Merge branch 'master' into bael-7169-update-readme

2023-12-10 19:00:44 +01:00
parent 2dba12e694 a4f17e64f4
commit 3d685dc3b6
483 changed files with 5781 additions and 1037 deletions
@@ -45,7 +45,7 @@
    <properties>
        <maven.compiler.source.version>11</maven.compiler.source.version>
        <maven.compiler.target.version>11</maven.compiler.target.version>
-        <jackson.version>2.14.1</jackson.version>
+        <jackson.version>2.16.0</jackson.version>
        <gson.version>2.10</gson.version>
    </properties>

@@ -21,8 +21,4 @@
        </dependency>
    </dependencies>

-    <properties>
-        <java.version>17</java.version>
-    </properties>
-
 </project>
@@ -13,8 +13,4 @@
        <version>0.0.1-SNAPSHOT</version>
    </parent>

-    <properties>
-        <java.version>17</java.version>
-    </properties>
-
 </project>
@@ -26,8 +26,4 @@
        </dependency>
    </dependencies>

-    <properties>
-        <java.version>17</java.version>
-    </properties>
-
 </project>
@@ -9,3 +9,4 @@
 - [Migrate From Java 8 to Java 17](https://www.baeldung.com/java-migrate-8-to-17)
 - [Format Multiple ‘or’ Conditions in an If Statement in Java](https://www.baeldung.com/java-multiple-or-conditions-if-statement)
 - [Get All Record Fields and Its Values via Reflection](https://www.baeldung.com/java-reflection-record-fields-values)
+- [Context-Specific Deserialization Filters in Java 17](https://www.baeldung.com/java-context-specific-deserialization-filters)
@@ -3,19 +3,34 @@
    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-20</artifactId>
+
    <parent>
        <groupId>com.baeldung.core-java-modules</groupId>
        <artifactId>core-java-modules</artifactId>
        <version>0.0.1-SNAPSHOT</version>
    </parent>

-    <artifactId>core-java-20</artifactId>
-
-    <properties>
-        <maven.compiler.source>20</maven.compiler.source>
-        <maven.compiler.target>20</maven.compiler.target>
-        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-    </properties>
+    <dependencies>
+        <dependency>
+            <groupId>jakarta.servlet</groupId>
+            <artifactId>jakarta.servlet-api</artifactId>
+            <version>6.0.0</version>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>3.24.2</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-junit-jupiter</artifactId>
+            <version>5.2.0</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>

    <build>
        <plugins>
@@ -41,25 +56,10 @@
        </plugins>
    </build>

-    <dependencies>
-        <dependency>
-            <groupId>jakarta.servlet</groupId>
-            <artifactId>jakarta.servlet-api</artifactId>
-            <version>6.0.0</version>
-            <scope>provided</scope>
-        </dependency>
-        <dependency>
-            <groupId>org.assertj</groupId>
-            <artifactId>assertj-core</artifactId>
-            <version>3.24.2</version>
-            <scope>test</scope>
-        </dependency>
-        <dependency>
-            <groupId>org.mockito</groupId>
-            <artifactId>mockito-junit-jupiter</artifactId>
-            <version>5.2.0</version>
-            <scope>test</scope>
-        </dependency>
-    </dependencies>
+    <properties>
+        <maven.compiler.source>20</maven.compiler.source>
+        <maven.compiler.target>20</maven.compiler.target>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    </properties>

 </project>
@@ -0,0 +1,5 @@
+package com.baeldung.deserialization;
+
+public record Contact(String email, String phone) {
+    // Constructor, getters, and other methods are automatically generated
+}
@@ -0,0 +1,5 @@
+package com.baeldung.deserialization;
+
+public record Person(String name, int age, String address, Contact contact) {
+    // Constructor, getters, and other methods are automatically generated
+}
@@ -0,0 +1,39 @@
+package com.baeldung.deserialization;
+
+import com.google.gson.Gson;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+public class DeserializationUnitTest {
+
+    @Test
+    public void givenJsonString_whenDeserialized_thenPersonRecordCreated() {
+        String json = "{\"name\":\"John Doe\",\"age\":30,\"address\":\"123 Main St\"}";
+
+        Person person = new Gson().fromJson(json, Person.class);
+
+        assertEquals("John Doe", person.name());
+        assertEquals(30, person.age());
+        assertEquals("123 Main St", person.address());
+    }
+
+    @Test
+    public void givenNestedJsonString_whenDeserialized_thenPersonRecordCreated() {
+        String json = "{\"name\":\"John Doe\",\"age\":30,\"address\":\"123 Main St\",\"contact\":{\"email\":\"[email protected]\",\"phone\":\"555-1234\"}}";
+
+        Person person = new Gson().fromJson(json, Person.class);
+
+        assertNotNull(person);
+        assertEquals("John Doe", person.name());
+        assertEquals(30, person.age());
+        assertEquals("123 Main St", person.address());
+
+        Contact contact = person.contact();
+
+        assertNotNull(contact);
+        assertEquals("[email protected]", contact.email());
+        assertEquals("555-1234", contact.phone());
+    }
+}
@@ -8,4 +8,5 @@
 - [Add Minutes to a Time String in Java](https://www.baeldung.com/java-string-time-add-mins)
 - [Round the Date in Java](https://www.baeldung.com/java-round-the-date)
 - [Representing Furthest Possible Date in Java](https://www.baeldung.com/java-date-represent-max)
+- [Retrieving Unix Time in Java](https://www.baeldung.com/java-retrieve-unix-time)
 - [[<-- Prev]](/core-java-modules/core-java-datetime-java8-1)
@@ -0,0 +1,42 @@
+package com.baeldung.unixtime;
+
+import static org.junit.Assert.assertEquals;
+import java.time.Instant;
+import java.time.LocalDate;
+
+import java.time.Month;
+import java.time.ZoneId;
+import java.util.Date;
+
+import org.joda.time.DateTime;
+
+import org.junit.jupiter.api.Test;
+
+public class UnixTimeUnitTest {
+
+    @Test
+    public void givenTimeUsingDateApi_whenConvertedToUnixTime_thenMatch() {
+        Date date = new Date(2023 - 1900, 1, 15, 0, 0, 0);
+        long expected = 1676419200;
+        long actual = date.getTime() / 1000L;
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    public void givenTimeUsingJodaTime_whenConvertedToUnixTime_thenMatch() {
+        DateTime dateTime = new DateTime(2023, 2, 15, 00, 00, 00, 0);
+        long expected = 1676419200;
+        long actual = dateTime.getMillis() / 1000L;
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    public void givenTimeUsingLocalDate_whenConvertedToUnixTime_thenMatch() {
+        LocalDate date = LocalDate.of(2023, Month.FEBRUARY, 15);
+        Instant instant = date.atStartOfDay().atZone(ZoneId.of("UTC")).toInstant();
+        long expected = 1676419200;
+        long actual = instant.getEpochSecond();
+        assertEquals(expected, actual);
+    }
+
+}
@@ -11,3 +11,4 @@ This module contains articles about arrays conversion in Java
 - [Converting an int[] to HashSet in Java](https://www.baeldung.com/java-converting-int-array-to-hashset)
 - [Convert an ArrayList of String to a String Array in Java](https://www.baeldung.com/java-convert-string-arraylist-array)
 - [Convert Char Array to Int Array in Java](https://www.baeldung.com/java-convert-char-int-array)
+- [How to Convert Byte Array to Char Array](https://www.baeldung.com/java-convert-byte-array-char)
@@ -0,0 +1,47 @@
+package com.baeldung.array.conversions;
+
+import org.junit.Test;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.nio.ByteBuffer;
+import java.nio.CharBuffer;
+import java.nio.charset.StandardCharsets;
+
+import static org.junit.Assert.assertArrayEquals;
+
+public class ByteToCharArrayUnitTest {
+    public static byte[] byteArray = {65, 66, 67, 68};
+    public static char[] expected = {'A', 'B', 'C', 'D'};
+
+    @Test
+    public void givenByteArray_WhenUsingStandardCharsets_thenConvertToCharArray() {
+        char[] charArray = new String(byteArray, StandardCharsets.UTF_8).toCharArray();
+        assertArrayEquals(expected, charArray);
+    }
+
+    @Test
+    public void givenByteArray_WhenUsingSUsingStreams_thenConvertToCharArray() throws IOException {
+        ByteArrayInputStream inputStream = new ByteArrayInputStream(byteArray);
+        InputStreamReader reader = new InputStreamReader(inputStream);
+        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+        int data;
+        while ((data = reader.read()) != -1) {
+            char ch = (char) data;
+            outputStream.write(ch);
+        }
+        char[] charArray = outputStream.toString().toCharArray();
+        assertArrayEquals(expected, charArray);
+    }
+
+    @Test
+    public void givenByteArray_WhenUsingCharBuffer_thenConvertToCharArray() {
+        ByteBuffer byteBuffer = ByteBuffer.wrap(byteArray);
+        CharBuffer charBuffer = StandardCharsets.UTF_8.decode(byteBuffer);
+        char[] charArray = new char[charBuffer.remaining()];
+        charBuffer.get(charArray);
+        assertArrayEquals(expected, charArray);
+    }
+}
@@ -57,7 +57,7 @@
            </plugin>
        </plugins>
    </build>
-    
+
    <properties>
        <maven.compiler.release>11</maven.compiler.release>
    </properties>
@@ -10,4 +10,5 @@
 - [Remove Elements From a Queue Using Loop](https://www.baeldung.com/java-remove-elements-queue)
 - [Intro to Vector Class in Java](https://www.baeldung.com/java-vector-guide)
 - [HashSet toArray() Method in Java](https://www.baeldung.com/java-hashset-toarray)
+- [Time Complexity of Java Collections Sort in Java](https://www.baeldung.com/java-time-complexity-collections-sort)
 - More articles: [[<-- prev]](/core-java-modules/core-java-collections-4)
@@ -43,7 +43,6 @@

    <properties>
        <vavr.version>0.10.3</vavr.version>
-        <java.version>11</java.version>
        <modelmapper.version>3.2.0</modelmapper.version>
    </properties>
 </project>
@@ -39,7 +39,7 @@
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
-            <version>1.18.26</version>
+            <version>${lombok.version}</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
@@ -67,7 +67,7 @@
        <jmh.version>1.21</jmh.version>
        <commons-lang.version>2.2</commons-lang.version>
        <gson.version>2.10.1</gson.version>
-        <jackson.version>2.15.2</jackson.version>
+        <jackson.version>2.16.0</jackson.version>
        <org.json.version>20230618</org.json.version>
    </properties>
 </project>
@@ -13,14 +13,11 @@
        <version>0.0.1-SNAPSHOT</version>
    </parent>

-    <properties>
-        <spring.version>5.2.5.RELEASE</spring.version>
-    </properties>
    <dependencies>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
-            <version>2.13.1</version>
+            <version>2.16.0</version>
        </dependency>
        <dependency>
            <groupId>org.openjdk.jmh</groupId>
@@ -40,7 +37,7 @@
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
-            <version>4.13.1</version>
+            <version>${junit.version}</version>
            <scope>test</scope>
        </dependency>
        <dependency>
@@ -51,4 +48,8 @@
        </dependency>
    </dependencies>

+    <properties>
+        <spring.version>5.2.5.RELEASE</spring.version>
+    </properties>
+
 </project>
@@ -4,4 +4,7 @@
 - [How to Write Hashmap to CSV File](https://www.baeldung.com/java-write-hashmap-csv)
 - [How to Get First or Last Entry From a LinkedHashMap in Java](https://www.baeldung.com/java-linkedhashmap-first-last-key-value-pair)
 - [How to Write and Read a File with a Java HashMap](https://www.baeldung.com/java-hashmap-write-read-file)
- More articles: [[<-- prev]](/core-java-modules/core-java-collections-maps-6)
+- [Limiting the Max Size of a HashMap in Java](https://www.baeldung.com/java-hashmap-size-bound)
+- [How to Sort LinkedHashMap By Values in Java](https://www.baeldung.com/java-sort-linkedhashmap-using-values)
+- [How to Increment a Map Value in Java](https://www.baeldung.com/java-increment-map-value)
+- More articles: [[<-- prev]](/core-java-modules/core-java-collections-maps-6)
@@ -1,15 +1,11 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project xmlns="http://maven.apache.org/POM/4.0.0"
-         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <artifactId>core-java-collections-maps-7</artifactId>
    <name>core-java-collections-maps-7</name>
    <packaging>jar</packaging>
-    <properties>
-        <gson.version>2.10.1</gson.version>
-        <csv.version>1.5</csv.version>
-    </properties>

    <parent>
        <artifactId>core-java-modules</artifactId>
@@ -38,6 +34,16 @@
            <artifactId>guava</artifactId>
            <version>32.1.2-jre</version>
        </dependency>
+        <dependency>
+            <groupId>org.openjdk.jmh</groupId>
+            <artifactId>jmh-core</artifactId>
+            <version>1.37</version>
+        </dependency>
+        <dependency>
+            <groupId>org.openjdk.jmh</groupId>
+            <artifactId>jmh-generator-annprocess</artifactId>
+            <version>1.37</version>
+        </dependency>
    </dependencies>

    <build>
@@ -53,4 +59,10 @@
            </plugin>
        </plugins>
    </build>
+
+    <properties>
+        <gson.version>2.10.1</gson.version>
+        <csv.version>1.5</csv.version>
+    </properties>
+
 </project>
@@ -1,4 +1,4 @@
-package com.baeldung.map;
+package com.baeldung.map.incrementmapkey;

 import java.util.HashMap;
 import java.util.Map;
@@ -0,0 +1,68 @@
+package com.baeldung.map.incrementmapkey;
+
+import java.util.concurrent.TimeUnit;
+
+import org.openjdk.jmh.annotations.Benchmark;
+import org.openjdk.jmh.annotations.BenchmarkMode;
+import org.openjdk.jmh.annotations.Fork;
+import org.openjdk.jmh.annotations.Mode;
+import org.openjdk.jmh.annotations.OutputTimeUnit;
+import org.openjdk.jmh.annotations.Scope;
+import org.openjdk.jmh.annotations.State;
+
+@State(Scope.Benchmark)
+public class BenchmarkMapMethodsJMH {
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    @OutputTimeUnit(TimeUnit.NANOSECONDS)
+    @Fork(value = 1, warmups = 1)
+    public void benchMarkGuavaMap() {
+        IncrementMapValueWays im = new IncrementMapValueWays();
+        im.charFrequencyUsingAtomicMap(getString());
+    }
+
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    @OutputTimeUnit(TimeUnit.NANOSECONDS)
+    @Fork(value = 1, warmups = 1)
+    public void benchContainsKeyMap() {
+        IncrementMapValueWays im = new IncrementMapValueWays();
+        im.charFrequencyUsingContainsKey(getString());
+    }
+
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    @OutputTimeUnit(TimeUnit.NANOSECONDS)
+    @Fork(value = 1, warmups = 1)
+    public void benchMarkComputeMethod() {
+        IncrementMapValueWays im = new IncrementMapValueWays();
+        im.charFrequencyUsingCompute(getString());
+    }
+
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    @OutputTimeUnit(TimeUnit.NANOSECONDS)
+    @Fork(value = 1, warmups = 1)
+    public void benchMarkMergeMethod() {
+        IncrementMapValueWays im = new IncrementMapValueWays();
+        im.charFrequencyUsingMerge(getString());
+    }
+
+    public static void main(String[] args) throws Exception {
+        org.openjdk.jmh.Main.main(args);
+    }
+
+    private String getString() {
+        return
+          "Once upon a time in a quaint village nestled between rolling hills and whispering forests, there lived a solitary storyteller named Elias. Elias was known for spinning tales that transported listeners to magical realms and awakened forgotten dreams.\n"
+            + "\n"
+            + "His favorite spot was beneath an ancient oak tree, its sprawling branches offering shade to those who sought refuge from the bustle of daily life. Villagers of all ages would gather around Elias, their faces illuminated by the warmth of his stories.\n"
+            + "\n" + "One evening, as dusk painted the sky in hues of orange and purple, a curious young girl named Lily approached Elias. Her eyes sparkled with wonder as she asked for a tale unlike any other.\n" + "\n"
+            + "Elias smiled, sensing her thirst for adventure, and began a story about a forgotten kingdom veiled by mist, guarded by mystical creatures and enchanted by ancient spells. With each word, the air grew thick with anticipation, and the listeners were transported into a world where magic danced on the edges of reality.\n"
+            + "\n" + "As Elias weaved the story, Lily's imagination took flight. She envisioned herself as a brave warrior, wielding a shimmering sword against dark forces, her heart fueled by courage and kindness.\n" + "\n"
+            + "The night wore on, but the spell of the tale held everyone captive. The villagers laughed, gasped, and held their breaths, journeying alongside the characters through trials and triumphs.\n" + "\n"
+            + "As the final words lingered in the air, a sense of enchantment settled upon the listeners. They thanked Elias for the gift of his storytelling, each carrying a piece of the magical kingdom within their hearts.\n" + "\n"
+            + "Lily, inspired by the story, vowed to cherish the spirit of adventure and kindness in her own life. With a newfound spark in her eyes, she bid Elias goodnight, already dreaming of the countless adventures awaiting her.\n" + "\n"
+            + "Under the star-studded sky, Elias remained beneath the ancient oak, his heart aglow with the joy of sharing tales that ignited imagination and inspired dreams. And as the night embraced the village, whispers of the enchanted kingdom lingered in the breeze, promising endless possibilities to those who dared to believe.";
+    }
+}
@@ -1,4 +1,4 @@
-package com.baeldung.map;
+package com.baeldung.map.incrementmapkey;

 import java.util.HashMap;
 import java.util.Map;
@@ -0,0 +1,141 @@
+package com.baeldung.map;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+
+import org.junit.jupiter.api.Test;
+
+class Player {
+    private String name;
+    private Integer score = 0;
+
+    public Player(String name, Integer score) {
+        this.name = name;
+        this.score = score;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (!(o instanceof Player)) {
+            return false;
+        }
+
+        Player player = (Player) o;
+
+        if (!Objects.equals(name, player.name)) {
+            return false;
+        }
+        return Objects.equals(score, player.score);
+    }
+
+    @Override
+    public int hashCode() {
+        int result = name != null ? name.hashCode() : 0;
+        result = 31 * result + (score != null ? score.hashCode() : 0);
+        return result;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public int getScore() {
+        return score;
+    }
+}
+
+public class LinkedHashMapSortByValueUnitTest {
+    private static LinkedHashMap<String, Integer> MY_MAP = new LinkedHashMap<>();
+
+    static {
+        MY_MAP.put("key a", 4);
+        MY_MAP.put("key b", 1);
+        MY_MAP.put("key c", 3);
+        MY_MAP.put("key d", 2);
+        MY_MAP.put("key e", 5);
+    }
+
+    private static LinkedHashMap<String, Integer> EXPECTED_MY_MAP = new LinkedHashMap<>();
+
+    static {
+        EXPECTED_MY_MAP.put("key b", 1);
+        EXPECTED_MY_MAP.put("key d", 2);
+        EXPECTED_MY_MAP.put("key c", 3);
+        EXPECTED_MY_MAP.put("key a", 4);
+        EXPECTED_MY_MAP.put("key e", 5);
+    }
+
+    private static final LinkedHashMap<String, Player> PLAYERS = new LinkedHashMap<>();
+    static {
+        PLAYERS.put("player a", new Player("Eric", 9));
+        PLAYERS.put("player b", new Player("Kai", 7));
+        PLAYERS.put("player c", new Player("Amanda", 20));
+        PLAYERS.put("player d", new Player("Kevin", 4));
+    }
+
+    private static final LinkedHashMap<String, Player> EXPECTED_PLAYERS = new LinkedHashMap<>();
+
+    static {
+        EXPECTED_PLAYERS.put("player d", new Player("Kevin", 4));
+        EXPECTED_PLAYERS.put("player b", new Player("Kai", 7));
+        EXPECTED_PLAYERS.put("player a", new Player("Eric", 9));
+        EXPECTED_PLAYERS.put("player c", new Player("Amanda", 20));
+    }
+
+    @Test
+    void whenUsingCollectionSort_thenGetExpectedResult() {
+        List<Map.Entry<String, Integer>> entryList = new ArrayList<>(MY_MAP.entrySet());
+        Collections.sort(entryList, new Comparator<Map.Entry<String, Integer>>() {
+            @Override
+            public int compare(Map.Entry<String, Integer> o1, Map.Entry<String, Integer> o2) {
+                return o1.getValue()
+                  .compareTo(o2.getValue());
+            }
+        });
+
+        LinkedHashMap<String, Integer> result = new LinkedHashMap<>();
+        for (Map.Entry<String, Integer> e : entryList) {
+            result.put(e.getKey(), e.getValue());
+        }
+        assertEquals(EXPECTED_MY_MAP, result);
+    }
+
+    @Test
+    void whenUsingEntrycomparingByValueAndFillAMap_thenGetExpectedResult() {
+        LinkedHashMap<String, Integer> result = new LinkedHashMap<>();
+        MY_MAP.entrySet()
+          .stream()
+          .sorted(Map.Entry.comparingByValue())
+          .forEachOrdered(entry -> result.put(entry.getKey(), entry.getValue()));
+        assertEquals(EXPECTED_MY_MAP, result);
+    }
+
+    @Test
+    void whenUsingEntrycomparingByValueAndCollect_thenGetExpectedResult() {
+        LinkedHashMap<String, Integer> result = MY_MAP.entrySet()
+          .stream()
+          .sorted(Map.Entry.comparingByValue())
+          .collect(LinkedHashMap::new, (map, entry) -> map.put(entry.getKey(), entry.getValue()), Map::putAll);
+        assertEquals(EXPECTED_MY_MAP, result);
+    }
+
+    @Test
+    void whenUsingEntrycomparingByValueAndComparator_thenGetExpectedResult() {
+        LinkedHashMap<String, Player> result = PLAYERS.entrySet()
+          .stream()
+          .sorted(Map.Entry.comparingByValue(Comparator.comparing(Player::getScore)))
+          .collect(LinkedHashMap::new, (map, entry) -> map.put(entry.getKey(), entry.getValue()), Map::putAll);
+        assertEquals(EXPECTED_PLAYERS, result);
+    }
+
+}
@@ -1,4 +1,4 @@
-package com.baeldung.map;
+package com.baeldung.map.incrementmapkey;

 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
@@ -9,6 +9,8 @@ import java.util.stream.Stream;
 import org.junit.Assert;
 import org.junit.Test;

+import com.baeldung.map.incrementmapkey.IncrementMapValueWays;
+
 public class IncrementMapValueUnitTest {

    @Test
@@ -0,0 +1,150 @@
+package com.baeldung.concurrent.completablefuture;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.CompletionException;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Executor;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+import java.util.stream.Collectors;
+
+import org.junit.Test;
+
+public class CompletableFutureUnitTest {
+
+    @Test
+    public void givenAsyncTask_whenProcessingAsyncSucceed_thenReturnSuccess() throws ExecutionException, InterruptedException {
+        Microservice mockMicroserviceA = mock(Microservice.class);
+        Microservice mockMicroserviceB = mock(Microservice.class);
+
+        when(mockMicroserviceA.retrieveAsync(any())).thenReturn(CompletableFuture.completedFuture("Hello"));
+        when(mockMicroserviceB.retrieveAsync(any())).thenReturn(CompletableFuture.completedFuture("World"));
+
+        CompletableFuture<String> resultFuture = processAsync(List.of(mockMicroserviceA, mockMicroserviceB));
+
+        String result = resultFuture.get();
+        assertEquals("HelloWorld", result);
+    }
+
+    @Test
+    public void givenAsyncTask_whenProcessingAsyncWithException_thenReturnException() throws ExecutionException, InterruptedException {
+        Microservice mockMicroserviceA = mock(Microservice.class);
+        Microservice mockMicroserviceB = mock(Microservice.class);
+
+        when(mockMicroserviceA.retrieveAsync(any())).thenReturn(CompletableFuture.completedFuture("Hello"));
+        when(mockMicroserviceB.retrieveAsync(any())).thenReturn(CompletableFuture.failedFuture(new RuntimeException("Simulated Exception")));
+        CompletableFuture<String> resultFuture = processAsync(List.of(mockMicroserviceA, mockMicroserviceB));
+        // Use assertThrows to verify that the expected exception is thrown
+        ExecutionException exception = assertThrows(ExecutionException.class, resultFuture::get);
+        // Assert the exception message
+        assertEquals("Simulated Exception", exception.getCause()
+            .getMessage());
+    }
+
+    @Test
+    public void givenAsyncTask_whenProcessingAsyncWithTimeout_thenHandleTimeoutException() throws ExecutionException, InterruptedException {
+        Microservice mockMicroserviceA = mock(Microservice.class);
+        Microservice mockMicroserviceB = mock(Microservice.class);
+        Executor delayedExecutor = CompletableFuture.delayedExecutor(200, TimeUnit.MILLISECONDS);
+        when(mockMicroserviceA.retrieveAsync(any())).thenReturn(CompletableFuture.supplyAsync(() -> "Hello", delayedExecutor));
+        Executor delayedExecutor2 = CompletableFuture.delayedExecutor(500, TimeUnit.MILLISECONDS);
+        when(mockMicroserviceB.retrieveAsync(any())).thenReturn(CompletableFuture.supplyAsync(() -> "World", delayedExecutor2));
+        CompletableFuture<String> resultFuture = processAsync(List.of(mockMicroserviceA, mockMicroserviceB));
+        assertThrows(TimeoutException.class, () -> resultFuture.get(300, TimeUnit.MILLISECONDS));
+    }
+
+    @Test
+    public void givenCompletableFuture_whenCompleted_thenStateIsDone() {
+        Executor delayedExecutor = CompletableFuture.delayedExecutor(200, TimeUnit.MILLISECONDS);
+        CompletableFuture<String> cf1 = CompletableFuture.supplyAsync(() -> "Hello", delayedExecutor);
+        CompletableFuture<String> cf2 = CompletableFuture.supplyAsync(() -> " World");
+        CompletableFuture<String> cf3 = CompletableFuture.supplyAsync(() -> "!");
+        CompletableFuture<String>[] cfs = new CompletableFuture[] { cf1, cf2, cf3 };
+
+        CompletableFuture<Void> allCf = CompletableFuture.allOf(cfs);
+
+        assertFalse(allCf.isDone());
+        allCf.join();
+        String result = Arrays.stream(cfs)
+            .map(CompletableFuture::join)
+            .collect(Collectors.joining());
+
+        assertFalse(allCf.isCancelled());
+        assertTrue(allCf.isDone());
+        assertFalse(allCf.isCompletedExceptionally());
+        assertEquals(result, "Hello World!");
+    }
+
+    @Test
+    public void givenCompletableFuture_whenCompletedWithException_thenStateIsCompletedExceptionally() throws ExecutionException, InterruptedException {
+        Executor delayedExecutor = CompletableFuture.delayedExecutor(200, TimeUnit.MILLISECONDS);
+        CompletableFuture<String> cf1 = CompletableFuture.supplyAsync(() -> "Hello", delayedExecutor);
+        CompletableFuture<String> cf2 = CompletableFuture.failedFuture(new RuntimeException("Simulated Exception"));
+        CompletableFuture<String> cf3 = CompletableFuture.supplyAsync(() -> "!");
+        CompletableFuture<String>[] cfs = new CompletableFuture[] { cf1, cf2, cf3 };
+
+        CompletableFuture<Void> allCf = CompletableFuture.allOf(cfs);
+
+        assertFalse(allCf.isDone());
+        assertFalse(allCf.isCompletedExceptionally());
+
+        // Exception is expected, assert the cause
+        CompletionException exception = assertThrows(CompletionException.class, allCf::join);
+
+        assertEquals("Simulated Exception", exception.getCause()
+            .getMessage());
+        assertTrue(allCf.isCompletedExceptionally());
+        assertTrue(allCf.isDone());
+        assertFalse(allCf.isCancelled());
+    }
+
+    @Test
+    public void givenCompletableFuture_whenCancelled_thenStateIsCancelled() throws ExecutionException, InterruptedException {
+        Executor delayedExecutor = CompletableFuture.delayedExecutor(200, TimeUnit.MILLISECONDS);
+        CompletableFuture<String> cf1 = CompletableFuture.supplyAsync(() -> "Hello", delayedExecutor);
+        CompletableFuture<String> cf2 = CompletableFuture.supplyAsync(() -> " World");
+        CompletableFuture<String> cf3 = CompletableFuture.supplyAsync(() -> "!");
+        CompletableFuture<String>[] cfs = new CompletableFuture[] { cf1, cf2, cf3 };
+        CompletableFuture<Void> allCf = CompletableFuture.allOf(cfs);
+        assertFalse(allCf.isDone());
+        assertFalse(allCf.isCompletedExceptionally());
+        allCf.cancel(true);
+        assertTrue(allCf.isCancelled());
+        assertTrue(allCf.isDone());
+    }
+
+    CompletableFuture<String> processAsync(List<Microservice> microservices) {
+        List<CompletableFuture<String>> dataFetchFutures = fetchDataAsync(microservices);
+        return combineResults(dataFetchFutures);
+    }
+
+    private List<CompletableFuture<String>> fetchDataAsync(List<Microservice> microservices) {
+        return microservices.stream()
+            .map(client -> client.retrieveAsync(""))
+            .collect(Collectors.toList());
+    }
+
+    private CompletableFuture<String> combineResults(List<CompletableFuture<String>> dataFetchFutures) {
+        return CompletableFuture.allOf(dataFetchFutures.toArray(new CompletableFuture[0]))
+            .thenApply(v -> dataFetchFutures.stream()
+                .map(future -> future.exceptionally(ex -> {
+                        throw new CompletionException(ex);
+                    })
+                    .join())
+                .collect(Collectors.joining()));
+    }
+
+    interface Microservice {
+        CompletableFuture<String> retrieveAsync(String input);
+    }
+}
@@ -1,3 +1,4 @@

 ### Relevant Articles:
 - [Why wait() Requires Synchronization?](https://www.baeldung.com/java-wait-necessary-synchronization)
+- [Working with Exceptions in Java CompletableFuture](https://www.baeldung.com/java-exceptions-completablefuture)
@@ -2,7 +2,7 @@ package com.baeldung.wait_synchronization;

 public class ConditionChecker {

-    private volatile Boolean jobIsDone;
+    private volatile boolean jobIsDone;
    private final Object lock = new Object();

    public void ensureCondition() {
@@ -21,4 +21,4 @@ public class ConditionChecker {
            lock.notify();
        }
    }
-}
+}
@@ -159,7 +159,7 @@
    </profiles>

    <properties>
-        <maven-javadoc-plugin.version>3.0.0-M1</maven-javadoc-plugin.version>
+        <maven-javadoc-plugin.version>3.6.2</maven-javadoc-plugin.version>
        <source.version>1.8</source.version>
        <target.version>1.8</target.version>
        <ascii.version>0.3.2</ascii.version>
@@ -10,3 +10,5 @@ This module contains articles about converting between Java date and time object
 - [Convert Between LocalDateTime and ZonedDateTime](https://www.baeldung.com/java-localdatetime-zoneddatetime)
 - [Conversion From 12-Hour Time to 24-Hour Time in Java](https://www.baeldung.com/java-convert-time-format)
 - [Convert Epoch Time to LocalDate and LocalDateTime](https://www.baeldung.com/java-convert-epoch-localdate)
+- [Convert Timestamp String to Long in Java](https://www.baeldung.com/java-convert-timestamp-string-long)
+- [Convert Long Timestamp to LocalDateTime in Java](https://www.baeldung.com/java-convert-long-timestamp-localdatetime)
--- a/Show More
+++ b/Show More