Java 17 — Enhanced Pesudo Random Generators

Git Link:

https://github.com/prakashbtech87/PrakashJavaRepository/tree/main/src/main/java/com/prakash/version/java17/random

Official Read :

https://openjdk.org/jeps/356

In Java 17, a new set of interfaces and classes for Pseudo Random Number Generators (PRNGs) were introduced in the java.util.random package, as part of the JEP 356: Enhanced Pseudo-Random Number Generators. This new API is designed to offer a more flexible, efficient, and customizable way of generating random numbers.

Key Components:

1.RandomGenerator Interface :

• This is a new common interface that all random number generators (RNGs) implement. It provides a standard set of methods for generating random numbers of different types like nextInt(), nextDouble(), and nextLong().
• java.util.Random and java.security.SecureRandom now implement this interface.

2. RandomGeneratorFactory :

• This is a factory class that can create instances of random number generators.
• You can select different PRNG algorithms (e.g., Xoroshiro128PlusPlus, L128X1024MixRandom, etc.).

Benefits of the New API:

• Pluggable Algorithms: You can choose different algorithms for random number generation.
• Better Performance: Some of the new algorithms (like Xoroshiro128PlusPlus) are more performant than the legacy Random.
• Thread-safety: Some implementations are designed to work well in concurrent environments.
• Customizability: The ability to fine-tune the generator for specific needs

Example to illustrate the RandomGenerator:

package com.prakash.version.java17.random;

import java.util.random.RandomGenerator;
import java.util.random.RandomGeneratorFactory;

/**
 * @author prakashkaruppusamy
 */
public class RandomGeneratorDemo {

    public static void main(String[] args) {

        // Get the default random generator (likely an instance of SplittableRandom)
        RandomGenerator randomGenerator = RandomGeneratorFactory.of("Random").create();

        // Generate a random int
        int randomInt = randomGenerator.nextInt();
        System.out.println("Random Integer: " + randomInt);

        // Generate a random double
        double randomDouble = randomGenerator.nextDouble();
        System.out.println("Random Double: " + randomDouble);

        // Generate a random long
        long randomLong = randomGenerator.nextLong();
        System.out.println("Random Long: " + randomLong);
    }

}

Output:

Example to display all the available :

package com.prakash.version.java17.random;

import java.util.random.RandomGenerator;
import java.util.random.RandomGeneratorFactory;

/**
 * @author prakashkaruppusamy
 */
public class RandomGeneratorMethods {

    public static void main(String[] args) {

        // Get the default random generator (likely an instance of SplittableRandom)
        RandomGenerator randomGenerator = RandomGeneratorFactory.of("Random").create();
        RandomGeneratorFactory.all().map(factory -> factory.group() + ":" + factory.name())
                .sorted()
                .forEach(System.out::println);

    }

}

Output:

Example Using a SpecificAlgorithm :

Using (Xoroshiro128PlusPlus):

package com.prakash.version.java17.random;

import java.util.random.RandomGenerator;
import java.util.random.RandomGeneratorFactory;

/**
 * @author prakashkaruppusamy
 */
public class RandomGeneratorUsingAlgorithm {

    public static void main(String[] args) {

        // Use a specific PRNG algorithm (Xoroshiro128PlusPlus)
        RandomGenerator xoroshiro = RandomGeneratorFactory.of("Xoroshiro128PlusPlus").create();

        // Generate a random int
        int randomInt = xoroshiro.nextInt();
        System.out.println("Random Integer (Xoroshiro128PlusPlus): " + randomInt);

        // Generate a random double
        double randomDouble = xoroshiro.nextDouble();
        System.out.println("Random Double (Xoroshiro128PlusPlus): " + randomDouble);

    }

}

Output:

Key Take Aways:

• RandomGenerator is the new interface introduced for generating random numbers.
• You can use different algorithms like Xoroshiro128PlusPlus for better performance or characteristics.
• Java 17 enhances the ability to generate streams of random numbers, making it easier to work with parallel streams.

This new API is more efficient and flexible than the legacy java.util.Random class, giving developers more control over the randomness algorithms used in their applications.