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BAEL-3678 - Generating Random Numbers - Initial commit (#8491) 

* BAEL-3678 - Initial commit

* BAEL-3678 - Test added

* BAEL-3678 - Generated multiple methods and tests

* BAEL-3678 - Test improvement
This commit is contained in:
aitorcuesta 2020-01-10 22:48:48 +01:00 committed by maibin
parent e5b4048419
commit d8b0fd59a8
3 changed files with 233 additions and 0 deletions
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5
java-numbers-2/pom.xml
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@ -21,6 +21,11 @@
<artifactId>jmh-generator-annprocess</artifactId>
<version>${jmh-generator.version}</version>
</dependency>
<dependency>
<groupId>it.unimi.dsi</groupId>
<artifactId>dsiutils</artifactId>
<version>2.6.0</version>
</dependency>
</dependencies>
<build>

91
java-numbers-2/src/main/java/com/baeldung/randomnumbers/RandomNumbersGenerator.java Normal file
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@ -0,0 +1,91 @@
package com.baeldung.randomnumbers;
import java.security.SecureRandom;
import java.util.Random;
import java.util.SplittableRandom;
import java.util.concurrent.ThreadLocalRandom;
import java.util.stream.IntStream;
import org.apache.commons.math3.random.RandomDataGenerator;
import it.unimi.dsi.util.XoRoShiRo128PlusRandom;
public class RandomNumbersGenerator {
public Integer generateRandomWithMathRandom(int max, int min) {
return (int) ((Math.random() * (max - min)) + min);
}
public Integer generateRandomWithNextInt() {
Random random = new Random();
int randomWithNextInt = random.nextInt();
return randomWithNextInt;
}
public Integer generateRandomWithNextIntWithinARange(int min, int max) {
Random random = new Random();
int randomWintNextIntWithinARange = random.nextInt(max - min) + min;
return randomWintNextIntWithinARange;
}
public IntStream generateRandomUnlimitedIntStream() {
Random random = new Random();
IntStream unlimitedIntStream = random.ints();
return unlimitedIntStream;
}
public IntStream generateRandomLimitedIntStream(long streamSize) {
Random random = new Random();
IntStream limitedIntStream = random.ints(streamSize);
return limitedIntStream;
}
public IntStream generateRandomLimitedIntStreamWithinARange(int min, int max, long streamSize) {
Random random = new Random();
IntStream limitedIntStreamWithinARange = random.ints(streamSize, min, max);
return limitedIntStreamWithinARange;
}
public Integer generateRandomWithThreadLocalRandom() {
int randomWithThreadLocalRandom = ThreadLocalRandom.current()
.nextInt();
return randomWithThreadLocalRandom;
}
public Integer generateRandomWithThreadLocalRandomInARange(int min, int max) {
int randomWithThreadLocalRandomInARange = ThreadLocalRandom.current()
.nextInt(min, max);
return randomWithThreadLocalRandomInARange;
}
public Integer generateRandomWithThreadLocalRandomFromZero(int max) {
int randomWithThreadLocalRandomFromZero = ThreadLocalRandom.current()
.nextInt(max);
return randomWithThreadLocalRandomFromZero;
}
public Integer generateRandomWithSplittableRandom(int min, int max) {
SplittableRandom splittableRandom = new SplittableRandom();
int randomWithSplittableRandom = splittableRandom.nextInt(min, max);
return randomWithSplittableRandom;
}
public Integer generateRandomWithSecureRandom() {
SecureRandom secureRandom = new SecureRandom();
int randomWithSecureRandom = secureRandom.nextInt();
return randomWithSecureRandom;
}
public Integer generateRandomWithRandomDataGenerator(int min, int max) {
RandomDataGenerator randomDataGenerator = new RandomDataGenerator();
int randomWithRandomDataGenerator = randomDataGenerator.nextInt(min, max);
return randomWithRandomDataGenerator;
}
public Integer generateRandomWithXoRoShiRo128PlusRandom(int min, int max) {
XoRoShiRo128PlusRandom xoroRandom = new XoRoShiRo128PlusRandom();
int randomWithXoRoShiRo128PlusRandom = xoroRandom.nextInt(max - min) + min;
return randomWithXoRoShiRo128PlusRandom;
}
}

137
java-numbers-2/src/test/java/com/baeldung/randomnumbers/RandomNumbersGeneratorUnitTest.java Normal file
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@ -0,0 +1,137 @@
package com.baeldung.randomnumbers;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertTrue;
import java.util.stream.IntStream;
import org.junit.Test;
public class RandomNumbersGeneratorUnitTest {
private static final int MIN_RANGE = 1;
private static final int MAX_RANGE = 10;
private static final int ITERATIONS = 50;
private static final long STREAM_SIZE = 50;
@Test
public void whenGenerateRandomWithMathRandom_returnsSuccessfully() {
RandomNumbersGenerator generator = new RandomNumbersGenerator();
for (int i = 0; i < ITERATIONS; i++) {
int randomNumer = generator.generateRandomWithMathRandom(MIN_RANGE, MAX_RANGE);
assertTrue(isInRange(randomNumer, Integer.MIN_VALUE, Integer.MAX_VALUE));
}
}
@Test
public void whenGenerateRandomWithNextInt_returnsSuccessfully() {
RandomNumbersGenerator generator = new RandomNumbersGenerator();
for (int i = 0; i < ITERATIONS; i++) {
int randomNumber = generator.generateRandomWithNextInt();
assertTrue(isInRange(randomNumber, Integer.MIN_VALUE, Integer.MAX_VALUE));
}
}
@Test
public void whenGenerateRandomWithNextIntWithinARange_returnsSuccessfully() {
RandomNumbersGenerator generator = new RandomNumbersGenerator();
for (int i = 0; i < ITERATIONS; i++) {
int randomNumber = generator.generateRandomWithNextIntWithinARange(MIN_RANGE, MAX_RANGE);
assertTrue(isInRange(randomNumber, MIN_RANGE, MAX_RANGE));
}
}
@Test
public void whenGenerateRandomUnlimitedIntStream_returnsSuccessfully() {
RandomNumbersGenerator generator = new RandomNumbersGenerator();
IntStream stream = generator.generateRandomUnlimitedIntStream();
assertNotNull(stream);
Integer randomNumber = stream.findFirst()
.getAsInt();
assertNotNull(randomNumber);
assertTrue(isInRange(randomNumber, Integer.MIN_VALUE, Integer.MAX_VALUE));
}
@Test
public void whenGenerateRandomLimitedIntStream_returnsSuccessfully() {
RandomNumbersGenerator generator = new RandomNumbersGenerator();
generator.generateRandomLimitedIntStream(STREAM_SIZE)
.forEach(randomNumber -> assertTrue(isInRange(randomNumber, Integer.MIN_VALUE, Integer.MAX_VALUE)));
}
@Test
public void whenGenerateRandomLimitedIntStreamWithinARange_returnsSuccessfully() {
RandomNumbersGenerator generator = new RandomNumbersGenerator();
generator.generateRandomLimitedIntStreamWithinARange(MIN_RANGE, MAX_RANGE, STREAM_SIZE)
.forEach(randomNumber -> assertTrue(isInRange(randomNumber, MIN_RANGE, MAX_RANGE)));
}
@Test
public void whenGenerateRandomWithThreadLocalRandom_returnsSuccessfully() {
RandomNumbersGenerator generator = new RandomNumbersGenerator();
for (int i = 0; i < ITERATIONS; i++) {
int randomNumber = generator.generateRandomWithThreadLocalRandom();
assertTrue(isInRange(randomNumber, Integer.MIN_VALUE, Integer.MAX_VALUE));
}
}
@Test
public void whenGenerateRandomWithThreadLocalRandomInARange_returnsSuccessfully() {
RandomNumbersGenerator generator = new RandomNumbersGenerator();
for (int i = 0; i < ITERATIONS; i++) {
int randomNumber = generator.generateRandomWithThreadLocalRandomInARange(MIN_RANGE, MAX_RANGE);
assertTrue(isInRange(randomNumber, MIN_RANGE, MAX_RANGE));
}
}
@Test
public void whenGenerateRandomWithThreadLocalRandomFromZero_returnsSuccessfully() {
RandomNumbersGenerator generator = new RandomNumbersGenerator();
for (int i = 0; i < ITERATIONS; i++) {
int randomNumber = generator.generateRandomWithThreadLocalRandomFromZero(MAX_RANGE);
assertTrue(isInRange(randomNumber, 0, MAX_RANGE));
}
}
@Test
public void whenGenerateRandomWithSplittableRandom_returnsSuccessfully() {
RandomNumbersGenerator generator = new RandomNumbersGenerator();
for (int i = 0; i < ITERATIONS; i++) {
int randomNumber = generator.generateRandomWithSplittableRandom(MIN_RANGE, MAX_RANGE);
assertTrue(isInRange(randomNumber, MIN_RANGE, MAX_RANGE));
}
}
@Test
public void whenGenerateRandomWithSecureRandom_returnsSuccessfully() {
RandomNumbersGenerator generator = new RandomNumbersGenerator();
for (int i = 0; i < ITERATIONS; i++) {
int randomNumber = generator.generateRandomWithSecureRandom();
assertTrue(isInRange(randomNumber, Integer.MIN_VALUE, Integer.MAX_VALUE));
}
}
@Test
public void whenGenerateRandomWithRandomDataGenerator_returnsSuccessfully() {
RandomNumbersGenerator generator = new RandomNumbersGenerator();
for (int i = 0; i < ITERATIONS; i++) {
int randomNumber = generator.generateRandomWithRandomDataGenerator(MIN_RANGE, MAX_RANGE);
// RandomDataGenerator top is inclusive
assertTrue(isInRange(randomNumber, MIN_RANGE, MAX_RANGE + 1));
}
}
@Test
public void whenGenerateRandomWithXoRoShiRo128PlusRandom_returnsSuccessfully() {
RandomNumbersGenerator generator = new RandomNumbersGenerator();
for (int i = 0; i < ITERATIONS; i++) {
int randomNumber = generator.generateRandomWithXoRoShiRo128PlusRandom(MIN_RANGE, MAX_RANGE);
assertTrue(isInRange(randomNumber, MIN_RANGE, MAX_RANGE));
}
}
private boolean isInRange(int number, int min, int max) {
return min <= number && number < max;
}
}