testing work in core java

core-java/pom.xml

@@ -1,4 +1,5 @@
-<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">
 	<modelVersion>4.0.0</modelVersion>
 	<groupId>org.baeldung</groupId>
 	<artifactId>core-java</artifactId>
@@ -34,6 +35,12 @@
 			<version>${commons-lang3.version}</version>
 		</dependency>
 
+		<dependency>
+			<groupId>org.apache.commons</groupId>
+			<artifactId>commons-math3</artifactId>
+			<version>3.3</version>
+		</dependency>
+
 		<!-- web -->
 
 		<!-- marshalling -->

core-java/src/test/java/org/baeldung/java/CoreJavaRandomUnitTest.java

@@ -0,0 +1,126 @@
+package org.baeldung.java;
+
+import java.util.Random;
+
+import org.apache.commons.math3.random.RandomDataGenerator;
+import org.junit.Test;
+
+public class CoreJavaRandomUnitTest {
+
+    // tests - random long
+
+    @Test
+    public void givenUsingPlainJava_whenGeneratingRandomLongUnbounded_thenCorrect() {
+        final long generatedLong = new Random().nextLong();
+
+        System.out.println(generatedLong);
+    }
+
+    @Test
+    public void givenUsingPlainJava_whenGeneratingRandomLongBounded_thenCorrect() {
+        final long leftLimit = 1L;
+        final long rightLimit = 10L;
+        final long generatedLong = leftLimit + (long) (Math.random() * (rightLimit - leftLimit));
+
+        System.out.println(generatedLong);
+    }
+
+    @Test
+    public void givenUsingApacheCommons_whenGeneratingRandomLongBounded_thenCorrect() {
+        final long leftLimit = 10L;
+        final long rightLimit = 100L;
+        final long generatedLong = new RandomDataGenerator().nextLong(leftLimit, rightLimit);
+
+        System.out.println(generatedLong);
+    }
+
+    // tests - random int
+
+    @Test
+    public void givenUsingPlainJava_whenGeneratingRandomIntegerUnbounded_thenCorrect() {
+        final int generatedInteger = new Random().nextInt();
+
+        System.out.println(generatedInteger);
+    }
+
+    @Test
+    public void givenUsingPlainJava_whenGeneratingRandomIntegerBounded_thenCorrect() {
+        final int leftLimit = 1;
+        final int rightLimit = 10;
+        final int generatedInteger = leftLimit + (int) (new Random().nextFloat() * (rightLimit - leftLimit));
+
+        System.out.println(generatedInteger);
+    }
+
+    @Test
+    public void givenUsingApache_whenGeneratingRandomIntegerBounded_thenCorrect() {
+        final int leftLimit = 1;
+        final int rightLimit = 10;
+        final int generatedInteger = new RandomDataGenerator().nextInt(leftLimit, rightLimit);
+
+        System.out.println(generatedInteger);
+    }
+
+    // tests - random float
+
+    @Test
+    public void givenUsingPlainJava_whenGeneratingRandomFloatUnbouned_thenCorrect() {
+        final float generatedFloat = new Random().nextFloat();
+
+        System.out.println(generatedFloat);
+    }
+
+    @Test
+    public void givenUsingPlainJava_whenGeneratingRandomFloatBouned_thenCorrect() {
+        final float leftLimit = 1F;
+        final float rightLimit = 10F;
+        final float generatedFloat = leftLimit + new Random().nextFloat() * (rightLimit - leftLimit);
+
+        System.out.println(generatedFloat);
+    }
+
+    @Test
+    public void givenUsingApache_whenGeneratingRandomFloatBounded_thenCorrect() {
+        final float leftLimit = 1F;
+        final float rightLimit = 10F;
+        final float randomFloat = new RandomDataGenerator().getRandomGenerator().nextFloat();
+        final float generatedFloat = leftLimit + randomFloat * (rightLimit - leftLimit);
+
+        System.out.println(generatedFloat);
+    }
+
+    // tests - random double
+
+    @Test
+    public void givenUsingPlainJava_whenGeneratingRandomDoubleUnbounded_thenCorrect() {
+        final double generatedDouble = Math.random();
+
+        System.out.println(generatedDouble);
+    }
+
+    @Test
+    public void givenUsingPlainJava_whenGeneratingRandomDoubleBounded_thenCorrect() {
+        final double leftLimit = 1D;
+        final double rightLimit = 10D;
+        final double generatedDouble = leftLimit + new Random().nextDouble() * (rightLimit - leftLimit);
+
+        System.out.println(generatedDouble);
+    }
+
+    @Test
+    public void givenUsingApache_whenGeneratingRandomDoubleUnbounded_thenCorrect() {
+        final double generatedDouble = new RandomDataGenerator().getRandomGenerator().nextDouble();
+
+        System.out.println(generatedDouble);
+    }
+
+    @Test
+    public void givenUsingApache_whenGeneratingRandomDoubleBounded_thenCorrect() {
+        final double leftLimit = 1D;
+        final double rightLimit = 100D;
+        final double generatedDouble = new RandomDataGenerator().nextUniform(leftLimit, rightLimit);
+
+        System.out.println(generatedDouble);
+    }
+
+}