Merge branch 'eugenp:master' into master

2023-04-26 17:02:40 -05:00
parent 1628c013c6 e3cc8abadb
commit bf1e9aa588
1040 changed files with 14610 additions and 2156 deletions
@@ -1,3 +1,4 @@
 ## Relevant Articles
 - [Record Patterns in Java 19](https://www.baeldung.com/java-19-record-patterns)
 - [Structured Concurrency in Java 19](https://www.baeldung.com/java-structured-concurrency)
+- [Possible Root Causes for High CPU Usage in Java](https://www.baeldung.com/java-high-cpu-usage-causes)
@@ -11,4 +11,6 @@ This module contains articles about Java 8 core features
 - [Convert Between Byte Array and UUID in Java](https://www.baeldung.com/java-byte-array-to-uuid)
 - [Create a Simple “Rock-Paper-Scissors” Game in Java](https://www.baeldung.com/java-rock-paper-scissors)
 - [VarArgs vs Array Input Parameters in Java](https://www.baeldung.com/varargs-vs-array)
+- [Lambda Expression vs. Anonymous Inner Class](https://www.baeldung.com/java-lambdas-vs-anonymous-class)
+- [Java Helper vs. Utility Classes](https://www.baeldung.com/java-helper-vs-utility-classes)
 - [[<-- Prev]](/core-java-modules/core-java-8)
@@ -2,4 +2,5 @@

 - [Generating Random Dates in Java](https://www.baeldung.com/java-random-dates)
 - [Creating a LocalDate with Values in Java](https://www.baeldung.com/java-creating-localdate-with-values)
- [[<-- Prev]](/core-java-modules/core-java-datetime-java8-1)
+- [Parsing Date Strings with Varying Formats](https://www.baeldung.com/java-parsing-dates-many-formats)
+- [[<-- Prev]](/core-java-modules/core-java-datetime-java8-1)
@@ -0,0 +1,20 @@
+package com.baeldung.parsingDates;
+
+import java.util.Arrays;
+import java.util.List;
+import org.joda.time.LocalDate;
+import org.joda.time.format.DateTimeFormat;
+
+public class SimpleDateTimeFormat {
+
+    public static LocalDate parseDate(String date) {
+        List<String> patternList = Arrays.asList("MM/dd/yyyy", "dd.MM.yyyy", "yyyy-MM-dd");
+        for (String pattern : patternList) {
+            try {
+                return DateTimeFormat.forPattern(pattern).parseLocalDate(date);
+            } catch (IllegalArgumentException e) {
+            }
+        }
+        return null;
+    }
+}
@@ -0,0 +1,17 @@
+package com.baeldung.parsingDates;
+
+import java.time.LocalDate;
+import java.time.format.DateTimeFormatter;
+import java.time.format.DateTimeFormatterBuilder;
+
+public class SimpleDateTimeFormater {
+
+    public static LocalDate parseDate(String date) {
+        DateTimeFormatterBuilder dateTimeFormatterBuilder = new DateTimeFormatterBuilder()
+                .append(DateTimeFormatter.ofPattern("[MM/dd/yyyy]" + "[dd-MM-yyyy]" + "[yyyy-MM-dd]"));
+
+        DateTimeFormatter dateTimeFormatter = dateTimeFormatterBuilder.toFormatter();
+
+        return LocalDate.parse(date, dateTimeFormatter);
+    }
+}
@@ -0,0 +1,18 @@
+package com.baeldung.parsingDates;
+
+import java.text.ParseException;
+import java.util.Date;
+import org.apache.commons.lang3.time.DateUtils;
+
+public class SimpleDateUtils {
+
+    public static Date parseDate(String date) {
+        try {
+            return DateUtils.parseDateStrictly(date,
+                    new String[]{"yyyy/MM/dd", "dd/MM/yyyy", "yyyy-MM-dd"});
+        } catch (ParseException ex) {
+            return null;
+        }
+    }
+
+}
@@ -0,0 +1,19 @@
+package com.baeldung.parsingDates;
+
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+import java.util.Date;
+import java.util.List;
+
+public class SimpleParseDate {
+
+    public Date parseDate(String dateString, List<String> formatStrings) {
+        for (String formatString : formatStrings) {
+            try {
+                return new SimpleDateFormat(formatString).parse(dateString);
+            } catch (ParseException e) {
+            }
+        }
+        return null;
+    }
+}
@@ -0,0 +1,43 @@
+package com.baeldung.parsingDates;
+
+import com.baeldung.parsingDates.SimpleDateTimeFormat;
+import com.baeldung.parsingDates.SimpleDateTimeFormater;
+import com.baeldung.parsingDates.SimpleDateUtils;
+import com.baeldung.parsingDates.SimpleParseDate;
+import java.time.format.DateTimeParseException;
+import java.util.Arrays;
+import org.junit.*;
+import static org.junit.Assert.*;
+import org.joda.time.LocalDate;
+
+public class SimpleParseDateUnitTest {
+
+    @Test
+    public void whenInvalidInput_thenGettingUnexpectedResult() {
+        SimpleParseDate simpleParseDate = new SimpleParseDate();
+        String date = "2022-40-40";
+        assertEquals("Sat May 10 00:00:00 UTC 2025", simpleParseDate.parseDate(date, Arrays.asList("MM/dd/yyyy", "dd.MM.yyyy", "yyyy-MM-dd")).toString());
+    }
+
+    @Test
+    public void whenInvalidDate_thenAssertThrows() {
+        SimpleDateTimeFormater simpleDateTimeFormater = new SimpleDateTimeFormater();
+        assertEquals(java.time.LocalDate.parse("2022-12-04"), simpleDateTimeFormater.parseDate("2022-12-04"));
+        assertThrows(DateTimeParseException.class, () -> simpleDateTimeFormater.parseDate("2022-13-04"));
+    }
+
+    @Test
+    public void whenDateIsCorrect_thenParseCorrect() {
+        SimpleDateUtils simpleDateUtils = new SimpleDateUtils();
+        assertNull(simpleDateUtils.parseDate("53/10/2014"));
+        assertEquals("Wed Sep 10 00:00:00 UTC 2014", simpleDateUtils.parseDate("10/09/2014").toString());
+    }
+
+    @Test
+    public void whenDateIsCorrect_thenResultCorrect() {
+        SimpleDateTimeFormat simpleDateTimeFormat = new SimpleDateTimeFormat();
+        assertNull(simpleDateTimeFormat.parseDate("53/10/2014"));
+        assertEquals(LocalDate.parse("2014-10-10"), simpleDateTimeFormat.parseDate("2014-10-10"));
+    }
+
+}
@@ -8,5 +8,5 @@ This module contains articles about Project Jigsaw and the Java Platform Module
 - [A Guide to Java 9 Modularity](https://www.baeldung.com/java-9-modularity)
 - [Java 9 java.lang.Module API](https://www.baeldung.com/java-9-module-api)
 - [Java 9 Illegal Reflective Access Warning](https://www.baeldung.com/java-illegal-reflective-access)
-
+- [Java Modularity and Unit Testing](https://www.baeldung.com/java-modularity-unit-testing)

@@ -0,0 +1,2 @@
+#!/usr/bin/env bash
+javac -d mods/com.baeldung.library.core $(find library-core/src/main -name "*.java")
@@ -0,0 +1,10 @@
+#!/usr/bin/env bash
+javac --class-path outDir/library-core/:\
+libs/junit-jupiter-engine-5.9.2.jar:\
+libs/junit-platform-engine-1.9.2.jar:\
+libs/apiguardian-api-1.1.2.jar:\
+libs/junit-jupiter-params-5.9.2.jar:\
+libs/junit-jupiter-api-5.9.2.jar:\
+libs/opentest4j-1.2.0.jar:\
+libs/junit-platform-commons-1.9.2.jar \
+-d outDir/library-test library-core/src/test/java/com/baeldung/library/core/LibraryUnitTest.java
@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+javac --class-path libs/junit-jupiter-engine-5.9.2.jar:\
+libs/junit-platform-engine-1.9.2.jar:\
+libs/apiguardian-api-1.1.2.jar:\
+libs/junit-jupiter-params-5.9.2.jar:\
+libs/junit-jupiter-api-5.9.2.jar:\
+libs/opentest4j-1.2.0.jar:\
+libs/junit-platform-commons-1.9.2.jar \
+-d outDir/library-core \
+library-core/src/main/java/com/baeldung/library/core/Book.java \
+library-core/src/main/java/com/baeldung/library/core/Library.java \
+library-core/src/main/java/com/baeldung/library/core/Main.java \
+library-core/src/test/java/com/baeldung/library/core/LibraryUnitTest.java
@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+javac --class-path libs/junit-jupiter-engine-5.9.2.jar:\
+libs/junit-platform-engine-1.9.2.jar:\
+libs/apiguardian-api-1.1.2.jar:\
+libs/junit-jupiter-params-5.9.2.jar:\
+libs/junit-jupiter-api-5.9.2.jar:\
+libs/opentest4j-1.2.0.jar:\
+libs/junit-platform-commons-1.9.2.jar \
+-d outDir/library-core \
+library-core/src/main/java/com/baeldung/library/core/Book.java \
+library-core/src/main/java/com/baeldung/library/core/Library.java \
+library-core/src/main/java/com/baeldung/library/core/Main.java
@@ -0,0 +1,2 @@
+#!/usr/bin/env bash
+javac --module-path mods:libs -d mods/com.baeldung.library.test $(find library-test/src/test -name "*.java")
@@ -0,0 +1,10 @@
+#!/usr/bin/env bash
+wget -P libs/ https://repo1.maven.org/maven2/org/apiguardian/apiguardian-api/1.1.2/apiguardian-api-1.1.2.jar /
+wget -P libs/ https://repo1.maven.org/maven2/org/opentest4j/opentest4j/1.2.0/opentest4j-1.2.0.jar /
+wget -P libs/ https://repo1.maven.org/maven2/org/junit/platform/junit-platform-commons/1.9.2/junit-platform-commons-1.9.2.jar /
+wget -P libs/ https://repo1.maven.org/maven2/org/junit/platform/junit-platform-engine/1.9.2/junit-platform-engine-1.9.2.jar /
+wget -P libs/ https://repo1.maven.org/maven2/org/junit/platform/junit-platform-reporting/1.9.2/junit-platform-reporting-1.9.2.jar /
+wget -P libs/ https://repo1.maven.org/maven2/org/junit/platform/junit-platform-console/1.9.2/junit-platform-console-1.9.2.jar /
+wget -P libs/ https://repo1.maven.org/maven2/org/junit/platform/junit-platform-launcher/1.9.2/junit-platform-launcher-1.9.2.jar /
+wget -P libs/ https://repo1.maven.org/maven2/org/junit/jupiter/junit-jupiter-engine/5.9.2/junit-jupiter-engine-5.9.2.jar /
+wget -P libs/ https://repo1.maven.org/maven2/org/junit/jupiter/junit-jupiter-params/5.9.2/junit-jupiter-params-5.9.2.jar
@@ -0,0 +1,55 @@
+<?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>
+  <parent>
+    <groupId>com.baeldung</groupId>
+    <artifactId>core-java-9-jigsaw</artifactId>
+    <version>0.2-SNAPSHOT</version>
+  </parent>
+
+  <artifactId>library-core</artifactId>
+
+  <properties>
+    <maven.compiler.source>19</maven.compiler.source>
+    <maven.compiler.target>19</maven.compiler.target>
+    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+  </properties>
+
+  <dependencies>
+    <dependency>
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter-api</artifactId>
+      <version>5.9.2</version>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter-engine</artifactId>
+      <version>5.9.2</version>
+      <scope>test</scope>
+    </dependency>
+  </dependencies>
+
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-compiler-plugin</artifactId>
+        <version>3.8.1</version>
+        <configuration>
+          <release>9</release>
+        </configuration>
+      </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-surefire-plugin</artifactId>
+        <version>3.0.0-M5</version>
+        <configuration>
+          <useModulePath>false</useModulePath>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
+</project>
@@ -0,0 +1,52 @@
+package com.baeldung.library.core;
+
+import java.util.Objects;
+
+public class Book {
+
+    private String title;
+    private String author;
+
+    public Book(String title, String author) {
+        this.title = title;
+        this.author = author;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public String getAuthor() {
+        return author;
+    }
+
+
+    @Override
+    public String toString() {
+        return "Book [title=" + title + ", author=" + author + "]";
+    }
+
+    @Override
+    public boolean equals(final Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+
+        final Book book = (Book) o;
+
+        if (!Objects.equals(title, book.title)) {
+            return false;
+        }
+        return Objects.equals(author, book.author);
+    }
+
+    @Override
+    public int hashCode() {
+        int result = title != null ? title.hashCode() : 0;
+        result = 31 * result + (author != null ? author.hashCode() : 0);
+        return result;
+    }
+}
@@ -0,0 +1,25 @@
+package com.baeldung.library.core;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class Library {
+
+    private List<Book> books = new ArrayList<>();
+
+    public void addBook(Book book) {
+        books.add(book);
+    }
+
+    public List<Book> getBooks() {
+        return books;
+    }
+
+    void removeBook(Book book) {
+        books.remove(book);
+    }
+
+    protected void removeBookByAuthor(String author) {
+        books.removeIf(book -> book.getAuthor().equals(author));
+    }
+}
@@ -0,0 +1,16 @@
+package com.baeldung.library.core;
+
+public class Main {
+
+    public static void main(String[] args) {
+        Library library = new Library();
+        library.addBook(new Book("The Lord of the Rings", "J.R.R. Tolkien"));
+        library.addBook(new Book("The Hobbit", "J.R.R. Tolkien"));
+        library.addBook(new Book("The Silmarillion", "J.R.R. Tolkien"));
+        library.addBook(new Book("The Chronicles of Narnia", "C.S. Lewis"));
+        library.addBook(new Book("The Lion, the Witch and the Wardrobe", "C.S. Lewis"));
+        System.out.println("Welcome to our library!");
+        System.out.println("We have the following books:");
+        library.getBooks().forEach(System.out::println);
+    }
+}
@@ -0,0 +1,3 @@
+module com.baeldung.library.core {
+    exports com.baeldung.library.core;
+}
@@ -0,0 +1,47 @@
+package com.baeldung.library.core;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import org.junit.jupiter.api.Test;
+
+class LibraryUnitTest {
+
+    @Test
+    void givenEmptyLibrary_whenAddABook_thenLibraryHasOneBook() {
+        Library library = new Library();
+        Book theLordOfTheRings = new Book("The Lord of the Rings", "J.R.R. Tolkien");
+        library.addBook(theLordOfTheRings);
+        int expected = 1;
+        int actual = library.getBooks().size();
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void givenTheLibraryWithABook_whenRemoveABook_thenLibraryIsEmpty() {
+        Library library = new Library();
+        Book theLordOfTheRings = new Book("The Lord of the Rings", "J.R.R. Tolkien");
+        library.addBook(theLordOfTheRings);
+        library.removeBook(theLordOfTheRings);
+        int expected = 0;
+        int actual = library.getBooks().size();
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void givenTheLibraryWithSeveralBook_whenRemoveABookByAuthor_thenLibraryHasNoBooksByTheAuthor() {
+        Library library = new Library();
+        Book theLordOfTheRings = new Book("The Lord of the Rings", "J.R.R. Tolkien");
+        Book theHobbit = new Book("The Hobbit", "J.R.R. Tolkien");
+        Book theSilmarillion = new Book("The Silmarillion", "J.R.R. Tolkien");
+        Book theHungerGames = new Book("The Hunger Games", "Suzanne Collins");
+        library.addBook(theLordOfTheRings);
+        library.addBook(theHobbit);
+        library.addBook(theSilmarillion);
+        library.addBook(theHungerGames);
+        library.removeBookByAuthor("J.R.R. Tolkien");
+        int expected = 1;
+        int actual = library.getBooks().size();
+        assertEquals(expected, actual);
+    }
+
+}
@@ -0,0 +1,53 @@
+package com.baeldung.library.test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import com.baeldung.library.core.Book;
+import com.baeldung.library.core.Library;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import org.junit.jupiter.api.Test;
+
+class LibraryUnitTest {
+
+    @Test
+    void givenEmptyLibrary_whenAddABook_thenLibraryHasOneBook() {
+        Library library = new Library();
+        Book theLordOfTheRings = new Book("The Lord of the Rings", "J.R.R. Tolkien");
+        library.addBook(theLordOfTheRings);
+        int expected = 1;
+        int actual = library.getBooks().size();
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    void givenTheLibraryWithABook_whenRemoveABook_thenLibraryIsEmpty()
+        throws NoSuchMethodException, InvocationTargetException, IllegalAccessException {
+        Library library = new Library();
+        Book theLordOfTheRings = new Book("The Lord of the Rings", "J.R.R. Tolkien");
+        library.addBook(theLordOfTheRings);
+        Method removeBook = Library.class.getDeclaredMethod("removeBook", Book.class);
+        removeBook.setAccessible(true);
+        removeBook.invoke(library, theLordOfTheRings);
+        int expected = 0;
+        int actual = library.getBooks().size();
+        assertEquals(expected, actual);
+    }
+@Test
+void givenTheLibraryWithSeveralBook_whenRemoveABookByAuthor_thenLibraryHasNoBooksByTheAuthor() {
+    TestLibrary library = new TestLibrary();
+    Book theLordOfTheRings = new Book("The Lord of the Rings", "J.R.R. Tolkien");
+    Book theHobbit = new Book("The Hobbit", "J.R.R. Tolkien");
+    Book theSilmarillion = new Book("The Silmarillion", "J.R.R. Tolkien");
+    Book theHungerGames = new Book("The Hunger Games", "Suzanne Collins");
+    library.addBook(theLordOfTheRings);
+    library.addBook(theHobbit);
+    library.addBook(theSilmarillion);
+    library.addBook(theHungerGames);
+    library.removeBookByAuthor("J.R.R. Tolkien");
+    int expected = 1;
+    int actual = library.getBooks().size();
+    assertEquals(expected, actual);
+}
+
+}
@@ -0,0 +1,10 @@
+package com.baeldung.library.test;
+
+import com.baeldung.library.core.Library;
+
+public class TestLibrary extends Library {
+    @Override
+    public void removeBookByAuthor(final String author) {
+        super.removeBookByAuthor(author);
+    }
+}
@@ -0,0 +1,5 @@
+module com.baeldung.library.test {
+    requires com.baeldung.library.core;
+    requires org.junit.jupiter.api;
+    opens com.baeldung.library.test to org.junit.platform.commons;
+}
@@ -5,6 +5,10 @@
    <modelVersion>4.0.0</modelVersion>
    <artifactId>core-java-9-jigsaw</artifactId>
    <name>core-java-9-jigsaw</name>
+    <packaging>pom</packaging>
+    <modules>
+        <module>library-core</module>
+    </modules>

    <parent>
        <groupId>com.baeldung</groupId>
@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+java --module-path mods:libs \
+--add-modules com.baeldung.library.core \
+--add-opens com.baeldung.library.core/com.baeldung.library.core=org.junit.platform.commons \
+--add-reads com.baeldung.library.core=org.junit.jupiter.api \
+--patch-module com.baeldung.library.core=outDir/library-test \
+--module org.junit.platform.console --select-class com.baeldung.library.core.LibraryUnitTest
@@ -0,0 +1,2 @@
+#!/usr/bin/env bash
+java --module-path mods --module com.baeldung.library.core/com.baeldung.library.core.Main
@@ -0,0 +1,5 @@
+#!/usr/bin/env bash
+java --module-path libs \
+org.junit.platform.console.ConsoleLauncher \
+--classpath ./outDir/library-core \
+--select-class com.baeldung.library.core.LibraryUnitTest
@@ -0,0 +1,5 @@
+#!/usr/bin/env bash
+java --module-path mods:libs \
+--add-modules com.baeldung.library.test \
+--add-opens com.baeldung.library.core/com.baeldung.library.core=com.baeldung.library.test \
+org.junit.platform.console.ConsoleLauncher --select-class com.baeldung.library.test.LibraryUnitTest
@@ -1,84 +1,126 @@
 package com.baeldung.map;

-import com.google.common.collect.ImmutableMap;
-import org.junit.jupiter.api.Test;
+import static org.hamcrest.MatcherAssert.assertThat;
+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 java.util.AbstractMap;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;

-import static org.junit.jupiter.api.Assertions.*;
+import org.hamcrest.collection.IsMapContaining;
+import org.junit.jupiter.api.Test;

+import com.google.common.collect.ImmutableMap;

-public class ImmutableMapUnitTest {
+class ImmutableMapUnitTest {

-	@Test
-	public void whenCollectionsUnModifiableMapMethod_thenOriginalCollectionChangesReflectInUnmodifiableMap() {
+    @Test
+    void whenCollectionsUnModifiableMapMethod_thenOriginalCollectionChangesReflectInUnmodifiableMap() {

-		Map<String, String> mutableMap = new HashMap<>();
-		mutableMap.put("USA", "North America");
+        Map<String, String> mutableMap = new HashMap<>();
+        mutableMap.put("USA", "North America");

-		Map<String, String> unmodifiableMap = Collections.unmodifiableMap(mutableMap);
-		assertThrows(UnsupportedOperationException.class, () -> unmodifiableMap.put("Canada", "North America"));
-		
-		mutableMap.remove("USA");
-		assertFalse(unmodifiableMap.containsKey("USA"));
-		
-		mutableMap.put("Mexico", "North America");
-		assertTrue(unmodifiableMap.containsKey("Mexico"));
-	}
-	
-	@Test
-	@SuppressWarnings("deprecation")
-	public void whenGuavaImmutableMapFromCopyOfMethod_thenOriginalCollectionChangesDoNotReflectInImmutableMap() {
+        Map<String, String> unmodifiableMap = Collections.unmodifiableMap(mutableMap);
+        assertThrows(UnsupportedOperationException.class, () -> unmodifiableMap.put("Canada", "North America"));

-		Map<String, String> mutableMap = new HashMap<>();
-		mutableMap.put("USA", "North America");
+        mutableMap.remove("USA");
+        assertFalse(unmodifiableMap.containsKey("USA"));

-		ImmutableMap<String, String> immutableMap = ImmutableMap.copyOf(mutableMap);
-		assertTrue(immutableMap.containsKey("USA"));
-		
-		assertThrows(UnsupportedOperationException.class, () -> immutableMap.put("Canada", "North America"));
-		
-		mutableMap.remove("USA");
-		assertTrue(immutableMap.containsKey("USA"));
-		
-		mutableMap.put("Mexico", "North America");
-		assertFalse(immutableMap.containsKey("Mexico"));
-	}
-	
-	@Test
-	@SuppressWarnings("deprecation")
-	public void whenGuavaImmutableMapFromBuilderMethod_thenOriginalCollectionChangesDoNotReflectInImmutableMap() {
+        mutableMap.put("Mexico", "North America");
+        assertTrue(unmodifiableMap.containsKey("Mexico"));
+    }

-		Map<String, String> mutableMap = new HashMap<>();
-		mutableMap.put("USA", "North America");
+    @Test
+    @SuppressWarnings("deprecation")
+    void whenGuavaImmutableMapFromCopyOfMethod_thenOriginalCollectionChangesDoNotReflectInImmutableMap() {

-		ImmutableMap<String, String> immutableMap = ImmutableMap.<String, String>builder()
-				.putAll(mutableMap)
-				.put("Costa Rica", "North America")
-				.build();
-		assertTrue(immutableMap.containsKey("USA"));
-		assertTrue(immutableMap.containsKey("Costa Rica"));
-		
-		assertThrows(UnsupportedOperationException.class, () -> immutableMap.put("Canada", "North America"));
-		
-		mutableMap.remove("USA");
-		assertTrue(immutableMap.containsKey("USA"));
-		
-		mutableMap.put("Mexico", "North America");
-		assertFalse(immutableMap.containsKey("Mexico"));
-	}
-	
-	@Test
-	@SuppressWarnings("deprecation")
-	public void whenGuavaImmutableMapFromOfMethod_thenOriginalCollectionChangesDoNotReflectInImmutableMap() {
+        Map<String, String> mutableMap = new HashMap<>();
+        mutableMap.put("USA", "North America");

-		ImmutableMap<String, String> immutableMap = ImmutableMap.of("USA", "North America", "Costa Rica", "North America");
-		assertTrue(immutableMap.containsKey("USA"));
-		assertTrue(immutableMap.containsKey("Costa Rica"));
+        ImmutableMap<String, String> immutableMap = ImmutableMap.copyOf(mutableMap);
+        assertTrue(immutableMap.containsKey("USA"));
+
+        assertThrows(UnsupportedOperationException.class, () -> immutableMap.put("Canada", "North America"));
+
+        mutableMap.remove("USA");
+        assertTrue(immutableMap.containsKey("USA"));
+
+        mutableMap.put("Mexico", "North America");
+        assertFalse(immutableMap.containsKey("Mexico"));
+    }
+
+    @Test
+    @SuppressWarnings("deprecation")
+    void whenGuavaImmutableMapFromBuilderMethod_thenOriginalCollectionChangesDoNotReflectInImmutableMap() {
+
+        Map<String, String> mutableMap = new HashMap<>();
+        mutableMap.put("USA", "North America");
+
+        ImmutableMap<String, String> immutableMap = ImmutableMap.<String, String>builder()
+            .putAll(mutableMap)
+            .put("Costa Rica", "North America")
+            .build();
+        assertTrue(immutableMap.containsKey("USA"));
+        assertTrue(immutableMap.containsKey("Costa Rica"));
+
+        assertThrows(UnsupportedOperationException.class, () -> immutableMap.put("Canada", "North America"));
+
+        mutableMap.remove("USA");
+        assertTrue(immutableMap.containsKey("USA"));
+
+        mutableMap.put("Mexico", "North America");
+        assertFalse(immutableMap.containsKey("Mexico"));
+    }
+
+    @Test
+    @SuppressWarnings("deprecation")
+    void whenGuavaImmutableMapFromOfMethod_thenOriginalCollectionChangesDoNotReflectInImmutableMap() {
+
+        ImmutableMap<String, String> immutableMap = ImmutableMap.of("USA", "North America", "Costa Rica", "North America");
+        assertTrue(immutableMap.containsKey("USA"));
+        assertTrue(immutableMap.containsKey("Costa Rica"));
+
+        assertThrows(UnsupportedOperationException.class, () -> immutableMap.put("Canada", "North America"));
+    }
+
+    @Test
+    @SuppressWarnings("deprecation")
+    void givenGuavaImmutableMapFromOfEntriesMethodwhenModifyEntry_thenThrowUnsupportedOperationException() {
+
+        ImmutableMap<Integer, String> immutableMap = ImmutableMap.ofEntries(new AbstractMap.SimpleEntry<>(1, "USA"), new AbstractMap.SimpleEntry<>(2, "Canada"));
+
+        assertThrows(UnsupportedOperationException.class, () -> immutableMap.put(2, "Mexico"));
+    }
+
+    @Test
+    void givenEntrieswhenCreatingGuavaImmutableMapFromOfEntriesMethod_thenCorrect() {
+
+        ImmutableMap<Integer, String> immutableMap = ImmutableMap.ofEntries(new AbstractMap.SimpleEntry<>(1, "USA"));
+
+        assertEquals(1, immutableMap.size());
+        assertThat(immutableMap, IsMapContaining.hasEntry(1, "USA"));
+    }
+
+    @Test
+    void givenGuavaImmutableMapFromOfEntriesMethodwhenEntryKeyExists_thenThrowIllegalArgumentException() {
+
+        assertThrows(IllegalArgumentException.class, () -> ImmutableMap.ofEntries(new AbstractMap.SimpleEntry<>(1, "USA"), new AbstractMap.SimpleEntry<>(1, "Canada")));
+    }
+
+    @Test
+    void givenGuavaImmutableMapFromOfEntriesMethodwhenEntryKeyIsNull_thenThrowNullPointerException() {
+
+        assertThrows(NullPointerException.class, () -> ImmutableMap.ofEntries(new AbstractMap.SimpleEntry<>(null, "USA")));
+    }
+
+    @Test
+    void givenGuavaImmutableMapFromOfEntriesMethodwhenEntryValueIsNull_thenThrowNullPointerException() {
+
+        assertThrows(NullPointerException.class, () -> ImmutableMap.ofEntries(new AbstractMap.SimpleEntry<>(1, null)));
+    }

-		assertThrows(UnsupportedOperationException.class, () -> immutableMap.put("Canada", "North America"));
-	}
-	
 }
@@ -0,0 +1,6 @@
+## Core Java Compiler
+
+### Relevant Articles: 
+
+- [Compiling Java *.class Files with javac](http://www.baeldung.com/javac)
+- [Illegal Character Compilation Error](https://www.baeldung.com/java-illegal-character-error)
@@ -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-compiler</artifactId>
+    <version>0.1.0-SNAPSHOT</version>
+    <name>core-java-compiler</name>
+    <packaging>jar</packaging>
+
+    <parent>
+        <groupId>com.baeldung.core-java-modules</groupId>
+        <artifactId>core-java-modules</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>com.google.gdata</groupId>
+            <artifactId>core</artifactId>
+            <version>${gdata.version}</version>
+        </dependency>
+    </dependencies>
+
+    <properties>
+        <gdata.version>1.47.1</gdata.version>
+    </properties>
+
+</project>
@@ -0,0 +1,6 @@
+## Core Java Documentation
+
+### Relevant Articles: 
+
+- [Introduction to Javadoc](http://www.baeldung.com/javadoc)
+
@@ -0,0 +1,41 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>core-java-documentation</artifactId>
+    <version>0.1.0-SNAPSHOT</version>
+    <name>core-java-documentation</name>
+    <packaging>jar</packaging>
+
+    <parent>
+        <groupId>com.baeldung.core-java-modules</groupId>
+        <artifactId>core-java-modules</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-javadoc-plugin</artifactId>
+                <version>${maven-javadoc-plugin.version}</version>
+                <configuration>
+                    <source>${source.version}</source>
+                    <target>${target.version}</target>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+    <properties>
+        <!-- maven plugins -->
+        <maven-javadoc-plugin.version>3.0.0-M1</maven-javadoc-plugin.version>
+        <source.version>1.8</source.version>
+        <target.version>1.8</target.version>
+    </properties>
+
+</project>
@@ -5,3 +5,5 @@ This module contains articles about core Java input/output(IO) APIs.
 ### Relevant Articles:
 - [Constructing a Relative Path From Two Absolute Paths in Java](https://www.baeldung.com/java-relative-path-absolute)
 - [Java Scanner Taking a Character Input](https://www.baeldung.com/java-scanner-character-input)
+- [Get the Desktop Path in Java](https://www.baeldung.com/java-desktop-path)
+
@@ -0,0 +1,85 @@
+package com.baeldung.scanner;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import java.util.InputMismatchException;
+import java.util.Scanner;
+
+import org.junit.jupiter.api.Test;
+
+public class NextLineVsNextIntUnitTest {
+
+    @Test
+    void whenInputLineIsNumber_thenNextLineAndNextIntBothWork() {
+        String input = "42\n";
+
+        //nextLine()
+        Scanner sc1 = new Scanner(input);
+        int num1 = Integer.parseInt(sc1.nextLine());
+        assertEquals(42, num1);
+
+        //nextInt()
+        Scanner sc2 = new Scanner(input);
+        int num2 = sc2.nextInt();
+        assertEquals(42, num2);
+
+    }
+
+    @Test
+    void whenInputIsNotValidNumber_thenNextLineAndNextIntThrowDifferentException() {
+        String input = "Nan\n";
+
+        //nextLine() -> NumberFormatException
+        Scanner sc1 = new Scanner(input);
+        assertThrows(NumberFormatException.class, () -> Integer.parseInt(sc1.nextLine()));
+
+        //nextInt() -> InputMismatchException
+        Scanner sc2 = new Scanner(input);
+        assertThrows(InputMismatchException.class, sc2::nextInt);
+    }
+
+    @Test
+    void whenUsingNextInt_thenTheNextTokenAfterItFailsToParseIsNotConsumed() {
+        String input = "42 is a magic number\n";
+
+        //nextInt() to read '42'
+        Scanner sc2 = new Scanner(input);
+        int num2 = sc2.nextInt();
+        assertEquals(42, num2);
+
+        // call nextInt() again on "is"
+        assertThrows(InputMismatchException.class, sc2::nextInt);
+
+        String theNextToken = sc2.next();
+        assertEquals("is", theNextToken);
+
+        theNextToken = sc2.next();
+        assertEquals("a", theNextToken);
+    }
+
+    @Test
+    void whenReadingTwoInputLines_thenNextLineAndNextIntBehaveDifferently() {
+
+        String input = new StringBuilder().append("42\n")
+          .append("It is a magic number.\n")
+          .toString();
+
+        //nextLine()
+        Scanner sc1 = new Scanner(input);
+        int num1 = Integer.parseInt(sc1.nextLine());
+        String nextLineText1 = sc1.nextLine();
+        assertEquals(42, num1);
+        assertEquals("It is a magic number.", nextLineText1);
+
+        //nextInt()
+        Scanner sc2 = new Scanner(input);
+        int num2 = sc2.nextInt();
+        assertEquals(42, num2);
+
+        // nextInt() leaves the newline character (\n) behind
+        String nextLineText2 = sc2.nextLine();
+        assertEquals("", nextLineText2);
+    }
+
+}
@@ -4,7 +4,6 @@
    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-jpms</artifactId>
-    <version>0.0.1-SNAPSHOT</version>
    <name>core-java-jpms</name>
    <packaging>pom</packaging>

@@ -15,8 +14,8 @@
    </parent>

    <modules>
-        <module>decoupling-pattern1</module>
-        <module>decoupling-pattern2</module>
+        <module>service-provider-factory-pattern</module>
+        <module>service-loader-api-pattern</module>
    </modules>

    <build>
@@ -8,8 +8,8 @@
    <version>1.0</version>

    <parent>
-        <groupId>com.baeldung.decoupling-pattern2</groupId>
-        <artifactId>decoupling-pattern2</artifactId>
+        <groupId>com.baeldung.service-loader-api-pattern</groupId>
+        <artifactId>service-loader-api-pattern</artifactId>
        <version>1.0-SNAPSHOT</version>
    </parent>

@@ -3,8 +3,8 @@
    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.decoupling-pattern2</groupId>
-    <artifactId>decoupling-pattern2</artifactId>
+    <groupId>com.baeldung.service-loader-api-pattern</groupId>
+    <artifactId>service-loader-api-pattern</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>pom</packaging>

@@ -8,8 +8,8 @@
    <version>1.0</version>

    <parent>
-        <groupId>com.baeldung.decoupling-pattern2</groupId>
-        <artifactId>decoupling-pattern2</artifactId>
+        <groupId>com.baeldung.service-loader-api-pattern</groupId>
+        <artifactId>service-loader-api-pattern</artifactId>
        <version>1.0-SNAPSHOT</version>
    </parent>

@@ -8,8 +8,8 @@
    <version>1.0</version>

    <parent>
-        <groupId>com.baeldung.decoupling-pattern2</groupId>
-        <artifactId>decoupling-pattern2</artifactId>
+        <groupId>com.baeldung.service-loader-api-pattern</groupId>
+        <artifactId>service-loader-api-pattern</artifactId>
        <version>1.0-SNAPSHOT</version>
    </parent>

@@ -8,8 +8,8 @@
    <packaging>jar</packaging>

    <parent>
-        <groupId>com.baeldung.decoupling-pattern1</groupId>
-        <artifactId>decoupling-pattern1</artifactId>
+        <groupId>com.baeldung.service-provider-factory-pattern</groupId>
+        <artifactId>service-provider-factory-pattern</artifactId>
        <version>1.0-SNAPSHOT</version>
    </parent>

@@ -3,8 +3,8 @@
    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.decoupling-pattern1</groupId>
-    <artifactId>decoupling-pattern1</artifactId>
+    <groupId>com.baeldung.service-provider-factory-pattern</groupId>
+    <artifactId>service-provider-factory-pattern</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>pom</packaging>

@@ -9,8 +9,8 @@
    <packaging>jar</packaging>

    <parent>
-        <groupId>com.baeldung.decoupling-pattern1</groupId>
-        <artifactId>decoupling-pattern1</artifactId>
+        <groupId>com.baeldung.service-provider-factory-pattern</groupId>
+        <artifactId>service-provider-factory-pattern</artifactId>
        <version>1.0-SNAPSHOT</version>
    </parent>

@@ -10,4 +10,3 @@
 - [Serialize a Lambda in Java](https://www.baeldung.com/java-serialize-lambda)
 - [Convert Anonymous Class into Lambda in Java](https://www.baeldung.com/java-from-anonymous-class-to-lambda)
 - [When to Use Callable and Supplier in Java](https://www.baeldung.com/java-callable-vs-supplier)
- [Lambda Expression vs. Anonymous Inner Class](https://www.baeldung.com/java-lambdas-vs-anonymous-class)
@@ -10,4 +10,5 @@
 - [Create a BMI Calculator in Java](https://www.baeldung.com/java-body-mass-index-calculator)
 - [Java Program to Calculate the Standard Deviation](https://www.baeldung.com/java-calculate-standard-deviation)
 - [Java Program to Print Pascal’s Triangle](https://www.baeldung.com/java-pascal-triangle)
+- [Java Money and the Currency API](http://www.baeldung.com/java-money-and-currency)
 - More articles: [[<-- Prev]](/core-java-modules/core-java-lang-math-2)
@@ -23,11 +23,17 @@
            <artifactId>javaluator</artifactId>
            <version>${javaluator.version}</version>
        </dependency>
+        <dependency>
+            <groupId>org.javamoney</groupId>
+            <artifactId>moneta</artifactId>
+            <version>${javamoney.moneta.version}</version>
+        </dependency>
    </dependencies>

    <properties>
        <exp4j.version>0.4.8</exp4j.version>
        <javaluator.version>3.0.3</javaluator.version>
+        <javamoney.moneta.version>1.1</javamoney.moneta.version>
    </properties>

 </project>
@@ -0,0 +1,98 @@
+package com.baeldung.methods;
+
+public class Car {
+
+    private final String make;
+    private final String model;
+    private final int year;
+    private final String color;
+    private final boolean automatic;
+    private final int numDoors;
+    private final String features;
+
+    private Car(CarBuilder carBuilder) {
+        this.make = carBuilder.make;
+        this.model = carBuilder.model;
+        this.year = carBuilder.year;
+        this.color = carBuilder.color;
+        this.automatic = carBuilder.automatic;
+        this.numDoors = carBuilder.numDoors;
+        this.features = carBuilder.features;
+    }
+
+    public String getMake() {
+        return make;
+    }
+
+    public String getModel() {
+        return model;
+    }
+
+    public int getYear() {
+        return year;
+    }
+
+    public String getColor() {
+        return color;
+    }
+
+    public boolean isAutomatic() {
+        return automatic;
+    }
+
+    public int getNumDoors() {
+        return numDoors;
+    }
+
+    public String getFeatures() {
+        return features;
+    }
+
+    public static class CarBuilder {
+
+        private final String make;
+        private final String model;
+        private final int year;
+
+        private String color = "unknown";
+        private boolean automatic = false;
+        private int numDoors = 4;
+        private String features = "";
+
+        public CarBuilder(String make, String model, int year) {
+            this.make = make;
+            this.model = model;
+            this.year = year;
+        }
+
+        public CarBuilder color(String color) {
+            this.color = color;
+            return this;
+        }
+
+        public CarBuilder automatic(boolean automatic) {
+            this.automatic = automatic;
+            return this;
+        }
+
+        public CarBuilder numDoors(int numDoors) {
+            this.numDoors = numDoors;
+            return this;
+        }
+
+        public CarBuilder features(String features) {
+            this.features = features;
+            return this;
+        }
+
+        public Car build() {
+            return new Car(this);
+        }
+    }
+
+    @Override
+    public String toString() {
+        return "Car [make=" + make + ", model=" + model + ", year=" + year + ", color=" + color + ", automatic=" + automatic + ", numDoors=" + numDoors + ", features=" + features + "]";
+    }
+
+}
@@ -0,0 +1,52 @@
+package com.baeldung.methods;
+
+import java.io.Serializable;
+
+public class Motorcycle extends Vehicle implements Serializable {
+
+    private static final long serialVersionUID = 5973661295933599929L;
+
+    private int year;
+    private String features = "";
+
+    public Motorcycle() {
+        super();
+    }
+
+    public Motorcycle(String make, String model, String color, int weight, boolean statusNew, int year) {
+        super(make, model, color, weight, statusNew);
+        this.year = year;
+    }
+
+    public Motorcycle(Vehicle vehicle, int year) {
+        super(vehicle);
+        this.year = year;
+    }
+
+    public int getYear() {
+        return year;
+    }
+
+    public void setYear(int year) {
+        this.year = year;
+    }
+
+    public void setFeatures(String features) {
+        this.features = features;
+    }
+
+    public String getFeatures() {
+        return features;
+    }
+
+    public void addMotorcycleFeatures(String... features) {
+        StringBuilder str = new StringBuilder(this.getFeatures());
+        for (String feature : features) {
+            if (!str.toString().isEmpty())
+                str.append(", ");
+            str.append(feature);
+        }
+        this.setFeatures(str.toString());
+    }
+
+}
@@ -0,0 +1,33 @@
+package com.baeldung.methods;
+
+public class Vehicle {
+
+    static String defaultValue = "DEFAULT";
+    private String make = defaultValue;
+    private String model = defaultValue;
+    private String color = defaultValue;
+    private int weight = 0;
+    private boolean statusNew = true;
+
+    public Vehicle() {
+        super();
+    }
+
+    public Vehicle(String make, String model, String color, int weight, boolean statusNew) {
+        this.make = make;
+        this.model = model;
+        this.color = color;
+        this.weight = weight;
+        this.statusNew = statusNew;
+    }
+
+    public Vehicle(Vehicle vehicle) {
+        this(vehicle.make, vehicle.model, vehicle.color, vehicle.weight, vehicle.statusNew);
+    }
+
+    @Override
+    public String toString() {
+        return "Vehicle [make=" + make + ", model=" + model + ", color=" + color + ", weight=" + weight + ", statusNew=" + statusNew + "]";
+    }
+
+}
@@ -0,0 +1,20 @@
+package com.baeldung.methods;
+
+public class VehicleProcessor {
+
+    Vehicle processVehicle(String make, String model, String color, int weight, boolean status) {
+        return new Vehicle(make, model, color, weight, status);
+    }
+
+    Vehicle processVehicle(Vehicle vehicle) {
+        return new Vehicle(vehicle);
+    }
+
+    Car processCar(Car car) {
+        return new Car.CarBuilder(car.getMake(), car.getModel(), car.getYear()).color(car.getColor())
+            .automatic(car.isAutomatic())
+            .features(car.getFeatures())
+            .build();
+    }
+
+}
@@ -0,0 +1,58 @@
+package com.baeldung.methods;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.junit.jupiter.api.Test;
+
+class VehicleProcessorUnitTest {
+
+    VehicleProcessor vehicleProcessor = new VehicleProcessor();
+    Vehicle vehicle = new Vehicle("Ford", "Focus", "red", 2200, true);
+
+    @Test
+    void givenAllArguments_whenMethodCall_thenVerifyCallIsDoneCorrectly() {
+        Vehicle veh = vehicleProcessor.processVehicle("Ford", "Focus", "red", 2200, true);
+        assertThat(veh.toString()).hasToString(vehicle.toString());
+    }
+
+    @Test
+    void givenParameterObject_whenMethodCall_thenVerifyCallIsDoneCorrectly() {
+        Vehicle veh = vehicleProcessor.processVehicle(vehicle);
+        assertThat(veh.toString()).hasToString(vehicle.toString());
+    }
+
+    @Test
+    void givenJavaBeanPattern_whenMethodCall_thenVerifyCallIsDoneCorrectly() {
+        Motorcycle motorcycle = new Motorcycle("Ducati", "Monster", "yellow", 235, true, 2023);
+        motorcycle.setFeatures("GPS");
+
+        vehicleProcessor.processVehicle(motorcycle);
+        assertThat(motorcycle.getFeatures()).isEqualToIgnoringCase("GPS");
+    }
+
+    @Test
+    void givenJavaVarargs_whenMethodCall_thenAssertTheReturnedConcatenatedString() {
+        Motorcycle motorcycle = new Motorcycle("Ducati", "Monster", "red", 350, true, 2023);
+        motorcycle.addMotorcycleFeatures("abs");
+        assertThat(motorcycle.getFeatures()).isEqualToIgnoringCase("abs");
+
+        motorcycle.addMotorcycleFeatures("navi", "charger");
+        assertThat(motorcycle.getFeatures()).isEqualToIgnoringCase("abs, navi, charger");
+
+        motorcycle.addMotorcycleFeatures("wifi", "phone", "satellite");
+        assertThat(motorcycle.getFeatures()).isEqualToIgnoringCase("abs, navi, charger, wifi, phone, satellite");
+    }
+
+    @Test
+    void givenJavaBuilderPattern_whenMethodCall_thenVerifyCallIsDoneCorrectly() {
+        Car car = new Car.CarBuilder("Ford", "Focus", 2023).color("blue")
+            .automatic(true)
+            .features("abs, navi, charger, wifi, phone, satellite")
+            .build();
+
+        Car result = vehicleProcessor.processCar(car);
+
+        assertThat(result.toString()).hasToString(car.toString());
+    }
+
+}
@@ -15,9 +15,9 @@

    <dependencies>
        <dependency>
-            <groupId>org.apache.httpcomponents</groupId>
-            <artifactId>httpclient</artifactId>
-            <version>${httpclient.version}</version>
+            <groupId>commons-codec</groupId>
+            <artifactId>commons-codec</artifactId>
+            <version>${commons-codec.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.commons</groupId>
@@ -52,11 +52,11 @@
    </build>

    <properties>
-        <httpclient.version>4.5.9</httpclient.version>
        <angus.mail.version>2.0.1</angus.mail.version>
        <async-http-client.version>2.4.5</async-http-client.version>
        <jakarta.bind.version>2.3.3</jakarta.bind.version>
        <greenmail.version>2.0.0-alpha-3</greenmail.version>
+        <commons-codec.version>1.15</commons-codec.version>
    </properties>

 </project>
@@ -21,7 +21,7 @@ public class HttpClient {
        this.password = password;
    }

-    public int sendRquestWithAuthHeader(String url) throws IOException {
+    public int sendRequestWithAuthHeader(String url) throws IOException {
        HttpURLConnection connection = null;
        try {
            connection = createConnection(url);
@@ -34,7 +34,7 @@ public class HttpClient {
        }
    }

-    public int sendRquestWithAuthenticator(String url) throws IOException {
+    public int sendRequestWithAuthenticator(String url) throws IOException {
        setAuthenticator();

        HttpURLConnection connection = null;
@@ -7,28 +7,28 @@ import org.junit.Test;
 public class HttpClientLiveTest {

    @Test
-    public void sendRquestWithAuthHeader() throws Exception {
+    public void sendRequestWithAuthHeader() throws Exception {
        HttpClient httpClient = new HttpClient("user1", "pass1");

-        int status = httpClient.sendRquestWithAuthHeader("https://httpbin.org/basic-auth/user1/pass1");
+        int status = httpClient.sendRequestWithAuthHeader("https://httpbin.org/basic-auth/user1/pass1");

        assertTrue(isSuccess(status));
    }

    @Test
-    public void sendRquestWithAuthHeader_whenIncorrectCredentials_thenNotSuccessful() throws Exception {
+    public void sendRequestWithAuthHeader_whenIncorrectCredentials_thenNotSuccessful() throws Exception {
        HttpClient httpClient = new HttpClient("John", "Smith");

-        int status = httpClient.sendRquestWithAuthHeader("https://httpbin.org/basic-auth/user1/pass1");
+        int status = httpClient.sendRequestWithAuthHeader("https://httpbin.org/basic-auth/user1/pass1");

        assertTrue(isUnauthorized(status));
    }

    @Test
-    public void sendRquestWithAuthenticator() throws Exception {
+    public void sendRequestWithAuthenticator() throws Exception {
        HttpClient httpClient = new HttpClient("user2", "pass2");

-        int status = httpClient.sendRquestWithAuthenticator("https://httpbin.org/basic-auth/user2/pass2");
+        int status = httpClient.sendRequestWithAuthenticator("https://httpbin.org/basic-auth/user2/pass2");

        assertTrue(isSuccess(status));
    }
@@ -37,7 +37,7 @@ public class HttpClientLiveTest {
    public void sendRquestWithAuthenticator_whenIncorrectCredentials_thenNotSuccessful() throws Exception {
        HttpClient httpClient = new HttpClient("John", "Smith");

-        int status = httpClient.sendRquestWithAuthenticator("https://httpbin.org/basic-auth/user2/pass2");
+        int status = httpClient.sendRequestWithAuthenticator("https://httpbin.org/basic-auth/user2/pass2");

        assertTrue(isUnauthorized(status));
    }
@@ -24,6 +24,30 @@
            <artifactId>jsoup</artifactId>
            <version>${jsoup.version}</version>
        </dependency>
+        <!-- https://mvnrepository.com/artifact/org.apache.httpcomponents/httpclient -->
+        <dependency>
+            <groupId>org.apache.httpcomponents</groupId>
+            <artifactId>httpclient</artifactId>
+            <version>4.5.2</version>
+        </dependency>
+        <!-- https://mvnrepository.com/artifact/javax.ws.rs/javax.ws.rs-api -->
+        <dependency>
+            <groupId>javax.ws.rs</groupId>
+            <artifactId>javax.ws.rs-api</artifactId>
+            <version>2.1.1</version>
+        </dependency>
+        <dependency>
+            <groupId>org.glassfish.jersey.core</groupId>
+            <artifactId>jersey-common</artifactId>
+            <version>2.22.2</version>
+            <scope>test</scope>
+        </dependency>
+        <!-- https://mvnrepository.com/artifact/org.springframework/spring-web -->
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-web</artifactId>
+            <version>6.0.6</version>
+        </dependency>
    </dependencies>

    <build>
@@ -0,0 +1,53 @@
+package com.baeldung.urlquerymanipulation;
+
+import static junit.framework.TestCase.assertEquals;
+
+import java.net.URI;
+import java.net.URISyntaxException;
+
+import javax.ws.rs.core.UriBuilder;
+
+import org.apache.http.client.utils.URIBuilder;
+
+import org.junit.Test;
+import org.springframework.web.util.UriComponentsBuilder;
+
+public class UrlQueryManipulationUnitTest {
+
+    @Test
+    public void whenUsingApacheUriBuilder_thenParametersAreCorrectlyAdded() throws URISyntaxException {
+        String url = "baeldung.com";
+        String key = "article";
+        String value = "alpha";
+        URI uri = new URIBuilder(url).addParameter(key, value)
+          .build();
+
+        assertEquals("baeldung.com?article=alpha", uri.toString());
+    }
+
+    @Test
+    public void whenUsingJavaUriBuilder_thenParametersAreCorrectlyAdded() {
+        String url = "baeldung.com";
+        String key = "article";
+        String value = "beta";
+        URI uri = UriBuilder.fromUri(url)
+          .queryParam(key, value)
+          .build();
+
+        assertEquals("baeldung.com?article=beta", uri.toString());
+    }
+
+    @Test
+    public void whenUsingSpringUriComponentsBuilder_thenParametersAreCorrectlyAdded() {
+        String url = "baeldung.com";
+        String key = "article";
+        String value = "charlie";
+        URI uri = UriComponentsBuilder.fromUriString(url)
+          .queryParam(key, value)
+          .build()
+          .toUri();
+
+        assertEquals("baeldung.com?article=charlie", uri.toString());
+    }
+
+}
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project xmlns="http://maven.apache.org/POM/4.0.0"
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <artifactId>core-java-networking</artifactId>
    <name>core-java-networking</name>
@@ -19,6 +19,11 @@
            <artifactId>spring-web</artifactId>
            <version>${springframework.spring-web.version}</version>
        </dependency>
+        <dependency>
+            <groupId>org.apache.httpcomponents</groupId>
+            <artifactId>httpclient</artifactId>
+            <version>${apache.httpclient.version}</version>
+        </dependency>
    </dependencies>

    <build>
@@ -27,6 +32,7 @@

    <properties>
        <springframework.spring-web.version>4.3.4.RELEASE</springframework.spring-web.version>
+        <apache.httpclient.version>4.5.14</apache.httpclient.version>
    </properties>

 </project>
@@ -1,11 +1,19 @@
 package com.baeldung.networking.url;

+import static java.util.stream.Collectors.toList;
 import static org.junit.Assert.assertEquals;

 import java.net.MalformedURLException;
+import java.net.URISyntaxException;
 import java.net.URL;
+import java.util.Map;

+import org.apache.http.client.utils.URIBuilder;
+import org.apache.http.message.BasicNameValuePair;
 import org.junit.Test;
+import org.springframework.web.util.UriComponentsBuilder;
+
+import com.google.common.collect.ImmutableMap;

 public class UrlUnitTest {

@@ -101,4 +109,44 @@ public class UrlUnitTest {
        assertEquals("http://baeldung.com:9000/guidelines.txt", url.toString());
    }

-}
+    @Test
+    public void givenUrlParameters_whenBuildUrlWithURIBuilder_thenSuccess() throws URISyntaxException, MalformedURLException {
+        URIBuilder uriBuilder = new URIBuilder("http://baeldung.com/articles");
+        uriBuilder.setPort(9090);
+        uriBuilder.addParameter("topic", "java");
+        uriBuilder.addParameter("version", "8");
+        URL url = uriBuilder.build().toURL();
+        assertEquals("http://baeldung.com:9090/articles?topic=java&version=8", url.toString());
+    }
+
+    @Test
+    public void givenUrlParametersInMap_whenBuildUrlWithURIBuilder_thenSuccess() throws URISyntaxException, MalformedURLException {
+        Map<String, String> paramMap = ImmutableMap.of("topic", "java", "version", "8");
+        URIBuilder uriBuilder = new URIBuilder("http://baeldung.com/articles");
+        uriBuilder.setPort(9090);
+        uriBuilder.addParameters(paramMap.entrySet()
+          .stream()
+          .map(entry -> new BasicNameValuePair(entry.getKey(), entry.getValue()))
+          .collect(toList()));
+
+        URL url = uriBuilder.build().toURL();
+        assertEquals("http://baeldung.com:9090/articles?topic=java&version=8", url.toString());
+    }
+
+    @Test
+    public void givenUrlParameters_whenBuildUrlWithSpringUriComponentsBuilder_thenSuccess() throws MalformedURLException {
+        URL url = UriComponentsBuilder.newInstance()
+          .scheme("http")
+          .host("baeldung.com")
+          .port(9090)
+          .path("articles")
+          .queryParam("topic", "java")
+          .queryParam("version", "8")
+          .build()
+          .toUri()
+          .toURL();
+
+        assertEquals("http://baeldung.com:9090/articles?topic=java&version=8", url.toString());
+    }
+
+}
@@ -14,5 +14,4 @@ This module contains articles about core Java non-blocking input and output (IO)
 - [What Is the Difference Between NIO and NIO.2?](https://www.baeldung.com/java-nio-vs-nio-2)
 - [Guide to ByteBuffer](https://www.baeldung.com/java-bytebuffer)
 - [Find Files that Match Wildcard Strings in Java](https://www.baeldung.com/java-files-match-wildcard-strings)
- [Get the Desktop Path in Java](https://www.baeldung.com/java-desktop-path)
 - [[<-- Prev]](/core-java-modules/core-java-nio)
@@ -45,8 +45,9 @@ public class EchoServer {

    private static void answerWithEcho(ByteBuffer buffer, SelectionKey key) throws IOException {
        SocketChannel client = (SocketChannel) key.channel();
-        client.read(buffer);
-        if (new String(buffer.array()).trim().equals(POISON_PILL)) {
+        int r = client.read(buffer);
+        if (r == -1 || new String(buffer.array()).trim()
+            .equals(POISON_PILL)) {
            client.close();
            System.out.println("Not accepting client messages anymore");
        } else {
@@ -1,2 +1,4 @@
 ### Relevant Articles:
 - [Java Program to Calculate Pi](https://www.baeldung.com/java-monte-carlo-compute-pi)
+- [Convert Integer to Hexadecimal in Java](https://www.baeldung.com/java-convert-int-to-hex)
+- More articles: [[<-- prev]](../core-java-numbers-5)
@@ -12,6 +12,21 @@
        <version>0.0.1-SNAPSHOT</version>
    </parent>

+    <dependencies>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-engine</artifactId>
+            <version>${junit-jupiter.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>commons-codec</groupId>
+            <artifactId>commons-codec</artifactId>
+            <version>${commons-codec}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
    <build>
        <finalName>core-java-numbers-6</finalName>
        <resources>
@@ -22,4 +37,7 @@
        </resources>
    </build>

+    <properties>
+        <commons-codec>1.15</commons-codec>
+    </properties>
 </project>
@@ -0,0 +1,16 @@
+package com.baeldung.integertohex;
+
+class IntegerToHex {
+    static final String digits = "0123456789ABCDEF";
+    static String integerToHex(int input) {
+        if (input <= 0)
+            return "0";
+        StringBuilder hex = new StringBuilder();
+        while (input > 0) {
+            int digit = input % 16;
+            hex.insert(0, digits.charAt(digit));
+            input = input / 16;
+        }
+        return hex.toString();
+    }
+}
@@ -0,0 +1,75 @@
+package com.baeldung.integertohex;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.apache.commons.codec.binary.Hex;
+import org.junit.jupiter.api.Test;
+
+class IntegerToHexUnitTest {
+
+    @Test
+    void givenIntegerValue_whenUseRawMethod_thenWillGetHexValue() {
+        String result = IntegerToHex.integerToHex(1055);
+        assertEquals("41F", result);
+    }
+
+    @Test
+    void givenIntegerNegativeValue_whenUseRawMethod_thenZeroValue() {
+        String result = IntegerToHex.integerToHex(-1055);
+        assertEquals("0", result);
+    }
+
+    @Test
+    void givenIntegerPositiveValue_whenUseStringFormat_thenWillGetHexValue() {
+        String result = String.format("%02x", 255);
+        assertEquals("ff", result);
+    }
+
+    @Test
+    void givenIntegerPositiveValue_whenUseStringFormat_thenWillGetHexValueWithLeftZeros() {
+        String result = String.format("%04x", 255);
+        assertEquals("00ff", result);
+    }
+
+    @Test
+    void givenIntegerPositiveValue_whenUseStringFormat_thenWillGetHexValueWithLeftZerosAndUpperLetter() {
+        String result = String.format("%04X", 255);
+        assertEquals("00FF", result);
+    }
+
+    @Test
+    void givenIntegerValue_whenUseIntegerToHexString_thenWillGetHexValue() {
+        String result = Integer.toHexString(1000);
+        assertEquals("3e8", result);
+    }
+
+    @Test
+    void givenIntegerValue_whenUseLongToHexString_thenWillGetHexValue() {
+        String result = Long.toHexString(255L);
+        assertEquals("ff", result);
+    }
+
+    @Test
+    public void givenNegativeIntegerValue_whenUseIntegerToString_thenWillGetHexValue() {
+        String result = Integer.toString(-1458, 16);
+        assertEquals("-5b2", result);
+    }
+
+    @Test
+    public void givenIntegerValue_whenUseIntegerToString_thenWillGetHexValue() {
+        String result = Integer.toString(1458, 16);
+        assertEquals("5b2", result);
+    }
+
+    @Test
+    public void givenLongValue_whenUseLongToString_thenWillGetHexValue() {
+        String result = Long.toString(158, 16);
+        assertEquals("9e", result);
+    }
+
+    @Test
+    public void givenIntegerValue_whenUseApacheCommons_thenWillGetHexSignedValue() {
+        String result = Hex.encodeHexString(new byte[] { (byte) 254 });
+        assertEquals("fe", result);
+    }
+}
@@ -0,0 +1 @@
+## Relevant Articles
@@ -0,0 +1,16 @@
+<?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-perf-2</artifactId>
+    <name>core-java-perf-2</name>
+    <packaging>jar</packaging>
+
+    <parent>
+        <groupId>com.baeldung.core-java-modules</groupId>
+        <artifactId>core-java-modules</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+    </parent>
+
+</project>
@@ -0,0 +1,20 @@
+package com.baeldung.highcpu;
+
+import java.util.LinkedList;
+import java.util.List;
+import java.util.function.IntUnaryOperator;
+import java.util.stream.IntStream;
+
+public class Application {
+
+    static List<Integer> generateList() {
+        return IntStream.range(0, 10000000).parallel().map(IntUnaryOperator.identity()).collect(LinkedList::new, List::add, List::addAll);
+    }
+
+    public static void main(String[] args) {
+        List<Integer> list = generateList();
+        long start = System.nanoTime();
+        int value = list.get(9500000);
+        System.out.printf("Found value %d in %d nanos\n", value, (System.nanoTime() - start));
+    }
+}
@@ -0,0 +1,16 @@
+package com.baeldung.jmxterm;
+
+import java.util.UUID;
+
+public abstract class AbstractPlayerMBean implements PlayerMBean{
+
+    private final UUID id;
+
+    protected AbstractPlayerMBean() {
+        this.id = UUID.randomUUID();
+    }
+
+    String getId() {
+        return getName() + id.toString();
+    }
+}
@@ -0,0 +1,42 @@
+package com.baeldung.jmxterm;
+
+import javax.management.ListenerNotFoundException;
+import javax.management.MBeanNotificationInfo;
+import javax.management.Notification;
+import javax.management.NotificationBroadcaster;
+import javax.management.NotificationBroadcasterSupport;
+import javax.management.NotificationFilter;
+import javax.management.NotificationListener;
+
+public abstract class BroadcastingGuessGame implements NotificationBroadcaster, GuessGameMBean {
+    private final NotificationBroadcasterSupport broadcaster =
+        new NotificationBroadcasterSupport();
+
+    private long notificationSequence = 0;
+
+    private final MBeanNotificationInfo[] notificationInfo;
+
+    protected BroadcastingGuessGame() {
+        this.notificationInfo = new MBeanNotificationInfo[]{
+            new MBeanNotificationInfo(new String[]{"game"}, Notification.class.getName(), "Game notification")
+        };
+    }
+
+    protected void notifyAboutWinner(Player winner) {
+        String message = "Winner is " + winner.getName() + " with score " + winner.getScore();
+        Notification notification = new Notification("game.winner", this, notificationSequence++, message);
+        broadcaster.sendNotification(notification);
+    }
+
+    public void addNotificationListener(NotificationListener listener, NotificationFilter filter, Object handback) {
+        broadcaster.addNotificationListener(listener, filter, handback);
+    }
+
+    public void removeNotificationListener(NotificationListener listener) throws ListenerNotFoundException {
+        broadcaster.removeNotificationListener(listener);
+    }
+
+    public MBeanNotificationInfo[] getNotificationInfo() {
+        return notificationInfo;
+    }
+}
--- a/Show More
+++ b/Show More