Merge pull request #2 from eugenp/master

Sync with upstream

algorithms-miscellaneous-3/README.md

@@ -1,4 +1,4 @@
-## Relevant articles:
+## Relevant Articles:
 
 - [Java Two Pointer Technique](https://www.baeldung.com/java-two-pointer-technique)
 - [Implementing Simple State Machines with Java Enums](https://www.baeldung.com/java-enum-simple-state-machine)

algorithms-miscellaneous-3/pom.xml

@@ -30,6 +30,19 @@
         	<artifactId>guava</artifactId>
         	<version>${guava.version}</version>
         </dependency>
+
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-lang3</artifactId>
+            <version>3.8.1</version>
+        </dependency>
+
+        <dependency>
+            <groupId>pl.pragmatists</groupId>
+            <artifactId>JUnitParams</artifactId>
+            <version>1.1.0</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <build>

algorithms-miscellaneous-3/src/main/java/com/baeldung/algorithms/printtriangles/PrintTriangleExamples.java

@@ -0,0 +1,49 @@
+package com.baeldung.algorithms.printtriangles;
+
+import org.apache.commons.lang3.StringUtils;
+
+public class PrintTriangleExamples {
+
+    public static String printARightAngledTriangle(int N) {
+        StringBuilder result = new StringBuilder();
+        for (int r = 1; r <= N; r++) {
+            for (int j = 1; j <= r; j++) {
+                result.append("*");
+            }
+            result.append(System.lineSeparator());
+        }
+        return result.toString();
+    }
+
+    public static String printAnIsoscelesTriangle(int N) {
+        StringBuilder result = new StringBuilder();
+        for (int r = 1; r <= N; r++) {
+            for (int sp = 1; sp <= N - r; sp++) {
+                result.append(" ");
+            }
+            for (int c = 1; c <= (r * 2) - 1; c++) {
+                result.append("*");
+            }
+            result.append(System.lineSeparator());
+        }
+        return result.toString();
+    }
+
+    public static String printAnIsoscelesTriangleUsingSubstring(int N) {
+        StringBuilder result = new StringBuilder();
+        String helperString = StringUtils.repeat(' ', N - 1) + StringUtils.repeat('*', N * 2 - 1);
+
+        for (int r = 0; r < N; r++) {
+            result.append(helperString.substring(r, N + 2 * r));
+            result.append(System.lineSeparator());
+        }
+        return result.toString();
+    }
+
+    public static void main(String[] args) {
+        System.out.println(printARightAngledTriangle(5));
+        System.out.println(printAnIsoscelesTriangle(5));
+        System.out.println(printAnIsoscelesTriangleUsingSubstring(5));
+    }
+
+}

algorithms-miscellaneous-3/src/test/java/com/baeldung/algorithms/printtriangles/PrintTriangleExamplesUnitTest.java

@@ -0,0 +1,93 @@
+package com.baeldung.algorithms.printtriangles;
+
+import junitparams.JUnitParamsRunner;
+import junitparams.Parameters;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import static org.junit.Assert.assertEquals;
+
+@RunWith(JUnitParamsRunner.class)
+public class PrintTriangleExamplesUnitTest {
+    
+    private static Object[][] rightAngledTriangles() {
+        String expected0 = ""; 
+        
+        String expected2 = "*" + System.lineSeparator() 
+                         + "**" + System.lineSeparator();
+        
+        String expected5 = "*" + System.lineSeparator() 
+                         + "**" + System.lineSeparator()
+                         + "***" + System.lineSeparator()
+                         + "****" + System.lineSeparator()
+                         + "*****" + System.lineSeparator();
+        
+        String expected7 = "*" + System.lineSeparator() 
+                         + "**" + System.lineSeparator()
+                         + "***" + System.lineSeparator()
+                         + "****" + System.lineSeparator()
+                         + "*****" + System.lineSeparator()
+                         + "******" + System.lineSeparator()
+                         + "*******" + System.lineSeparator();
+        
+        return new Object[][] {
+            { 0, expected0 },
+            { 2, expected2 },
+            { 5, expected5 },
+            { 7, expected7 }
+        };
+    }
+
+    @Test
+    @Parameters(method = "rightAngledTriangles")
+    public void whenPrintARightAngledTriangleIsCalled_ThenTheCorrectStringIsReturned(int nrOfRows, String expected) {
+        String actual = PrintTriangleExamples.printARightAngledTriangle(nrOfRows);
+
+        assertEquals(expected, actual);
+    }
+    
+    private static Object[][] isoscelesTriangles() {
+        String expected0 = ""; 
+        
+        String expected2 = " *" + System.lineSeparator() 
+                         + "***" + System.lineSeparator();
+        
+        String expected5 = "    *" + System.lineSeparator() 
+                         + "   ***" + System.lineSeparator()
+                         + "  *****" + System.lineSeparator()
+                         + " *******" + System.lineSeparator()
+                         + "*********" + System.lineSeparator();
+        
+        String expected7 = "      *" + System.lineSeparator() 
+                         + "     ***" + System.lineSeparator()
+                         + "    *****" + System.lineSeparator()
+                         + "   *******" + System.lineSeparator()
+                         + "  *********" + System.lineSeparator()
+                         + " ***********" + System.lineSeparator()
+                         + "*************" + System.lineSeparator();
+        
+        return new Object[][] {
+            { 0, expected0 },
+            { 2, expected2 },
+            { 5, expected5 },
+            { 7, expected7 }
+        };
+    }
+
+    @Test
+    @Parameters(method = "isoscelesTriangles")
+    public void whenPrintAnIsoscelesTriangleIsCalled_ThenTheCorrectStringIsReturned(int nrOfRows, String expected) {
+        String actual = PrintTriangleExamples.printAnIsoscelesTriangle(nrOfRows);
+
+        assertEquals(expected, actual);
+    }
+    
+    @Test
+    @Parameters(method = "isoscelesTriangles")
+    public void whenPrintAnIsoscelesTriangleUsingSubstringIsCalled_ThenTheCorrectStringIsReturned(int nrOfRows, String expected) {
+        String actual = PrintTriangleExamples.printAnIsoscelesTriangleUsingSubstring(nrOfRows);
+
+        assertEquals(expected, actual);
+    }
+
+}

algorithms-sorting/src/main/java/com/baeldung/algorithms/selectionsort/SelectionSort.java

@@ -0,0 +1,38 @@
+package com.baeldung.algorithms.selectionsort;
+
+public class SelectionSort {
+
+    public static void sortAscending(final int[] arr) {
+        for (int i = 0; i < arr.length - 1; i++) {
+            int minElementIndex = i;
+            for (int j = i + 1; j < arr.length; j++) {
+                if (arr[minElementIndex] > arr[j]) {
+                    minElementIndex = j;
+                }
+            }
+
+            if (minElementIndex != i) {
+                int temp = arr[i];
+                arr[i] = arr[minElementIndex];
+                arr[minElementIndex] = temp;
+            }
+        }
+    }
+
+    public static void sortDescending(final int[] arr) {
+        for (int i = 0; i < arr.length - 1; i++) {
+            int maxElementIndex = i;
+            for (int j = i + 1; j < arr.length; j++) {
+                if (arr[maxElementIndex] < arr[j]) {
+                    maxElementIndex = j;
+                }
+            }
+
+            if (maxElementIndex != i) {
+                int temp = arr[i];
+                arr[i] = arr[maxElementIndex];
+                arr[maxElementIndex] = temp;
+            }
+        }
+    }
+}

algorithms-sorting/src/test/java/com/baeldung/algorithms/selectionsort/SelectionSortUnitTest.java

@@ -0,0 +1,25 @@
+package com.baeldung.algorithms.selectionsort;
+
+import static org.junit.Assert.*;
+import static org.junit.Assert.assertArrayEquals;
+
+import org.junit.Test;
+
+public class SelectionSortUnitTest {
+
+    @Test
+    public void givenUnsortedArray_whenSelectionSort_SortAscending_thenSortedAsc() {
+        int[] input = { 5, 4, 1, 6, 2 };
+        SelectionSort.sortAscending(input);
+        int[] expected = {1, 2, 4, 5, 6};
+        assertArrayEquals("the two arrays are not equal", expected, input);
+    }
+    
+    @Test
+    public void givenUnsortedArray_whenSelectionSort_SortDescending_thenSortedDesc() {
+        int[] input = { 5, 4, 1, 6, 2 };
+        SelectionSort.sortDescending(input);
+        int[] expected = {6, 5, 4, 2, 1};
+        assertArrayEquals("the two arrays are not equal", expected, input);
+    }
+}

core-groovy-2/src/main/groovy/com/baeldung/metaprogramming/Employee.groovy

@@ -0,0 +1,45 @@
+package com.baeldung.metaprogramming
+
+import groovy.transform.AutoClone
+import groovy.transform.Canonical
+import groovy.transform.EqualsAndHashCode
+import groovy.transform.ToString
+import groovy.transform.TupleConstructor
+import groovy.util.logging.*
+
+@Canonical
+@TupleConstructor
+@EqualsAndHashCode
+@ToString(includePackage=false, excludes=['id'])
+@Log 
+@AutoClone
+class Employee {
+
+    long id
+    String firstName
+    String lastName
+    int age
+
+    //method to catch missing property's getter
+    def propertyMissing(String propertyName) {
+        log.info "$propertyName is not available"
+        "property '$propertyName' is not available"
+    }
+
+    //method to catch missing property's setter
+    def propertyMissing(String propertyName, propertyValue) {
+        println "property '$propertyName' is not available"
+        log.info "$propertyName is not available"
+        "property '$propertyName' is not available"
+    }
+
+    def methodMissing(String methodName, def methodArgs) {
+        log.info "$methodName is not defined"
+        "method '$methodName' is not defined"
+    }
+    
+    def logEmp() {
+        log.info "Employee: $lastName, $firstName is of $age years age"
+    }
+
+}

core-groovy-2/src/main/groovy/com/baeldung/metaprogramming/extension/BasicExtensions.groovy

@@ -0,0 +1,30 @@
+package com.baeldung.metaprogramming.extension
+
+import com.baeldung.metaprogramming.Employee
+
+class BasicExtensions {
+    
+    static int getYearOfBirth(Employee self) {
+        return (new Date().getYear() + 1900) - self.age;
+    }
+    
+    static String capitalize(String self) {
+        return self.substring(0, 1).toUpperCase() + self.substring(1)
+    }
+
+    static void printCounter(Integer self) {
+        while (self>0) {
+            println self
+            self--
+        }
+    }
+    
+    static Long square(Long self) {
+        return self*self
+    }
+    
+    static BigDecimal cube(BigDecimal self) {
+        return self*self*self
+    }
+    
+}

core-groovy-2/src/main/groovy/com/baeldung/metaprogramming/extension/StaticEmployeeExtension.groovy

@@ -0,0 +1,10 @@
+package com.baeldung.metaprogramming.extension
+
+import com.baeldung.metaprogramming.Employee
+
+class StaticEmployeeExtension {
+    
+    static Employee getDefaultObj(Employee self) {
+        return new Employee(firstName: "firstName", lastName: "lastName", age: 20)
+    }
+}

core-groovy-2/src/main/resources/META-INF/services/org.codehaus.groovy.runtime.ExtensionModule

@@ -0,0 +1,4 @@
+moduleName=core-groovy-2
+moduleVersion=1.0-SNAPSHOT
+extensionClasses=com.baeldung.metaprogramming.extension.BasicExtensions
+staticExtensionClasses=com.baeldung.metaprogramming.extension.StaticEmployeeExtension

core-groovy-2/src/test/groovy/com/baeldung/metaprogramming/MetaprogrammingUnitTest.groovy

@@ -0,0 +1,118 @@
+package com.baeldung.metaprogramming
+
+import groovy.time.TimeCategory
+
+class MetaprogrammingUnitTest extends GroovyTestCase {
+
+    Employee emp = new Employee(firstName: "Norman", lastName: "Lewis")
+
+    void testPropertyMissing() {
+        assert emp.address == "property 'address' is not available"
+    }
+
+    void testMethodMissing() {
+        Employee emp = new Employee()
+        try {
+            emp.getFullName()
+        } catch(MissingMethodException e) {
+            println "method is not defined"
+        }
+        assert emp.getFullName() == "method 'getFullName' is not defined"
+    }
+
+    void testMetaClassProperty() {
+        Employee.metaClass.address = ""
+        emp = new Employee(firstName: "Norman", lastName: "Lewis", address: "US")
+        assert emp.address == "US"
+    }
+
+    void testMetaClassMethod() {
+        emp.metaClass.getFullName = {
+            "$lastName, $firstName"
+        }
+        assert emp.getFullName() == "Lewis, Norman"
+    }
+
+    void testMetaClassConstructor() {
+        try {
+            Employee emp = new Employee("Norman")
+        } catch(GroovyRuntimeException e) {
+            assert e.message == "Could not find matching constructor for: com.baeldung.metaprogramming.Employee(String)"
+        }
+
+        Employee.metaClass.constructor = { String firstName ->
+            new Employee(firstName: firstName)
+        }
+
+        Employee norman = new Employee("Norman")
+        assert norman.firstName == "Norman"
+        assert norman.lastName == null
+    }
+
+    void testJavaMetaClass() {
+        String.metaClass.capitalize = { String str ->
+            str.substring(0, 1).toUpperCase() + str.substring(1);
+        }
+        assert "norman".capitalize() == "Norman"
+    }
+
+    void testEmployeeExtension() {
+        Employee emp = new Employee(age: 28)
+        assert emp.getYearOfBirth() == 1991
+    }
+
+    void testJavaClassesExtensions() {
+        5.printCounter()
+
+        assert 40l.square() == 1600l
+
+        assert (2.98).cube() == 26.463592
+    }
+
+    void testStaticEmployeeExtension() {
+        assert Employee.getDefaultObj().firstName == "firstName"
+        assert Employee.getDefaultObj().lastName == "lastName"
+        assert Employee.getDefaultObj().age == 20
+    }
+
+    void testToStringAnnotation() {
+        Employee employee = new Employee()
+        employee.id = 1
+        employee.firstName = "norman"
+        employee.lastName = "lewis"
+        employee.age = 28
+
+        assert employee.toString() == "Employee(norman, lewis, 28)"
+    }
+
+    void testTupleConstructorAnnotation() {
+        Employee norman = new Employee(1, "norman", "lewis", 28)
+        assert norman.toString() == "Employee(norman, lewis, 28)"
+
+        Employee snape = new Employee(2, "snape")
+        assert snape.toString() == "Employee(snape, null, 0)"
+
+    }
+    
+    void testEqualsAndHashCodeAnnotation() {
+        Employee norman = new Employee(1, "norman", "lewis", 28)
+        Employee normanCopy = new Employee(1, "norman", "lewis", 28)
+        assert norman.equals(normanCopy)
+        assert norman.hashCode() == normanCopy.hashCode()
+    }
+    
+    void testAutoCloneAnnotation() {
+        try {
+            Employee norman = new Employee(1, "norman", "lewis", 28)
+            def normanCopy = norman.clone()
+            assert norman == normanCopy
+        } catch(CloneNotSupportedException e) {
+            e.printStackTrace()
+        }
+    }
+
+    void testLoggingAnnotation() {
+        Employee employee = new Employee(1, "Norman", "Lewis", 28)
+        employee.logEmp()
+    }
+}

core-java-modules/core-java-8-2/README.md

@@ -7,3 +7,4 @@
 - [How to Delay Code Execution in Java](https://www.baeldung.com/java-delay-code-execution)
 - [Run JAR Application With Command Line Arguments](https://www.baeldung.com/java-run-jar-with-arguments)
 - [Java 8 Stream skip() vs limit()](https://www.baeldung.com/java-stream-skip-vs-limit)
+- [Guide to Java BiFunction Interface](https://www.baeldung.com/java-bifunction-interface)

core-java-modules/core-java-8/README.md

@@ -4,14 +4,10 @@
 
 ### Relevant Articles: 
 - [Guide to Java 8’s Collectors](http://www.baeldung.com/java-8-collectors)
-- [Functional Interfaces in Java 8](http://www.baeldung.com/java-8-functional-interfaces)
-- [Java 8 – Powerful Comparison with Lambdas](http://www.baeldung.com/java-8-sort-lambda)
 - [New Features in Java 8](http://www.baeldung.com/java-8-new-features)
-- [Lambda Expressions and Functional Interfaces: Tips and Best Practices](http://www.baeldung.com/java-8-lambda-expressions-tips)
 - [The Double Colon Operator in Java 8](http://www.baeldung.com/java-8-double-colon-operator)
 - [Guide to Java 8 groupingBy Collector](http://www.baeldung.com/java-groupingby-collector)
 - [Strategy Design Pattern in Java 8](http://www.baeldung.com/java-strategy-pattern)
-- [Exceptions in Java 8 Lambda Expressions](http://www.baeldung.com/java-lambda-exceptions)
 - [Guide to Java 8 Comparator.comparing()](http://www.baeldung.com/java-8-comparator-comparing)
 - [Guide To Java 8 Optional](http://www.baeldung.com/java-optional)
 - [Guide to the Java 8 forEach](http://www.baeldung.com/foreach-java)
@@ -38,6 +34,5 @@
 - [Java @SafeVarargs Annotation](https://www.baeldung.com/java-safevarargs)
 - [Java @Deprecated Annotation](https://www.baeldung.com/java-deprecated)
 - [Java 8 Predicate Chain](https://www.baeldung.com/java-predicate-chain)
-- [Method References in Java](https://www.baeldung.com/java-method-references)
 - [Creating a Custom Annotation in Java](https://www.baeldung.com/java-custom-annotation)
 - [The Difference Between Collection.stream().forEach() and Collection.forEach()](https://www.baeldung.com/java-collection-stream-foreach)

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

@@ -7,7 +7,7 @@
 - [Check if a Java Array Contains a Value](http://www.baeldung.com/java-array-contains-value)
 - [Initializing Arrays in Java](http://www.baeldung.com/java-initialize-array)
 - [Guide to the java.util.Arrays Class](http://www.baeldung.com/java-util-arrays)
-- [Jagged Arrays In Java](http://www.baeldung.com/java-jagged-arrays)
+- [Multi-Dimensional Arrays In Java](http://www.baeldung.com/java-jagged-arrays)
 - [Find Sum and Average in a Java Array](http://www.baeldung.com/java-array-sum-average)
 - [Arrays in Java: A Reference Guide](https://www.baeldung.com/java-arrays-guide)
 - [How to Invert an Array in Java](http://www.baeldung.com/java-invert-array)
@@ -16,3 +16,4 @@
 - [Sorting Arrays in Java](https://www.baeldung.com/java-sorting-arrays)
 - [Convert a Float to a Byte Array in Java](https://www.baeldung.com/java-convert-float-to-byte-array)
 - [Converting Between Stream and Array in Java](https://www.baeldung.com/java-stream-to-array)
+- [Removing an Element from an Array in Java](https://www.baeldung.com/java-array-remove-element)

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

@@ -0,0 +1,3 @@
+### Relevant Articles
+
+- [Design Strategies for Decoupling Java Modules](https://www.baeldung.com/java-modules-decoupling-design-strategies)

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

@@ -1,3 +1,8 @@
 ## Relevant articles:
 
 - [Why Do Local Variables Used in Lambdas Have to Be Final or Effectively Final?](https://www.baeldung.com/java-lambda-effectively-final-local-variables)
+- [Java 8 – Powerful Comparison with Lambdas](http://www.baeldung.com/java-8-sort-lambda)
+- [Functional Interfaces in Java 8](http://www.baeldung.com/java-8-functional-interfaces)
+- [Lambda Expressions and Functional Interfaces: Tips and Best Practices](http://www.baeldung.com/java-8-lambda-expressions-tips)
+- [Exceptions in Java 8 Lambda Expressions](http://www.baeldung.com/java-lambda-exceptions)
+- [Method References in Java](https://www.baeldung.com/java-method-references)

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

@@ -15,5 +15,11 @@
     <relativePath>../../parent-java</relativePath>
   </parent>
 
-
+  <dependencies>
+    <dependency>
+      <groupId>org.apache.commons</groupId>
+      <artifactId>commons-lang3</artifactId>
+      <version>${commons-lang3.version}</version>
+    </dependency>
+  </dependencies>
 </project>

core-java-modules/core-java-lang-operators/pom.xml

@@ -0,0 +1,43 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <groupId>com.baeldung</groupId>
+    <artifactId>core-java-lang-operators</artifactId>
+    <version>0.1.0-SNAPSHOT</version>
+    <name>core-java-lang-operators</name>
+    <packaging>jar</packaging>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-java</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../../parent-java</relativePath>
+    </parent>
+
+    <dependencies>
+        <!-- test scoped -->
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${assertj-core.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <finalName>core-java-lang-operators</finalName>
+        <resources>
+            <resource>
+                <directory>src/main/resources</directory>
+                <filtering>true</filtering>
+            </resource>
+        </resources>
+    </build>
+
+    <properties>
+        <!-- testing -->
+        <assertj-core.version>3.10.0</assertj-core.version>
+    </properties>
+
+</project>

core-java-modules/core-java-lang-operators/src/test/java/com/baeldung/incrementdecrementunaryoperators/IncrementDecrementUnaryOperatorUnitTest.java

@@ -0,0 +1,64 @@
+package com.baeldung.incrementdecrementunaryoperators;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.junit.Test;
+
+public class IncrementDecrementUnaryOperatorUnitTest {
+
+    @Test
+    public void givenAnOperand_whenUsingPreIncrementUnaryOperator_thenOperandIsIncrementedByOne() {
+        int operand = 1;
+        ++operand;
+        assertThat(operand).isEqualTo(2);
+    }
+
+    @Test
+    public void givenANumber_whenUsingPreIncrementUnaryOperatorInEvaluation_thenNumberIsIncrementedByOne() {
+        int operand = 1;
+        int number = ++operand;
+        assertThat(number).isEqualTo(2);
+    }
+
+    @Test
+    public void givenAnOperand_whenUsingPreDecrementUnaryOperator_thenOperandIsDecrementedByOne() {
+        int operand = 1;
+        --operand;
+        assertThat(operand).isEqualTo(0);
+    }
+
+    @Test
+    public void givenANumber_whenUsingPreDecrementUnaryOperatorInEvaluation_thenNumberIsDecrementedByOne() {
+        int operand = 1;
+        int number = --operand;
+        assertThat(number).isEqualTo(0);
+    }
+
+    @Test
+    public void givenAnOperand_whenUsingPostIncrementUnaryOperator_thenOperandIsIncrementedByOne() {
+        int operand = 1;
+        operand++;
+        assertThat(operand).isEqualTo(2);
+    }
+
+    @Test
+    public void givenANumber_whenUsingPostIncrementUnaryOperatorInEvaluation_thenNumberIsSameAsOldValue() {
+        int operand = 1;
+        int number = operand++;
+        assertThat(number).isEqualTo(1);
+    }
+
+    @Test
+    public void givenAnOperand_whenUsingPostDecrementUnaryOperator_thenOperandIsDecrementedByOne() {
+        int operand = 1;
+        operand--;
+        assertThat(operand).isEqualTo(0);
+    }
+
+    @Test
+    public void givenANumber_whenUsingPostDecrementUnaryOperatorInEvaluation_thenNumberIsSameAsOldValue() {
+        int operand = 1;
+        int number = operand--;
+        assertThat(number).isEqualTo(1);
+    }
+}

core-java-modules/core-java-lang-syntax/README.md

@@ -18,3 +18,4 @@
 - [The Modulo Operator in Java](https://www.baeldung.com/modulo-java)
 - [Ternary Operator In Java](https://www.baeldung.com/java-ternary-operator)
 - [Java instanceof Operator](https://www.baeldung.com/java-instanceof)
+- [Breaking Out of Nested Loops](https://www.baeldung.com/java-breaking-out-nested-loop)

core-java-modules/core-java-networking-2/.gitignore

@@ -1,25 +0,0 @@
-*.class
-
-0.*
-
-#folders#
-/target
-/neoDb*
-/data
-/src/main/webapp/WEB-INF/classes
-*/META-INF/*
-.resourceCache
-
-# Packaged files #
-*.jar
-*.war
-*.ear
-
-# Files generated by integration tests
-backup-pom.xml
-/bin/
-/temp
-
-#IntelliJ specific
-.idea/
-*.iml

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

@@ -1,3 +1,3 @@
-## Relevant articles:
+## Relevant Articles:
 
-- [Determine File Creating Date in Java](https://www.baeldung.com/java-file-creation-date)
+- [Determine File Creation Date in Java](https://www.baeldung.com/java-file-creation-date)

core-java-modules/core-java-nio/src/main/java/com/baeldung/file/Main.java

@@ -0,0 +1,26 @@
+package com.baeldung.file;
+
+import static com.baeldung.file.NumberOfLineFinder.getTotalNumberOfLinesUsingApacheCommonsIO;
+import static com.baeldung.file.NumberOfLineFinder.getTotalNumberOfLinesUsingBufferedReader;
+import static com.baeldung.file.NumberOfLineFinder.getTotalNumberOfLinesUsingGoogleGuava;
+import static com.baeldung.file.NumberOfLineFinder.getTotalNumberOfLinesUsingLineNumberReader;
+import static com.baeldung.file.NumberOfLineFinder.getTotalNumberOfLinesUsingNIOFileChannel;
+import static com.baeldung.file.NumberOfLineFinder.getTotalNumberOfLinesUsingNIOFiles;
+import static com.baeldung.file.NumberOfLineFinder.getTotalNumberOfLinesUsingNIOFilesReadAllLines;
+import static com.baeldung.file.NumberOfLineFinder.getTotalNumberOfLinesUsingScanner;
+
+public class Main {
+
+    private static final String INPUT_FILE_NAME = "src/main/resources/input.txt";
+
+    public static void main(String... args) throws Exception {
+        System.out.printf("Total Number of Lines Using BufferedReader: %s%n", getTotalNumberOfLinesUsingBufferedReader(INPUT_FILE_NAME));
+        System.out.printf("Total Number of Lines Using LineNumberReader: %s%n", getTotalNumberOfLinesUsingLineNumberReader(INPUT_FILE_NAME));
+        System.out.printf("Total Number of Lines Using Scanner: %s%n", getTotalNumberOfLinesUsingScanner(INPUT_FILE_NAME));
+        System.out.printf("Total Number of Lines Using NIO Files: %s%n", getTotalNumberOfLinesUsingNIOFiles(INPUT_FILE_NAME));
+        System.out.printf("Total Number of Lines Using NIO Files#readAllLines: %s%n", getTotalNumberOfLinesUsingNIOFilesReadAllLines(INPUT_FILE_NAME));
+        System.out.printf("Total Number of Lines Using NIO FileChannel: %s%n", getTotalNumberOfLinesUsingNIOFileChannel(INPUT_FILE_NAME));
+        System.out.printf("Total Number of Lines Using Apache Commons IO: %s%n", getTotalNumberOfLinesUsingApacheCommonsIO(INPUT_FILE_NAME));
+        System.out.printf("Total Number of Lines Using NIO Google Guava: %s%n", getTotalNumberOfLinesUsingGoogleGuava(INPUT_FILE_NAME));
+    }
+}

core-java-modules/core-java-nio/src/main/java/com/baeldung/file/NumberOfLineFinder.java

@@ -0,0 +1,123 @@
+package com.baeldung.file;
+
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.FileReader;
+import java.io.IOException;
+import java.io.LineNumberReader;
+import java.nio.ByteBuffer;
+import java.nio.channels.FileChannel;
+import java.nio.channels.FileChannel.MapMode;
+import java.nio.charset.Charset;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.nio.file.StandardOpenOption;
+import java.util.List;
+import java.util.Scanner;
+import java.util.stream.Stream;
+
+import org.apache.commons.io.FileUtils;
+import org.apache.commons.io.LineIterator;
+
+public class NumberOfLineFinder {
+
+    public static int getTotalNumberOfLinesUsingBufferedReader(String fileName) {
+        int lines = 0;
+        try (BufferedReader reader = new BufferedReader(new FileReader(fileName))) {
+            while (reader.readLine() != null) {
+                lines++;
+            }
+        } catch (IOException ioe) {
+            ioe.printStackTrace();
+        }
+        return lines;
+    }
+
+    public static int getTotalNumberOfLinesUsingLineNumberReader(String fileName) {
+        int lines = 0;
+        try (LineNumberReader reader = new LineNumberReader(new FileReader(fileName))) {
+            reader.skip(Integer.MAX_VALUE);
+            lines = reader.getLineNumber() + 1;
+        } catch (IOException ioe) {
+            ioe.printStackTrace();
+        }
+        return lines;
+    }
+
+    public static int getTotalNumberOfLinesUsingScanner(String fileName) {
+        int lines = 0;
+        try (Scanner scanner = new Scanner(new FileReader(fileName))) {
+            while (scanner.hasNextLine()) {
+                scanner.nextLine();
+                lines++;
+            }
+        } catch (IOException ioe) {
+            ioe.printStackTrace();
+        }
+        return lines;
+    }
+
+    public static int getTotalNumberOfLinesUsingNIOFiles(String fileName) {
+        int lines = 0;
+        try (Stream<String> fileStream = Files.lines(Paths.get(fileName))) {
+            lines = (int) fileStream.count();
+        } catch (IOException ioe) {
+            ioe.printStackTrace();
+        }
+        return lines;
+    }
+
+    public static int getTotalNumberOfLinesUsingNIOFilesReadAllLines(String fileName) {
+        int lines = 0;
+        try {
+            List<String> fileStream = Files.readAllLines(Paths.get(fileName));
+            lines = fileStream.size();
+        } catch (IOException ioe) {
+            ioe.printStackTrace();
+        }
+        return lines;
+    }
+
+    public static int getTotalNumberOfLinesUsingNIOFileChannel(String fileName) {
+        int lines = 1;
+        try (FileChannel channel = FileChannel.open(Paths.get(fileName), StandardOpenOption.READ)) {
+            ByteBuffer byteBuffer = channel.map(MapMode.READ_ONLY, 0, channel.size());
+            while (byteBuffer.hasRemaining()) {
+                byte currentChar = byteBuffer.get();
+                if (currentChar == '\n') {
+                    lines++;
+                }
+            }
+        } catch (IOException ioe) {
+            ioe.printStackTrace();
+        }
+        return lines;
+    }
+
+    public static int getTotalNumberOfLinesUsingApacheCommonsIO(String fileName) {
+        int lines = 0;
+        try {
+            LineIterator lineIterator = FileUtils.lineIterator(new File(fileName));
+            while (lineIterator.hasNext()) {
+                lineIterator.nextLine();
+                lines++;
+            }
+        } catch (IOException ioe) {
+            ioe.printStackTrace();
+        }
+        return lines;
+    }
+
+    public static int getTotalNumberOfLinesUsingGoogleGuava(String fileName) {
+        int lines = 0;
+        try {
+            List<String> lineItems = com.google.common.io.Files.readLines(Paths.get(fileName)
+                .toFile(), Charset.defaultCharset());
+            lines = lineItems.size();
+        } catch (IOException ioe) {
+            ioe.printStackTrace();
+        }
+        return lines;
+    }
+
+}

core-java-modules/core-java-nio/src/main/resources/input.txt

@@ -0,0 +1,45 @@
+Lorem ipsum dolor sit amet, consectetur adipiscing elit. In lacus enim, scelerisque id sapien ut, semper euismod quam. Nunc ullamcorper semper blandit. Praesent quis quam mollis, iaculis lectus a, fringilla leo. Interdum et malesuada fames ac ante ipsum primis in faucibus. Duis vitae auctor mauris. Pellentesque eu pellentesque lorem, vel ultricies libero. Pellentesque vestibulum sagittis eros. In vestibulum lacus elit. Interdum et malesuada fames ac ante ipsum primis in faucibus.
+
+Vivamus pharetra lacus fringilla nisl molestie eleifend. Donec et dolor non quam mattis mattis. Proin malesuada maximus elit id semper. Donec facilisis dolor ut feugiat auctor. Proin accumsan semper consectetur. Vivamus facilisis odio vel bibendum imperdiet. Sed rutrum nisi nec nisi interdum fringilla. Aliquam laoreet velit ullamcorper egestas ultrices. Aliquam ultricies sem sed orci interdum, eu porta purus malesuada. Sed accumsan, nunc ut maximus rhoncus, arcu ante pretium ex, non ultrices magna nisi et velit. Pellentesque tempor mi quis lacus consectetur, quis imperdiet enim efficitur. Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas.
+
+Nunc sed maximus erat. Aenean imperdiet finibus massa ac aliquam. Interdum et malesuada fames ac ante ipsum primis in faucibus. Duis dignissim cursus purus, eu tempus urna. Nunc sed mauris scelerisque, luctus eros ut, viverra nisi. Maecenas congue sed ligula in eleifend. Praesent nec dignissim enim, dictum efficitur massa. Nullam eros dui, rutrum quis aliquam accumsan, sollicitudin cursus eros. Phasellus euismod, lorem vitae vehicula ullamcorper, leo lorem vestibulum magna, vitae malesuada libero ipsum id lorem. Aenean finibus turpis facilisis tortor bibendum, vitae dignissim dolor dictum. Ut quis ornare nisi, non rutrum sapien.
+
+Etiam placerat, est eget placerat imperdiet, neque urna tristique est, a dictum nisl dolor vitae leo. Vivamus porttitor mi vitae volutpat ultrices. Quisque at ante porta mauris ultricies iaculis. Phasellus iaculis sollicitudin urna nec facilisis. Suspendisse dapibus vulputate scelerisque. Fusce felis diam, eleifend in tristique in, malesuada a purus. Suspendisse euismod ipsum sed urna imperdiet, quis venenatis lacus dapibus. Maecenas vitae est vel sem fringilla ornare at ut mi. Quisque porta, nulla at rutrum fringilla, mi ligula egestas libero, ac convallis elit diam et sapien. Vestibulum purus tortor, ornare ut enim sed, mattis lobortis erat. Maecenas ac ante tincidunt, euismod mauris a, fermentum diam. Nullam arcu est, consequat sed enim in, bibendum aliquet velit. Donec bibendum magna ac augue sagittis vehicula. Curabitur nec mauris eu augue bibendum volutpat. Fusce fringilla varius fringilla.
+
+Aliquam faucibus massa non orci accumsan, porta consectetur diam vulputate. Nullam nec erat mollis, imperdiet libero nec, tincidunt neque. Aenean varius purus nec est auctor, sed vulputate libero varius. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Praesent vel neque elit. Donec vulputate fermentum nulla, ut aliquam neque tempor in. Orci varius natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Donec vel venenatis est. Suspendisse luctus elit quis dui dapibus, id sodales dolor cursus. Curabitur ut vehicula dui. Fusce aliquet est et ante feugiat, et tempus ex congue. Nunc eget dapibus leo. Nunc eu accumsan diam. Suspendisse risus eros, rutrum et volutpat in, consequat in nulla. Suspendisse id felis a orci accumsan iaculis.
+
+Duis tincidunt diam eget tortor aliquet sodales. Etiam sodales purus ac urna mollis, et cursus enim porttitor. Nulla viverra ligula nunc, ornare condimentum felis posuere sed. Fusce aliquet pretium sagittis. Sed ac mi elementum massa dictum ornare. Integer quis dapibus lectus. Curabitur in rhoncus justo, et vulputate justo. Integer eget efficitur felis.
+
+Sed finibus vel tortor ac egestas. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Maecenas vestibulum nulla mi, blandit efficitur sapien fermentum eu. Integer sed turpis eros. Phasellus sed aliquam ligula. Etiam dictum quam in dapibus mattis. Donec et tristique quam. Pellentesque gravida luctus dolor, eu ornare sapien. Donec justo ante, lacinia non sem et, ultricies dignissim nibh. Vivamus eu nisl et magna pulvinar efficitur. Sed at vehicula lectus, sit amet luctus sem. Morbi vehicula sapien nisi, nec sagittis orci vestibulum et.
+
+Praesent non finibus diam. Quisque sit amet nisl vitae augue lobortis commodo. Morbi ullamcorper, tortor id ornare maximus, erat ipsum ullamcorper ipsum, in imperdiet diam sem vel erat. Sed pellentesque quis ex sed volutpat. Vestibulum volutpat diam ac dignissim sollicitudin. Praesent at luctus ex, at volutpat dui. Nunc nulla dui, lobortis et pharetra quis, efficitur in turpis. Donec sodales auctor purus id mollis. Sed auctor eu erat eget bibendum. Mauris tincidunt ornare neque id consequat. Suspendisse non massa ante. Quisque velit enim, rhoncus at erat eget, scelerisque placerat elit. Donec finibus luctus dolor. In sed eleifend lorem. Sed tempor ullamcorper lorem nec tristique. Fusce nec volutpat neque, id elementum est.
+
+Orci varius natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Vestibulum mattis elementum tellus, vitae maximus nulla eleifend ut. Vestibulum eu nibh vulputate, posuere felis eget, aliquet ex. Nullam leo ex, lacinia a ante ac, accumsan efficitur ligula. Vestibulum ornare gravida tempus. Proin rhoncus felis sit amet dolor commodo facilisis. Integer aliquet, diam sed pharetra feugiat, sem massa mollis orci, eget pretium libero nunc at quam. Ut rhoncus quam vitae massa hendrerit, ornare condimentum odio varius. Donec odio sapien, tristique eget libero ac, interdum facilisis odio. Phasellus nec mauris vel dolor semper mattis et quis ligula. Donec nec porttitor nunc. Integer maximus quam vitae sem gravida, ut commodo ex porttitor.
+
+Sed cursus nisi turpis, vel laoreet massa blandit ut. Cras posuere velit nulla, nec pellentesque ipsum dignissim eget. Donec pharetra, ex et commodo viverra, leo dolor dapibus tellus, vel dignissim est sem ac lectus. Quisque a arcu dapibus, aliquet magna sed, rhoncus neque. Integer suscipit, nulla ac varius lacinia, orci metus scelerisque neque, a laoreet nibh risus vitae dolor. Pellentesque felis metus, pulvinar vel cursus id, ultrices non purus. Donec mi lectus, faucibus sit amet nunc at, sagittis pretium lectus. Fusce nec purus arcu. Mauris neque neque, blandit eget mi at, auctor tempus orci. Mauris sapien lorem, luctus nec tellus non, porttitor aliquam dui.
+
+Mauris non ex risus. Aliquam imperdiet in eros eget placerat. Sed congue sed sapien porta sollicitudin. Phasellus tempor hendrerit metus vitae tincidunt. Suspendisse congue nisi sed augue dapibus, at pretium ante mollis. Cras non posuere nulla. Proin malesuada finibus magna vel iaculis. Cras in dapibus lorem. Pellentesque volutpat dolor sit amet magna tincidunt mollis. Nunc et lectus sodales, accumsan est vitae, ornare augue. Maecenas malesuada arcu leo, eget blandit lectus porttitor et. Nam aliquam sapien sit amet purus consequat lobortis. Aenean varius, augue porta dignissim efficitur, felis velit dapibus leo, tincidunt ultricies magna felis id ligula. Duis hendrerit, lectus eu elementum euismod, elit lectus consequat mi, sit amet egestas justo massa ut urna. Proin eleifend interdum ultrices.
+
+Donec lacinia orci pharetra ornare tincidunt. Nulla facilisi. Maecenas malesuada dui ac elit sagittis tincidunt id dictum dolor. Quisque lobortis purus ac metus volutpat viverra. Proin finibus sapien ut odio semper consectetur. Sed gravida luctus egestas. Mauris pretium volutpat elit, at commodo arcu sagittis nec. Ut condimentum fringilla urna ac dignissim. Cras aliquam metus pulvinar, pulvinar nibh at, placerat arcu. Nulla ornare tortor sed lectus mollis, vitae fringilla tellus egestas. Vivamus efficitur tincidunt sapien, sed finibus mi congue eu. Nullam magna velit, lacinia vitae ligula eget, molestie consectetur felis. Suspendisse varius turpis orci, ac laoreet arcu accumsan sed. Fusce quis fermentum lacus, nec varius libero. Pellentesque ac odio ut justo lobortis elementum sit amet vehicula lorem. Nulla interdum nulla eget mi tristique, vitae egestas nunc egestas.
+
+Curabitur commodo libero eu elit tincidunt, quis placerat risus vehicula. Vestibulum vehicula id nunc iaculis fermentum. Aenean semper, tellus ac semper rutrum, justo lorem feugiat leo, quis vulputate neque dui non ligula. Etiam egestas, enim eget tempor porta, nunc est tristique ante, vel suscipit massa lorem vel diam. Donec faucibus ante id turpis rhoncus congue. Nullam laoreet, diam efficitur scelerisque consequat, ligula leo ultrices est, non fermentum elit mauris ut dolor. Morbi non porttitor lorem. Sed volutpat sapien et lorem porttitor, ultricies ultricies tellus congue. Mauris sodales, tortor nec sagittis finibus, dui odio aliquet nibh, in luctus sapien massa eu risus. Nulla in est sed ante molestie vehicula vel nec lectus. Fusce maximus a quam eget aliquam. Vivamus pulvinar quis nisi a maximus. Proin cursus lacus sapien, et hendrerit elit pretium a. Donec tellus lectus, consectetur id dolor a, luctus rutrum libero. Suspendisse auctor scelerisque dui, nec pellentesque felis viverra nec. Cras elit ex, varius sed pulvinar sed, suscipit ultrices lacus.
+
+Vivamus eu luctus lectus. Maecenas congue magna orci, quis semper nulla blandit vel. Phasellus dignissim risus placerat lacinia sagittis. Praesent at gravida nisi, at pulvinar diam. Nulla egestas lectus sed felis facilisis egestas. Curabitur posuere gravida urna eu vestibulum. Pellentesque at dolor gravida, placerat quam sit amet, fermentum ligula. Morbi fringilla, mi eget mollis dictum, neque dolor ullamcorper leo, a rutrum libero ipsum eget orci. Curabitur consectetur iaculis vestibulum. Suspendisse ultricies ligula et neque lacinia luctus. Sed dignissim neque id eros sollicitudin pellentesque.
+
+Donec et magna quis lectus pharetra finibus a fringilla sapien. Phasellus accumsan, erat eu sodales cursus, tortor elit dapibus risus, ut ornare neque arcu in tellus. Nam ac vehicula diam, at aliquam nisl. Cras in sem eget nisi ultrices rutrum sit amet eu velit. Sed molestie tellus eget ante scelerisque, sit amet pulvinar neque fringilla. Nunc volutpat facilisis egestas. Cras sodales dui ac massa egestas, in mattis leo rhoncus. Pellentesque vitae urna vehicula ipsum sodales suscipit. Sed commodo tempus fringilla.
+
+Etiam egestas elit vitae mi maximus fringilla quis eget libero. Fusce finibus ultrices tellus at molestie. Pellentesque posuere blandit elementum. Etiam eu erat eu urna hendrerit euismod. Nulla quis lectus rhoncus, ultricies urna eget, pretium neque. Cras sit amet ipsum sit amet purus rutrum ultricies nec vitae tortor. Sed tempor dapibus augue in pulvinar. Ut pretium sapien in malesuada accumsan. Donec eget ultrices erat, ut efficitur ligula. Sed posuere mauris est, nec convallis ipsum tempus non.
+
+Duis a ullamcorper ante. Quisque eu ultricies metus, at aliquet odio. Nullam tempus molestie augue ut varius. Fusce purus eros, dictum nec finibus sed, sodales et diam. Suspendisse sed mi purus. Donec eleifend ipsum diam, nec fringilla enim laoreet non. Phasellus condimentum, magna sit amet porttitor suscipit, arcu risus lobortis dolor, ac fringilla nibh nisl vel purus. Phasellus facilisis posuere orci sit amet tempus. Nam nec enim maximus, rhoncus felis a, rutrum diam.
+
+Suspendisse potenti. Donec vel tempor neque. In aliquet nulla in eleifend bibendum. Sed sapien sem, finibus in sodales vitae, euismod in sem. Phasellus nec elit a erat pulvinar semper. Aliquam luctus nisl in libero molestie aliquam. Nunc ac ornare felis. Ut non mauris ut ipsum rhoncus pretium. Curabitur tristique lacus a sagittis aliquam. Morbi vel volutpat tellus. Maecenas volutpat, lacus sed tempus imperdiet, eros tellus volutpat nisi, a egestas augue nulla quis arcu. In sollicitudin imperdiet efficitur. Suspendisse viverra aliquet nisi, congue ultrices arcu hendrerit in.
+
+Maecenas vitae vestibulum nunc. Nullam semper faucibus tincidunt. Etiam sed hendrerit risus. Proin gravida, urna nec tincidunt tempus, nulla sapien porttitor nibh, porttitor lobortis nunc quam et tortor. Praesent ut varius lacus, ut hendrerit enim. Ut nec turpis ac felis imperdiet bibendum. Phasellus porttitor enim odio, et vehicula mi convallis vel. Quisque porta scelerisque sagittis. Praesent dignissim sagittis vulputate. Aenean non justo ac est volutpat bibendum. Aliquam mattis, sapien dapibus pellentesque semper, velit urna malesuada diam, nec varius nibh eros at erat. Proin leo ante, ultricies id velit ut, faucibus porta nibh. Sed nec fermentum urna, sed mollis leo. Aliquam erat volutpat.
+
+Donec condimentum, urna sed hendrerit vestibulum, ante nibh lacinia dui, in tincidunt odio sem eget orci. In hac habitasse platea dictumst. Mauris id ex id ante tempus finibus eu sagittis erat. Quisque interdum urna risus, vel varius nibh euismod non. Nulla eget pellentesque quam. Aliquam vestibulum ac tortor non lobortis. Sed vitae erat sed libero dignissim dictum nec in turpis. Vivamus id ornare elit, ut facilisis lectus. Morbi dictum purus eget ipsum dignissim porttitor. Sed at vehicula purus, nec rhoncus quam. Nunc a nisl quis arcu blandit fermentum vel quis odio. Vivamus rhoncus, sapien sed lacinia hendrerit, velit urna fermentum dolor, id feugiat magna ligula sed urna. Proin euismod efficitur libero, eget porttitor lacus tempus quis. Duis tincidunt quis est a laoreet. Nam sit amet tristique nisl, sit amet mattis mi.
+
+Aenean id dictum nulla, sed laoreet magna. Morbi consectetur in turpis at aliquam. Maecenas rutrum feugiat metus, at ullamcorper augue fermentum ut. Vivamus in magna pretium nibh dictum rhoncus luctus at orci. In hac habitasse platea dictumst. Fusce convallis, nulla nec hendrerit suscipit, ipsum diam lobortis sem, vitae elementum lectus erat sit amet magna. Quisque sollicitudin fringilla purus, ac molestie justo congue vitae. Nulla sapien leo, ullamcorper ac tellus in, cursus rhoncus enim. Suspendisse rutrum magna non ex elementum elementum id vitae enim. Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas. Suspendisse ornare libero eu molestie pulvinar. Phasellus faucibus, magna eget rutrum porta, lorem turpis blandit lectus, eu viverra massa risus et ex.
+
+Ut consectetur eros lacus, ac ullamcorper lacus mattis a. Cras congue justo ut erat interdum, et scelerisque nisi malesuada. Quisque sed sapien sollicitudin purus tincidunt finibus vestibulum vel dolor. Cras iaculis bibendum erat, a dictum urna viverra et. Integer non neque vulputate, tincidunt purus nec, rutrum arcu. Aliquam nec magna non sem semper laoreet quis at quam. Mauris dui lectus, convallis eu efficitur at, facilisis nec lorem. Cras felis sem, egestas ac rutrum vel, mollis et ex. Aenean semper egestas libero, nec commodo mi blandit efficitur. Duis nec quam in massa dignissim sagittis vel vitae leo. Nam molestie hendrerit auctor.
+
+Sed suscipit egestas tellus sed cursus. Donec vel massa sit amet dui condimentum accumsan. Phasellus libero eros, lobortis a nisi id, porttitor maximus lectus. Praesent consectetur diam urna, id viverra turpis elementum in. Vivamus vitae pretium justo, nec tempor felis. Vivamus volutpat ultricies magna. Suspendisse vulputate lectus ac orci volutpat ullamcorper. Nulla eu leo pretium, commodo arcu accumsan, tempor nisl. Fusce sit amet tellus a ipsum vehicula laoreet sed vitae mauris. Duis porttitor massa mattis nibh placerat consequat. Fusce rutrum commodo tortor eget pellentesque. Suspendisse tempor enim libero, consequat dictum nibh dictum varius. Pellentesque feugiat sit amet urna sed facilisis. Curabitur a sagittis augue.

core-java-modules/core-java-nio/src/test/java/com/baeldung/file/NumberOfLineFinderUnitTest.java

@@ -0,0 +1,67 @@
+package com.baeldung.file;
+
+import static com.baeldung.file.NumberOfLineFinder.getTotalNumberOfLinesUsingApacheCommonsIO;
+import static com.baeldung.file.NumberOfLineFinder.getTotalNumberOfLinesUsingBufferedReader;
+import static com.baeldung.file.NumberOfLineFinder.getTotalNumberOfLinesUsingGoogleGuava;
+import static com.baeldung.file.NumberOfLineFinder.getTotalNumberOfLinesUsingLineNumberReader;
+import static com.baeldung.file.NumberOfLineFinder.getTotalNumberOfLinesUsingNIOFileChannel;
+import static com.baeldung.file.NumberOfLineFinder.getTotalNumberOfLinesUsingNIOFiles;
+import static com.baeldung.file.NumberOfLineFinder.getTotalNumberOfLinesUsingNIOFilesReadAllLines;
+import static com.baeldung.file.NumberOfLineFinder.getTotalNumberOfLinesUsingScanner;
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+public class NumberOfLineFinderUnitTest {
+    private static final String INPUT_FILE_NAME = "src/main/resources/input.txt";
+    private static final int ACTUAL_LINE_COUNT = 45;
+
+    @Test
+    public void whenUsingBufferedReader_thenReturnTotalNumberOfLines() {
+        int lines = getTotalNumberOfLinesUsingBufferedReader(INPUT_FILE_NAME);
+        assertEquals(ACTUAL_LINE_COUNT, lines);
+    }
+
+    @Test
+    public void whenUsingLineNumberReader_thenReturnTotalNumberOfLines() {
+        int lines = getTotalNumberOfLinesUsingLineNumberReader(INPUT_FILE_NAME);
+        assertEquals(ACTUAL_LINE_COUNT, lines);
+    }
+
+    @Test
+    public void whenUsingScanner_thenReturnTotalNumberOfLines() {
+        int lines = getTotalNumberOfLinesUsingScanner(INPUT_FILE_NAME);
+        assertEquals(ACTUAL_LINE_COUNT, lines);
+    }
+
+    @Test
+    public void whenUsingNIOFiles_thenReturnTotalNumberOfLines() {
+        int lines = getTotalNumberOfLinesUsingNIOFiles(INPUT_FILE_NAME);
+        assertEquals(ACTUAL_LINE_COUNT, lines);
+    }
+
+    @Test
+    public void whenUsingNIOFilesReadAllLines_thenReturnTotalNumberOfLines() {
+        int lines = getTotalNumberOfLinesUsingNIOFilesReadAllLines(INPUT_FILE_NAME);
+        assertEquals(ACTUAL_LINE_COUNT, lines);
+    }
+
+    @Test
+    public void whenUsingNIOFileChannel_thenReturnTotalNumberOfLines() {
+        int lines = getTotalNumberOfLinesUsingNIOFileChannel(INPUT_FILE_NAME);
+        assertEquals(ACTUAL_LINE_COUNT, lines);
+    }
+
+    @Test
+    public void whenUsingApacheCommonsIO_thenReturnTotalNumberOfLines() {
+        int lines = getTotalNumberOfLinesUsingApacheCommonsIO(INPUT_FILE_NAME);
+        assertEquals(ACTUAL_LINE_COUNT, lines);
+    }
+
+    @Test
+    public void whenUsingGoogleGuava_thenReturnTotalNumberOfLines() {
+        int lines = getTotalNumberOfLinesUsingGoogleGuava(INPUT_FILE_NAME);
+        assertEquals(ACTUAL_LINE_COUNT, lines);
+    }
+
+}

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

@@ -10,3 +10,4 @@
 - [SSL Handshake Failures](https://www.baeldung.com/java-ssl-handshake-failures)
 - [SHA-256 and SHA3-256 Hashing in Java](https://www.baeldung.com/sha-256-hashing-java)
 - [Enabling TLS v1.2 in Java 7](https://www.baeldung.com/java-7-tls-v12)
+- [The Java SecureRandom Class](https://www.baeldung.com/java-secure-random)

core-java-modules/core-java-security/src/main/java/com/baeldung/sasl/ClientCallbackHandler.java

@@ -0,0 +1,29 @@
+package com.baeldung.sasl;
+
+import java.io.IOException;
+
+import javax.security.auth.callback.Callback;
+import javax.security.auth.callback.CallbackHandler;
+import javax.security.auth.callback.NameCallback;
+import javax.security.auth.callback.PasswordCallback;
+import javax.security.auth.callback.UnsupportedCallbackException;
+import javax.security.sasl.RealmCallback;
+
+public class ClientCallbackHandler implements CallbackHandler {
+
+    @Override
+    public void handle(Callback[] cbs) throws IOException, UnsupportedCallbackException {
+        for (Callback cb : cbs) {
+            if (cb instanceof NameCallback) {
+                NameCallback nc = (NameCallback) cb;
+                nc.setName("username");
+            } else if (cb instanceof PasswordCallback) {
+                PasswordCallback pc = (PasswordCallback) cb;
+                pc.setPassword("password".toCharArray());
+            } else if (cb instanceof RealmCallback) {
+                RealmCallback rc = (RealmCallback) cb;
+                rc.setText("myServer");
+            }
+        }
+    }
+}

core-java-modules/core-java-security/src/main/java/com/baeldung/sasl/ServerCallbackHandler.java

@@ -0,0 +1,34 @@
+package com.baeldung.sasl;
+
+import java.io.IOException;
+
+import javax.security.auth.callback.Callback;
+import javax.security.auth.callback.CallbackHandler;
+import javax.security.auth.callback.NameCallback;
+import javax.security.auth.callback.PasswordCallback;
+import javax.security.auth.callback.UnsupportedCallbackException;
+import javax.security.sasl.AuthorizeCallback;
+import javax.security.sasl.RealmCallback;
+
+public class ServerCallbackHandler implements CallbackHandler {
+
+    @Override
+    public void handle(Callback[] cbs) throws IOException, UnsupportedCallbackException {
+        for (Callback cb : cbs) {
+            if (cb instanceof AuthorizeCallback) {
+                AuthorizeCallback ac = (AuthorizeCallback) cb;
+                ac.setAuthorized(true);
+            } else if (cb instanceof NameCallback) {
+                NameCallback nc = (NameCallback) cb;
+                nc.setName("username");
+
+            } else if (cb instanceof PasswordCallback) {
+                PasswordCallback pc = (PasswordCallback) cb;
+                pc.setPassword("password".toCharArray());
+            } else if (cb instanceof RealmCallback) {
+                RealmCallback rc = (RealmCallback) cb;
+                rc.setText("myServer");
+            }
+        }
+    }
+}

core-java-modules/core-java-security/src/test/java/com/baeldung/jgss/JgssIntegrationTest.java

@@ -0,0 +1,84 @@
+package com.baeldung.jgss;
+
+import static org.junit.Assert.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import javax.security.sasl.SaslException;
+
+import org.ietf.jgss.GSSContext;
+import org.ietf.jgss.GSSCredential;
+import org.ietf.jgss.GSSException;
+import org.ietf.jgss.GSSManager;
+import org.ietf.jgss.GSSName;
+import org.ietf.jgss.MessageProp;
+import org.ietf.jgss.Oid;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Ignore;
+import org.junit.Test;
+
+@Ignore
+public class JgssIntegrationTest {
+
+    private static final String SERVER_PRINCIPAL = "HTTP/localhost@EXAMPLE.COM";
+    private static final String MECHANISM = "1.2.840.113554.1.2.2";
+
+    GSSContext serverContext;
+    GSSContext clientContext;
+
+    @Before
+    public void setUp() throws SaslException, GSSException {
+        GSSManager manager = GSSManager.getInstance();
+        serverContext = manager.createContext((GSSCredential) null);
+        String serverPrinciple = SERVER_PRINCIPAL;
+        GSSName serverName = manager.createName(serverPrinciple, null);
+        Oid krb5Oid = new Oid(MECHANISM);
+        clientContext = manager.createContext(serverName, krb5Oid, (GSSCredential) null, GSSContext.DEFAULT_LIFETIME);
+        clientContext.requestMutualAuth(true);
+        clientContext.requestConf(true);
+        clientContext.requestInteg(true);
+    }
+
+    @Test
+    public void givenCredential_whenStarted_thenAutenticationWorks() throws SaslException, GSSException {
+        byte[] serverToken;
+        byte[] clientToken;
+
+        // On the client-side
+        clientToken = clientContext.initSecContext(new byte[0], 0, 0);
+        // sendToServer(clientToken); // This is supposed to be send over the network
+
+        // On the server-side
+        serverToken = serverContext.acceptSecContext(clientToken, 0, clientToken.length);
+        // sendToClient(serverToken); // This is supposed to be send over the network
+
+        // Back on the client-side
+        clientContext.initSecContext(serverToken, 0, serverToken.length);
+
+        assertTrue(serverContext.isEstablished());
+        assertTrue(clientContext.isEstablished());
+    }
+
+    @Test
+    public void givenContext_whenStarted_thenSecurityWorks() throws SaslException, GSSException {
+        // On the client-side
+        byte[] messageBytes = "Baeldung".getBytes();
+        MessageProp clientProp = new MessageProp(0, true);
+        byte[] clientToken = clientContext.wrap(messageBytes, 0, messageBytes.length, clientProp);
+        // sendToServer(clientToken); // This is supposed to be send over the network
+
+        // On the server-side
+        MessageProp serverProp = new MessageProp(0, false);
+        byte[] bytes = serverContext.unwrap(clientToken, 0, clientToken.length, serverProp);
+        String string = new String(bytes);
+
+        assertEquals("Baeldung", string);
+    }
+
+    @After
+    public void tearDown() throws SaslException, GSSException {
+        serverContext.dispose();
+        clientContext.dispose();
+    }
+
+}

core-java-modules/core-java-security/src/test/java/com/baeldung/sasl/SaslUnitTest.java

@@ -0,0 +1,76 @@
+package com.baeldung.sasl;
+
+import static org.junit.Assert.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.nio.charset.StandardCharsets;
+import java.util.HashMap;
+import java.util.Map;
+
+import javax.security.sasl.Sasl;
+import javax.security.sasl.SaslClient;
+import javax.security.sasl.SaslException;
+import javax.security.sasl.SaslServer;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+public class SaslUnitTest {
+
+    private static final String MECHANISM = "DIGEST-MD5";
+    private static final String SERVER_NAME = "myServer";
+    private static final String PROTOCOL = "myProtocol";
+    private static final String AUTHORIZATION_ID = null;
+    private static final String QOP_LEVEL = "auth-conf";
+
+    private SaslServer saslServer;
+    private SaslClient saslClient;
+
+    @Before
+    public void setUp() throws SaslException {
+
+        ServerCallbackHandler serverHandler = new ServerCallbackHandler();
+        ClientCallbackHandler clientHandler = new ClientCallbackHandler();
+
+        Map<String, String> props = new HashMap<>();
+        props.put(Sasl.QOP, QOP_LEVEL);
+
+        saslServer = Sasl.createSaslServer(MECHANISM, PROTOCOL, SERVER_NAME, props, serverHandler);
+        saslClient = Sasl.createSaslClient(new String[] { MECHANISM }, AUTHORIZATION_ID, PROTOCOL, SERVER_NAME, props, clientHandler);
+
+    }
+
+    @Test
+    public void givenHandlers_whenStarted_thenAutenticationWorks() throws SaslException {
+
+        byte[] challenge;
+        byte[] response;
+
+        challenge = saslServer.evaluateResponse(new byte[0]);
+        response = saslClient.evaluateChallenge(challenge);
+
+        challenge = saslServer.evaluateResponse(response);
+        response = saslClient.evaluateChallenge(challenge);
+
+        assertTrue(saslServer.isComplete());
+        assertTrue(saslClient.isComplete());
+
+        String qop = (String) saslClient.getNegotiatedProperty(Sasl.QOP);
+        assertEquals("auth-conf", qop);
+
+        byte[] outgoing = "Baeldung".getBytes();
+        byte[] secureOutgoing = saslClient.wrap(outgoing, 0, outgoing.length);
+
+        byte[] secureIncoming = secureOutgoing;
+        byte[] incoming = saslServer.unwrap(secureIncoming, 0, secureIncoming.length);
+        assertEquals("Baeldung", new String(incoming, StandardCharsets.UTF_8));
+    }
+
+    @After
+    public void tearDown() throws SaslException {
+        saslClient.dispose();
+        saslServer.dispose();
+    }
+
+}

core-java-modules/pom.xml

@@ -17,6 +17,7 @@
         <module>pre-jpms</module>
         <module>core-java-exceptions</module>
         <module>core-java-optional</module>
+        <module>core-java-lang-operators</module>
         <module>core-java-networking-2</module>
     </modules>
     

data-structures/README.md

@@ -1,4 +1,5 @@
 ## Relevant articles:
 
-[The Trie Data Structure in Java](https://www.baeldung.com/trie-java)
-[Implementing a Binary Tree in Java](https://www.baeldung.com/java-binary-tree)
+- [The Trie Data Structure in Java](https://www.baeldung.com/trie-java)
+- [Implementing a Binary Tree in Java](https://www.baeldung.com/java-binary-tree)
+- [Depth First Search in Java](https://www.baeldung.com/java-depth-first-search)

data-structures/src/main/java/com/baeldung/graph/Graph.java

@@ -2,6 +2,7 @@ package com.baeldung.graph;
 
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.Stack;
@@ -29,7 +30,7 @@ public class Graph {
         while (!stack.isEmpty()) {
             int current = stack.pop();
             isVisited[current] = true;
-            System.out.print(" " + current);
+            visit(current);
             for (int dest : adjVertices.get(current)) {
                 if (!isVisited[dest])
                     stack.push(dest);
@@ -44,29 +45,30 @@ public class Graph {
 
     private void dfsRecursive(int current, boolean[] isVisited) {
         isVisited[current] = true;
-        System.out.print(" " + current);
+        visit(current);
         for (int dest : adjVertices.get(current)) {
             if (!isVisited[dest])
                 dfsRecursive(dest, isVisited);
         }
     }
 
-    public void topologicalSort(int start) {
-        Stack<Integer> result = new Stack<Integer>();
+    public List<Integer> topologicalSort(int start) {
+        LinkedList<Integer> result = new LinkedList<Integer>();
         boolean[] isVisited = new boolean[adjVertices.size()];
         topologicalSortRecursive(start, isVisited, result);
-        while (!result.isEmpty()) {
-            System.out.print(" " + result.pop());
-        }
+        return result;
     }
 
-    private void topologicalSortRecursive(int current, boolean[] isVisited, Stack<Integer> result) {
+    private void topologicalSortRecursive(int current, boolean[] isVisited, LinkedList<Integer> result) {
         isVisited[current] = true;
         for (int dest : adjVertices.get(current)) {
             if (!isVisited[dest])
                 topologicalSortRecursive(dest, isVisited, result);
         }
-        result.push(current);
+        result.addFirst(current);
     }
 
+    private void visit(int value) {
+        System.out.print(" " + value);        
+    }
 }

data-structures/src/main/java/com/baeldung/tree/BinaryTree.java

@@ -103,14 +103,14 @@ public class BinaryTree {
     public void traverseInOrder(Node node) {
         if (node != null) {
             traverseInOrder(node.left);
-            System.out.print(" " + node.value);
+            visit(node.value);
             traverseInOrder(node.right);
         }
     }
 
     public void traversePreOrder(Node node) {
         if (node != null) {
-            System.out.print(" " + node.value);
+            visit(node.value);
             traversePreOrder(node.left);
             traversePreOrder(node.right);
         }
@@ -120,7 +120,7 @@ public class BinaryTree {
         if (node != null) {
             traversePostOrder(node.left);
             traversePostOrder(node.right);
-            System.out.print(" " + node.value);
+            visit(node.value);
         }
     }
 
@@ -159,7 +159,7 @@ public class BinaryTree {
                 stack.push(current);                
             }
             current = stack.pop();
-            System.out.print(" " + current.value);
+            visit(current.value);
             if(current.right != null) {
                 current = current.right;                
                 stack.push(current);
@@ -173,7 +173,7 @@ public class BinaryTree {
         stack.push(root);
         while(! stack.isEmpty()) {
             current = stack.pop();
-            System.out.print(" " + current.value);
+            visit(current.value);
             
             if(current.right != null)
                 stack.push(current.right);
@@ -196,7 +196,7 @@ public class BinaryTree {
 
             if (!hasChild || isPrevLastChild) {
                 current = stack.pop();
-                System.out.print(" " + current.value);
+                visit(current.value);
                 prev = current;
             } else {
                 if (current.right != null) {
@@ -209,6 +209,9 @@ public class BinaryTree {
         }   
     }    
     
+    private void visit(int value) {
+        System.out.print(" " + value);        
+    }
     
     class Node {
         int value;

data-structures/src/test/java/com/baeldung/graph/GraphUnitTest.java

@@ -1,5 +1,7 @@
 package com.baeldung.graph;
 
+import java.util.List;
+
 import org.junit.Test;
 
 public class GraphUnitTest {
@@ -15,7 +17,8 @@ public class GraphUnitTest {
     @Test
     public void givenDirectedGraph_whenGetTopologicalSort_thenPrintValuesSorted() {
         Graph graph = createDirectedGraph();
-        graph.topologicalSort(0);
+        List<Integer> list = graph.topologicalSort(0);
+        System.out.println(list);
     }
 
     private Graph createDirectedGraph() {

intelliJ/intelliJ-formatter.xml

@@ -1,19 +1,15 @@
-<code_scheme name="baeldung">
+<code_scheme name="baeldung-formatter" version="173">
   <option name="RIGHT_MARGIN" value="260" />
-  <option name="ENABLE_JAVADOC_FORMATTING" value="false" />
   <option name="FORMATTER_TAGS_ENABLED" value="true" />
   <JavaCodeStyleSettings>
-    <option name="SPACE_AFTER_CLOSING_ANGLE_BRACKET_IN_TYPE_ARGUMENT" value="true" />
-    <option name="DO_NOT_WRAP_AFTER_SINGLE_ANNOTATION" value="true" />
-    <option name="ALIGN_MULTILINE_ANNOTATION_PARAMETERS" value="true" />
+    <option name="CLASS_COUNT_TO_USE_IMPORT_ON_DEMAND" value="500" />
+    <option name="NAMES_COUNT_TO_USE_IMPORT_ON_DEMAND" value="300" />
+    <option name="ENABLE_JAVADOC_FORMATTING" value="false" />
   </JavaCodeStyleSettings>
-  <JetCodeStyleSettings>
-    <option name="NAME_COUNT_TO_USE_STAR_IMPORT" value="99" />
-    <option name="NAME_COUNT_TO_USE_STAR_IMPORT_FOR_MEMBERS" value="99" />
-  </JetCodeStyleSettings>
   <codeStyleSettings language="JAVA">
     <option name="KEEP_LINE_BREAKS" value="false" />
     <option name="KEEP_FIRST_COLUMN_COMMENT" value="false" />
+    <option name="KEEP_CONTROL_STATEMENT_IN_ONE_LINE" value="false" />
     <option name="KEEP_BLANK_LINES_IN_DECLARATIONS" value="1" />
     <option name="KEEP_BLANK_LINES_IN_CODE" value="1" />
     <option name="KEEP_BLANK_LINES_BEFORE_RBRACE" value="1" />
@@ -29,19 +25,18 @@
     <option name="THROWS_LIST_WRAP" value="1" />
     <option name="EXTENDS_KEYWORD_WRAP" value="1" />
     <option name="THROWS_KEYWORD_WRAP" value="1" />
-    <option name="METHOD_CALL_CHAIN_WRAP" value="2" />
-    <option name="WRAP_FIRST_METHOD_IN_CALL_CHAIN" value="true" />
+    <option name="METHOD_CALL_CHAIN_WRAP" value="5" />
     <option name="BINARY_OPERATION_WRAP" value="1" />
     <option name="BINARY_OPERATION_SIGN_ON_NEXT_LINE" value="true" />
     <option name="TERNARY_OPERATION_WRAP" value="5" />
-    <option name="TERNARY_OPERATION_SIGNS_ON_NEXT_LINE" value="true" />
     <option name="ARRAY_INITIALIZER_WRAP" value="1" />
-    <option name="ARRAY_INITIALIZER_LBRACE_ON_NEXT_LINE" value="true" />
-    <option name="ARRAY_INITIALIZER_RBRACE_ON_NEXT_LINE" value="true" />
-    <option name="PLACE_ASSIGNMENT_SIGN_ON_NEXT_LINE" value="true" />
+    <option name="METHOD_ANNOTATION_WRAP" value="0" />
+    <option name="CLASS_ANNOTATION_WRAP" value="0" />
+    <option name="FIELD_ANNOTATION_WRAP" value="0" />
     <indentOptions>
-      <option name="CONTINUATION_INDENT_SIZE" value="2" />
-      <option name="TAB_SIZE" value="8" />
+      <option name="INDENT_SIZE" value="8" />
+      <option name="CONTINUATION_INDENT_SIZE" value="4" />
+      <option name="SMART_TABS" value="true" />
     </indentOptions>
   </codeStyleSettings>
 </code_scheme>

jackson-2/README.md

@@ -2,7 +2,7 @@
 
 ## Jackson Cookbooks and Examples
 
-###The Course
+### The Course
 The "REST With Spring" Classes: http://bit.ly/restwithspring
 
 ### Relevant Articles: 
@@ -10,3 +10,4 @@ The "REST With Spring" Classes: http://bit.ly/restwithspring
 - [How to Process YAML with Jackson](https://www.baeldung.com/jackson-yaml)
 - [Working with Tree Model Nodes in Jackson](https://www.baeldung.com/jackson-json-node-tree-model)
 - [Converting JSON to CSV in Java](https://www.baeldung.com/java-converting-json-to-csv)
+- [Compare Two JSON Objects with Jackson](https://www.baeldung.com/jackson-compare-two-json-objects)

java-dates-2/README.md

@@ -1,3 +1,4 @@
 ## Relevant Articles:
 - [Converting Between LocalDate and XMLGregorianCalendar](https://www.baeldung.com/java-localdate-to-xmlgregoriancalendar)
 - [Convert Time to Milliseconds in Java](https://www.baeldung.com/java-time-milliseconds)
+- [Check If a String Is a Valid Date in Java](https://www.baeldung.com/java-string-valid-date)

java-dates/README.md

@@ -29,3 +29,4 @@
 - [A Guide to SimpleDateFormat](https://www.baeldung.com/java-simple-date-format)
 - [ZoneOffset in Java](https://www.baeldung.com/java-zone-offset)
 - [Differences Between ZonedDateTime and OffsetDateTime](https://www.baeldung.com/java-zoneddatetime-offsetdatetime)
+- [Introduction to Joda-Time](http://www.baeldung.com/joda-time)

java-math/pom.xml

@@ -17,6 +17,26 @@
             <artifactId>commons-math3</artifactId>
             <version>${commons-math3.version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.ejml</groupId>
+            <artifactId>ejml-all</artifactId>
+            <version>${ejml.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.nd4j</groupId>
+            <artifactId>nd4j-native</artifactId>
+            <version>${nd4j.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.la4j</groupId>
+            <artifactId>la4j</artifactId>
+            <version>${la4j.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>colt</groupId>
+            <artifactId>colt</artifactId>
+            <version>${colt.version}</version>
+        </dependency>
         <dependency>
             <groupId>com.google.guava</groupId>
             <artifactId>guava</artifactId>
@@ -44,6 +64,17 @@
             <artifactId>combinatoricslib3</artifactId>
             <version>${combinatoricslib3.version}</version>
          </dependency>
+        <!-- Benchmarking -->
+        <dependency>
+            <groupId>org.openjdk.jmh</groupId>
+            <artifactId>jmh-core</artifactId>
+            <version>${jmh.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.openjdk.jmh</groupId>
+            <artifactId>jmh-generator-annprocess</artifactId>
+            <version>${jmh.version}</version>
+        </dependency>
     </dependencies>
 
     <build>
@@ -64,6 +95,11 @@
         <commons-codec.version>1.11</commons-codec.version>
         <guava.version>27.0.1-jre</guava.version>
         <combinatoricslib3.version>3.3.0</combinatoricslib3.version>
+        <ejml.version>0.38</ejml.version>
+        <nd4j.version>1.0.0-beta4</nd4j.version>
+        <colt.version>1.2.0</colt.version>
+        <la4j.version>0.6.0</la4j.version>
+        <jmh.version>1.19</jmh.version>
     </properties>
 
 </project>

java-numbers-2/.gitignore

@@ -1,26 +0,0 @@
-*.class
-
-0.*
-
-#folders#
-/target
-/neoDb*
-/data
-/src/main/webapp/WEB-INF/classes
-*/META-INF/*
-.resourceCache
-
-# Packaged files #
-*.jar
-*.war
-*.ear
-
-# Files generated by integration tests
-*.txt
-backup-pom.xml
-/bin/
-/temp
-
-#IntelliJ specific
-.idea/
-*.iml

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

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

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

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

java-strings-2/README.MD

@@ -1,7 +0,0 @@
-## Relevant Articles
-
-- [Java Localization – Formatting Messages](https://www.baeldung.com/java-localization-messages-formatting)
-- [Check If a String Contains a Substring](https://www.baeldung.com/java-string-contains-substring)
-- [Removing Stopwords from a String in Java](https://www.baeldung.com/java-string-remove-stopwords)
-- [Blank and Empty Strings in Java](https://www.baeldung.com/java-blank-empty-strings)
-- [String Initialization in Java](https://www.baeldung.com/java-string-initialization)

java-strings-2/README.md

@@ -0,0 +1,25 @@
+## Relevant Articles:
+
+- [Java Localization – Formatting Messages](https://www.baeldung.com/java-localization-messages-formatting)
+- [Check If a String Contains a Substring](https://www.baeldung.com/java-string-contains-substring)
+- [Removing Stopwords from a String in Java](https://www.baeldung.com/java-string-remove-stopwords)
+- [Java – Generate Random String](http://www.baeldung.com/java-random-string)
+- [Image to Base64 String Conversion](http://www.baeldung.com/java-base64-image-string)
+- [Java Base64 Encoding and Decoding](https://www.baeldung.com/java-base64-encode-and-decode)
+- [Generate a Secure Random Password in Java](https://www.baeldung.com/java-generate-secure-password)
+- [Removing Repeated Characters from a String](https://www.baeldung.com/java-remove-repeated-char)
+- [Join Array of Primitives with Separator in Java](https://www.baeldung.com/java-join-primitive-array)
+- [Pad a String with Zeros or Spaces in Java](https://www.baeldung.com/java-pad-string)
+- [Remove Emojis from a Java String](https://www.baeldung.com/java-string-remove-emojis)
+- [Convert a Comma Separated String to a List in Java](https://www.baeldung.com/java-string-with-separator-to-list)
+- [Guide to java.util.Formatter](http://www.baeldung.com/java-string-formatter)
+- [Remove Leading and Trailing Characters from a String](https://www.baeldung.com/java-remove-trailing-characters)
+- [Concatenating Strings In Java](https://www.baeldung.com/java-strings-concatenation)
+- [Java String Interview Questions and Answers](https://www.baeldung.com/java-string-interview-questions)
+- [Check if a String is a Pangram in Java](https://www.baeldung.com/java-string-pangram)
+- [Check If a String Contains Multiple Keywords](https://www.baeldung.com/string-contains-multiple-words)
+- [Checking for Empty or Blank Strings in Java](https://www.baeldung.com/java-blank-empty-strings)
+- [String Initialization in Java](https://www.baeldung.com/java-string-initialization)
+- [Java Multi-line String](https://www.baeldung.com/java-multiline-string)
+- [Checking If a String Is a Repeated Substring](https://www.baeldung.com/java-repeated-substring)
+- [How to Reverse a String in Java](https://www.baeldung.com/java-reverse-string)

java-strings-2/pom.xml

@@ -40,6 +40,16 @@
             <artifactId>commons-lang3</artifactId>
             <version>${commons-lang3.version}</version>
         </dependency>
+        <dependency>
+            <groupId>commons-io</groupId>
+            <artifactId>commons-io</artifactId>
+            <version>${commons-io.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>commons-codec</groupId>
+            <artifactId>commons-codec</artifactId>
+            <version>${commons-codec.version}</version>
+        </dependency>
         <dependency>
             <groupId>junit</groupId>
             <artifactId>junit</artifactId>
@@ -52,32 +62,54 @@
             <version>${org.hamcrest.version}</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${assertj.version}</version>
+            <scope>test</scope>
+        </dependency>
+
+        <!-- Added for password generation -->
+        <dependency>
+            <groupId>org.passay</groupId>
+            <artifactId>passay</artifactId>
+            <version>${passay.version}</version>
+        </dependency>
         <dependency>
             <groupId>org.apache.commons</groupId>
             <artifactId>commons-text</artifactId>
             <version>${commons-text.version}</version>
         </dependency>
+        <dependency>
+            <groupId>com.vdurmont</groupId>
+            <artifactId>emoji-java</artifactId>
+            <version>${emoji-java.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.ahocorasick</groupId>
+            <artifactId>ahocorasick</artifactId>
+            <version>${ahocorasick.version}</version>
+        </dependency>
         <dependency>
             <groupId>javax.validation</groupId>
             <artifactId>validation-api</artifactId>
-            <version>2.0.0.Final</version>
+            <version>${validation-api.version}</version>
         </dependency>
         <dependency>
             <groupId>org.hibernate.validator</groupId>
             <artifactId>hibernate-validator</artifactId>
-            <version>6.0.2.Final</version>
+            <version>${hibernate-validator.version}</version>
         </dependency>
         <dependency>
             <groupId>javax.el</groupId>
             <artifactId>javax.el-api</artifactId>
-            <version>3.0.0</version>
+            <version>${javax.el-api.version}</version>
         </dependency>
         <dependency>
             <groupId>org.glassfish.web</groupId>
             <artifactId>javax.el</artifactId>
-            <version>2.2.6</version>
+            <version>${javax.el.version}</version>
         </dependency>
-
     </dependencies>
 
     <build>
@@ -105,9 +137,19 @@
 
     <properties>
         <commons-lang3.version>3.8.1</commons-lang3.version>
+        <commons-codec.version>1.10</commons-codec.version>
+        <passay.version>1.3.1</passay.version>
+        <!-- testing -->
+        <assertj.version>3.6.1</assertj.version>
+        <emoji-java.version>4.0.0</emoji-java.version>
+        <ahocorasick.version>0.4.0</ahocorasick.version>
         <icu4j.version>61.1</icu4j.version>
         <guava.version>28.0-jre</guava.version>
         <commons-text.version>1.4</commons-text.version>
+        <validation-api.version>2.0.0.Final</validation-api.version>
+        <hibernate-validator.version>6.0.2.Final</hibernate-validator.version>
+        <javax.el-api.version>3.0.0</javax.el-api.version>
+        <javax.el.version>2.2.6</javax.el.version>
     </properties>
 
 </project>