Merge branch 'eugenp:master' into master

apache-cxf-modules/README.md

@@ -4,6 +4,4 @@ This module contains articles about Apache CXF
 
 ## Relevant Articles:
 
-- [Apache CXF Support for RESTful Web Services](https://www.baeldung.com/apache-cxf-rest-api)
+- [Introduction to Apache CXF Aegis Data Binding](https://www.baeldung.com/aegis-data-binding-in-apache-cxf)
-- [A Guide to Apache CXF with Spring](https://www.baeldung.com/apache-cxf-with-spring)
-- [Introduction to Apache CXF](https://www.baeldung.com/introduction-to-apache-cxf)

apache-cxf-modules/cxf-introduction/README.md

@@ -1,2 +1,2 @@
 ### Relevant Articles:
-- [Introduction to Apache CXF](http://www.baeldung.com/introduction-to-apache-cxf)
+- [Introduction to Apache CXF](https://www.baeldung.com/introduction-to-apache-cxf)

axon/pom.xml

@@ -19,7 +19,7 @@
             <dependency>
                 <groupId>org.axonframework</groupId>
                 <artifactId>axon-bom</artifactId>
-                <version>${axon.version}</version>
+                <version>${axon-bom.version}</version>
                 <type>pom</type>
                 <scope>import</scope>
             </dependency>
@@ -57,7 +57,7 @@
     </dependencies>
 
     <properties>
-        <axon.version>4.5.0</axon.version>
+        <axon-bom.version>4.5.13</axon-bom.version>
     </properties>
 
 </project>

core-java-modules/core-java-11-2/src/test/java/com/baeldung/httpclient/parameters/HttpClientParametersLiveTest.java

@@ -0,0 +1,45 @@
+package com.baeldung.httpclient.parameters;
+
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+import java.io.IOException;
+import java.net.URI;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class HttpClientParametersLiveTest {
+
+    private static HttpClient client;
+
+    @BeforeAll
+    public static void setUp() {
+        client = HttpClient.newHttpClient();
+    }
+
+    @Test
+    public void givenQueryParams_whenGetRequest_thenResponseOk() throws IOException, InterruptedException {
+        HttpRequest request = HttpRequest.newBuilder()
+          .version(HttpClient.Version.HTTP_2)
+          .uri(URI.create("https://postman-echo.com/get?param1=value1&param2=value2"))
+          .GET()
+          .build();
+        HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());
+
+        assertEquals(response.statusCode(), 200);
+    }
+
+    @Test
+    public void givenQueryParams_whenGetRequestWithDefaultConfiguration_thenResponseOk() throws IOException, InterruptedException {
+        HttpRequest request = HttpRequest.newBuilder()
+          .uri(URI.create("https://postman-echo.com/get?param1=value1&param2=value2"))
+          .build();
+        HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());
+
+        assertEquals(response.statusCode(), 200);
+    }
+
+}

core-java-modules/core-java-9/src/main/java/com/baeldung/java9/finalizers/CleaningDemo.java

@@ -0,0 +1,17 @@
+package com.bealdung.java9.finalizers;
+
+import java.lang.ref.Cleaner;
+
+class CleaningDemo {
+
+    public static void main(String[] args) {
+        final Cleaner cleaner = Cleaner.create();
+        try (Order order = new Order(cleaner)) {
+            for (int i = 0; i < 10; i++) {
+                order.register(new Product(i), i);
+            }
+        } catch (Exception e) {
+            System.err.println("Error: " + e);
+        }
+    }
+}

core-java-modules/core-java-9/src/main/java/com/baeldung/java9/finalizers/Order.java

@@ -0,0 +1,36 @@
+package com.bealdung.java9.finalizers;
+
+import java.lang.ref.Cleaner;
+
+class Order implements AutoCloseable {
+
+    private final Cleaner cleaner;
+    private Cleaner.Cleanable cleanable;
+
+    public Order(Cleaner cleaner) {
+        this.cleaner = cleaner;
+    }
+
+    public void register(Product product, int id) {
+        this.cleanable = cleaner.register(product, new CleaningAction(id));
+    }
+
+    public void close() {
+        cleanable.clean();
+        System.out.println("Cleanable closed");
+    }
+
+    static class CleaningAction implements Runnable {
+
+        private final int id;
+
+        public CleaningAction(int id) {
+            this.id = id;
+        }
+
+        @Override
+        public void run() {
+            System.out.printf("Object with id %s is garbage collected. %n", id);
+        }
+    }
+}

core-java-modules/core-java-9/src/main/java/com/baeldung/java9/finalizers/Product.java

@@ -0,0 +1,13 @@
+package com.bealdung.java9.finalizers;
+
+class Product {
+    private final int id;
+
+    public Product(int id) {
+        this.id = id;
+    }
+
+    public int getId() {
+        return id;
+    }
+}

core-java-modules/core-java-9/src/main/java/com/baeldung/java9/finalizers/Resource.java

@@ -0,0 +1,25 @@
+package com.bealdung.java9.finalizers;
+
+import java.io.BufferedReader;
+import java.io.FileNotFoundException;
+import java.io.FileReader;
+
+class Resource implements AutoCloseable {
+
+    final BufferedReader reader;
+
+    public Resource(String filename) throws FileNotFoundException {
+        reader = new BufferedReader(new FileReader(filename));
+    }
+
+    public long getLineNumber() {
+        return reader.lines()
+            .count();
+    }
+
+    @Override
+    public void close() throws Exception {
+        reader.close();
+        System.out.println("BufferedReader resource closed");
+    }
+}

core-java-modules/core-java-9/src/test/java/com/baeldung/java9/finalizers/FinalizeUnitTest.java

@@ -0,0 +1,30 @@
+package com.bealdung.java9.finalizers;
+
+import org.junit.jupiter.api.Test;
+
+import java.io.BufferedWriter;
+import java.io.File;
+import java.io.FileWriter;
+import java.io.IOException;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class FinalizeUnitTest {
+
+    @Test
+    void givenFilename_whenGetLineNumber_thenReturnCorrectNumber() throws IOException {
+        final File tmpFile = File.createTempFile("test", ".tmp");
+        final BufferedWriter writer = new BufferedWriter(new FileWriter(tmpFile));
+        writer.write("Baeldung");
+        writer.close();
+
+        long lineNumber = 0;
+        try (Resource resource = new Resource(tmpFile.getAbsolutePath())) {
+            lineNumber = resource.getLineNumber();
+        } catch (Exception e) {
+            System.err.println("Error " + e);
+        }
+
+        assertEquals(1, lineNumber);
+    }
+}

core-java-modules/core-java-collections-list-3/README.md

@@ -13,5 +13,4 @@ This module contains articles about the Java List collection
 - [Finding the Differences Between Two Lists in Java](https://www.baeldung.com/java-lists-difference)
 - [List vs. ArrayList in Java](https://www.baeldung.com/java-list-vs-arraylist)
 - [How to Store HashMap<String, ArrayList> Inside a List](https://www.baeldung.com/java-hashmap-inside-list)
-- [Working With a List of Lists in Java](https://www.baeldung.com/java-list-of-lists)
 - [[<-- Prev]](/core-java-modules/core-java-collections-list-2)

core-java-modules/core-java-collections-list-4/README.md

@@ -5,4 +5,5 @@ This module contains articles about the Java List collection
 ### Relevant Articles: 
 - [Working With a List of Lists in Java](https://www.baeldung.com/java-list-of-lists)
 - [Reverse an ArrayList in Java](https://www.baeldung.com/java-reverse-arraylist)
+- [Sort a List Alphabetically in Java](https://www.baeldung.com/java-sort-list-alphabetically)
 - [[<-- Prev]](/core-java-modules/core-java-collections-list-3)

core-java-modules/core-java-exceptions/src/main/java/com/baeldung/exceptions/sneakythrows/SneakyRunnable.java

@@ -1,23 +0,0 @@
-package com.baeldung.exceptions.sneakythrows;
-
-import lombok.SneakyThrows;
-
-public class SneakyRunnable implements Runnable {
-
-    @SneakyThrows
-    public void run() {
-        try {
-            throw new InterruptedException();
-        } catch (InterruptedException e) {
-            e.printStackTrace();
-        }
-    }
-
-    public static void main(String[] args) {
-        try {
-            new SneakyRunnable().run();
-        } catch (Exception e) {
-            e.printStackTrace();
-        }
-    }
-}

core-java-modules/core-java-exceptions/src/main/java/com/baeldung/exceptions/sneakythrows/SneakyThrows.java

@@ -1,25 +0,0 @@
-package com.baeldung.exceptions.sneakythrows;
-
-import java.io.IOException;
-
-public class SneakyThrows {
-
-
-    public static <E extends Throwable> void sneakyThrow(Throwable e) throws E {
-        throw (E) e;
-    }
-
-    public static void throwsSneakyIOException() {
-        sneakyThrow(new IOException("sneaky"));
-    }
-
-
-    public static void main(String[] args) {
-        try {
-            throwsSneakyIOException();
-        } catch (Exception ex) {
-            ex.printStackTrace();
-        }
-
-    }
-}

core-java-modules/core-java-exceptions/src/main/java/com/baeldung/exceptions/sneakythrows/SneakyThrowsExamples.java

@@ -0,0 +1,22 @@
+package com.baeldung.exceptions.sneakythrows;
+
+import java.io.IOException;
+
+import lombok.SneakyThrows;
+
+public class SneakyThrowsExamples {
+
+    public static <E extends Throwable> void sneakyThrow(Throwable e) throws E {
+        throw (E) e;
+    }
+
+    public static void throwSneakyIOException() {
+        sneakyThrow(new IOException("sneaky"));
+    }
+
+    @SneakyThrows
+    public static void throwSneakyIOExceptionUsingLombok() {
+        throw new IOException("lombok sneaky");
+    }
+
+}

core-java-modules/core-java-exceptions/src/test/java/com/baeldung/exceptions/sneakythrows/SneakyRunnableUnitTest.java

@@ -1,17 +0,0 @@
-package com.baeldung.exceptions.sneakythrows;
-
-import org.junit.Test;
-
-import static junit.framework.TestCase.assertEquals;
-
-public class SneakyRunnableUnitTest {
-
-    @Test
-    public void whenCallSneakyRunnableMethod_thenThrowException() {
-        try {
-            new SneakyRunnable().run();
-        } catch (Exception e) {
-            assertEquals(InterruptedException.class, e.getStackTrace());
-        }
-    }
-}

core-java-modules/core-java-exceptions/src/test/java/com/baeldung/exceptions/sneakythrows/SneakyThrowsExamplesUnitTest.java

@@ -0,0 +1,28 @@
+package com.baeldung.exceptions.sneakythrows;
+
+import static com.baeldung.exceptions.sneakythrows.SneakyThrowsExamples.throwSneakyIOException;
+import static com.baeldung.exceptions.sneakythrows.SneakyThrowsExamples.throwSneakyIOExceptionUsingLombok;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+import java.io.IOException;
+
+import org.junit.Test;
+
+public class SneakyThrowsExamplesUnitTest {
+
+    @Test
+    public void throwSneakyIOException_IOExceptionShouldBeThrown() {
+        assertThatThrownBy(() -> throwSneakyIOException())
+            .isInstanceOf(IOException.class)
+            .hasMessage("sneaky")
+            .hasStackTraceContaining("SneakyThrowsExamples.throwSneakyIOException");
+    }
+
+    @Test
+    public void throwSneakyIOExceptionUsingLombok_IOExceptionShouldBeThrown() {
+        assertThatThrownBy(() -> throwSneakyIOExceptionUsingLombok())
+            .isInstanceOf(IOException.class)
+            .hasMessage("lombok sneaky")
+            .hasStackTraceContaining("SneakyThrowsExamples.throwSneakyIOExceptionUsingLombok");
+    }
+}

core-java-modules/core-java-exceptions/src/test/java/com/baeldung/exceptions/sneakythrows/SneakyThrowsUnitTest.java

@@ -1,18 +0,0 @@
-package com.baeldung.exceptions.sneakythrows;
-
-import org.junit.Test;
-
-import static junit.framework.TestCase.assertEquals;
-
-public class SneakyThrowsUnitTest {
-
-    @Test
-    public void whenCallSneakyMethod_thenThrowSneakyException() {
-        try {
-            SneakyThrows.throwsSneakyIOException();
-        } catch (Exception ex) {
-            assertEquals("sneaky", ex.getMessage().toString());
-        }
-    }
-
-}

core-java-modules/core-java-lang-operators-2/src/main/java/com/baeldung/threebool/ThreeBooleans.java

@@ -0,0 +1,45 @@
+package com.baeldung.threebool;
+
+import java.util.Arrays;
+
+public class ThreeBooleans {
+    public static boolean twoOrMoreAreTrueByLoop(boolean a, boolean b, boolean c) {
+        int count = 0;
+        for (boolean i : new Boolean[] { a, b, c }) {
+            count += i ? 1 : 0;
+            if (count >= 2)
+                return true;
+        }
+        return false;
+    }
+
+    public static boolean xOrMoreAreTrueByLoop(boolean[] booleans, int x) {
+        int count = 0;
+        for (boolean i : booleans) {
+            count += i ? 1 : 0;
+            if (count >= x)
+                return true;
+        }
+        return false;
+    }
+
+    public static boolean twoOrMoreAreTrueBySum(boolean a, boolean b, boolean c) {
+        return (a ? 1 : 0) + (b ? 1 : 0) + (c ? 1 : 0) >= 2;
+    }
+
+    public static boolean xOrMoreAreTrueBySum(Boolean[] booleans, int x) {
+        return Arrays.stream(booleans).mapToInt(b -> Boolean.TRUE.equals(b) ? 1 : 0).sum() >= x;
+    }
+
+    public static boolean twoorMoreAreTrueByKarnaughMap(boolean a, boolean b, boolean c) {
+        return (c && (a || b)) || (a && b);
+    }
+
+    public static boolean twoOrMoreAreTrueByOperators(boolean a, boolean b, boolean c) {
+        return (a && b) || (a && c) || (b && c);
+    }
+
+    public static boolean twoOrMoreAreTrueByXor(boolean a, boolean b, boolean c) {
+        return a ^ b ? c : a;
+    }
+}

core-java-modules/core-java-lang-operators-2/src/test/java/com/baeldung/threebool/ThreeBooleansUnitTest.java

@@ -0,0 +1,44 @@
+package com.baeldung.threebool;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import com.google.common.collect.ImmutableMap;
+import java.util.Map;
+import org.junit.jupiter.api.Test;
+
+class ThreeBooleansUnitTest {
+    // @formatter:off
+    private static final Map<boolean[], Boolean> TEST_CASES_AND_EXPECTED = ImmutableMap.of(
+        new boolean[]{true, true, true}, true,
+        new boolean[]{true, true, false}, true,
+        new boolean[]{true, false, false}, false,
+        new boolean[]{false, false, false}, false
+        );
+    // @formatter:on
+
+    @Test
+    void given3Booleans_whenCallingTwoOrMoreAreTrueByLoop_thenGetExpectedResult() {
+        TEST_CASES_AND_EXPECTED.forEach((array, expected) -> assertThat(ThreeBooleans.twoOrMoreAreTrueByLoop(array[0], array[1], array[2])).isEqualTo(expected));
+    }
+
+    @Test
+    void given3Booleans_whenCallingTwoOrMoreAreTrueByCounting_thenGetExpectedResult() {
+        TEST_CASES_AND_EXPECTED.forEach((array, expected) -> assertThat(ThreeBooleans.twoOrMoreAreTrueBySum(array[0], array[1], array[2])).isEqualTo(expected));
+    }
+
+    @Test
+    void given3Booleans_whenCallingTwoOrMoreAreTrueByKarnaughMap_thenGetExpectedResult() {
+        TEST_CASES_AND_EXPECTED.forEach((array, expected) -> assertThat(ThreeBooleans.twoorMoreAreTrueByKarnaughMap(array[0], array[1], array[2])).isEqualTo(expected));
+    }
+
+    @Test
+    void given3Booleans_whenCallingTwoOrMoreAreTrueByOperators_thenGetExpectedResult() {
+        TEST_CASES_AND_EXPECTED.forEach((array, expected) -> assertThat(ThreeBooleans.twoOrMoreAreTrueByOperators(array[0], array[1], array[2])).isEqualTo(expected));
+    }
+
+    @Test
+    void given3Booleans_whenCallingTwoOrMoreAreTrueByXor_thenGetExpectedResult() {
+        TEST_CASES_AND_EXPECTED.forEach((array, expected) -> assertThat(ThreeBooleans.twoOrMoreAreTrueByXor(array[0], array[1], array[2])).isEqualTo(expected));
+    }
+
+}

core-java-modules/core-java-reflection-2/pom.xml

@@ -47,6 +47,25 @@
                     <compilerArgument>-parameters</compilerArgument>
                 </configuration>
             </plugin>
+            <plugin>
+                <groupId>org.jacoco</groupId>
+                <artifactId>jacoco-maven-plugin</artifactId>
+                <version>0.8.8</version>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>prepare-agent</goal>
+                        </goals>
+                    </execution>
+                    <execution>
+                        <id>report</id>
+                        <phase>prepare-package</phase>
+                        <goals>
+                            <goal>report</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
         </plugins>
     </build>
 

core-java-modules/core-java-reflection-2/src/main/java/com/baeldung/reflection/privatemethods/Utils.java

@@ -0,0 +1,19 @@
+package com.baeldung.reflection.privatemethods;
+
+public class Utils {
+
+    public static Integer validateAndDouble(Integer input) {
+        if (input == null) {
+            throw new IllegalArgumentException("input should not be null");
+        }
+        return doubleInteger(input);
+    }
+
+    private static Integer doubleInteger(Integer input) {
+        if (input == null) {
+            return null;
+        }
+        return 2 * input;
+    }
+
+}

core-java-modules/core-java-reflection-2/src/test/java/com/baeldung/reflection/privatemethods/UtilsUnitTest.java

@@ -0,0 +1,42 @@
+package com.baeldung.reflection.privatemethods;
+
+import static com.baeldung.reflection.privatemethods.Utils.validateAndDouble;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+
+import org.junit.jupiter.api.Test;
+
+public class UtilsUnitTest {
+
+    // Let's start with the tests of the public API
+    @Test
+    void givenNull_WhenValidateAndDouble_ThenThrows() {
+        assertThrows(IllegalArgumentException.class, () -> validateAndDouble(null));
+    }
+
+    @Test
+    void givenANonNullInteger_WhenValidateAndDouble_ThenDoublesIt() {
+        assertEquals(4, validateAndDouble(2));
+    }
+
+    // Further on, let's test the private method
+    @Test
+    void givenNull_WhenDoubleInteger_ThenNull() throws InvocationTargetException, IllegalAccessException, NoSuchMethodException {
+        assertEquals(null, getDoubleIntegerMethod().invoke(null, new Integer[] { null }));
+    }
+
+    @Test
+    void givenANonNullInteger_WhenDoubleInteger_ThenDoubleIt() throws NoSuchMethodException, InvocationTargetException, IllegalAccessException {
+        assertEquals(74, getDoubleIntegerMethod().invoke(null, 37));
+    }
+
+    private Method getDoubleIntegerMethod() throws NoSuchMethodException {
+        Method method = Utils.class.getDeclaredMethod("doubleInteger", Integer.class);
+        method.setAccessible(true);
+        return method;
+    }
+
+}

core-java-modules/core-java-string-conversions-2/src/test/java/com/baeldung/stringtointeger/StringToIntegerUnitTest.java

@@ -0,0 +1,73 @@
+package com.baeldung.stringtointeger;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+public class StringToIntegerUnitTest {
+
+    @Test
+    public void whenValidNumericStringIsPassed_thenShouldConvertToPrimitiveInt() {
+        assertEquals(11, Integer.parseInt("11")); 
+        assertEquals(11, Integer.parseInt("+11")); 
+        assertEquals(-11, Integer.parseInt("-11"));
+    }
+
+    @Test
+    public void whenValidNumericStringWithRadixIsPassed_thenShouldConvertToPrimitiveInt() {
+        assertEquals(17, Integer.parseInt("11", 16)); 
+        assertEquals(10, Integer.parseInt("A", 16)); 
+        assertEquals(7, Integer.parseInt("7", 8));
+    }
+
+//    public static int parseInt(CharSequence s, int beginIndex, int endIndex, int radix) throws NumberFormatException 
+//    This method is available in JDK 9 and above  
+//    @Test
+//    public void whenValidNumericStringWithRadixAndSubstringIsPassed_thenShouldConvertToPrimitiveInt() {
+//        assertEquals(5, Integer.parseInt("100101", 3, 6, 2));
+//        assertEquals(101, Integer.parseInt("100101", 3, 6, 10));
+//    }
+
+    @Test(expected = NumberFormatException.class)
+    public void whenInValidNumericStringIsPassed_thenShouldThrowNumberFormatException() {
+        int number = Integer.parseInt("abcd");
+    }
+
+    @Test
+    public void whenValidNumericStringIsPassed_thenShouldConvertToInteger() {
+        Integer expectedNumber = 11;
+        Integer expectedNegativeNumber = -11;
+        
+        assertEquals(expectedNumber, Integer.valueOf("11"));
+        assertEquals(expectedNumber, Integer.valueOf("+11"));
+        assertEquals(expectedNegativeNumber, Integer.valueOf("-11"));
+    }
+
+    @Test
+    public void whenNumberIsPassed_thenShouldConvertToInteger() {
+        Integer expectedNumber = 11;
+        Integer expectedNegativeNumber = -11;
+        Integer expectedUnicodeValue = 65;
+        
+        assertEquals(expectedNumber, Integer.valueOf(11));
+        assertEquals(expectedNumber, Integer.valueOf(+11));
+        assertEquals(expectedNegativeNumber, Integer.valueOf(-11));
+        assertEquals(expectedUnicodeValue, Integer.valueOf('A'));
+    }
+
+    @Test
+    public void whenValidNumericStringWithRadixIsPassed_thenShouldConvertToInetger() {
+        Integer expectedNumber1 = 17;
+        Integer expectedNumber2 = 10;
+        Integer expectedNumber3 = 7;
+        
+        assertEquals(expectedNumber1, Integer.valueOf("11", 16));
+        assertEquals(expectedNumber2, Integer.valueOf("A", 16));
+        assertEquals(expectedNumber3, Integer.valueOf("7", 8));
+    }
+
+    @Test(expected = NumberFormatException.class)
+    public void whenInvalidValueOfNumericStringPassed_thenShouldThrowException() {
+        Integer number = Integer.valueOf("abcd");
+    }
+}

core-java-modules/java-numbers-2/README.md

@@ -13,4 +13,4 @@ This module contains articles about numbers in Java.
 - [Binary Numbers in Java](https://www.baeldung.com/java-binary-numbers)
 - [Finding the Least Common Multiple in Java](https://www.baeldung.com/java-least-common-multiple)
 - [Binary Numbers in Java](https://www.baeldung.com/java-binary-numbers)
-- More articles: [[<-- prev]](/java-numbers) [[next -->]](/java-numbers-3)
+- More articles: [[<-- prev]](../java-numbers) [[next -->]](../java-numbers-3)

core-java-modules/java-numbers-2/pom.xml

@@ -9,10 +9,9 @@
     <packaging>jar</packaging>
 
     <parent>
-        <groupId>com.baeldung</groupId>
+        <groupId>com.baeldung.core-java-modules</groupId>
-        <artifactId>parent-java</artifactId>
+        <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../parent-java</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/java-numbers-3/README.md

@@ -14,4 +14,4 @@ This module contains articles about numbers in Java.
 - [Print an Integer in Binary Format in Java](https://www.baeldung.com/java-print-integer-binary)
 - [Number Formatting in Java](https://www.baeldung.com/java-number-formatting)
 - [Division by Zero in Java: Exception, Infinity, or Not a Number](https://www.baeldung.com/java-division-by-zero)
-- More articles: [[<-- prev]](/java-numbers-2)
+- More articles: [[<-- prev]](../java-numbers-2) [[next -->]](../java-numbers-4)

core-java-modules/java-numbers-3/pom.xml

@@ -7,10 +7,9 @@
     <packaging>jar</packaging>
 
     <parent>
-        <groupId>com.baeldung</groupId>
+        <groupId>com.baeldung.core-java-modules</groupId>
-        <artifactId>parent-java</artifactId>
+        <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../parent-java</relativePath>
     </parent>
 
     <dependencies>

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

@@ -9,3 +9,5 @@
 - [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]](../java-numbers-3)

core-java-modules/java-numbers-4/pom.xml

@@ -7,10 +7,9 @@
     <packaging>jar</packaging>
 
     <parent>
-        <groupId>com.baeldung</groupId>
+        <groupId>com.baeldung.core-java-modules</groupId>
-        <artifactId>parent-java</artifactId>
+        <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../parent-java</relativePath>
     </parent>
 
     <dependencies>

core-java-modules/java-numbers-4/src/test/java/com/baeldung/bigdecimalzero/BigDecimalZeroChkUnitTest.java

@@ -0,0 +1,34 @@
+package com.baeldung.bigdecimalzero;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.math.BigDecimal;
+
+import org.junit.jupiter.api.Test;
+
+class BigDecimalZeroChkUnitTest {
+    private static final BigDecimal BD1 = new BigDecimal("0");
+    private static final BigDecimal BD2 = new BigDecimal("0.0000");
+
+    @Test
+    void givenBD_whenCheckedWithEquals_shouldCheckedAsZero() {
+        assertThat(BigDecimal.ZERO.equals(BD1)).isTrue();
+
+        // in the article, we show the failure of the assertion below
+        // assertThat(BigDecimal.ZERO.equals(BD2)).isTrue();
+
+        assertThat(BigDecimal.ZERO.equals(BD2)).isFalse();
+    }
+
+    @Test
+    void givenBD_whenCheckedWithCompareTo_shouldCheckedAsZero() {
+        assertThat(BigDecimal.ZERO.compareTo(BD1)).isSameAs(0);
+        assertThat(BigDecimal.ZERO.compareTo(BD2)).isSameAs(0);
+    }
+
+    @Test
+    void givenBD_whenCheckedWithSignum_shouldCheckedAsZero() {
+        assertThat(BD1.signum()).isSameAs(0);
+        assertThat(BD2.signum()).isSameAs(0);
+    }
+}

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

@@ -13,4 +13,4 @@ This module contains articles about numbers in Java.
 - [Convert Double to String, Removing Decimal Places](https://www.baeldung.com/java-double-to-string)
 - [Changing the Order in a Sum Operation Can Produce Different Results?](https://www.baeldung.com/java-floating-point-sum-order)
 - [Using Math.sin with Degrees](https://www.baeldung.com/java-math-sin-degrees)
-- More articles: [[next -->]](/../java-numbers-2)
+- More articles: [[next -->]](../java-numbers-2)

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

@@ -9,10 +9,9 @@
     <packaging>jar</packaging>
 
     <parent>
-        <groupId>com.baeldung</groupId>
+        <groupId>com.baeldung.core-java-modules</groupId>
-        <artifactId>parent-java</artifactId>
+        <artifactId>core-java-modules</artifactId>
         <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../parent-java</relativePath>
     </parent>
 
     <dependencies>