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-2/src/main/java/com/baeldung/binarynumbers/BinaryNumbers.java

@@ -1,140 +1,140 @@
-package com.baeldung.binarynumbers;
+package com.baeldung.binarynumbers;
-
+
-public class BinaryNumbers {
+public class BinaryNumbers {
-
+
-    /**
+    /**
-     * This method takes a decimal number and convert it into a binary number.
+     * This method takes a decimal number and convert it into a binary number.
-     * example:- input:10, output:1010
+     * example:- input:10, output:1010
-     *
+     *
-     * @param decimalNumber
+     * @param decimalNumber
-     * @return binary number
+     * @return binary number
-     */
+     */
-    public Integer convertDecimalToBinary(Integer decimalNumber) {
+    public Integer convertDecimalToBinary(Integer decimalNumber) {
-
+
-        if (decimalNumber == 0) {
+        if (decimalNumber == 0) {
-            return decimalNumber;
+            return decimalNumber;
-        }
+        }
-
+
-        StringBuilder binaryNumber = new StringBuilder();
+        StringBuilder binaryNumber = new StringBuilder();
-        Integer quotient = decimalNumber;
+        Integer quotient = decimalNumber;
-
+
-        while (quotient > 0) {
+        while (quotient > 0) {
-
+
-            int remainder = quotient % 2;
+            int remainder = quotient % 2;
-            binaryNumber.append(remainder);
+            binaryNumber.append(remainder);
-            quotient /= 2;
+            quotient /= 2;
-        }
+        }
-
+
-        binaryNumber = binaryNumber.reverse();
+        binaryNumber = binaryNumber.reverse();
-        return Integer.valueOf(binaryNumber.toString());
+        return Integer.valueOf(binaryNumber.toString());
-    }
+    }
-
+
-    /**
+    /**
-     * This method takes a binary number and convert it into a decimal number.
+     * This method takes a binary number and convert it into a decimal number.
-     * example:- input:101, output:5
+     * example:- input:101, output:5
-     *
+     *
-     * @param binary number
+     * @param binary number
-     * @return decimal Number
+     * @return decimal Number
-     */
+     */
-    public Integer convertBinaryToDecimal(Integer binaryNumber) {
+    public Integer convertBinaryToDecimal(Integer binaryNumber) {
-
+
-        Integer decimalNumber = 0;
+        Integer decimalNumber = 0;
-        Integer base = 1;
+        Integer base = 1;
-
+
-        while (binaryNumber > 0) {
+        while (binaryNumber > 0) {
-
+
-            int lastDigit = binaryNumber % 10;
+            int lastDigit = binaryNumber % 10;
-            binaryNumber = binaryNumber / 10;
+            binaryNumber = binaryNumber / 10;
-
+
-            decimalNumber += lastDigit * base;
+            decimalNumber += lastDigit * base;
-            base = base * 2;
+            base = base * 2;
-        }
+        }
-        return decimalNumber;
+        return decimalNumber;
-    }
+    }
-
+
-    /**
+    /**
-     * This method accepts two binary numbers and returns sum of input numbers.
+     * This method accepts two binary numbers and returns sum of input numbers.
-     * Example:- firstNum: 101, secondNum: 100, output: 1001
+     * Example:- firstNum: 101, secondNum: 100, output: 1001
-     *
+     *
-     * @param firstNum
+     * @param firstNum
-     * @param secondNum
+     * @param secondNum
-     * @return addition of input numbers
+     * @return addition of input numbers
-     */
+     */
-    public Integer addBinaryNumber(Integer firstNum, Integer secondNum) {
+    public Integer addBinaryNumber(Integer firstNum, Integer secondNum) {
-
+
-        StringBuilder output = new StringBuilder();
+        StringBuilder output = new StringBuilder();
-
+
-        int carry = 0;
+        int carry = 0;
-        int temp;
+        int temp;
-
+
-        while (firstNum != 0 || secondNum != 0) {
+        while (firstNum != 0 || secondNum != 0) {
-
+
-            temp = (firstNum % 10 + secondNum % 10 + carry) % 2;
+            temp = (firstNum % 10 + secondNum % 10 + carry) % 2;
-            output.append(temp);
+            output.append(temp);
-
+
-            carry = (firstNum % 10 + secondNum % 10 + carry) / 2;
+            carry = (firstNum % 10 + secondNum % 10 + carry) / 2;
-
+
-            firstNum = firstNum / 10;
+            firstNum = firstNum / 10;
-            secondNum = secondNum / 10;
+            secondNum = secondNum / 10;
-        }
+        }
-
+
-        if (carry != 0) {
+        if (carry != 0) {
-            output.append(carry);
+            output.append(carry);
-        }
+        }
-
+
-        return Integer.valueOf(output.reverse()
+        return Integer.valueOf(output.reverse()
-            .toString());
+            .toString());
-    }
+    }
-
+
-    /**
+    /**
-    * This method takes two binary number as input and subtract second number from the first number.
+    * This method takes two binary number as input and subtract second number from the first number.
-    * example:- firstNum: 1000, secondNum: 11, output: 101
+    * example:- firstNum: 1000, secondNum: 11, output: 101
-    * @param firstNum
+    * @param firstNum
-    * @param secondNum
+    * @param secondNum
-    * @return Result of subtraction of secondNum from first
+    * @return Result of subtraction of secondNum from first
-    */
+    */
-    public Integer substractBinaryNumber(Integer firstNum, Integer secondNum) {
+    public Integer substractBinaryNumber(Integer firstNum, Integer secondNum) {
-
+
-        int onesComplement = Integer.valueOf(getOnesComplement(secondNum));
+        int onesComplement = Integer.valueOf(getOnesComplement(secondNum));
-        StringBuilder output = new StringBuilder();
+        StringBuilder output = new StringBuilder();
-        int carry = 0;
+        int carry = 0;
-        int temp;
+        int temp;
-
+
-        while (firstNum != 0 || onesComplement != 0) {
+        while (firstNum != 0 || onesComplement != 0) {
-
+
-            temp = (firstNum % 10 + onesComplement % 10 + carry) % 2;
+            temp = (firstNum % 10 + onesComplement % 10 + carry) % 2;
-            output.append(temp);
+            output.append(temp);
-
+
-            carry = (firstNum % 10 + onesComplement % 10 + carry) / 2;
+            carry = (firstNum % 10 + onesComplement % 10 + carry) / 2;
-
+
-            firstNum = firstNum / 10;
+            firstNum = firstNum / 10;
-            onesComplement = onesComplement / 10;
+            onesComplement = onesComplement / 10;
-        }
+        }
-
+
-        String additionOfFirstNumAndOnesComplement = output.reverse()
+        String additionOfFirstNumAndOnesComplement = output.reverse()
-            .toString();
+            .toString();
-
+
-        if (carry == 1) {
+        if (carry == 1) {
-            return addBinaryNumber(Integer.valueOf(additionOfFirstNumAndOnesComplement), carry);
+            return addBinaryNumber(Integer.valueOf(additionOfFirstNumAndOnesComplement), carry);
-        } else {
+        } else {
-            return getOnesComplement(Integer.valueOf(additionOfFirstNumAndOnesComplement));
+            return getOnesComplement(Integer.valueOf(additionOfFirstNumAndOnesComplement));
-        }
+        }
-    }
+    }
-
+
-    public Integer getOnesComplement(Integer num) {
+    public Integer getOnesComplement(Integer num) {
-
+
-        StringBuilder onesComplement = new StringBuilder();
+        StringBuilder onesComplement = new StringBuilder();
-        while (num > 0) {
+        while (num > 0) {
-            int lastDigit = num % 10;
+            int lastDigit = num % 10;
-            if (lastDigit == 0) {
+            if (lastDigit == 0) {
-                onesComplement.append(1);
+                onesComplement.append(1);
-            } else {
+            } else {
-                onesComplement.append(0);
+                onesComplement.append(0);
-            }
+            }
-            num = num / 10;
+            num = num / 10;
-        }
+        }
-        return Integer.valueOf(onesComplement.reverse()
+        return Integer.valueOf(onesComplement.reverse()
-            .toString());
+            .toString());
-    }
+    }
-
+
 }

core-java-modules/java-numbers-2/src/test/java/com/baeldung/binarynumbers/BinaryNumbersUnitTest.java

@@ -1,73 +1,73 @@
-package com.baeldung.binarynumbers;
+package com.baeldung.binarynumbers;
-
+
-import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertEquals;
-
+
-import org.junit.Test;
+import org.junit.Test;
-
+
-public class BinaryNumbersUnitTest {
+public class BinaryNumbersUnitTest {
-
+
-    private BinaryNumbers binaryNumbers = new BinaryNumbers();
+    private BinaryNumbers binaryNumbers = new BinaryNumbers();
-
+
-    @Test
+    @Test
-    public void given_decimalNumber_then_returnBinaryNumber() {
+    public void given_decimalNumber_then_returnBinaryNumber() {
-        assertEquals(Integer.valueOf(1000), binaryNumbers.convertDecimalToBinary(8));
+        assertEquals(Integer.valueOf(1000), binaryNumbers.convertDecimalToBinary(8));
-        assertEquals(Integer.valueOf(10100), binaryNumbers.convertDecimalToBinary(20));
+        assertEquals(Integer.valueOf(10100), binaryNumbers.convertDecimalToBinary(20));
-    }
+    }
-
+
-    @Test
+    @Test
-    public void given_decimalNumber_then_convertToBinaryNumber() {
+    public void given_decimalNumber_then_convertToBinaryNumber() {
-        assertEquals("1000", Integer.toBinaryString(8));
+        assertEquals("1000", Integer.toBinaryString(8));
-        assertEquals("10100", Integer.toBinaryString(20));
+        assertEquals("10100", Integer.toBinaryString(20));
-    }
+    }
-
+
-    @Test
+    @Test
-    public void given_binaryNumber_then_ConvertToDecimalNumber() {
+    public void given_binaryNumber_then_ConvertToDecimalNumber() {
-        assertEquals(8, Integer.parseInt("1000", 2));
+        assertEquals(8, Integer.parseInt("1000", 2));
-        assertEquals(20, Integer.parseInt("10100", 2));
+        assertEquals(20, Integer.parseInt("10100", 2));
-    }
+    }
-
+
-    @Test
+    @Test
-    public void given_binaryNumber_then_returnDecimalNumber() {
+    public void given_binaryNumber_then_returnDecimalNumber() {
-        assertEquals(Integer.valueOf(8), binaryNumbers.convertBinaryToDecimal(1000));
+        assertEquals(Integer.valueOf(8), binaryNumbers.convertBinaryToDecimal(1000));
-        assertEquals(Integer.valueOf(20), binaryNumbers.convertBinaryToDecimal(10100));
+        assertEquals(Integer.valueOf(20), binaryNumbers.convertBinaryToDecimal(10100));
-    }
+    }
-
+
-    @Test
+    @Test
-    public void given_twoBinaryNumber_then_returnAddition() {
+    public void given_twoBinaryNumber_then_returnAddition() {
-        // adding 4 and 10
+        // adding 4 and 10
-        assertEquals(Integer.valueOf(1110), binaryNumbers.addBinaryNumber(100, 1010));
+        assertEquals(Integer.valueOf(1110), binaryNumbers.addBinaryNumber(100, 1010));
-
+
-        // adding 26 and 14
+        // adding 26 and 14
-        assertEquals(Integer.valueOf(101000), binaryNumbers.addBinaryNumber(11010, 1110));
+        assertEquals(Integer.valueOf(101000), binaryNumbers.addBinaryNumber(11010, 1110));
-    }
+    }
-
+
-    @Test
+    @Test
-    public void given_twoBinaryNumber_then_returnSubtraction() {
+    public void given_twoBinaryNumber_then_returnSubtraction() {
-        // subtracting 16 from 25
+        // subtracting 16 from 25
-        assertEquals(Integer.valueOf(1001), binaryNumbers.substractBinaryNumber(11001, 10000));
+        assertEquals(Integer.valueOf(1001), binaryNumbers.substractBinaryNumber(11001, 10000));
-
+
-        // subtracting 29 from 16, the output here is negative
+        // subtracting 29 from 16, the output here is negative
-        assertEquals(Integer.valueOf(1101), binaryNumbers.substractBinaryNumber(10000, 11101));
+        assertEquals(Integer.valueOf(1101), binaryNumbers.substractBinaryNumber(10000, 11101));
-    }
+    }
-
+
-    @Test
+    @Test
-    public void given_binaryLiteral_thenReturnDecimalValue() {
+    public void given_binaryLiteral_thenReturnDecimalValue() {
-
+
-        byte five = 0b101;
+        byte five = 0b101;
-        assertEquals((byte) 5, five);
+        assertEquals((byte) 5, five);
-
+
-        short three = 0b11;
+        short three = 0b11;
-        assertEquals((short) 3, three);
+        assertEquals((short) 3, three);
-
+
-        int nine = 0B1001;
+        int nine = 0B1001;
-        assertEquals(9, nine);
+        assertEquals(9, nine);
-
+
-        long twentyNine = 0B11101;
+        long twentyNine = 0B11101;
-        assertEquals(29, twentyNine);
+        assertEquals(29, twentyNine);
-
+
-        int minusThirtySeven = -0B100101;
+        int minusThirtySeven = -0B100101;
-        assertEquals(-37, minusThirtySeven);
+        assertEquals(-37, minusThirtySeven);
-
+
-    }
+    }
-
+
-}
+}

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>

core-java-modules/java-numbers/src/main/java/com/baeldung/maths/FloatingPointArithmetic.java

@@ -1,51 +1,51 @@
-package com.baeldung.maths;
+package com.baeldung.maths;
-
+
-import java.math.BigDecimal;
+import java.math.BigDecimal;
-
+
-public class FloatingPointArithmetic {
+public class FloatingPointArithmetic {
-    public static void main(String[] args) {
+    public static void main(String[] args) {
-        
+        
-        double a = 13.22;
+        double a = 13.22;
-        double b = 4.88;
+        double b = 4.88;
-        double c = 21.45;
+        double c = 21.45;
-        
+        
-        System.out.println("a =         " + a);
+        System.out.println("a =         " + a);
-        System.out.println("b =         " + b);
+        System.out.println("b =         " + b);
-        System.out.println("c =         " + c);
+        System.out.println("c =         " + c);
-        
+        
-        double sum_ab = a + b;
+        double sum_ab = a + b;
-        System.out.println("a + b =     " + sum_ab);
+        System.out.println("a + b =     " + sum_ab);
-        
+        
-        double abc =  a + b + c;
+        double abc =  a + b + c;
-        System.out.println("a + b + c = " + abc);
+        System.out.println("a + b + c = " + abc);
-        
+        
-        double ab_c = sum_ab + c;
+        double ab_c = sum_ab + c;
-        System.out.println("ab + c =    " + ab_c);
+        System.out.println("ab + c =    " + ab_c);
-        
+        
-        double sum_ac = a + c;
+        double sum_ac = a + c;
-        System.out.println("a + c =     " + sum_ac);
+        System.out.println("a + c =     " + sum_ac);
-        
+        
-        double acb = a + c + b;
+        double acb = a + c + b;
-        System.out.println("a + c + b = " + acb);
+        System.out.println("a + c + b = " + acb);
-        
+        
-        double ac_b = sum_ac + b;
+        double ac_b = sum_ac + b;
-        System.out.println("ac + b =    " + ac_b);
+        System.out.println("ac + b =    " + ac_b);
-        
+        
-        double ab = 18.1;
+        double ab = 18.1;
-        double ac = 34.67;
+        double ac = 34.67;
-        double sum_ab_c = ab + c;
+        double sum_ab_c = ab + c;
-        double sum_ac_b = ac + b;
+        double sum_ac_b = ac + b;
-        System.out.println("ab + c =    " + sum_ab_c);
+        System.out.println("ab + c =    " + sum_ab_c);
-        System.out.println("ac + b =    " + sum_ac_b);
+        System.out.println("ac + b =    " + sum_ac_b);
-        
+        
-        BigDecimal d = new BigDecimal(String.valueOf(a));
+        BigDecimal d = new BigDecimal(String.valueOf(a));
-        BigDecimal e = new BigDecimal(String.valueOf(b));
+        BigDecimal e = new BigDecimal(String.valueOf(b));
-        BigDecimal f = new BigDecimal(String.valueOf(c));
+        BigDecimal f = new BigDecimal(String.valueOf(c));
-        
+        
-        BigDecimal def = d.add(e).add(f);
+        BigDecimal def = d.add(e).add(f);
-        BigDecimal dfe = d.add(f).add(e);
+        BigDecimal dfe = d.add(f).add(e);
-        
+        
-        System.out.println("d + e + f = " + def);
+        System.out.println("d + e + f = " + def);
-        System.out.println("d + f + e = " + dfe);
+        System.out.println("d + f + e = " + dfe);
-    }
+    }
-}
+}

core-java-modules/java-numbers/src/main/java/com/baeldung/numberofdigits/Benchmarking.java

@@ -1,67 +1,67 @@
-package com.baeldung.numberofdigits;
+package com.baeldung.numberofdigits;
-
+
-import java.io.IOException;
+import java.io.IOException;
-import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeUnit;
-
+
-import org.openjdk.jmh.annotations.Benchmark;
+import org.openjdk.jmh.annotations.Benchmark;
-import org.openjdk.jmh.annotations.BenchmarkMode;
+import org.openjdk.jmh.annotations.BenchmarkMode;
-import org.openjdk.jmh.annotations.Mode;
+import org.openjdk.jmh.annotations.Mode;
-import org.openjdk.jmh.annotations.OutputTimeUnit;
+import org.openjdk.jmh.annotations.OutputTimeUnit;
-import org.openjdk.jmh.annotations.Scope;
+import org.openjdk.jmh.annotations.Scope;
-import org.openjdk.jmh.annotations.State;
+import org.openjdk.jmh.annotations.State;
-import org.openjdk.jmh.runner.RunnerException;
+import org.openjdk.jmh.runner.RunnerException;
-
+
-public class Benchmarking {
+public class Benchmarking {
-    public static void main(String[] args) throws RunnerException, IOException {
+    public static void main(String[] args) throws RunnerException, IOException {
-        org.openjdk.jmh.Main.main(args);
+        org.openjdk.jmh.Main.main(args);
-    }
+    }
-
+
-    @State(Scope.Thread)
+    @State(Scope.Thread)
-    public static class ExecutionPlan {
+    public static class ExecutionPlan {
-        public int number = Integer.MAX_VALUE;
+        public int number = Integer.MAX_VALUE;
-        public int length = 0;
+        public int length = 0;
-        public NumberOfDigits numberOfDigits= new NumberOfDigits();
+        public NumberOfDigits numberOfDigits= new NumberOfDigits();
-    }
+    }
-    
+    
-    @Benchmark 
+    @Benchmark 
-    @BenchmarkMode(Mode.AverageTime)
+    @BenchmarkMode(Mode.AverageTime)
-    @OutputTimeUnit(TimeUnit.NANOSECONDS)
+    @OutputTimeUnit(TimeUnit.NANOSECONDS)
-    public void stringBasedSolution(ExecutionPlan plan) {
+    public void stringBasedSolution(ExecutionPlan plan) {
-        plan.length = plan.numberOfDigits.stringBasedSolution(plan.number);
+        plan.length = plan.numberOfDigits.stringBasedSolution(plan.number);
-    }
+    }
-    
+    
-    @Benchmark 
+    @Benchmark 
-    @BenchmarkMode(Mode.AverageTime)
+    @BenchmarkMode(Mode.AverageTime)
-    @OutputTimeUnit(TimeUnit.NANOSECONDS)
+    @OutputTimeUnit(TimeUnit.NANOSECONDS)
-    public void logarithmicApproach(ExecutionPlan plan) {
+    public void logarithmicApproach(ExecutionPlan plan) {
-        plan.length = plan.numberOfDigits.logarithmicApproach(plan.number);
+        plan.length = plan.numberOfDigits.logarithmicApproach(plan.number);
-    }
+    }
-    
+    
-    @Benchmark 
+    @Benchmark 
-    @BenchmarkMode(Mode.AverageTime)
+    @BenchmarkMode(Mode.AverageTime)
-    @OutputTimeUnit(TimeUnit.NANOSECONDS)
+    @OutputTimeUnit(TimeUnit.NANOSECONDS)
-    public void repeatedMultiplication(ExecutionPlan plan) {
+    public void repeatedMultiplication(ExecutionPlan plan) {
-        plan.length = plan.numberOfDigits.repeatedMultiplication(plan.number);
+        plan.length = plan.numberOfDigits.repeatedMultiplication(plan.number);
-    }
+    }
-    
+    
-    @Benchmark 
+    @Benchmark 
-    @BenchmarkMode(Mode.AverageTime)
+    @BenchmarkMode(Mode.AverageTime)
-    @OutputTimeUnit(TimeUnit.NANOSECONDS)
+    @OutputTimeUnit(TimeUnit.NANOSECONDS)
-    public void shiftOperators(ExecutionPlan plan) {
+    public void shiftOperators(ExecutionPlan plan) {
-        plan.length = plan.numberOfDigits.shiftOperators(plan.number);
+        plan.length = plan.numberOfDigits.shiftOperators(plan.number);
-    }
+    }
-    
+    
-    @Benchmark 
+    @Benchmark 
-    @BenchmarkMode(Mode.AverageTime)
+    @BenchmarkMode(Mode.AverageTime)
-    @OutputTimeUnit(TimeUnit.NANOSECONDS)
+    @OutputTimeUnit(TimeUnit.NANOSECONDS)
-    public void dividingWithPowersOf2(ExecutionPlan plan) {
+    public void dividingWithPowersOf2(ExecutionPlan plan) {
-        plan.length = plan.numberOfDigits.dividingWithPowersOf2(plan.number);
+        plan.length = plan.numberOfDigits.dividingWithPowersOf2(plan.number);
-    }
+    }
-    
+    
-    @Benchmark 
+    @Benchmark 
-    @BenchmarkMode(Mode.AverageTime)
+    @BenchmarkMode(Mode.AverageTime)
-    @OutputTimeUnit(TimeUnit.NANOSECONDS)
+    @OutputTimeUnit(TimeUnit.NANOSECONDS)
-    public void divideAndConquer(ExecutionPlan plan) {
+    public void divideAndConquer(ExecutionPlan plan) {
-        plan.length = plan.numberOfDigits.divideAndConquer(plan.number);
+        plan.length = plan.numberOfDigits.divideAndConquer(plan.number);
-    }
+    }
-}
+}

core-java-modules/java-numbers/src/main/java/com/baeldung/numberofdigits/NumberOfDigits.java

@@ -1,97 +1,97 @@
-package com.baeldung.numberofdigits;
+package com.baeldung.numberofdigits;
-
+
-public class NumberOfDigits {
+public class NumberOfDigits {
-    public int stringBasedSolution(int number) {
+    public int stringBasedSolution(int number) {
-        int length = String.valueOf(number).length();
+        int length = String.valueOf(number).length();
-        return length;
+        return length;
-    }
+    }
-    
+    
-    public int logarithmicApproach(int number) {
+    public int logarithmicApproach(int number) {
-        int length = (int) Math.log10(number) + 1;
+        int length = (int) Math.log10(number) + 1;
-        return length;
+        return length;
-    }
+    }
-    
+    
-    public int repeatedMultiplication(int number) {
+    public int repeatedMultiplication(int number) {
-        int length = 0;
+        int length = 0;
-        long temp = 1;
+        long temp = 1;
-        while(temp <= number) {
+        while(temp <= number) {
-            length++;
+            length++;
-            temp *= 10;
+            temp *= 10;
-        }
+        }
-        return length;
+        return length;
-    }
+    }
-
+
-    public int shiftOperators(int number) {
+    public int shiftOperators(int number) {
-        int length = 0;
+        int length = 0;
-        long temp = 1;
+        long temp = 1;
-        while(temp <= number) {
+        while(temp <= number) {
-            length++;
+            length++;
-            temp = (temp << 3) + (temp << 1);
+            temp = (temp << 3) + (temp << 1);
-        }
+        }
-        return length;
+        return length;
-    }
+    }
-    
+    
-    public int dividingWithPowersOf2(int number) {
+    public int dividingWithPowersOf2(int number) {
-        int length = 1;
+        int length = 1;
-        if (number >= 100000000) {
+        if (number >= 100000000) {
-            length += 8;
+            length += 8;
-            number /= 100000000;
+            number /= 100000000;
-        }
+        }
-        if (number >= 10000) {
+        if (number >= 10000) {
-            length += 4;
+            length += 4;
-            number /= 10000;
+            number /= 10000;
-        }
+        }
-        if (number >= 100) {
+        if (number >= 100) {
-            length += 2;
+            length += 2;
-            number /= 100;
+            number /= 100;
-        }
+        }
-        if (number >= 10) {
+        if (number >= 10) {
-            length += 1;
+            length += 1;
-        }
+        }
-        return length;
+        return length;
-    }
+    }
-    
+    
-    public int divideAndConquer(int number) {
+    public int divideAndConquer(int number) {
-        if (number < 100000){
+        if (number < 100000){
-            // 5 digits or less
+            // 5 digits or less
-            if (number < 100){
+            if (number < 100){
-                // 1 or 2
+                // 1 or 2
-                if (number < 10)
+                if (number < 10)
-                    return 1;
+                    return 1;
-                else
+                else
-                    return 2;
+                    return 2;
-            }else{
+            }else{
-                // 3 to 5 digits
+                // 3 to 5 digits
-                if (number < 1000)
+                if (number < 1000)
-                    return 3;
+                    return 3;
-                else{
+                else{
-                    // 4 or 5 digits
+                    // 4 or 5 digits
-                    if (number < 10000)
+                    if (number < 10000)
-                        return 4;
+                        return 4;
-                    else
+                    else
-                        return 5;
+                        return 5;
-                }
+                }
-            }
+            }
-        } else {
+        } else {
-            // 6 digits or more
+            // 6 digits or more
-            if (number < 10000000) {
+            if (number < 10000000) {
-                // 6 or 7 digits
+                // 6 or 7 digits
-                if (number < 1000000)
+                if (number < 1000000)
-                    return 6;
+                    return 6;
-                else
+                else
-                    return 7;
+                    return 7;
-            } else {
+            } else {
-                // 8 to 10 digits
+                // 8 to 10 digits
-                if (number < 100000000)
+                if (number < 100000000)
-                    return 8;
+                    return 8;
-                else {
+                else {
-                    // 9 or 10 digits
+                    // 9 or 10 digits
-                    if (number < 1000000000)
+                    if (number < 1000000000)
-                        return 9;
+                        return 9;
-                    else
+                    else
-                        return 10;
+                        return 10;
-                }
+                }
-            }
+            }
-        }
+        }
-    }
+    }
-}
+}

core-java-modules/java-numbers/src/main/java/com/baeldung/numberofdigits/NumberOfDigitsDriver.java

@@ -1,35 +1,35 @@
-package com.baeldung.numberofdigits;
+package com.baeldung.numberofdigits;
-
+
-import org.apache.log4j.Logger;
+import org.apache.log4j.Logger;
-
+
-public class NumberOfDigitsDriver {
+public class NumberOfDigitsDriver {
-    private static NumberOfDigits numberOfDigits;
+    private static NumberOfDigits numberOfDigits;
-
+
-    private static Logger LOG = Logger.getLogger(NumberOfDigitsDriver.class);
+    private static Logger LOG = Logger.getLogger(NumberOfDigitsDriver.class);
-
+
-    static {
+    static {
-        numberOfDigits = new NumberOfDigits();
+        numberOfDigits = new NumberOfDigits();
-    }
+    }
-
+
-    public static void main(String[] args) {
+    public static void main(String[] args) {
-        LOG.info("Testing all methods...");
+        LOG.info("Testing all methods...");
-
+
-        long length = numberOfDigits.stringBasedSolution(602);
+        long length = numberOfDigits.stringBasedSolution(602);
-        LOG.info("String Based Solution : " + length);
+        LOG.info("String Based Solution : " + length);
-
+
-        length = numberOfDigits.logarithmicApproach(602);
+        length = numberOfDigits.logarithmicApproach(602);
-        LOG.info("Logarithmic Approach : " + length);
+        LOG.info("Logarithmic Approach : " + length);
-
+
-        length = numberOfDigits.repeatedMultiplication(602);
+        length = numberOfDigits.repeatedMultiplication(602);
-        LOG.info("Repeated Multiplication : " + length);
+        LOG.info("Repeated Multiplication : " + length);
-
+
-        length = numberOfDigits.shiftOperators(602);
+        length = numberOfDigits.shiftOperators(602);
-        LOG.info("Shift Operators : " + length);
+        LOG.info("Shift Operators : " + length);
-
+
-        length = numberOfDigits.dividingWithPowersOf2(602);
+        length = numberOfDigits.dividingWithPowersOf2(602);
-        LOG.info("Dividing with Powers of 2 : " + length);
+        LOG.info("Dividing with Powers of 2 : " + length);
-
+
-        length = numberOfDigits.divideAndConquer(602);
+        length = numberOfDigits.divideAndConquer(602);
-        LOG.info("Divide And Conquer : " + length);
+        LOG.info("Divide And Conquer : " + length);
-    }
+    }
 }