Merge remote-tracking branch 'upstream/master'

algorithms-miscellaneous-2/src/main/java/com/baeldung/algorithms/relativelyprime/RelativelyPrime.java

@@ -0,0 +1,45 @@
+package com.baeldung.algorithms.relativelyprime;
+
+import java.math.BigInteger;
+
+class RelativelyPrime {
+
+    static boolean iterativeRelativelyPrime(int a, int b) {
+        return iterativeGCD(a, b) == 1;
+    }
+
+    static boolean recursiveRelativelyPrime(int a, int b) {
+        return recursiveGCD(a, b) == 1;
+    }
+
+    static boolean bigIntegerRelativelyPrime(int a, int b) {
+        return BigInteger.valueOf(a).gcd(BigInteger.valueOf(b)).equals(BigInteger.ONE);
+    }
+
+    private static int iterativeGCD(int a, int b) {
+        int tmp;
+        while (b != 0) {
+            if (a < b) {
+                tmp = a;
+                a = b;
+                b = tmp;
+            }
+            tmp = b;
+            b = a % b;
+            a = tmp;
+        }
+        return a;
+    }
+
+    private static int recursiveGCD(int a, int b) {
+        if (b == 0) {
+            return a;
+        }
+        if (a < b) {
+            return recursiveGCD(b, a);
+        }
+        return recursiveGCD(b, a % b);
+    }
+
+
+}

algorithms-miscellaneous-2/src/test/java/com/baeldung/algorithms/relativelyprime/RelativelyPrimeUnitTest.java

@@ -0,0 +1,51 @@
+package com.baeldung.algorithms.relativelyprime;
+
+import org.junit.Test;
+
+import static com.baeldung.algorithms.relativelyprime.RelativelyPrime.*;
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class RelativelyPrimeUnitTest {
+
+    @Test
+    public void givenNonRelativelyPrimeNumbers_whenCheckingIteratively_shouldReturnFalse() {
+
+        boolean result = iterativeRelativelyPrime(45, 35);
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    public void givenRelativelyPrimeNumbers_whenCheckingIteratively_shouldReturnTrue() {
+
+        boolean result = iterativeRelativelyPrime(500, 501);
+        assertThat(result).isTrue();
+    }
+
+    @Test
+    public void givenNonRelativelyPrimeNumbers_whenCheckingRecursively_shouldReturnFalse() {
+
+        boolean result = recursiveRelativelyPrime(45, 35);
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    public void givenRelativelyPrimeNumbers_whenCheckingRecursively_shouldReturnTrue() {
+
+        boolean result = recursiveRelativelyPrime(500, 501);
+        assertThat(result).isTrue();
+    }
+
+    @Test
+    public void givenNonRelativelyPrimeNumbers_whenCheckingUsingBigIntegers_shouldReturnFalse() {
+
+        boolean result = bigIntegerRelativelyPrime(45, 35);
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    public void givenRelativelyPrimeNumbers_whenCheckingBigIntegers_shouldReturnTrue() {
+
+        boolean result = bigIntegerRelativelyPrime(500, 501);
+        assertThat(result).isTrue();
+    }
+}

core-groovy/README.md

@@ -9,3 +9,5 @@
 - [A Quick Guide to Iterating a Map in Groovy](https://www.baeldung.com/groovy-map-iterating)
 - [An Introduction to Traits in Groovy](https://www.baeldung.com/groovy-traits)
 - [Lists in Groovy](https://www.baeldung.com/groovy-lists)
+- [Converting a String to a Date in Groovy](https://www.baeldung.com/groovy-string-to-date)
+- [Guide to I/O in Groovy](https://www.baeldung.com/groovy-io)

core-java-11/README.md

@@ -5,3 +5,4 @@
 - [Java 11 String API Additions](https://www.baeldung.com/java-11-string-api)
 - [Java 11 Nest Based Access Control](https://www.baeldung.com/java-nest-based-access-control)
 - [Exploring the New HTTP Client in Java 9 and 11](https://www.baeldung.com/java-9-http-client)
+- [An Introduction to Epsilon GC: A No-Op Experimental Garbage Collector](https://www.baeldung.com/jvm-epsilon-gc-garbage-collector)

core-java-9/README.md

@@ -27,3 +27,4 @@
 - [Immutable Set in Java](https://www.baeldung.com/java-immutable-set)
 - [Multi-Release Jar Files](https://www.baeldung.com/java-multi-release-jar)
 - [Ahead of Time Compilation (AoT)](https://www.baeldung.com/ahead-of-time-compilation)
+

core-java-collections/README.md

@@ -33,3 +33,4 @@
 - [Differences Between HashMap and Hashtable](https://www.baeldung.com/hashmap-hashtable-differences)
 - [Java ArrayList vs Vector](https://www.baeldung.com/java-arraylist-vs-vector)
 - [Defining a Char Stack in Java](https://www.baeldung.com/java-char-stack)
+- [Time Comparison of Arrays.sort(Object[]) and Arrays.sort(int[])](https://www.baeldung.com/arrays-sortobject-vs-sortint)

core-java-concurrency-basic/README.md

@@ -16,3 +16,4 @@
 - [Life Cycle of a Thread in Java](http://www.baeldung.com/java-thread-lifecycle)
 - [Runnable vs. Callable in Java](http://www.baeldung.com/java-runnable-callable)
 - [What is Thread-Safety and How to Achieve it](https://www.baeldung.com/java-thread-safety)
+- [How to Start a Thread in Java](https://www.baeldung.com/java-start-thread)

core-java-os/README.md

@@ -6,3 +6,5 @@ This module uses Java 9, so make sure to have the JDK 9 installed to run it.
 ### Relevant Articles: 
 - [Java 9 Process API Improvements](http://www.baeldung.com/java-9-process-api)
 - [Guide to java.lang.Process API](https://www.baeldung.com/java-process-api)
+- [Guide to java.lang.ProcessBuilder API](https://www.baeldung.com/java-lang-processbuilder-api)
+

core-java/README.md

@@ -50,3 +50,4 @@
 - [Finding Leap Years in Java](https://www.baeldung.com/java-leap-year)
 - [Java Bitwise Operators](https://www.baeldung.com/java-bitwise-operators)
 - [Guide to Creating and Running a Jar File in Java](https://www.baeldung.com/java-create-jar)
+- [Making a JSON POST Request With HttpURLConnection](https://www.baeldung.com/httpurlconnection-post)

core-kotlin-2/README.md

@@ -3,4 +3,4 @@
 - [Void Type in Kotlin](https://www.baeldung.com/kotlin-void-type)
 - [How to use Kotlin Range Expressions](https://www.baeldung.com/kotlin-ranges)
 - [Split a List into Parts in Kotlin](https://www.baeldung.com/kotlin-split-list-into-parts)
-
+- [String Comparison in Kotlin](https://www.baeldung.com/kotlin-string-comparison)

core-kotlin-2/pom.xml

@@ -13,4 +13,66 @@
         <relativePath>../parent-kotlin</relativePath>
     </parent>
 
-</project>
+    <dependencies>
+        <dependency>
+            <groupId>org.jetbrains.kotlin</groupId>
+            <artifactId>kotlin-stdlib-jdk8</artifactId>
+            <version>${kotlin.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.platform</groupId>
+            <artifactId>junit-platform-runner</artifactId>
+            <version>${junit.platform.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${assertj.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.jetbrains.kotlin</groupId>
+            <artifactId>kotlin-test</artifactId>
+            <version>${kotlin.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.jetbrains.kotlin</groupId>
+                <artifactId>kotlin-maven-plugin</artifactId>
+                <version>${kotlin.version}</version>
+                <executions>
+                    <execution>
+                        <id>compile</id>
+                        <phase>compile</phase>
+                        <goals>
+                            <goal>compile</goal>
+                        </goals>
+                    </execution>
+                    <execution>
+                        <id>test-compile</id>
+                        <phase>test-compile</phase>
+                        <goals>
+                            <goal>test-compile</goal>
+                        </goals>
+                    </execution>
+                </executions>
+                <configuration>
+                    <jvmTarget>1.8</jvmTarget>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+    <properties>
+        <kotlin.version>1.2.71</kotlin.version>
+        <junit.platform.version>1.1.1</junit.platform.version>
+        <junit.vintage.version>5.2.0</junit.vintage.version>
+        <assertj.version>3.10.0</assertj.version>
+    </properties>
+
+</project>

core-kotlin-2/src/main/kotlin/com/baeldung/range/CharRange.kt

@@ -0,0 +1,13 @@
+package com.baeldung.range
+
+fun main(args: Array<String>) {
+
+    for (ch in 'a'..'f') {
+        print(ch)
+    }
+    println()
+
+    for (ch in 'f' downTo 'a') {
+        print(ch)
+    }
+}

core-kotlin-2/src/main/kotlin/com/baeldung/range/Color.kt

@@ -0,0 +1,21 @@
+package com.baeldung.range
+
+enum class Color(val rgb: Int) {
+    BLUE(0x0000FF),
+    GREEN(0x008000),
+    RED(0xFF0000),
+    MAGENTA(0xFF00FF),
+    YELLOW(0xFFFF00);
+}
+
+fun main(args: Array<String>) {
+
+    println(Color.values().toList());
+    val red = Color.RED
+    val yellow = Color.YELLOW
+    val range = red..yellow
+
+    println(range.contains(Color.MAGENTA))
+    println(range.contains(Color.BLUE))
+    println(range.contains(Color.GREEN))
+}

core-kotlin-2/src/main/kotlin/com/baeldung/range/Filter.kt

@@ -0,0 +1,18 @@
+package com.baeldung.range
+
+fun main(args: Array<String>) {
+    val r = 1..10
+
+    //Apply filter
+    val f = r.filter { it -> it % 2 == 0 }
+    println(f)
+
+    //Map
+    val m = r.map { it -> it * it }
+    println(m)
+
+    //Reduce
+    val rdc = r.reduce { a, b -> a + b }
+    println(rdc)
+
+}

core-kotlin-2/src/main/kotlin/com/baeldung/range/FirstLast.kt

@@ -0,0 +1,8 @@
+package com.baeldung.range
+
+fun main(args: Array<String>) {
+
+    println((1..9).first)
+    println((1..9 step 2).step)
+    println((3..9).reversed().last)
+}

core-kotlin-2/src/main/kotlin/com/baeldung/range/OtherRangeFunctions.kt

@@ -0,0 +1,14 @@
+package com.baeldung.range
+
+fun main(args: Array<String>) {
+
+    val r = 1..20
+    println(r.min())
+    println(r.max())
+    println(r.sum())
+    println(r.average())
+    println(r.count())
+
+    val repeated = listOf(1, 1, 2, 4, 4, 6, 10)
+    println(repeated.distinct())
+}

core-kotlin-2/src/main/kotlin/com/baeldung/range/Range.kt

@@ -0,0 +1,28 @@
+package com.baeldung.range
+
+fun main(args: Array<String>) {
+
+    for (i in 1..9) {
+        print(i)
+    }
+    println()
+
+    for (i in 9 downTo 1) {
+        print(i)
+    }
+    println()
+
+    for (i in 1.rangeTo(9)) {
+        print(i)
+    }
+    println()
+
+    for (i in 9.downTo(1)) {
+        print(i)
+    }
+    println()
+
+    for (i in 1 until 9) {
+        print(i)
+    }
+}

core-kotlin-2/src/main/kotlin/com/baeldung/range/ReverseRange.kt

@@ -0,0 +1,14 @@
+package com.baeldung.range
+
+fun main(args: Array<String>) {
+
+    (1..9).reversed().forEach {
+        print(it)
+    }
+
+    println()
+
+    (1..9).reversed().step(3).forEach {
+        print(it)
+    }
+}

core-kotlin-2/src/main/kotlin/com/baeldung/range/Step.kt

@@ -0,0 +1,15 @@
+package com.baeldung.range
+
+fun main(args: Array<String>) {
+
+    for(i in 1..9 step 2){
+        print(i)
+    }
+
+    println()
+
+    for (i in 9 downTo 1 step 2){
+        print(i)
+    }
+
+}

core-kotlin-2/src/main/kotlin/com/baeldung/range/UntilRange.kt

@@ -0,0 +1,8 @@
+package com.baeldung.range
+
+fun main(args: Array<String>) {
+
+    for (i in 1 until 9) {
+        print(i)
+    }
+}

core-kotlin-2/src/test/kotlin/com/baeldung/range/CharRangeTest.kt

@@ -0,0 +1,17 @@
+package com.baeldung.range
+
+import org.junit.Test
+import kotlin.test.assertEquals
+
+class CharRangeTest {
+
+    @Test
+    fun testCharRange() {
+        assertEquals(listOf('a', 'b', 'c'), ('a'..'c').toList())
+    }
+
+    @Test
+    fun testCharDownRange() {
+        assertEquals(listOf('c', 'b', 'a'), ('c'.downTo('a')).toList())
+    }
+}

core-kotlin-2/src/test/kotlin/com/baeldung/range/ColorTest.kt

@@ -0,0 +1,20 @@
+package com.baeldung.range
+
+import org.junit.Test
+import kotlin.test.assertFalse
+import kotlin.test.assertTrue
+
+class ColorTest {
+
+    @Test
+    fun testEnumRange() {
+
+        println(Color.values().toList());
+        val red = Color.RED
+        val yellow = Color.YELLOW
+        val range = red..yellow
+
+        assertTrue { range.contains(Color.MAGENTA) }
+        assertFalse { range.contains(Color.BLUE) }
+    }
+}

core-kotlin-2/src/test/kotlin/com/baeldung/range/FilterTest.kt

@@ -0,0 +1,24 @@
+package com.baeldung.range
+
+import org.junit.Test
+import kotlin.test.assertEquals
+
+class FilterTest {
+
+    val r = 1..10
+
+    @Test
+    fun filterTest() {
+        assertEquals(listOf(2, 4, 6, 8, 10), r.filter { it -> it % 2 == 0 }.toList())
+    }
+
+    @Test
+    fun mapTest() {
+        assertEquals(listOf(1, 4, 9, 16, 25, 36, 49, 64, 81, 100), r.map { it -> it * it }.toList())
+    }
+
+    @Test
+    fun reduceTest() {
+        assertEquals(55, r.reduce { a, b -> a + b })
+    }
+}

core-kotlin-2/src/test/kotlin/com/baeldung/range/FirstLastTest.kt

@@ -0,0 +1,22 @@
+package com.baeldung.range
+
+import org.junit.Test
+import kotlin.test.assertEquals
+
+class FirstLastTest {
+
+    @Test
+    fun testFirst() {
+        assertEquals(1, (1..9).first)
+    }
+
+    @Test
+    fun testLast() {
+        assertEquals(9, (1..9).last)
+    }
+
+    @Test
+    fun testStep() {
+        assertEquals(2, (1..9 step 2).step)
+    }
+}

core-kotlin-2/src/test/kotlin/com/baeldung/range/OtherRangeFunctionsTest.kt

@@ -0,0 +1,40 @@
+package com.baeldung.range
+
+import org.junit.Test
+import kotlin.test.assertEquals
+
+class OtherRangeFunctionsTest {
+
+    val r = 1..20
+    val repeated = listOf(1, 1, 2, 4, 4, 6, 10)
+
+    @Test
+    fun testMin() {
+        assertEquals(1, r.min())
+    }
+
+    @Test
+    fun testMax() {
+        assertEquals(20, r.max())
+    }
+
+    @Test
+    fun testSum() {
+        assertEquals(210, r.sum())
+    }
+
+    @Test
+    fun testAverage() {
+        assertEquals(10.5, r.average())
+    }
+
+    @Test
+    fun testCount() {
+        assertEquals(20, r.count())
+    }
+
+    @Test
+    fun testDistinct() {
+        assertEquals(listOf(1, 2, 4, 6, 10), repeated.distinct())
+    }
+}

core-kotlin-2/src/test/kotlin/com/baeldung/range/RangeTest.kt

@@ -0,0 +1,22 @@
+package com.baeldung.range
+
+import org.junit.Test
+import kotlin.test.assertEquals
+
+class RangeTest {
+
+    @Test
+    fun testRange() {
+        assertEquals(listOf(1,2,3), (1.rangeTo(3).toList()))
+    }
+
+    @Test
+    fun testDownTo(){
+        assertEquals(listOf(3,2,1), (3.downTo(1).toList()))
+    }
+
+    @Test
+    fun testUntil(){
+        assertEquals(listOf(1,2), (1.until(3).toList()))
+    }
+}

core-kotlin-2/src/test/kotlin/com/baeldung/range/ReverseRangeTest.kt

@@ -0,0 +1,12 @@
+package com.baeldung.range
+
+import org.junit.Test
+import kotlin.test.assertEquals
+
+class ReverseRangeTest {
+
+    @Test
+    fun reversedTest() {
+        assertEquals(listOf(9, 6, 3), (1..9).reversed().step(3).toList())
+    }
+}

core-kotlin-2/src/test/kotlin/com/baeldung/range/StepTest.kt

@@ -0,0 +1,17 @@
+package com.baeldung.range
+
+import org.junit.Test
+import kotlin.test.assertEquals
+
+class StepTest {
+
+    @Test
+    fun testStep() {
+        assertEquals(listOf(1, 3, 5, 7, 9), (1..9 step 2).toList())
+    }
+
+    @Test
+    fun testStepDown() {
+        assertEquals(listOf(9, 7, 5, 3, 1), (9 downTo 1 step 2).toList())
+    }
+}

core-kotlin-2/src/test/kotlin/com/baeldung/range/UntilRangeTest.kt

@@ -0,0 +1,12 @@
+package com.baeldung.range
+
+import org.junit.Test
+import kotlin.test.assertEquals
+
+class UntilRangeTest {
+
+    @Test
+    fun testUntil() {
+        assertEquals(listOf(1, 2, 3, 4), (1 until 5).toList())
+    }
+}

core-kotlin/README.md

@@ -55,3 +55,4 @@
 - [Building DSLs in Kotlin](https://www.baeldung.com/kotlin-dsl)
 - [Static Methods Behavior in Kotlin](https://www.baeldung.com/kotlin-static-methods)
 - [Inline Functions in Kotlin](https://www.baeldung.com/kotlin-inline-functions)
+- [Delegation Pattern in Kotlin](https://www.baeldung.com/kotlin-delegation-pattern)