Merge remote-tracking branch 'upstream/master'

algorithms-sorting-2/README.md

@@ -1,3 +1,7 @@
 ### Relevant Articles:
 
+- [Sorting a String Alphabetically in Java](https://www.baeldung.com/java-sort-string-alphabetically)
+- [Sorting Strings by Contained Numbers in Java](https://www.baeldung.com/java-sort-strings-contained-numbers)
+- [How an In-Place Sorting Algorithm Works](https://www.baeldung.com/java-in-place-sorting)
 - [Partitioning and Sorting Arrays with Many Repeated Entries](https://www.baeldung.com/java-sorting-arrays-with-repeated-entries)
+- More articles: [[<-- prev]](/algorithms-sorting)

algorithms-sorting-2/src/main/java/com/baeldung/algorithms/bynumber/NaturalOrderComparators.java

@@ -1,4 +1,4 @@
-package com.baeldung.algorithms.sort.bynumber;
+package com.baeldung.algorithms.bynumber;
 
 import java.util.Comparator;
 

algorithms-sorting-2/src/test/java/com/baeldung/algorithms/bynumber/NaturalOrderComparatorsUnitTest.java

@@ -1,6 +1,5 @@
-package com.baeldung.algorithms.sort.bynumber;
+package com.baeldung.algorithms.bynumber;
 
-import com.baeldung.algorithms.sort.bynumber.NaturalOrderComparators;
 import org.junit.Test;
 
 import java.util.ArrayList;

algorithms-sorting/README.md

@@ -11,10 +11,7 @@ This module contains articles about sorting algorithms.
 - [Heap Sort in Java](https://www.baeldung.com/java-heap-sort)
 - [Shell Sort in Java](https://www.baeldung.com/java-shell-sort)
 - [Counting Sort in Java](https://www.baeldung.com/java-counting-sort)
-- [Sorting Strings by Contained Numbers in Java](https://www.baeldung.com/java-sort-strings-contained-numbers)
-- [How an In-Place Sorting Algorithm Works](https://www.baeldung.com/java-in-place-sorting)
 - [Selection Sort in Java](https://www.baeldung.com/java-selection-sort)
-- [Sorting Strings by Contained Numbers in Java](https://www.baeldung.com/java-sort-strings-contained-numbers)
 - [Radix Sort in Java](https://www.baeldung.com/java-radix-sort)
-- [Sorting a String Alphabetically in Java](https://www.baeldung.com/java-sort-string-alphabetically)
 - [Bucket Sort in Java](https://www.baeldung.com/java-bucket-sort)
+- More articles: [[next -->]](/algorithms-sorintg-2)

cas/README.md

@@ -1,7 +1,18 @@
 ## CAS
 
-This module contains articles about the Central Authentication Service (CAS)
+This module contains articles about the Central Authentication Service (CAS).
+
+The module consists of 2 submodules:
+1. `cas-server` - it requires JDK11 and uses the Gradle War Overlay style to ease setup and deployment. To  start the server, simply run:
+
+`./gradlew run
+  -Dorg.gradle.java.home=$JAVA11_HOME
+  -Pargs="-Dcas.standalone.configurationDirectory=/cas-server/src/main/resources/etc/cas/config"`
+
+The server starts at https://localhost:8443. `casuser`/`Mellon` are the username and password for logging in.
+
+2. `cas-secured-app` - A Maven based Springboot Application
 
 ### Relevant Articles: 
 
-- [CAS SSO With Spring Security](baeldung.com/spring-security-cas-sso)
+- [CAS SSO With Spring Security](https://www.baeldung.com/spring-security-cas-sso)

core-groovy-2/determine-datatype/pom.xml

@@ -0,0 +1,40 @@
+<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <groupId>com.baeldung.groovy</groupId>
+    <artifactId>determine-datatype</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <build>
+        <sourceDirectory>src</sourceDirectory>
+        <plugins>
+            <plugin>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>3.8.0</version>
+                <configuration>
+                    <source>1.8</source>
+                    <target>1.8</target>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>org.codehaus.gmaven</groupId>
+                <artifactId>groovy-maven-plugin</artifactId>
+                <dependencies>
+                    <dependency>
+                        <groupId>org.codehaus.groovy</groupId>
+                        <artifactId>groovy-all</artifactId>
+                        <version>2.0.6</version>
+                    </dependency>
+                </dependencies>
+            </plugin>
+        </plugins>
+    </build>
+    <dependencies>
+        <!-- https://mvnrepository.com/artifact/org.junit/junit5-engine -->
+        <dependency>
+            <groupId>org.junit</groupId>
+            <artifactId>junit5-engine</artifactId>
+            <version>5.0.0-ALPHA</version>
+        </dependency>
+    </dependencies>
+</project>

core-groovy-2/determine-datatype/src/com/baeldung/groovy/determine/datatype/Person.groovy

@@ -0,0 +1,14 @@
+package com.baeldung.groovy.determine.datatype
+
+class Person {
+    
+    private int ageAsInt
+    private Double ageAsDouble
+    private String ageAsString
+    
+    Person() {}
+    Person(int ageAsInt) { this.ageAsInt =  ageAsInt}
+    Person(Double ageAsDouble) { this.ageAsDouble =  ageAsDouble}
+    Person(String ageAsString) { this.ageAsString =  ageAsString}    
+}
+class Student extends Person {}

core-groovy-2/determine-datatype/src/com/baeldung/groovy/determine/datatype/PersonTest.groovy

@@ -0,0 +1,55 @@
+package com.baeldung.groovy.determine.datatype;
+
+import org.junit.Assert
+import org.junit.Test;
+
+public class PersonTest {
+    
+    @Test
+    public void givenWhenParameterTypeIsInteger_thenReturnTrue() {
+        Person personObj = new Person(10)
+        Assert.assertTrue(personObj.ageAsInt instanceof Integer);
+    }
+    
+    @Test
+    public void givenWhenParameterTypeIsDouble_thenReturnTrue() {
+        Person personObj = new Person(10.0)
+        Assert.assertTrue((personObj.ageAsDouble).getClass() == Double)
+    }
+    
+    @Test
+    public void givenWhenParameterTypeIsString_thenReturnTrue() {
+        Person personObj = new Person("10 years")
+        Assert.assertTrue(personObj.ageAsString.class == String)
+    }
+    
+    @Test
+    public void givenClassName_WhenParameterIsInteger_thenReturnTrue() {
+        Assert.assertTrue(Person.class.getDeclaredField('ageAsInt').type == int.class)
+    }
+    
+    @Test
+    public void givenWhenObjectIsInstanceOfType_thenReturnTrue() {
+        Person personObj = new Person()
+        Assert.assertTrue(personObj instanceof Person)
+    }
+
+    @Test
+    public void givenWhenInstanceIsOfSubtype_thenReturnTrue() {
+        Student studentObj = new Student()
+        Assert.assertTrue(studentObj in Person)
+    }
+    
+    @Test
+    public void givenGroovyList_WhenFindClassName_thenReturnTrue() {
+      def ageList = ['ageAsString','ageAsDouble', 10]   
+      Assert.assertTrue(ageList.class == ArrayList)     
+      Assert.assertTrue(ageList.getClass() == ArrayList)
+    }
+    
+    @Test
+    public void givenGrooyMap_WhenFindClassName_thenReturnTrue() {
+      def ageMap = [ageAsString: '10 years', ageAsDouble: 10.0]
+      Assert.assertFalse(ageMap.class == LinkedHashMap)
+    }
+}

core-groovy/src/test/groovy/com/baeldung/stringtoint/ConvertStringToInt.groovy

@@ -0,0 +1,110 @@
+package com.baeldung.stringtoint
+
+import org.junit.Test
+
+import java.text.DecimalFormat
+
+import static org.junit.Assert.assertEquals
+import static org.junit.Assert.assertNull
+
+class ConvertStringToInt {
+
+    @Test
+    void givenString_whenUsingAsInteger_thenConvertToInteger() {
+        def stringNum = "123"
+        def invalidString = "123a"
+        Integer expectedInteger = 123
+        Integer integerNum = stringNum as Integer
+        def intNum = invalidString?.isInteger() ? invalidString as Integer : null
+
+        assertNull(null, intNum)
+        assertEquals(integerNum, expectedInteger)
+    }
+
+    @Test
+    void givenString_whenUsingAsInt_thenConvertToInt() {
+        def stringNum = "123"
+        int expectedInt = 123
+        int intNum = stringNum as int
+
+        assertEquals(intNum, expectedInt)
+    }
+
+    @Test
+    void givenString_whenUsingToInteger_thenConvertToInteger() {
+        def stringNum = "123"
+        int expectedInt = 123
+        int intNum = stringNum.toInteger()
+
+        assertEquals(intNum, expectedInt)
+    }
+
+    @Test
+    void givenString_whenUsingParseInt_thenConvertToInteger() {
+        def stringNum = "123"
+        int expectedInt = 123
+        int intNum = Integer.parseInt(stringNum)
+
+        assertEquals(intNum, expectedInt)
+    }
+
+    @Test
+    void givenString_whenUsingValueOf_thenConvertToInteger() {
+        def stringNum = "123"
+        int expectedInt = 123
+        int intNum = Integer.valueOf(stringNum)
+
+        assertEquals(intNum, expectedInt)
+    }
+
+    @Test
+    void givenString_whenUsingIntValue_thenConvertToInteger() {
+        def stringNum = "123"
+        int expectedInt = 123
+        int intNum = new Integer(stringNum).intValue()
+
+        assertEquals(intNum, expectedInt)
+    }
+
+    @Test
+    void givenString_whenUsingNewInteger_thenConvertToInteger() {
+        def stringNum = "123"
+        int expectedInt = 123
+        int intNum = new Integer(stringNum)
+
+        assertEquals(intNum, expectedInt)
+    }
+
+    @Test
+    void givenString_whenUsingDecimalFormat_thenConvertToInteger() {
+        def stringNum = "123"
+        int expectedInt = 123
+        DecimalFormat decimalFormat = new DecimalFormat("#")
+        int intNum = decimalFormat.parse(stringNum).intValue()
+
+        assertEquals(intNum, expectedInt)
+    }
+
+    @Test(expected = NumberFormatException.class)
+    void givenInvalidString_whenUsingAs_thenThrowNumberFormatException() {
+        def invalidString = "123a"
+        invalidString as Integer
+    }
+
+    @Test(expected = NullPointerException.class)
+    void givenNullString_whenUsingToInteger_thenThrowNullPointerException() {
+        def invalidString = null
+        invalidString.toInteger()
+    }
+
+    @Test
+    void givenString_whenUsingIsInteger_thenCheckIfCorrectValue() {
+        def invalidString = "123a"
+        def validString = "123"
+        def invalidNum = invalidString?.isInteger() ? invalidString as Integer : false
+        def correctNum = validString?.isInteger() ? validString as Integer : false
+
+        assertEquals(false, invalidNum)
+        assertEquals(123, correctNum)
+    }
+}

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

@@ -0,0 +1,5 @@
+### Relevant Articles:
+
+- [Generating Random Dates in Java](https://www.baeldung.com/java-random-dates)
+- [Creating a LocalDate with Values in Java](https://www.baeldung.com/java-creating-localdate-with-values)
+- [[<-- Prev]](/core-java-modules/core-java-datetime-java8-1)

core-java-modules/core-java-8-datetime-2/pom.xml

@@ -4,9 +4,9 @@
     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>
-    <artifactId>core-java-datetime-java8</artifactId>
+    <artifactId>core-java-8-datetime</artifactId>
     <version>${project.parent.version}</version>
-    <name>core-java-datetime-java8</name>
+    <name>core-java-8-datetime</name>
     <packaging>jar</packaging>
 
     <parent>
@@ -64,8 +64,8 @@
     </build>
 
     <properties>
-        <maven.compiler.source>1.9</maven.compiler.source>
-        <maven.compiler.target>1.9</maven.compiler.target>
+        <maven.compiler.source>1.8</maven.compiler.source>
+        <maven.compiler.target>1.8</maven.compiler.target>
         <joda-time.version>2.10</joda-time.version>
         <!-- testing -->
         <assertj.version>3.6.1</assertj.version>

core-java-modules/core-java-8-datetime-2/src/test/java/com/baeldung/localdate/LocalDateExampleUnitTest.java

@@ -11,31 +11,31 @@ public class LocalDateExampleUnitTest {
 
     @Test
     public void givenValues_whenUsingOfMethod_thenLocalDate() {
-        assertEquals("2020-01-08", date.getCustomDateOne(2020, 1, 8));
+        assertEquals("2020-01-08", date.getCustomDateOne(2020, 1, 8).toString());
     }
 
     @Test
     public void givenValuesWithMonthEnum_whenUsingOfMethod_thenLocalDate() {
-        assertEquals("2020-01-08", date.getCustomDateTwo(2020, Month.JANUARY, 8));
+        assertEquals("2020-01-08", date.getCustomDateTwo(2020, Month.JANUARY, 8).toString());
     }
 
     @Test
     public void givenValues_whenUsingEpochDay_thenLocalDate() {
-        assertEquals("2020-01-08", date.getDateFromEpochDay(18269));
+        assertEquals("2020-01-08", date.getDateFromEpochDay(18269).toString());
     }
 
     @Test
     public void givenValues_whenUsingYearDay_thenLocalDate() {
-        assertEquals("2020-01-08", date.getDateFromYearAndDayOfYear(2020, 8));
+        assertEquals("2020-01-08", date.getDateFromYearAndDayOfYear(2020, 8).toString());
     }
 
     @Test
     public void givenValues_whenUsingParse_thenLocalDate() {
-        assertEquals("2020-01-08", date.getDateFromString("2020-01-08"));
+        assertEquals("2020-01-08", date.getDateFromString("2020-01-08").toString());
     }
 
     @Test
     public void givenValuesWithFormatter_whenUsingParse_thenLocalDate() {
-        assertEquals("2020-01-08", date.getDateFromStringAndFormatter("8-Jan-2020", "d-MMM-yyyy"));
+        assertEquals("2020-01-08", date.getDateFromStringAndFormatter("8-Jan-2020", "d-MMM-yyyy").toString());
     }
 }

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

@@ -13,4 +13,4 @@ This module contains articles about the Date and Time API introduced with Java 8
 - [How to Get the Start and the End of a Day using Java](http://www.baeldung.com/java-day-start-end)
 - [Set the Time Zone of a Date in Java](https://www.baeldung.com/java-set-date-time-zone)
 - [Comparing Dates in Java](https://www.baeldung.com/java-comparing-dates)
-- [Generating Random Dates in Java](https://www.baeldung.com/java-random-dates)
+- [[Next -->]](/core-java-modules/core-java-datetime-java8-2)

core-java-modules/core-java-8-datetime/pom.xml

@@ -4,9 +4,9 @@
     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>
-    <artifactId>core-java-datetime-java8</artifactId>
+    <artifactId>core-java-8-datetime</artifactId>
     <version>${project.parent.version}</version>
-    <name>core-java-datetime-java8</name>
+    <name>core-java-8-datetime</name>
     <packaging>jar</packaging>
 
     <parent>
@@ -64,8 +64,8 @@
     </build>
 
     <properties>
-        <maven.compiler.source>1.9</maven.compiler.source>
-        <maven.compiler.target>1.9</maven.compiler.target>
+        <maven.compiler.source>1.8</maven.compiler.source>
+        <maven.compiler.target>1.8</maven.compiler.target>
         <joda-time.version>2.10</joda-time.version>
         <!-- testing -->
         <assertj.version>3.6.1</assertj.version>

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

@@ -1,17 +0,0 @@
-## Core Java Arrays (Part 2)
-
-This module contains articles about Java arrays
-
-## Relevant Articles
-
-- [Extending an Array’s Length](https://www.baeldung.com/java-array-add-element-at-the-end)
-- [Looping Diagonally Through a 2d Java Array](https://www.baeldung.com/java-loop-diagonal-array)
-- [Converting Between Stream and Array in Java](https://www.baeldung.com/java-stream-to-array)
-- [Convert a Float to a Byte Array in Java](https://www.baeldung.com/java-convert-float-to-byte-array)
-- [Array Operations in Java](https://www.baeldung.com/java-common-array-operations)
-- [Intersection Between two Integer Arrays](https://www.baeldung.com/java-array-intersection)
-- [Removing an Element from an Array in Java](https://www.baeldung.com/java-array-remove-element)
-- [Removing the First Element of an Array](https://www.baeldung.com/java-array-remove-first-element)
-- [Adding an Element to a Java Array vs an ArrayList](https://www.baeldung.com/java-add-element-to-array-vs-list)
-- [Arrays.sort vs Arrays.parallelSort](https://www.baeldung.com/java-arrays-sort-vs-parallelsort)
-- [[<-- Prev]](/core-java-modules/core-java-arrays)

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

@@ -1,3 +0,0 @@
-### Relevant Articles:
-
-- [Arrays.deepEquals](https://www.baeldung.com/java-arrays-deepequals)

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

@@ -0,0 +1,7 @@
+## Core Java Arrays - Conversions
+
+This module contains articles about arrays conversion in Java
+
+## Relevant Articles
+- [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)

core-java-modules/core-java-arrays-convert/pom.xml

@@ -0,0 +1,27 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<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">
+    <parent>
+        <artifactId>core-java-modules</artifactId>
+        <groupId>com.baeldung.core-java-modules</groupId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>core-java-arrays-convert</artifactId>
+    <name>core-java-arrays-convert</name>
+    <packaging>jar</packaging>
+
+    <dependencies>
+        <dependency>
+            <groupId>com.google.guava</groupId>
+            <artifactId>guava</artifactId>
+            <version>${guava.version}</version>
+        </dependency>
+    </dependencies>
+
+    <properties>
+        <guava.version>28.2-jre</guava.version>
+    </properties>
+</project>

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

@@ -0,0 +1,7 @@
+## Core Java Arrays - Guides
+
+This module contains complete guides about arrays in Java
+
+### Relevant Articles: 
+- [Arrays in Java: A Reference Guide](https://www.baeldung.com/java-arrays-guide)
+- [Guide to the java.util.Arrays Class](https://www.baeldung.com/java-util-arrays)

core-java-modules/core-java-arrays-guides/pom.xml

@@ -0,0 +1,32 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<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">
+    <parent>
+        <artifactId>core-java-modules</artifactId>
+        <groupId>com.baeldung.core-java-modules</groupId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>core-java-arrays-guides</artifactId>
+    <name>core-java-arrays-guides</name>
+    <packaging>jar</packaging>
+
+    <dependencies>
+        <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>
+
+    <properties>
+        <jmh.version>1.19</jmh.version>
+    </properties>
+</project>

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

@@ -0,0 +1,7 @@
+## Core Java Arrays - Multidimensional
+
+This module contains articles about multidimensional arrays in Java
+
+### Relevant Articles: 
+- [Multi-Dimensional Arrays In Java](https://www.baeldung.com/java-jagged-arrays)
+- [Looping Diagonally Through a 2d Java Array](https://www.baeldung.com/java-loop-diagonal-array)

core-java-modules/core-java-arrays-multidimensional/pom.xml

@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<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">
+    <parent>
+        <artifactId>core-java-modules</artifactId>
+        <groupId>com.baeldung.core-java-modules</groupId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>core-java-arrays-multidimensional</artifactId>
+    <name>core-java-arrays-multidimensional</name>
+    <packaging>jar</packaging>
+</project>

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

@@ -0,0 +1,9 @@
+## Core Java Arrays - Advanced Operations
+
+This module contains articles about advanced operations on arrays in Java. They assume some background knowledge with arrays in Java.
+
+### Relevant Articles: 
+- [How to Copy an Array in Java](https://www.baeldung.com/java-array-copy)
+- [Arrays.deepEquals](https://www.baeldung.com/java-arrays-deepequals)
+- [Find Sum and Average in a Java Array](https://www.baeldung.com/java-array-sum-average)
+- [Intersection Between two Integer Arrays](https://www.baeldung.com/java-array-intersection)

core-java-modules/core-java-arrays-operations-advanced/pom.xml

@@ -0,0 +1,36 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<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">
+    <parent>
+        <artifactId>core-java-modules</artifactId>
+        <groupId>com.baeldung.core-java-modules</groupId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>core-java-arrays-operations-advanced</artifactId>
+    <name>core-java-arrays-operations-advanced</name>
+    <packaging>jar</packaging>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-lang3</artifactId>
+            <version>${commons-lang3.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${assertj-core.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <properties>
+        <commons-lang3.version>3.9</commons-lang3.version>
+
+        <assertj-core.version>3.10.0</assertj-core.version>
+    </properties>
+</project>

core-java-modules/core-java-arrays-operations-advanced/src/main/java/com/baeldung/array/operations/ArraysIntersectionOperations.java

@@ -0,0 +1,27 @@
+package com.baeldung.array.operations;
+
+import java.util.Arrays;
+import java.util.LinkedList;
+import java.util.stream.Stream;
+
+public class ArraysIntersectionOperations {
+
+    public static Integer[] intersectionSimple(final Integer[] a, final Integer[] b) {
+        return Stream.of(a)
+            .filter(Arrays.asList(b)::contains)
+            .toArray(Integer[]::new);
+    }
+
+    public static Integer[] intersectionSet(final Integer[] a, final Integer[] b) {
+        return Stream.of(a)
+            .filter(Arrays.asList(b)::contains)
+            .distinct()
+            .toArray(Integer[]::new);
+    }
+
+    public static Integer[] intersectionMultiSet(final Integer[] a, final Integer[] b) {
+        return Stream.of(a)
+            .filter(new LinkedList<>(Arrays.asList(b))::remove)
+            .toArray(Integer[]::new);
+    }
+}

core-java-modules/core-java-arrays-operations-advanced/src/test/java/com/baeldung/array/operations/IntersectionUnitTest.java

@@ -2,7 +2,7 @@ package com.baeldung.array.operations;
 
 import org.junit.jupiter.api.Test;
 
-import static com.baeldung.array.operations.ArrayOperations.*;
+import static com.baeldung.array.operations.ArraysIntersectionOperations.*;
 import static org.assertj.core.api.Assertions.assertThat;
 
 class IntersectionUnitTest {

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

@@ -0,0 +1,12 @@
+## Core Java Arrays - Basic Operations
+
+This module contains articles about Java array fundamentals. They assume no previous background knowledge on working with arrays.
+
+### Relevant Articles: 
+- [Initializing Arrays in Java](https://www.baeldung.com/java-initialize-array)
+- [Array Operations in Java](https://www.baeldung.com/java-common-array-operations)
+- [Adding an Element to a Java Array vs an ArrayList](https://www.baeldung.com/java-add-element-to-array-vs-list)
+- [Check if a Java Array Contains a Value](https://www.baeldung.com/java-array-contains-value)
+- [Removing an Element from an Array in Java](https://www.baeldung.com/java-array-remove-element)
+- [Removing the First Element of an Array](https://www.baeldung.com/java-array-remove-first-element)
+- [Extending an Array’s Length](https://www.baeldung.com/java-array-add-element-at-the-end)

core-java-modules/core-java-arrays-operations-basic/pom.xml

@@ -1,54 +1,19 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<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">
+<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">
+    <parent>
+        <artifactId>core-java-modules</artifactId>
+        <groupId>com.baeldung.core-java-modules</groupId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
     <modelVersion>4.0.0</modelVersion>
-    <artifactId>core-java-arrays-2</artifactId>
-    <version>0.1.0-SNAPSHOT</version>
-    <name>core-java-arrays-2</name>
+
+    <artifactId>core-java-arrays-operations-basic</artifactId>
+    <name>core-java-arrays-operations-basic</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>
-        <dependency>
-            <groupId>org.apache.commons</groupId>
-            <artifactId>commons-lang3</artifactId>
-            <version>${commons-lang3.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>org.openjdk.jmh</groupId>
-            <artifactId>jmh-core</artifactId>
-            <version>${jmh.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>org.openjdk.jmh</groupId>
-            <artifactId>jmh-generator-annprocess</artifactId>
-            <version>${jmh.version}</version>
-        </dependency>
-        <!-- test scoped -->
-        <dependency>
-            <groupId>org.assertj</groupId>
-            <artifactId>assertj-core</artifactId>
-            <version>${assertj-core.version}</version>
-            <scope>test</scope>
-        </dependency>
-    </dependencies>
-
     <build>
-        <finalName>core-java-arrays-2</finalName>
-        <resources>
-            <resource>
-                <directory>src/main/resources</directory>
-                <filtering>true</filtering>
-            </resource>
-        </resources>
         <plugins>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
@@ -74,13 +39,40 @@
         </plugins>
     </build>
 
-    <properties>
-        <jmh.version>1.19</jmh.version>
-        <!-- util -->
-        <commons-lang3.version>3.9</commons-lang3.version>
-        <!-- testing -->
-        <assertj-core.version>3.10.0</assertj-core.version>
-        <shade.plugin.version>3.2.0</shade.plugin.version>
-    </properties>
+    <dependencies>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-lang3</artifactId>
+            <version>${commons-lang3.version}</version>
+        </dependency>
 
-</project>
+        <!-- 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>
+
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${assertj-core.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <properties>
+        <shade.plugin.version>3.2.0</shade.plugin.version>
+
+        <commons-lang3.version>3.9</commons-lang3.version>
+
+        <jmh.version>1.19</jmh.version>
+
+        <assertj-core.version>3.10.0</assertj-core.version>
+    </properties>
+</project>

core-java-modules/core-java-arrays-operations-basic/src/main/java/com/baeldung/array/ArrayBenchmarkRunner.java

@@ -9,7 +9,7 @@ public class ArrayBenchmarkRunner {
   public static void main(String[] args) throws Exception {
 
     Options options = new OptionsBuilder()
-        .include(SearchArrayUnitTest.class.getSimpleName()).threads(1)
+        .include(SearchArrayBenchmark.class.getSimpleName()).threads(1)
         .forks(1).shouldFailOnError(true).shouldDoGC(true)
         .jvmArgs("-server").build();
 

core-java-modules/core-java-arrays-operations-basic/src/main/java/com/baeldung/array/SearchArrayBenchmark.java

@@ -8,7 +8,7 @@ import java.util.concurrent.TimeUnit;
 @BenchmarkMode(Mode.AverageTime)
 @Warmup(iterations = 5)
 @OutputTimeUnit(TimeUnit.MICROSECONDS)
-public class SearchArrayUnitTest {
+public class SearchArrayBenchmark {
 
     @State(Scope.Benchmark)
     public static class SearchData {