</maven.compiler.target>
    </properties>

 </project>
@@ -0,0 +1,53 @@
+package com.baeldung.entries;
+
+import java.util.Map;
+import java.util.Objects;
+import java.util.StringJoiner;
+
+public class SimpleCustomKeyValue<K, V> implements Map.Entry<K, V> {
+
+    private final K key;
+    private V value;
+
+    public SimpleCustomKeyValue(K key, V value) {
+        this.key = key;
+        this.value = value;
+    }
+
+    @Override
+    public K getKey() {
+        return key;
+    }
+
+    @Override
+    public V getValue() {
+        return value;
+    }
+
+    @Override
+    public V setValue(V value) {
+        return this.value = value;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        SimpleCustomKeyValue<?, ?> that = (SimpleCustomKeyValue<?, ?>) o;
+        return Objects.equals(key, that.key) && Objects.equals(value, that.value);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(key, value);
+    }
+
+    @Override
+    public String toString() {
+        return new StringJoiner(", ", SimpleCustomKeyValue.class.getSimpleName() + "[", "]").add("key=" + key).add("value=" + value).toString();
+    }
+}
@@ -0,0 +1,113 @@
+package com.baeldung.entries;
+
+import com.google.common.collect.Maps;
+import org.apache.commons.collections4.KeyValue;
+import org.apache.commons.collections4.keyvalue.DefaultMapEntry;
+import org.apache.commons.collections4.keyvalue.UnmodifiableMapEntry;
+import org.junit.jupiter.api.Test;
+
+import java.util.AbstractMap;
+import java.util.Map;
+import java.util.stream.Stream;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.tuple;
+
+public class EntriesExampleUnitTest {
+
+    @Test
+    public void givenEntries_whenVerifying_thenShouldContainKeyValues() {
+        AbstractMap.SimpleEntry<String, String> firstEntry = new AbstractMap.SimpleEntry<>("key1", "value1");
+        AbstractMap.SimpleEntry<String, String> secondEntry = new AbstractMap.SimpleEntry<>("key2", "value2");
+        AbstractMap.SimpleEntry<String, String> thirdEntry = new AbstractMap.SimpleEntry<>(firstEntry);
+        thirdEntry.setValue("a different value");
+
+        assertThat(Stream.of(firstEntry, secondEntry, thirdEntry))
+          .extracting("key", "value")
+          .containsExactly(
+            tuple("key1", "value1"),
+            tuple("key2", "value2"),
+            tuple("key1", "a different value"));
+    }
+
+    @Test
+    public void givenImmutableEntries_whenVerifying_thenShouldContainKeyValues() {
+        AbstractMap.SimpleImmutableEntry<String, String> firstEntry = new AbstractMap.SimpleImmutableEntry<>("key1", "value1");
+        AbstractMap.SimpleImmutableEntry<String, String> secondEntry = new AbstractMap.SimpleImmutableEntry<>("key2", "value2");
+        AbstractMap.SimpleImmutableEntry<String, String> thirdEntry = new AbstractMap.SimpleImmutableEntry<>(firstEntry);
+
+        assertThat(Stream.of(firstEntry, secondEntry, thirdEntry))
+          .extracting("key", "value")
+          .containsExactly(
+            tuple("key1", "value1"),
+            tuple("key2", "value2"),
+            tuple("key1", "value1"));
+    }
+
+    @Test
+    public void givenImmutableEntryUsingJava9_whenVerifying_thenShouldContainKeyValues() {
+        Map.Entry<String, String> entry = Map.entry("key", "value");
+
+        assertThat(entry.getKey())
+          .isEqualTo("key");
+        assertThat(entry.getValue())
+          .isEqualTo("value");
+    }
+
+
+    @Test
+    public void givenEntriesWithApacheCommons_whenVerifying_thenShouldContainKeyValues() {
+        Map.Entry<String, String> firstEntry = new DefaultMapEntry<>("key1", "value1");
+        KeyValue<String, String> secondEntry = new DefaultMapEntry<>("key2", "value2");
+
+        KeyValue<String, String> thirdEntry = new DefaultMapEntry<>(firstEntry);
+        KeyValue<String, String> fourthEntry = new DefaultMapEntry<>(secondEntry);
+
+        firstEntry.setValue("a different value");
+
+        assertThat(firstEntry)
+          .extracting("key", "value")
+          .containsExactly("key1", "a different value");
+
+        assertThat(Stream.of(secondEntry, thirdEntry, fourthEntry))
+          .extracting("key", "value")
+          .containsExactly(
+            tuple("key2", "value2"),
+            tuple("key1", "value1"),
+            tuple("key2", "value2"));
+    }
+
+    @Test
+    public void givenImmutableEntriesWithApacheCommons_whenVerifying_thenShouldContainKeyValues() {
+        Map.Entry<String, String> firstEntry = new UnmodifiableMapEntry<>("key1", "value1");
+        KeyValue<String, String> secondEntry = new UnmodifiableMapEntry<>("key2", "value2");
+
+        KeyValue<String, String> thirdEntry = new UnmodifiableMapEntry<>(firstEntry);
+        KeyValue<String, String> fourthEntry = new UnmodifiableMapEntry<>(secondEntry);
+
+        assertThat(firstEntry)
+          .extracting("key", "value")
+          .containsExactly("key1", "value1");
+
+        assertThat(Stream.of(secondEntry, thirdEntry, fourthEntry))
+          .extracting("key", "value")
+          .containsExactly(
+            tuple("key2", "value2"),
+            tuple("key1", "value1"),
+            tuple("key2", "value2"));
+    }
+
+
+    @Test
+    public void givenImmutableEntriesWithGuava_whenVerifying_thenShouldContainKeyValues() {
+        Map.Entry<String, String> firstEntry = Maps.immutableEntry("key1", "value1");
+        Map.Entry<String, String> secondEntry = Maps.immutableEntry("key2", "value2");
+
+        assertThat(Stream.of(firstEntry, secondEntry))
+          .extracting("key", "value")
+          .containsExactly(
+            tuple("key1", "value1"),
+            tuple("key2", "value2"));
+    }
+
+}
@@ -0,0 +1,31 @@
+package com.baeldung.entries;
+
+import com.google.common.collect.ImmutableMap;
+import org.junit.jupiter.api.Test;
+
+import java.util.Map;
+import java.util.stream.Stream;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.tuple;
+
+class SimpleCustomKeyValueUnitTest {
+
+
+    @Test
+    public void givenModifiableEntries_whenVerifying_thenShouldContainKeyValues() {
+        Map.Entry<String, String> firstEntry = new SimpleCustomKeyValue<>("key1", "value1");
+
+        Map.Entry<String, String> secondEntry = new SimpleCustomKeyValue<>("key2", "value2");
+        secondEntry.setValue("different value");
+
+        Map<String, String> map = Map.ofEntries(firstEntry, secondEntry);
+
+        assertThat(map)
+          .isEqualTo(ImmutableMap.<String,String>builder()
+            .put("key1", "value1")
+            .put("key2", "different value")
+            .build());
+    }
+
+}
@@ -0,0 +1,45 @@
+package com.baeldung.exception.variablemightnothavebeeninitialized;
+
+public class VariableMightNotHaveBeenInitialized {
+
+    private static int instanceVariableCount;
+
+    /**
+     * Method would not compile if lines 14 and 18 are uncommented.
+     */
+    public static void countEven() {
+        //uninstantiated
+        int count;
+        int[] arr = new int[]{23, 56, 89, 12, 23};
+        for (int i = 0; i < arr.length; i++) {
+            if ((arr[i] % 2) == 0) {
+                // count++;
+            }
+
+        }
+        // System.out.println("Total Even Numbers : " + count);
+    }
+
+    public static int countEvenUsingInstanceVariable(int[] arr) {
+
+        for (int i = 0; i < arr.length; i++) {
+            if ((arr[i] % 2) == 0) {
+                instanceVariableCount++;
+            }
+
+        }
+        return instanceVariableCount;
+    }
+
+    public static int countEvenUsingIfElse(int[] arr, int args) {
+        int count;
+        count = args > 0 ? args : 0;
+        for (int i = 0; i < arr.length; i++) {
+            if ((arr[i] % 2) == 0) {
+                count++;
+            }
+
+        }
+        return count;
+    }
+}
@@ -0,0 +1,24 @@
+package com.baeldung.exception.variablemightnothavebeeninitialized;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class VariableMightNotHaveBeenInitializedUnitTest {
+
+    @Test
+    public void usingInstanceVariable_returnCount() {
+        int[] arr = new int[]{1, 2, 3, 4, 5, 6};
+        int value = VariableMightNotHaveBeenInitialized.countEvenUsingInstanceVariable(arr);
+
+        assertEquals(3, value);
+    }
+
+    @Test
+    public void usingArgumentsAndIfElse_returnCount() {
+        int[] arr = new int[]{1, 2, 3, 4, 5, 6};
+        int value = VariableMightNotHaveBeenInitialized.countEvenUsingIfElse(arr, 2);
+
+        assertEquals(5, value);
+    }
+}
@@ -10,4 +10,5 @@ This module contains articles about core Java Security
 - [HMAC in Java](https://www.baeldung.com/java-hmac)
 - [Generating a Secure AES Key in Java](https://www.baeldung.com/java-secure-aes-key)
 - [Computing an X509 Certificate’s Thumbprint in Java](https://www.baeldung.com/java-x509-certificate-thumbprint)
+- [Error: “trustAnchors parameter must be non-empty”](https://www.baeldung.com/java-trustanchors-parameter-must-be-non-empty)
 - More articles: [[<-- prev]](/core-java-modules/core-java-security-2)
@@ -38,7 +38,6 @@
        <module>core-java-collections-maps</module>
        <module>core-java-collections-maps-2</module>
        <module>core-java-collections-maps-3</module>
-        <module>core-java-collections-maps-4</module>
        <module>core-java-concurrency-2</module>
        <module>core-java-concurrency-advanced</module>
        <module>core-java-concurrency-advanced-2</module>
@@ -6,3 +6,4 @@
 - [How To Configure Java Heap Size Inside a Docker Container](https://www.baeldung.com/ops/docker-jvm-heap-size)
 - [Dockerfile Strategies for Git](https://www.baeldung.com/ops/dockerfile-git-strategies)
 - [How to Get Docker-Compose to Always Use the Latest Image](https://www.baeldung.com/ops/docker-compose-latest-image)
+- [How to Include Files Outside of Docker’s Build Context](https://www.baeldung.com/ops/docker-include-files-outside-build-context)
@@ -0,0 +1,21 @@
+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
@@ -0,0 +1,13 @@
+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
@@ -0,0 +1,25 @@
+<?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</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>
+        </dependency>
+    </dependencies>
+
+    <properties>
+        <maven.compiler.source>8</maven.compiler.source>
+        <maven.compiler.target>8</maven.compiler.target>
+    </properties>
+</project>
@@ -0,0 +1,14 @@
+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");
+    }
+}
@@ -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 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>
+    <description>Multi-module Maven caching example</description>
+    <packaging>pom</packaging>
+
+    <dependencyManagement>
+        <dependencies>
+            <dependency>
+                <groupId>com.google.guava</groupId>
+                <artifactId>guava</artifactId>
+                <version>31.0.1-jre</version>
+            </dependency>
+        </dependencies>
+    </dependencyManagement>
+
+    <properties>
+        <java.version>1.8</java.version>
+    </properties>
+
+    <modules>
+        <module>runner</module>
+        <module>core</module>
+    </modules>
+</project>
@@ -0,0 +1,56 @@
+<?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</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</artifactId>
+            <version>0.0.1-SNAPSHOT</version>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-assembly-plugin</artifactId>
+                <version>3.3.0</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.compiler.source>8</maven.compiler.source>
+        <maven.compiler.target>8</maven.compiler.target>
+    </properties>
+</project>
@@ -0,0 +1,11 @@
+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());
+    }
+
+}
@@ -0,0 +1,15 @@
+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
@@ -0,0 +1,13 @@
+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
@@ -0,0 +1,53 @@
+<?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>31.0.1-jre</version>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-assembly-plugin</artifactId>
+                <version>3.3.0</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>
+    </properties>
+</project>
@@ -0,0 +1,11 @@
+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"));
+    }
+}
@@ -26,6 +26,8 @@
        <module>docker-internal-dto</module>
        <module>docker-spring-boot</module>
        <module>docker-sample-app</module>
+        <module>docker-caching/single-module-caching</module>
+        <module>docker-caching/multi-module-caching</module>
    </modules>

 </project>
@@ -0,0 +1,3 @@
+### Relevant Articles:
+
+- [Gradle: sourceCompatiblity vs targetCompatibility](https://www.baeldung.com/gradle-sourcecompatiblity-vs-targetcompatibility)
@@ -7,3 +7,4 @@
 - [Update the Value Associated With a Key in a HashMap](https://www.baeldung.com/java-hashmap-update-value-by-key)
 - [Java Map – keySet() vs. entrySet() vs. values() Methods](https://www.baeldung.com/java-map-entries-methods)
 - [Java IdentityHashMap Class and Its Use Cases](https://www.baeldung.com/java-identityhashmap)
+- [How to Invert a Map in Java](https://www.baeldung.com/java-invert-map)
@@ -7,3 +7,4 @@ This module contains articles about the Java Native Interface (JNI).
 - [Guide to JNI (Java Native Interface)](https://www.baeldung.com/jni)
 - [Using JNA to Access Native Dynamic Libraries](https://www.baeldung.com/java-jna-dynamic-libraries)
 - [Check if a Java Program Is Running in 64-Bit or 32-Bit JVM](https://www.baeldung.com/java-detect-jvm-64-or-32-bit)
+- [How to use JNI’s RegisterNatives() method?](https://www.baeldung.com/jni-registernatives)
--- a/Show More
+++ b/Show More