Merge branch 'eugenp:master' into master

core-java-modules/core-java-14/pom.xml

@@ -14,6 +14,15 @@
         <version>1.0.0-SNAPSHOT</version>
     </parent>
 
+    <dependencies>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <version>1.18.24</version>
+            <scope>provided</scope>
+        </dependency>
+    </dependencies>
+
     <build>
         <plugins>
             <plugin>

core-java-modules/core-java-14/src/main/java/com/baeldung/java14/recordvslombok/ColorData.java

@@ -0,0 +1,18 @@
+package com.baeldung.java14.recordvslombok;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+
+@Data
+@AllArgsConstructor
+public class ColorData {
+
+    private int red;
+    private int green;
+    private int blue;
+
+    public String getHexString() {
+        return String.format("#%02X%02X%02X", red, green, blue);
+    }
+
+}

core-java-modules/core-java-14/src/main/java/com/baeldung/java14/recordvslombok/ColorRecord.java

@@ -0,0 +1,8 @@
+package com.baeldung.java14.recordvslombok;
+
+public record ColorRecord(int red, int green, int blue) {
+
+    public String getHexString() {
+        return String.format("#%02X%02X%02X", red, green, blue);
+    }
+}

core-java-modules/core-java-14/src/main/java/com/baeldung/java14/recordvslombok/ColorValueObject.java

@@ -0,0 +1,17 @@
+package com.baeldung.java14.recordvslombok;
+
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.Value;
+
+@Value
+@Getter(AccessLevel.NONE)
+public class ColorValueObject {
+    int red;
+    int green;
+    int blue;
+
+    public String getHexString() {
+        return String.format("#%02X%02X%02X", red, green, blue);
+    }
+}

core-java-modules/core-java-14/src/main/java/com/baeldung/java14/recordvslombok/MonochromeColor.java

@@ -0,0 +1,12 @@
+package com.baeldung.java14.recordvslombok;
+
+import lombok.Value;
+
+@Value
+public class MonochromeColor extends ColorData {
+
+    public MonochromeColor(int grayScale) {
+        super(grayScale, grayScale, grayScale);
+    }
+
+}

core-java-modules/core-java-14/src/main/java/com/baeldung/java14/recordvslombok/StudentBuilder.java

@@ -0,0 +1,17 @@
+package com.baeldung.java14.recordvslombok;
+
+import lombok.Builder;
+import lombok.Getter;
+
+@Getter
+@Builder
+public class StudentBuilder {
+    private String firstName;
+    private String lastName;
+    private Long studentId;
+    private String email;
+    private String phoneNumber;
+    private String address;
+    private String country;
+    private int age;
+}

core-java-modules/core-java-14/src/main/java/com/baeldung/java14/recordvslombok/StudentRecord.java

@@ -0,0 +1,4 @@
+package com.baeldung.java14.recordvslombok;
+
+public record StudentRecord(String firstName, String lastName, Long studentId, String email, String phoneNumber, String address, String country, int age) {
+}

core-java-modules/core-java-14/src/test/java/com/baeldung/java14/recordvslombok/RecordVsLombokUntTest.java

@@ -0,0 +1,43 @@
+package com.baeldung.java14.recordvslombok;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.junit.Test;
+
+public class RecordVsLombokUntTest {
+
+    @Test
+    public void givenAColorRecord_hexStringIsCorrect() {
+        var red = new ColorRecord(255, 0, 0);
+
+        assertThat(red.getHexString()).isEqualTo("#FF0000");
+    }
+
+    @Test
+    public void givenAColorValueObject_hexStringIsCorrect() {
+        var red = new ColorValueObject(255, 0, 0);
+
+        assertThat(red.getHexString()).isEqualTo("#FF0000");
+    }
+
+    @Test
+    public void givenRecordWithManyAttributes_firstNameShouldBeJohn() {
+        StudentRecord john = new StudentRecord("John", "Doe", null, "[email protected]", null, null, "England", 20);
+
+        assertThat(john.firstName()).isEqualTo("John");
+    }
+
+    @Test
+    public void givenBuilderWithManyAttributes_firstNameShouldBeJohn() {
+        StudentBuilder john = StudentBuilder.builder()
+            .firstName("John")
+            .lastName("Doe")
+            .email("[email protected]")
+            .country("England")
+            .age(20)
+            .build();
+
+        assertThat(john.getFirstName()).isEqualTo("John");
+    }
+
+}

core-java-modules/core-java-15/README.md

@@ -5,4 +5,3 @@ This module contains articles about Java 15.
 ### Relevant articles
 
 - [Hidden Classes in Java 15](https://www.baeldung.com/java-hidden-classes)
-- [Sealed Classes and Interfaces in Java 15](https://www.baeldung.com/java-sealed-classes-interfaces)

core-java-modules/core-java-17/README.md

@@ -5,3 +5,4 @@
 - [Introduction to HexFormat in Java 17](https://www.baeldung.com/java-hexformat)
 - [New Features in Java 17](https://www.baeldung.com/java-17-new-features)
 - [Random Number Generators in Java 17](https://www.baeldung.com/java-17-random-number-generators)
+- [Sealed Classes and Interfaces in Java 17](https://www.baeldung.com/java-sealed-classes-interfaces)

core-java-modules/core-java-17/src/test/java/com/baeldung/sealed/classes/VehicleUnitTest.java

@@ -21,7 +21,7 @@ public class VehicleUnitTest {
     public void givenCar_whenUsingReflectionAPI_thenSuperClassIsSealed() {
         Assertions.assertThat(car.getClass().isSealed()).isEqualTo(false);
         Assertions.assertThat(car.getClass().getSuperclass().isSealed()).isEqualTo(true);
-        Assertions.assertThat(car.getClass().getSuperclass().permittedSubclasses())
+        Assertions.assertThat(car.getClass().getSuperclass().getPermittedSubclasses())
                 .contains(ClassDesc.of(car.getClass().getCanonicalName()));
     }
 
@@ -29,7 +29,7 @@ public class VehicleUnitTest {
     public void givenTruck_whenUsingReflectionAPI_thenSuperClassIsSealed() {
         Assertions.assertThat(truck.getClass().isSealed()).isEqualTo(false);
         Assertions.assertThat(truck.getClass().getSuperclass().isSealed()).isEqualTo(true);
-        Assertions.assertThat(truck.getClass().getSuperclass().permittedSubclasses())
+        Assertions.assertThat(truck.getClass().getSuperclass().getPermittedSubclasses())
                 .contains(ClassDesc.of(truck.getClass().getCanonicalName()));
     }
 

core-java-modules/core-java-function/README.md

@@ -3,4 +3,5 @@
 ## Core Java 8 Cookbooks and Examples
 
 ### Relevant Articles: 
-- [Java 8 Predicate Chain](https://www.baeldung.com/java-predicate-chain)
+- [Java 8 Predicate Chain](https://www.baeldung.com/java-predicate-chain)
+- [Use Cases for Static Methods in Java](https://www.baeldung.com/java-static-methods-use-cases)

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

@@ -9,4 +9,5 @@ This module contains articles about core Java input/output(IO) conversions.
 - [Converting a BufferedReader to a JSONObject](https://www.baeldung.com/java-bufferedreader-to-jsonobject)
 - [Reading a CSV File into an Array](https://www.baeldung.com/java-csv-file-array)
 - [How to Write to a CSV File in Java](https://www.baeldung.com/java-csv)
+- [How to Convert InputStream to Base64 String](https://www.baeldung.com/java-inputstream-to-base64-string)
 - More articles: [[<-- prev]](/core-java-modules/core-java-io-conversions)

core-java-modules/core-java-jar/src/main/java/com/baeldung/jar/MySampleGUIAppn.java

@@ -0,0 +1,31 @@
+package com.baeldung.jar;
+
+import java.awt.event.*;
+import java.awt.*;
+
+import javax.swing.*;
+
+public class MySampleGUIAppn extends JFrame {
+    public  MySampleGUIAppn() {
+        if (!GraphicsEnvironment.isHeadless()) {
+            setSize(300,300);
+            setTitle("MySampleGUIAppn");
+            Button b = new Button("Click Me!");
+            b.setBounds(30,100,80,30);
+            add(b);
+            setVisible(true);
+            addWindowListener(new WindowAdapter() {
+                public void windowClosing(WindowEvent e) {
+                    dispose();
+                    System.exit(0);
+                }
+            });
+        }
+        else {
+            System.exit(0);
+        }
+    }
+    public static void main(String[] args) {
+        MySampleGUIAppn app=new  MySampleGUIAppn();
+    }
+}

core-java-modules/core-java-jar/src/test/java/com/baeldung/jar/MySampleGUIAppnUnitTest.java

@@ -0,0 +1,15 @@
+package com.baeldung.jar;
+
+import java.io.IOException;
+
+import org.junit.jupiter.api.Test;
+
+class MySampleGUIAppnUnitTest {
+    @Test
+    void testMain() throws IOException {
+        System.setProperty("java.awt.headless", "true");
+        String [] args = null;
+        System.exit(0);
+        MySampleGUIAppn.main(args);
+    }
+}

core-java-modules/core-java-lang-oop-types-2/README.md

@@ -6,3 +6,4 @@ This module contains articles about types in Java
 
 - [Convert an Array of Primitives to an Array of Objects](https://www.baeldung.com/java-primitive-array-to-object-array)
 - [Check if an Enum Value Exists in Java](https://www.baeldung.com/java-search-enum-values)
+- [Generate a Random Value From an Enum](https://www.baeldung.com/java-enum-random-value)

core-java-modules/core-java-numbers-4/README.md

@@ -7,7 +7,6 @@
 - [Automorphic Numbers in Java](https://www.baeldung.com/java-automorphic-numbers)
 - [Convert Byte Size Into a Human-Readable Format in Java](https://www.baeldung.com/java-human-readable-byte-size)
 - [Convert boolean to int in Java](https://www.baeldung.com/java-boolean-to-int)
-- [Generate a Random Value From an Enum](https://www.baeldung.com/java-enum-random-value)
 - [Reverse a Number in Java](https://www.baeldung.com/java-reverse-number)
 - [Check if BigDecimal Value Is Zero](https://www.baeldung.com/java-bigdecimal-zero)
 - More articles: [[<-- prev]](../core-java-numbers-3) [[next -->]](../core-java-numbers-5)

core-java-modules/core-java-streams-4/README.md

@@ -1,3 +1,4 @@
 ## Relevant Articles:
 
 - [Count Occurrences Using Java groupingBy Collector](https://www.baeldung.com/java-groupingby-count)
+- [How to Split a Stream into Multiple Streams](https://www.baeldung.com/java-split-stream)

core-java-modules/core-java-string-operations-4/src/main/java/com/baeldung/truncate/TruncateString.java

@@ -0,0 +1,105 @@
+package com.baeldung.truncate;
+
+import java.util.Optional;
+import java.util.regex.MatchResult;
+import java.util.regex.Pattern;
+
+import org.apache.commons.lang3.StringUtils;
+
+import com.google.common.base.Splitter;
+
+public class TruncateString {
+
+    private static final String EMPTY = "";
+
+    public static String usingSubstringMethod(String text, int length) {
+        if (length < 0) {
+            throw new IllegalArgumentException("length cannot be negative");
+        }
+
+        if (text == null) {
+            return EMPTY;
+        }
+
+        if (text.length() <= length) {
+            return text;
+        } else {
+            return text.substring(0, length);
+        }
+    }
+
+    public static String usingSplitMethod(String text, int length) {
+        if (length < 0) {
+            throw new IllegalArgumentException("length cannot be negative");
+        }
+
+        if (text == null) {
+            return EMPTY;
+        }
+
+        String[] results = text.split("(?<=\\G.{" + length + "})");
+
+        return results[0];
+    }
+
+    public static String usingPattern(String text, int length) {
+        if (length < 0) {
+            throw new IllegalArgumentException("length cannot be negative");
+        }
+
+        if (text == null) {
+            return EMPTY;
+        }
+
+        Optional<String> result = Pattern.compile(".{1," + length + "}")
+            .matcher(text)
+            .results()
+            .map(MatchResult::group)
+            .findFirst();
+
+        return result.isPresent() ? result.get() : EMPTY;
+
+    }
+
+    public static String usingCodePointsMethod(String text, int length) {
+        if (length < 0) {
+            throw new IllegalArgumentException("length cannot be negative");
+        }
+
+        if (text == null) {
+            return EMPTY;
+        }
+
+        return text.codePoints()
+            .limit(length)
+            .collect(StringBuilder::new, StringBuilder::appendCodePoint, StringBuilder::append)
+            .toString();
+    }
+
+    public static String usingLeftMethod(String text, int length) {
+
+        return StringUtils.left(text, length);
+    }
+
+    public static String usingTruncateMethod(String text, int length) {
+
+        return StringUtils.truncate(text, length);
+    }
+
+    public static String usingSplitter(String text, int length) {
+        if (length < 0) {
+            throw new IllegalArgumentException("length cannot be negative");
+        }
+
+        if (text == null) {
+            return EMPTY;
+        }
+
+        Iterable<String> parts = Splitter.fixedLength(length)
+            .split(text);
+
+        return parts.iterator()
+            .next();
+    }
+
+}

core-java-modules/core-java-string-operations-4/src/test/java/com/baeldung/truncate/TruncateStringUnitTest.java

@@ -0,0 +1,53 @@
+package com.baeldung.truncate;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+public class TruncateStringUnitTest {
+
+    private static final String TEXT = "Welcome to baeldung.com";
+
+    @Test
+    public void givenStringAndLength_whenUsingSubstringMethod_thenTruncate() {
+
+        assertEquals(TruncateString.usingSubstringMethod(TEXT, 10), "Welcome to");
+    }
+
+    @Test
+    public void givenStringAndLength_whenUsingSplitMethod_thenTruncate() {
+
+        assertEquals(TruncateString.usingSplitMethod(TEXT, 13), "Welcome to ba");
+    }
+
+    @Test
+    public void givenStringAndLength_whenUsingPattern_thenTruncate() {
+
+        assertEquals(TruncateString.usingPattern(TEXT, 19), "Welcome to baeldung");
+    }
+
+    @Test
+    public void givenStringAndLength_whenUsingCodePointsMethod_thenTruncate() {
+
+        assertEquals(TruncateString.usingCodePointsMethod(TEXT, 6), "Welcom");
+    }
+
+    @Test
+    public void givenStringAndLength_whenUsingLeftMethod_thenTruncate() {
+
+        assertEquals(TruncateString.usingLeftMethod(TEXT, 15), "Welcome to bael");
+    }
+
+    @Test
+    public void givenStringAndLength_whenUsingTruncateMethod_thenTruncate() {
+
+        assertEquals(TruncateString.usingTruncateMethod(TEXT, 20), "Welcome to baeldung.");
+    }
+
+    @Test
+    public void givenStringAndLength_whenUsingSplitter_thenTruncate() {
+
+        assertEquals(TruncateString.usingSplitter(TEXT, 3), "Wel");
+    }
+
+}

docker-modules/docker-environment-variables/README.md

@@ -0,0 +1,3 @@
+
+## Relevant Articles:
+- [How to Pass Environment Variable Value into Dockerfile](https://www.baeldung.com/ops/dockerfile-env-variable)