Merge branch 'master' into master

2023-07-20 16:30:42 +03:00
parent d88d2d3632 508a5e414b
commit c55d386498
264 changed files with 3533 additions and 1113 deletions
@@ -1,2 +1,3 @@
 ## Relevant Articles
 - [Scoped Values in Java 20](https://www.baeldung.com/java-20-scoped-values)
+- [How to Read Zip Files Entries With Java](https://www.baeldung.com/java-read-zip-files)
@@ -6,3 +6,4 @@
 - [Using a Mutex Object in Java](https://www.baeldung.com/java-mutex)
 - [Testing Multi-Threaded Code in Java](https://www.baeldung.com/java-testing-multithreaded)
 - [How to Check if All Runnables Are Done](https://www.baeldung.com/java-runnables-check-status)
+- [Parallelize for Loop in Java](https://www.baeldung.com/java-for-loop-parallel)
@@ -8,4 +8,5 @@ This module contains articles about basic Java concurrency.
 - [Thread.sleep() vs Awaitility.await()](https://www.baeldung.com/java-thread-sleep-vs-awaitility-await)
 - [Is CompletableFuture Non-blocking?](https://www.baeldung.com/java-completablefuture-non-blocking)
 - [Returning a Value After Finishing Thread’s Job in Java](https://www.baeldung.com/java-return-value-after-thread-finish)
+- [CompletableFuture and ThreadPool in Java](https://www.baeldung.com/java-completablefuture-threadpool)
 - [[<-- Prev]](../core-java-concurrency-basic-2)
@@ -8,4 +8,5 @@ This module contains articles about date operations in Java.
 - [How to Determine Date of the First Day of the Week Using LocalDate in Java](https://www.baeldung.com/java-first-day-of-the-week)
 - [Adding One Month to Current Date in Java](https://www.baeldung.com/java-adding-one-month-to-current-date)
 - [How to Get Last Day of a Month in Java](https://www.baeldung.com/java-last-day-month)
+- [Getting Yesterday’s Date in Java](https://www.baeldung.com/java-find-yesterdays-date)
 - [[<-- Prev]](/core-java-modules/core-java-date-operations-2)
@@ -4,13 +4,5 @@ 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)
- [Integer.parseInt(scanner.nextLine()) and scanner.nextInt() in Java](https://www.baeldung.com/java-scanner-integer)
- [Difference Between FileReader and BufferedReader in Java](https://www.baeldung.com/java-filereader-vs-bufferedreader)
- [Java: Read Multiple Inputs on Same Line](https://www.baeldung.com/java-read-multiple-inputs-same-line)
- [Storing Java Scanner Input in an Array](https://www.baeldung.com/java-store-scanner-input-in-array)
- [How to Take Input as String With Spaces in Java Using Scanner?](https://www.baeldung.com/java-scanner-input-with-spaces)
- [Write Console Output to Text File in Java](https://www.baeldung.com/java-write-console-output-file)
- [What’s the Difference between Scanner next() and nextLine() Methods?](https://www.baeldung.com/java-scanner-next-vs-nextline)
- [Handle NoSuchElementException When Reading a File Through Scanner](https://www.baeldung.com/java-scanner-nosuchelementexception-reading-file)
+- [Check if a File Is Empty in Java](https://www.baeldung.com/java-check-file-empty)
@@ -92,12 +92,6 @@
            <version>7.1.0</version>
            <scope>test</scope>
        </dependency>
-        <dependency>
-            <groupId>org.testng</groupId>
-            <artifactId>testng</artifactId>
-            <version>7.5</version>
-            <scope>compile</scope>
-        </dependency>
    </dependencies>
    <build>
        <finalName>core-java-io-apis-2</finalName>
@@ -0,0 +1,71 @@
+package com.baeldung.emptyfile;
+
+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.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.NoSuchFileException;
+import java.nio.file.Path;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+class CheckFileIsEmptyUnitTest {
+    @Test
+    void whenTheFileIsEmpty_thenFileLengthIsZero(@TempDir Path tempDir) throws IOException {
+        File emptyFile = tempDir.resolve("an-empty-file.txt")
+          .toFile();
+        emptyFile.createNewFile();
+        assertTrue(emptyFile.exists());
+        assertEquals(0, emptyFile.length());
+    }
+
+    @Test
+    void whenFileDoesNotExist_thenFileLengthIsZero(@TempDir Path tempDir) {
+        File aNewFile = tempDir.resolve("a-new-file.txt")
+          .toFile();
+        assertFalse(aNewFile.exists());
+        assertEquals(0, aNewFile.length());
+    }
+
+    boolean isFileEmpty(File file) {
+        if (!file.exists()) {
+            throw new IllegalArgumentException("Cannot check the file length. The file is not found: " + file.getAbsolutePath());
+        }
+        return file.length() == 0;
+    }
+
+    @Test
+    void whenTheFileDoesNotExist_thenIsFilesEmptyThrowsException(@TempDir Path tempDir) {
+        File aNewFile = tempDir.resolve("a-new-file.txt")
+          .toFile();
+        IllegalArgumentException ex = assertThrows(IllegalArgumentException.class, () -> isFileEmpty(aNewFile));
+        assertEquals(ex.getMessage(), "Cannot check the file length. The file is not found: " + aNewFile.getAbsolutePath());
+    }
+
+    @Test
+    void whenTheFileIsEmpty_thenIsFilesEmptyReturnsTrue(@TempDir Path tempDir) throws IOException {
+        File emptyFile = tempDir.resolve("an-empty-file.txt")
+          .toFile();
+        emptyFile.createNewFile();
+        assertTrue(isFileEmpty(emptyFile));
+
+    }
+
+    @Test
+    void whenTheFileIsEmpty_thenFilesSizeReturnsTrue(@TempDir Path tempDir) throws IOException {
+        Path emptyFilePath = tempDir.resolve("an-empty-file.txt");
+        Files.createFile(emptyFilePath);
+        assertEquals(0, Files.size(emptyFilePath));
+    }
+
+    @Test
+    void whenTheFileDoesNotExist_thenFilesSizeThrowsException(@TempDir Path tempDir) {
+        Path aNewFilePath = tempDir.resolve("a-new-file.txt");
+        assertThrows(NoSuchFileException.class, () -> Files.size(aNewFilePath));
+    }
+}
@@ -1,6 +0,0 @@
-## Core Java IO APIs
-
-This module contains articles about core Java input/output(IO) APIs.
-
-### Relevant Articles:
- [Read Date in Java Using Scanner](https://www.baeldung.com/java-scanner-read-date)
@@ -1,15 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xmlns="http://maven.apache.org/POM/4.0.0"
-         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-io-apis-3</artifactId>
-    <name>core-java-io-apis-3</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>
@@ -10,6 +10,6 @@ This module contains articles about core Java input/output(IO) APIs.
 - [Comparing getPath(), getAbsolutePath(), and getCanonicalPath() in Java](https://www.baeldung.com/java-path)
 - [Quick Use of FilenameFilter](https://www.baeldung.com/java-filename-filter)
 - [Guide to BufferedReader](https://www.baeldung.com/java-buffered-reader)
- [Java Scanner](https://www.baeldung.com/java-scanner)
- [Scanner nextLine() Method](https://www.baeldung.com/java-scanner-nextline)
- [Java Scanner hasNext() vs. hasNextLine()](https://www.baeldung.com/java-scanner-hasnext-vs-hasnextline)
+- [Difference Between FileReader and BufferedReader in Java](https://www.baeldung.com/java-filereader-vs-bufferedreader)
+- [Java: Read Multiple Inputs on Same Line](https://www.baeldung.com/java-read-multiple-inputs-same-line)
+- [Write Console Output to Text File in Java](https://www.baeldung.com/java-write-console-output-file)
@@ -31,6 +31,12 @@
            <version>${lombok.version}</version>
            <scope>provided</scope>
        </dependency>
+        <dependency>
+            <groupId>org.testng</groupId>
+            <artifactId>testng</artifactId>
+            <version>7.5</version>
+            <scope>compile</scope>
+        </dependency>
    </dependencies>

    <build>
@@ -1,36 +1,36 @@
-package com.baeldung.multinput;
-
-import java.util.InputMismatchException;
-import java.util.Scanner;
-
-public class MultiInputs {
-    public void UsingSpaceDelimiter(){
-        Scanner scanner = new Scanner(System.in);
-        System.out.print("Enter two numbers: ");
-        int num1 = scanner.nextInt();
-        int num2 = scanner.nextInt();
-        System.out.println("You entered " + num1 + " and " + num2);
-
-    }
-    public void UsingREDelimiter(){
-        Scanner scanner = new Scanner(System.in);
-        scanner.useDelimiter("[\\s,]+");
-        System.out.print("Enter two numbers separated by a space or a comma: ");
-        int num1 = scanner.nextInt();
-        int num2 = scanner.nextInt();
-        System.out.println("You entered " + num1 + " and " + num2);
-
-    }
-    public void UsingCustomDelimiter(){
-        Scanner scanner = new Scanner(System.in);
-        scanner.useDelimiter(";");
-        System.out.print("Enter two numbers separated by a semicolon: ");
-        try { int num1 = scanner.nextInt();
-            int num2 = scanner.nextInt();
-            System.out.println("You entered " + num1 + " and " + num2); }
-        catch (InputMismatchException e)
-        { System.out.println("Invalid input. Please enter two integers separated by a semicolon."); }
-
-    }
-}
-
+package com.baeldung.multinput;
+
+import java.util.InputMismatchException;
+import java.util.Scanner;
+
+public class MultiInputs {
+    public void UsingSpaceDelimiter(){
+        Scanner scanner = new Scanner(System.in);
+        System.out.print("Enter two numbers: ");
+        int num1 = scanner.nextInt();
+        int num2 = scanner.nextInt();
+        System.out.println("You entered " + num1 + " and " + num2);
+
+    }
+    public void UsingREDelimiter(){
+        Scanner scanner = new Scanner(System.in);
+        scanner.useDelimiter("[\\s,]+");
+        System.out.print("Enter two numbers separated by a space or a comma: ");
+        int num1 = scanner.nextInt();
+        int num2 = scanner.nextInt();
+        System.out.println("You entered " + num1 + " and " + num2);
+
+    }
+    public void UsingCustomDelimiter(){
+        Scanner scanner = new Scanner(System.in);
+        scanner.useDelimiter(";");
+        System.out.print("Enter two numbers separated by a semicolon: ");
+        try { int num1 = scanner.nextInt();
+            int num2 = scanner.nextInt();
+            System.out.println("You entered " + num1 + " and " + num2); }
+        catch (InputMismatchException e)
+        { System.out.println("Invalid input. Please enter two integers separated by a semicolon."); }
+
+    }
+}
+
@@ -1,36 +1,36 @@
-package com.baeldung.bufferedreadervsfilereader;
-
-import static org.junit.jupiter.api.Assertions.assertEquals;
-
-import java.io.BufferedReader;
-import java.io.File;
-import java.io.IOException;
-import java.io.InputStreamReader;
-import java.nio.charset.StandardCharsets;
-import java.nio.file.Files;
-import java.nio.file.Path;
-
-import org.junit.jupiter.api.Test;
-
-class BufferedReaderUnitTest {
-
-    @Test
-    void whenReadingAFile_thenReadsLineByLine() {
-        StringBuilder result = new StringBuilder();
-
-        final Path filePath = new File("src/test/resources/sampleText1.txt").toPath();
-        try (BufferedReader br = new BufferedReader(new InputStreamReader(Files.newInputStream(filePath), StandardCharsets.UTF_8))) {
-            String line;
-
-            while((line = br.readLine()) != null) {
-                result.append(line);
-                result.append('\n');
-            }
-        } catch (IOException e) {
-            e.printStackTrace();
-        }
-
-        assertEquals("first line\nsecond line\nthird line\n", result.toString());
-    }
-
-}
+package com.baeldung.bufferedreadervsfilereader;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+import org.junit.jupiter.api.Test;
+
+class BufferedReaderUnitTest {
+
+    @Test
+    void whenReadingAFile_thenReadsLineByLine() {
+        StringBuilder result = new StringBuilder();
+
+        final Path filePath = new File("src/test/resources/sampleText1.txt").toPath();
+        try (BufferedReader br = new BufferedReader(new InputStreamReader(Files.newInputStream(filePath), StandardCharsets.UTF_8))) {
+            String line;
+
+            while((line = br.readLine()) != null) {
+                result.append(line);
+                result.append('\n');
+            }
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+
+        assertEquals("first line\nsecond line\nthird line\n", result.toString());
+    }
+
+}
@@ -1,30 +1,30 @@
-package com.baeldung.bufferedreadervsfilereader;
-
-import static org.junit.jupiter.api.Assertions.assertEquals;
-
-import java.io.FileReader;
-import java.io.IOException;
-
-import org.junit.jupiter.api.Test;
-
-class FileReaderUnitTest {
-
-    @Test
-    void whenReadingAFile_thenReadsCharByChar() {
-        StringBuilder result = new StringBuilder();
-
-        try (FileReader fr = new FileReader("src/test/resources/sampleText2.txt")) {
-            int i = fr.read();
-
-            while(i != -1) {
-                result.append((char)i);
-
-                i = fr.read();
-            }
-        } catch (IOException e) {
-            e.printStackTrace();
-        }
-
-        assertEquals("qwerty", result.toString());
-    }
-}
+package com.baeldung.bufferedreadervsfilereader;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.io.FileReader;
+import java.io.IOException;
+
+import org.junit.jupiter.api.Test;
+
+class FileReaderUnitTest {
+
+    @Test
+    void whenReadingAFile_thenReadsCharByChar() {
+        StringBuilder result = new StringBuilder();
+
+        try (FileReader fr = new FileReader("src/test/resources/sampleText2.txt")) {
+            int i = fr.read();
+
+            while(i != -1) {
+                result.append((char)i);
+
+                i = fr.read();
+            }
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+
+        assertEquals("qwerty", result.toString());
+    }
+}
@@ -1,47 +1,49 @@
-package com.baeldung.multinput;
-    import java.io.ByteArrayInputStream;
-    import java.io.InputStream;
-    import java.util.InputMismatchException;
-    import org.junit.jupiter.api.Assertions;
-    import org.testng.annotations.Test;
-import com.baeldung.multinput.MultiInputs;
-public class TestMultipleInputsUnitTest {
-    @Test
-    public void givenMultipleInputs_whenUsingSpaceDelimiter_thenExpectPrintingOutputs() {
-        String input = "10 20\n";
-        InputStream in = new ByteArrayInputStream(input.getBytes());
-        System.setIn(in);
-        MultiInputs mi = new MultiInputs();
-        mi.UsingSpaceDelimiter();
-        // You can add assertions here to verify the behavior of the method
-    }
-
-    @Test
-    public void givenMultipleInputs_whenUsingREDelimiter_thenExpectPrintingOutputs() {
-        String input = "30, 40\n";
-        InputStream in = new ByteArrayInputStream(input.getBytes());
-        System.setIn(in);
-        MultiInputs mi = new MultiInputs();
-        mi.UsingREDelimiter();
-        // You can add assertions here to verify the behavior of the method
-    }
-
-    @Test
-    public void givenMultipleInputs_whenUsingCustomDelimiter_thenExpectPrintingOutputs() {
-        String input = "50; 60\n";
-        InputStream in = new ByteArrayInputStream(input.getBytes());
-        System.setIn(in);
-        MultiInputs mi = new MultiInputs();
-        mi.UsingCustomDelimiter();
-        // You can add assertions here to verify the behavior of the method
-    }
-
-    @Test
-    public void givenInvalidInput_whenUsingSpaceDelimiter_thenExpectInputMismatchException() {
-        String input = "abc\n";
-        InputStream in = new ByteArrayInputStream(input.getBytes());
-        System.setIn(in);
-        MultiInputs mi = new MultiInputs();
-        Assertions.assertThrows(InputMismatchException.class, mi::UsingSpaceDelimiter);
-    }
-}
+package com.baeldung.multinput;
+
+import java.io.ByteArrayInputStream;
+import java.io.InputStream;
+import java.util.InputMismatchException;
+
+import org.junit.jupiter.api.Assertions;
+import org.testng.annotations.Test;
+
+public class TestMultipleInputsUnitTest {
+    @Test
+    public void givenMultipleInputs_whenUsingSpaceDelimiter_thenExpectPrintingOutputs() {
+        String input = "10 20\n";
+        InputStream in = new ByteArrayInputStream(input.getBytes());
+        System.setIn(in);
+        MultiInputs mi = new MultiInputs();
+        mi.UsingSpaceDelimiter();
+        // You can add assertions here to verify the behavior of the method
+    }
+
+    @Test
+    public void givenMultipleInputs_whenUsingREDelimiter_thenExpectPrintingOutputs() {
+        String input = "30, 40\n";
+        InputStream in = new ByteArrayInputStream(input.getBytes());
+        System.setIn(in);
+        MultiInputs mi = new MultiInputs();
+        mi.UsingREDelimiter();
+        // You can add assertions here to verify the behavior of the method
+    }
+
+    @Test
+    public void givenMultipleInputs_whenUsingCustomDelimiter_thenExpectPrintingOutputs() {
+        String input = "50; 60\n";
+        InputStream in = new ByteArrayInputStream(input.getBytes());
+        System.setIn(in);
+        MultiInputs mi = new MultiInputs();
+        mi.UsingCustomDelimiter();
+        // You can add assertions here to verify the behavior of the method
+    }
+
+    @Test
+    public void givenInvalidInput_whenUsingSpaceDelimiter_thenExpectInputMismatchException() {
+        String input = "abc\n";
+        InputStream in = new ByteArrayInputStream(input.getBytes());
+        System.setIn(in);
+        MultiInputs mi = new MultiInputs();
+        Assertions.assertThrows(InputMismatchException.class, mi::UsingSpaceDelimiter);
+    }
+}
@@ -4,7 +4,7 @@ This module contains articles about JAR files

 ### Relevant Articles: 

- [How to Create an Executable JAR with Maven](http://www.baeldung.com/executable-jar-with-maven)
+- [How to Create an Executable JAR with Maven](https://www.baeldung.com/executable-jar-with-maven)
 - [Importance of Main Manifest Attribute in a Self-Executing JAR](http://www.baeldung.com/java-jar-executable-manifest-main-class)
 - [Guide to Creating and Running a Jar File in Java](https://www.baeldung.com/java-create-jar)
 - [Get Names of Classes Inside a JAR File](https://www.baeldung.com/jar-file-get-class-names)
@@ -0,0 +1,7 @@
+## Core Java Lang (Part 6)
+
+This module contains articles about core features in the Java language
+
+### Relevant Articles:
+
+- [Convert One Enum to Another Enum in Java](https://www.baeldung.com/java-convert-enums)
@@ -0,0 +1,52 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xmlns="http://maven.apache.org/POM/4.0.0"
+         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.core-java-modules</groupId>
+        <artifactId>core-java-modules</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+    </parent>
+
+    <artifactId>core-java-lang-6</artifactId>
+
+    <dependencies>
+        <!-- https://mvnrepository.com/artifact/org.mapstruct/mapstruct -->
+        <dependency>
+            <groupId>org.mapstruct</groupId>
+            <artifactId>mapstruct</artifactId>
+            <version>${mapstruct.version}</version>
+        </dependency>
+
+    </dependencies>
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>3.5.1</version>
+                <configuration>
+                    <source>17</source>
+                    <target>17</target>
+                    <annotationProcessorPaths>
+                        <!-- https://mvnrepository.com/artifact/org.mapstruct/mapstruct-processor -->
+                        <path>
+                            <groupId>org.mapstruct</groupId>
+                            <artifactId>mapstruct-processor</artifactId>
+                            <version>${mapstruct.version}</version>
+                        </path>
+                    </annotationProcessorPaths>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+    <properties>
+        <maven.compiler.source>17</maven.compiler.source>
+        <maven.compiler.target>17</maven.compiler.target>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <mapstruct.version>1.5.5.Final</mapstruct.version>
+    </properties>
+
+</project>
@@ -0,0 +1,26 @@
+package com.baeldung.enums.mapping;
+
+import org.mapstruct.Mapper;
+import org.mapstruct.MappingConstants;
+import org.mapstruct.ValueMapping;
+
+import com.baeldung.enums.mapping.order.CmsOrderStatus;
+import com.baeldung.enums.mapping.order.OrderStatus;
+import com.baeldung.enums.mapping.user.ExternalUserStatus;
+import com.baeldung.enums.mapping.user.UserStatus;
+
+@Mapper
+public interface EnumMapper {
+
+    CmsOrderStatus map(OrderStatus orderStatus);
+
+    @ValueMapping(source = "PENDING", target = "INACTIVE")
+    @ValueMapping(source = "BLOCKED", target = "INACTIVE")
+    @ValueMapping(source = "INACTIVATED_BY_SYSTEM", target = "INACTIVE")
+    @ValueMapping(source = "DELETED", target = "INACTIVE")
+    ExternalUserStatus map(UserStatus userStatus);
+
+    @ValueMapping(source = MappingConstants.ANY_REMAINING, target = "INACTIVE")
+    ExternalUserStatus mapDefault(UserStatus userStatus);
+
+}
@@ -0,0 +1,5 @@
+package com.baeldung.enums.mapping.order;
+
+public enum CmsOrderStatus {
+    PENDING, APPROVED, PACKED, DELIVERED
+}
@@ -0,0 +1,13 @@
+package com.baeldung.enums.mapping.order;
+
+public enum OrderStatus {
+    PENDING, APPROVED, PACKED, DELIVERED;
+
+    public CmsOrderStatus toCmsOrderStatus() {
+        return CmsOrderStatus.valueOf(this.name());
+    }
+
+    public CmsOrderStatus toCmsOrderStatusOrdinal() {
+        return CmsOrderStatus.values()[this.ordinal()];
+    }
+}
@@ -0,0 +1,5 @@
+package com.baeldung.enums.mapping.user;
+
+public enum ExternalUserStatus {
+    ACTIVE, INACTIVE
+}
@@ -0,0 +1,26 @@
+package com.baeldung.enums.mapping.user;
+
+public enum UserStatus {
+    PENDING, ACTIVE, BLOCKED, INACTIVATED_BY_SYSTEM, DELETED;
+
+    public ExternalUserStatus toExternalUserStatusViaSwitchStatement() {
+        return switch (this) {
+            case PENDING, BLOCKED, INACTIVATED_BY_SYSTEM, DELETED -> ExternalUserStatus.INACTIVE;
+            case ACTIVE -> ExternalUserStatus.ACTIVE;
+        };
+    }
+
+    public ExternalUserStatus toExternalUserStatusViaRegularSwitch() {
+        switch (this) {
+        case PENDING:
+        case BLOCKED:
+        case INACTIVATED_BY_SYSTEM:
+        case DELETED:
+            return ExternalUserStatus.INACTIVE;
+        case ACTIVE:
+            return ExternalUserStatus.ACTIVE;
+        }
+        return null;
+    }
+
+}
@@ -0,0 +1,20 @@
+package com.baeldung.enums.mapping.user;
+
+import java.util.EnumMap;
+
+public class UserStatusMapper {
+    public static EnumMap<UserStatus, ExternalUserStatus> statusesMap;
+
+    static {
+        statusesMap = new EnumMap<>(UserStatus.class);
+        statusesMap.put(UserStatus.PENDING, ExternalUserStatus.INACTIVE);
+        statusesMap.put(UserStatus.BLOCKED, ExternalUserStatus.INACTIVE);
+        statusesMap.put(UserStatus.DELETED, ExternalUserStatus.INACTIVE);
+        statusesMap.put(UserStatus.INACTIVATED_BY_SYSTEM, ExternalUserStatus.INACTIVE);
+        statusesMap.put(UserStatus.ACTIVE, ExternalUserStatus.ACTIVE);
+    }
+
+    public static ExternalUserStatus toExternalUserStatus(UserStatus userStatus) {
+        return statusesMap.get(userStatus);
+    }
+}
@@ -0,0 +1,19 @@
+package com.baeldung.enums.mapping.user;
+
+public enum UserStatusWithFieldVariable {
+    PENDING(ExternalUserStatus.INACTIVE),
+    ACTIVE(ExternalUserStatus.ACTIVE),
+    BLOCKED(ExternalUserStatus.INACTIVE),
+    INACTIVATED_BY_SYSTEM(ExternalUserStatus.INACTIVE),
+    DELETED(ExternalUserStatus.INACTIVE);
+
+    private final ExternalUserStatus externalUserStatus;
+
+    UserStatusWithFieldVariable(ExternalUserStatus externalUserStatus) {
+        this.externalUserStatus = externalUserStatus;
+    }
+
+    public ExternalUserStatus toExternalUserStatus() {
+        return externalUserStatus;
+    }
+}
@@ -0,0 +1,120 @@
+package com.baeldung.enums.mapping;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+import com.baeldung.enums.mapping.order.CmsOrderStatus;
+import com.baeldung.enums.mapping.order.OrderStatus;
+import com.baeldung.enums.mapping.user.ExternalUserStatus;
+import com.baeldung.enums.mapping.user.UserStatus;
+import com.baeldung.enums.mapping.user.UserStatusMapper;
+import com.baeldung.enums.mapping.user.UserStatusWithFieldVariable;
+
+public class EnumConversionUnitTest {
+
+    @Test
+    void whenUsingSwitchStatement_thenEnumConverted() {
+        UserStatus userStatusDeleted = UserStatus.DELETED;
+        UserStatus userStatusPending = UserStatus.PENDING;
+        UserStatus userStatusActive = UserStatus.ACTIVE;
+
+        assertEquals(ExternalUserStatus.INACTIVE, userStatusDeleted.toExternalUserStatusViaSwitchStatement());
+        assertEquals(ExternalUserStatus.INACTIVE, userStatusPending.toExternalUserStatusViaSwitchStatement());
+        assertEquals(ExternalUserStatus.ACTIVE, userStatusActive.toExternalUserStatusViaSwitchStatement());
+    }
+
+    @Test
+    void whenUsingSwitch_thenEnumConverted() {
+        UserStatus userStatusDeleted = UserStatus.DELETED;
+        UserStatus userStatusPending = UserStatus.PENDING;
+        UserStatus userStatusActive = UserStatus.ACTIVE;
+
+        assertEquals(ExternalUserStatus.INACTIVE, userStatusDeleted.toExternalUserStatusViaRegularSwitch());
+        assertEquals(ExternalUserStatus.INACTIVE, userStatusPending.toExternalUserStatusViaRegularSwitch());
+        assertEquals(ExternalUserStatus.ACTIVE, userStatusActive.toExternalUserStatusViaRegularSwitch());
+    }
+
+    @Test
+    void whenUsingFieldVariable_thenEnumConverted() {
+        UserStatusWithFieldVariable userStatusDeleted = UserStatusWithFieldVariable.DELETED;
+        UserStatusWithFieldVariable userStatusPending = UserStatusWithFieldVariable.PENDING;
+        UserStatusWithFieldVariable userStatusActive = UserStatusWithFieldVariable.ACTIVE;
+
+        assertEquals(ExternalUserStatus.INACTIVE, userStatusDeleted.toExternalUserStatus());
+        assertEquals(ExternalUserStatus.INACTIVE, userStatusPending.toExternalUserStatus());
+        assertEquals(ExternalUserStatus.ACTIVE, userStatusActive.toExternalUserStatus());
+    }
+
+    @Test
+    void whenUsingEnumMap_thenEnumConverted() {
+        UserStatus userStatusDeleted = UserStatus.DELETED;
+        UserStatus userStatusPending = UserStatus.PENDING;
+        UserStatus userStatusActive = UserStatus.ACTIVE;
+
+        assertEquals(ExternalUserStatus.INACTIVE, UserStatusMapper.toExternalUserStatus(userStatusDeleted));
+        assertEquals(ExternalUserStatus.INACTIVE, UserStatusMapper.toExternalUserStatus(userStatusPending));
+        assertEquals(ExternalUserStatus.ACTIVE, UserStatusMapper.toExternalUserStatus(userStatusActive));
+    }
+
+    @Test
+    void whenUsingOrdinalApproach_thenEnumConverted() {
+        OrderStatus orderStatusApproved = OrderStatus.APPROVED;
+        OrderStatus orderStatusDelivered = OrderStatus.DELIVERED;
+        OrderStatus orderStatusPending = OrderStatus.PENDING;
+
+        assertEquals(CmsOrderStatus.APPROVED, orderStatusApproved.toCmsOrderStatusOrdinal());
+        assertEquals(CmsOrderStatus.DELIVERED, orderStatusDelivered.toCmsOrderStatusOrdinal());
+        assertEquals(CmsOrderStatus.PENDING, orderStatusPending.toCmsOrderStatusOrdinal());
+    }
+
+    @Test
+    void whenUsingEnumName_thenEnumConverted() {
+        OrderStatus orderStatusApproved = OrderStatus.APPROVED;
+        OrderStatus orderStatusDelivered = OrderStatus.DELIVERED;
+        OrderStatus orderStatusPending = OrderStatus.PENDING;
+
+        assertEquals(CmsOrderStatus.APPROVED, orderStatusApproved.toCmsOrderStatus());
+        assertEquals(CmsOrderStatus.DELIVERED, orderStatusDelivered.toCmsOrderStatus());
+        assertEquals(CmsOrderStatus.PENDING, orderStatusPending.toCmsOrderStatus());
+    }
+
+    @Test
+    void whenUsingDefaultMapstruct_thenEnumConverted() {
+        UserStatus userStatusDeleted = UserStatus.DELETED;
+        UserStatus userStatusPending = UserStatus.PENDING;
+        UserStatus userStatusActive = UserStatus.ACTIVE;
+
+        EnumMapper enumMapper = new EnumMapperImpl();
+
+        assertEquals(ExternalUserStatus.INACTIVE, enumMapper.map(userStatusDeleted));
+        assertEquals(ExternalUserStatus.INACTIVE, enumMapper.map(userStatusPending));
+        assertEquals(ExternalUserStatus.ACTIVE, enumMapper.map(userStatusActive));
+    }
+
+    @Test
+    void whenUsingConfiguredMapstruct_thenEnumConverted() {
+        OrderStatus orderStatusApproved = OrderStatus.APPROVED;
+        OrderStatus orderStatusDelivered = OrderStatus.DELIVERED;
+        OrderStatus orderStatusPending = OrderStatus.PENDING;
+
+        EnumMapper enumMapper = new EnumMapperImpl();
+
+        assertEquals(CmsOrderStatus.APPROVED, enumMapper.map(orderStatusApproved));
+        assertEquals(CmsOrderStatus.DELIVERED, enumMapper.map(orderStatusDelivered));
+        assertEquals(CmsOrderStatus.PENDING, enumMapper.map(orderStatusPending));
+    }
+
+    @Test
+    void whenUsingConfiguredWithRemainingMapstruct_thenEnumConverted() {
+        UserStatus userStatusDeleted = UserStatus.DELETED;
+        UserStatus userStatusPending = UserStatus.PENDING;
+        UserStatus userStatusActive = UserStatus.ACTIVE;
+
+        EnumMapper enumMapper = new EnumMapperImpl();
+
+        assertEquals(ExternalUserStatus.INACTIVE, enumMapper.mapDefault(userStatusDeleted));
+        assertEquals(ExternalUserStatus.INACTIVE, enumMapper.mapDefault(userStatusPending));
+        assertEquals(ExternalUserStatus.ACTIVE, enumMapper.mapDefault(userStatusActive));
+    }
+}
@@ -9,3 +9,4 @@ This module contains articles about Object-oriented programming (OOP) patterns i
 - [How to Make a Deep Copy of an Object in Java](https://www.baeldung.com/java-deep-copy)
 - [Using an Interface vs. Abstract Class in Java](https://www.baeldung.com/java-interface-vs-abstract-class)
 - [Should We Create an Interface for Only One Implementation?](https://www.baeldung.com/java-interface-single-implementation)
+- [How to Deep Copy an ArrayList in Java](https://www.baeldung.com/java-arraylist-deep-copy)
@@ -65,6 +65,7 @@ public class NioVsNio2UnitTest {
    public void listFilesUsingWalk() throws Exception {
        Path path = Paths.get("src/test");
        Stream<Path> walk = Files.walk(path);
-        walk.forEach(System.out::println);
+
+        assertThat(walk.findAny()).isPresent();
    }
 }
@@ -1,4 +1,6 @@
 ### Relevant Articles:
 - [Java Program to Estimate 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)
+- [Integer.class Vs. Integer.TYPE Vs. int.class](https://www.baeldung.com/java-integer-class-vs-type-vs-int)
+- [Does Java Read Integers in Little Endian or Big Endian?](https://www.baeldung.com/java-integers-little-big-endian)
 - More articles: [[<-- prev]](../core-java-numbers-5)
@@ -0,0 +1,17 @@
+package com.baeldung.endianness;
+
+import java.nio.ByteBuffer;
+
+public class Endianness {
+
+    public static void main(String[] args) {
+        int value = 123456789;
+        byte[] bytes = ByteBuffer.allocate(4)
+          .putInt(value)
+          .array();
+
+        for (byte b : bytes) {
+            System.out.format("0x%x ", b);
+        }
+    }
+}
@@ -0,0 +1,45 @@
+package com.baeldung.integerclassintegertypeintclass;
+
+import org.junit.Test;
+import org.junit.jupiter.api.Assertions;
+
+public class IntegerClassIntegerTYPEIntClassUnitTest {
+
+    @Test
+    public void givenIntegerClass_whenGetName_thenVerifyClassName() {
+        Class<Integer> integerClass = Integer.class;
+        Assertions.assertEquals("java.lang.Integer", integerClass.getName());
+        Assertions.assertEquals(Number.class, integerClass.getSuperclass());
+        Assertions.assertFalse(integerClass.isPrimitive());
+    }
+
+    public int sum(int a, int b) {
+        return a + b;
+    }
+
+    public int sum(Integer a, Integer b) {
+        return a + b;
+    }
+
+    public int sum(int a, Integer b) {
+        return a + b;
+    }
+
+    @Test
+    public void givenIntAndInteger_whenAddingValues_thenVerifySum() {
+        int primitiveValue = 10;
+        Integer wrapperValue = Integer.valueOf(primitiveValue);
+        Assertions.assertEquals(20, sum(primitiveValue, primitiveValue));
+        Assertions.assertEquals(20, sum(primitiveValue, wrapperValue));
+        Assertions.assertEquals(20, sum(wrapperValue, wrapperValue));
+        Assertions.assertEquals(Integer.TYPE.getName(), int.class.getName());
+    }
+
+    @Test
+    public void givenIntValue_whenUsingIntClass_thenVerifyIntClassProperties() {
+        Class<?> intClass = int.class;
+        Assertions.assertEquals("int", intClass.getName());
+        Assertions.assertTrue(intClass.isPrimitive());
+        Assertions.assertEquals(int.class, intClass);
+    }
+}
@@ -1,2 +1,3 @@
 ### Relevant Articles:
 - [Convert a Number to a Letter in Java](https://www.baeldung.com/java-convert-number-to-letter)
+- [Convert Long to BigDecimal in Java](https://www.baeldung.com/java-convert-long-bigdecimal)
@@ -0,0 +1,15 @@
+## Core Java Scanner
+
+This module contains articles about the Scanner.
+
+### Relevant Articles:
+- [Java Scanner](https://www.baeldung.com/java-scanner)
+- [Scanner nextLine() Method](https://www.baeldung.com/java-scanner-nextline)
+- [Java Scanner hasNext() vs. hasNextLine()](https://www.baeldung.com/java-scanner-hasnext-vs-hasnextline)
+- [Read Date in Java Using Scanner](https://www.baeldung.com/java-scanner-read-date)
+- [Java Scanner Taking a Character Input](https://www.baeldung.com/java-scanner-character-input)
+- [Integer.parseInt(scanner.nextLine()) and scanner.nextInt() in Java](https://www.baeldung.com/java-scanner-integer)
+- [Storing Java Scanner Input in an Array](https://www.baeldung.com/java-store-scanner-input-in-array)
+- [How to Take Input as String With Spaces in Java Using Scanner?](https://www.baeldung.com/java-scanner-input-with-spaces)
+- [What’s the difference between Scanner next() and nextLine() methods?](https://www.baeldung.com/java-scanner-next-vs-nextline)
+- [Handle NoSuchElementException When Reading a File Through Scanner](https://www.baeldung.com/java-scanner-nosuchelementexception-reading-file)
@@ -0,0 +1,34 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xmlns="http://maven.apache.org/POM/4.0.0"
+         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-scanner</artifactId>
+    <name>core-java-scanner</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>log4j</groupId>
+            <artifactId>log4j</artifactId>
+            <version>${log4j.version}</version>
+        </dependency>
+        <dependency> <!-- needed to bridge to slf4j for projects that use the log4j APIs directly -->
+            <groupId>org.slf4j</groupId>
+            <artifactId>log4j-over-slf4j</artifactId>
+            <version>${org.slf4j.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <version>${lombok.version}</version>
+            <scope>provided</scope>
+        </dependency>
+    </dependencies>
+</project>
@@ -1,29 +1,29 @@
-package com.baeldung.scanner;
-
-import java.text.DateFormat;
-import java.text.ParseException;
-import java.text.SimpleDateFormat;
-import java.time.LocalDate;
-import java.time.format.DateTimeFormatter;
-import java.util.Date;
-import java.util.Scanner;
-
-public class DateScanner {
-
-    LocalDate scanToLocalDate(String input) {
-        try (Scanner scanner = new Scanner(input)) {
-            String dateString = scanner.next();
-            DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd");
-            return LocalDate.parse(dateString, formatter);
-        }
-    }
-
-    Date scanToDate(String input) throws ParseException {
-        try (Scanner scanner = new Scanner(input)) {
-            String dateString = scanner.next();
-            DateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");
-            return formatter.parse(dateString);
-        }
-    }
-
-}
+package com.baeldung.scanner;
+
+import java.text.DateFormat;
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+import java.time.LocalDate;
+import java.time.format.DateTimeFormatter;
+import java.util.Date;
+import java.util.Scanner;
+
+public class DateScanner {
+
+    LocalDate scanToLocalDate(String input) {
+        try (Scanner scanner = new Scanner(input)) {
+            String dateString = scanner.next();
+            DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd");
+            return LocalDate.parse(dateString, formatter);
+        }
+    }
+
+    Date scanToDate(String input) throws ParseException {
+        try (Scanner scanner = new Scanner(input)) {
+            String dateString = scanner.next();
+            DateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");
+            return formatter.parse(dateString);
+        }
+    }
+
+}
@@ -1,26 +1,26 @@
-package com.baeldung.scanner;
-
-import static org.junit.jupiter.api.Assertions.assertEquals;
-
-import java.text.ParseException;
-import java.text.SimpleDateFormat;
-import java.time.LocalDate;
-import java.time.format.DateTimeFormatter;
-
-import org.junit.jupiter.api.Test;
-
-class DateScannerUnitTest {
-
-    @Test
-    void whenScanToLocalDate_ThenCorrectLocalDate() {
-        String dateString = "2018-09-09";
-        assertEquals(LocalDate.parse(dateString, DateTimeFormatter.ofPattern("yyyy-MM-dd")), new DateScanner().scanToLocalDate(dateString));
-    }
-
-    @Test
-    void whenScanToDate_ThenCorrectDate() throws ParseException {
-        String dateString = "2018-09-09";
-        assertEquals(new SimpleDateFormat("yyyy-MM-dd").parse(dateString), new DateScanner().scanToDate(dateString));
-    }
-
-}
+package com.baeldung.scanner;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+import java.time.LocalDate;
+import java.time.format.DateTimeFormatter;
+
+import org.junit.jupiter.api.Test;
+
+class DateScannerUnitTest {
+
+    @Test
+    void whenScanToLocalDate_ThenCorrectLocalDate() {
+        String dateString = "2018-09-09";
+        assertEquals(LocalDate.parse(dateString, DateTimeFormatter.ofPattern("yyyy-MM-dd")), new DateScanner().scanToLocalDate(dateString));
+    }
+
+    @Test
+    void whenScanToDate_ThenCorrectDate() throws ParseException {
+        String dateString = "2018-09-09";
+        assertEquals(new SimpleDateFormat("yyyy-MM-dd").parse(dateString), new DateScanner().scanToDate(dateString));
+    }
+
+}
@@ -1,85 +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);
-    }
-
+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);
+    }
+
 }
@@ -1,38 +1,38 @@
-package com.baeldung.scanner;
-
-import static org.junit.jupiter.api.Assertions.assertEquals;
-
-import java.util.Scanner;
-
-import org.junit.jupiter.api.Test;
-
-public class ScanACharacterUnitTest {
-
-    // given - input scanner source, no need to scan from console
-    String input = new StringBuilder().append("abc\n")
-      .append("mno\n")
-      .append("xyz\n")
-      .toString();
-
-    @Test
-    public void givenInputSource_whenScanCharUsingNext_thenOneCharIsRead() {
-        Scanner sc = new Scanner(input);
-        char c = sc.next().charAt(0);
-        assertEquals('a', c);
-    }
-
-    @Test
-    public void givenInputSource_whenScanCharUsingFindInLine_thenOneCharIsRead() {
-        Scanner sc = new Scanner(input);
-        char c = sc.findInLine(".").charAt(0);
-        assertEquals('a', c);
-    }
-
-    @Test
-    public void givenInputSource_whenScanCharUsingUseDelimiter_thenOneCharIsRead() {
-        Scanner sc = new Scanner(input);
-        char c = sc.useDelimiter("").next().charAt(0);
-        assertEquals('a', c);
-    }
-
-}
+package com.baeldung.scanner;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.util.Scanner;
+
+import org.junit.jupiter.api.Test;
+
+public class ScanACharacterUnitTest {
+
+    // given - input scanner source, no need to scan from console
+    String input = new StringBuilder().append("abc\n")
+      .append("mno\n")
+      .append("xyz\n")
+      .toString();
+
+    @Test
+    public void givenInputSource_whenScanCharUsingNext_thenOneCharIsRead() {
+        Scanner sc = new Scanner(input);
+        char c = sc.next().charAt(0);
+        assertEquals('a', c);
+    }
+
+    @Test
+    public void givenInputSource_whenScanCharUsingFindInLine_thenOneCharIsRead() {
+        Scanner sc = new Scanner(input);
+        char c = sc.findInLine(".").charAt(0);
+        assertEquals('a', c);
+    }
+
+    @Test
+    public void givenInputSource_whenScanCharUsingUseDelimiter_thenOneCharIsRead() {
+        Scanner sc = new Scanner(input);
+        char c = sc.useDelimiter("").next().charAt(0);
+        assertEquals('a', c);
+    }
+
+}
@@ -1,11 +1,11 @@
 package com.baeldung.scannernextline;

-import org.junit.Test;
+import static org.junit.Assert.assertEquals;

 import java.util.NoSuchElementException;
 import java.util.Scanner;

-import static org.junit.Assert.assertEquals;
+import org.junit.Test;

 public class ScannerNextLineUnitTest {

@@ -1,57 +1,59 @@
 package com.baeldung.streams;

 import com.google.common.collect.ImmutableList;
-import org.junit.Test;

 import java.util.*;
 import java.util.stream.IntStream;

 import static java.util.stream.Collectors.*;
+import static org.junit.jupiter.api.Assertions.assertEquals;

-public class StreamToImmutableUnitTest {
+import org.junit.jupiter.api.Test;
+
+class StreamToImmutableUnitTest {

    @Test
-    public void whenUsingCollectingToImmutableSet_thenSuccess() {
+    void whenUsingCollectingToImmutableSet_thenSuccess() {
        List<String> givenList = Arrays.asList("a", "b", "c");
        List<String> result = givenList.stream()
            .collect(collectingAndThen(toSet(), ImmutableList::copyOf));

-        System.out.println(result.getClass());
+        assertEquals("com.google.common.collect.RegularImmutableList", result.getClass().getName());
    }

    @Test
-    public void whenUsingCollectingToUnmodifiableList_thenSuccess() {
+    void whenUsingCollectingToUnmodifiableList_thenSuccess() {
        List<String> givenList = new ArrayList<>(Arrays.asList("a", "b", "c"));
        List<String> result = givenList.stream()
            .collect(collectingAndThen(toList(), Collections::unmodifiableList));

-        System.out.println(result.getClass());
+        assertEquals("java.util.Collections$UnmodifiableRandomAccessList", result.getClass().getName());
    }

    @Test
-    public void whenCollectToImmutableList_thenSuccess() {
+    void whenCollectToImmutableList_thenSuccess() {
        List<Integer> list = IntStream.range(0, 9)
            .boxed()
            .collect(ImmutableList.toImmutableList());

-        System.out.println(list.getClass());
+        assertEquals("com.google.common.collect.RegularImmutableList", list.getClass().getName());
    }

    @Test
-    public void whenCollectToMyImmutableListCollector_thenSuccess() {
+    void whenCollectToMyImmutableListCollector_thenSuccess() {
        List<String> givenList = Arrays.asList("a", "b", "c", "d");
        List<String> result = givenList.stream()
            .collect(MyImmutableListCollector.toImmutableList());

-        System.out.println(result.getClass());
+        assertEquals("java.util.Collections$UnmodifiableRandomAccessList", result.getClass().getName());
    }

    @Test
-    public void whenPassingSupplier_thenSuccess() {
+    void whenPassingSupplier_thenSuccess() {
        List<String> givenList = Arrays.asList("a", "b", "c", "d");
        List<String> result = givenList.stream()
            .collect(MyImmutableListCollector.toImmutableList(LinkedList::new));

-        System.out.println(result.getClass());
+        assertEquals("java.util.Collections$UnmodifiableList", result.getClass().getName());
    }
 }
@@ -5,4 +5,6 @@
 - [Check if a String Is All Uppercase or Lowercase in Java](https://www.baeldung.com/java-check-string-uppercase-lowercase)
 - [Java – Generate Random String](https://www.baeldung.com/java-random-string)
 - [Fixing “constant string too long” Build Error](https://www.baeldung.com/java-constant-string-too-long-error)
- [Compact Strings in Java 9](https://www.baeldung.com/java-9-compact-string)
+- [Compact Strings in Java 9](https://www.baeldung.com/java-9-compact-string)
+- [Split a String Into Digit and Non-Digit Substrings](https://www.baeldung.com/java-split-string-digits-letters)
+- [Check if a String Contains Non-Alphanumeric Characters](https://www.baeldung.com/java-string-test-special-characters)
@@ -0,0 +1,60 @@
+package com.baeldung.uniquecharcheck;
+
+import org.apache.commons.lang3.StringUtils;
+
+import java.util.*;
+import java.util.stream.Collectors;
+
+public class UniqueCharChecker {
+
+    public static boolean checkV1(String str) {
+        char[] chars = str.toUpperCase().toCharArray();
+        for (int i = 0; i < chars.length; i++) {
+            for (int j = i + 1; j < chars.length; j++) {
+                if(chars[i] == chars[j]) {
+                    return false;
+                }
+            }
+        }
+        return true;
+    }
+
+    public static boolean checkV2(String str) {
+        char[] chars = str.toUpperCase().toCharArray();
+        Arrays.sort(chars);
+        for (int i = 0; i < chars.length - 1; i++) {
+            if(chars[i] == chars[i+1]) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    public static boolean checkV3(String str) {
+        char[] chars = str.toUpperCase().toCharArray();
+        Set <Character> set = new HashSet <>();
+        for (char c: chars) {
+            set.add(c);
+        }
+        return set.size() == str.length();
+    }
+
+    public static boolean checkV4(String str) {
+        boolean isUnique = str.toUpperCase().chars()
+                .mapToObj(c -> (char)c)
+                .collect(Collectors.toSet())
+                .size() == str.length();
+        return isUnique;
+    }
+
+    public static boolean checkV5(String str) {
+        for (int i = 0; i < str.length(); i++) {
+            String curChar = String.valueOf(str.charAt(i));
+            String remainingStr = str.substring(i+1);
+            if(StringUtils.containsIgnoreCase(remainingStr, curChar)) {
+                return false;
+            }
+        }
+        return true;
+    }
+}
@@ -0,0 +1,92 @@
+package com.baeldung.uniquecharcheck;
+
+import org.junit.Test;
+
+import java.util.Arrays;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+
+public class UniqueCharCheckerUnitTest {
+
+    @Test
+    public void givenMethCheck1_whenUnique_returnTrue() {
+        String[] sampleStrings = new String[]{"Justfewdi123", "$%&Hibusc", "Hibusc%$#", "მშვნიერ"};
+        final String MSG = "Duplicate found";
+        Arrays.stream(sampleStrings)
+                .forEach(sampleStr -> assertTrue(MSG + " in " + sampleStr, UniqueCharChecker.checkV1(sampleStr)));
+    }
+    @Test
+    public void givenMethCheck2_whenUnique_returnTrue() {
+        String[] sampleStrings = new String[]{"Justfewdi123", "$%&Hibusc", "Hibusc%$#", "მშვნიერ"};
+        final String MSG = "Duplicate found";
+        Arrays.stream(sampleStrings)
+                .forEach(sampleStr -> assertTrue(MSG + " in " + sampleStr, UniqueCharChecker.checkV2(sampleStr)));
+    }
+
+    @Test
+    public void givenMethCheck3_whenUnique_returnTrue() {
+        String[] sampleStrings = new String[]{"Justfewdi123", "$%&Hibusc", "Hibusc%$#", "მშვნიერ"};
+        final String MSG = "Duplicate found";
+        Arrays.stream(sampleStrings)
+                .forEach(sampleStr -> assertTrue(MSG + " in " + sampleStr, UniqueCharChecker.checkV3(sampleStr)));
+    }
+
+    @Test
+    public void givenMethCheck4_whenUnique_returnTrue() {
+        String[] sampleStrings = new String[]{"Justfewdi123", "$%&Hibusc", "Hibusc%$#", "მშვნიერ"};
+        final String MSG = "Duplicate found";
+        Arrays.stream(sampleStrings)
+                .forEach(sampleStr -> assertTrue(MSG + " in " + sampleStr, UniqueCharChecker.checkV1(sampleStr)));
+    }
+    @Test
+    public void givenMethCheck5_whenUnique_returnTrue() {
+        String[] sampleStrings = new String[]{"Justfewdi123", "$%&Hibusc", "Hibusc%$#", "მშვნიერ"};
+        final String MSG = "Duplicate found";
+        Arrays.stream(sampleStrings)
+                .forEach(sampleStr -> assertTrue(MSG + " in " + sampleStr, UniqueCharChecker.checkV5(sampleStr)));
+    }
+
+    @Test
+    public void givenMethCheck1_whenNotUnique_returnFalse() {
+        String[] sampleStrings = new String[]{"Justfewdif123", "$%&Hibushc", "Hibusuc%$#", "Hi%busc%$#", "მშვენიერი"};
+        final String MSG = "Duplicate not found";
+        Arrays.stream(sampleStrings)
+                .forEach(sampleStr -> assertFalse(MSG + " in " + sampleStr, UniqueCharChecker.checkV1(sampleStr)));
+    }
+
+    @Test
+    public void givenMethCheck2_whenNotUnique_returnFalse() {
+        String[] sampleStrings = new String[]{"Justfewdif123", "$%&Hibushc", "Hibusuc%$#", "Hi%busc%$#", "მშვენიერი"};
+        final String MSG = "Duplicate not found";
+        Arrays.stream(sampleStrings)
+                .forEach(sampleStr -> assertFalse(MSG + " in " + sampleStr, UniqueCharChecker.checkV2(sampleStr)));
+
+    }
+
+    @Test
+    public void givenMethCheck3_whenNotUnique_returnFalse() {
+        String[] sampleStrings = new String[]{"Justfewdif123", "$%&Hibushc", "Hibusuc%$#", "Hi%busc%$#", "მშვენიერი"};
+        final String MSG = "Duplicate not found";
+        Arrays.stream(sampleStrings)
+                .forEach(sampleStr -> assertFalse(MSG + " in " + sampleStr, UniqueCharChecker.checkV3(sampleStr)));
+    }
+
+    @Test
+    public void givenMethCheck4_whenNotUnique_returnFalse() {
+        String[] sampleStrings = new String[]{"Justfewdif123", "$%&Hibushc", "Hibusuc%$#", "Hi%busc%$#", "მშვენიერი"};
+        final String MSG = "Duplicate not found";
+        Arrays.stream(sampleStrings)
+                .forEach(sampleStr -> assertFalse(MSG + " in " + sampleStr, UniqueCharChecker.checkV4(sampleStr)));
+    }
+
+@Test
+public void givenMethCheck5_whenNotUnique_returnFalse() {
+    String[] sampleStrings = new String[]{"Justfewdif123", "$%&Hibushc", "Hibusuc%$#", "Hi%busc%$#", "მშვენიერი"};
+    final String MSG = "Duplicate not found";
+    Arrays.stream(sampleStrings)
+            .forEach(sampleStr -> assertFalse(MSG + " in " + sampleStr, UniqueCharChecker.checkV5(sampleStr)));
+}
+
+}
@@ -81,7 +81,6 @@
        <module>core-java-io-4</module>
        <module>core-java-io-apis</module>
        <module>core-java-io-apis-2</module>
-        <module>core-java-io-apis-3</module>
        <module>core-java-io-conversions</module>
        <module>core-java-jar</module>
        <module>core-java-jndi</module>
@@ -93,6 +92,7 @@
        <module>core-java-lang-3</module>
        <module>core-java-lang-4</module>
        <module>core-java-lang-5</module>
+        <module>core-java-lang-6</module>
        <module>core-java-lang-math</module>
        <module>core-java-lang-math-2</module>
        <module>core-java-lang-oop-constructors</module>
@@ -124,6 +124,7 @@
        <module>core-java-properties</module>
        <module>core-java-reflection</module>
        <module>core-java-reflection-2</module>
+        <module>core-java-scanner</module>
        <module>core-java-security-2</module>
        <module>core-java-security-3</module>
        <module>core-java-security-algorithms</module>