In Java, we can use SecureRandom.nextBytes(byte[] bytes) to generate a user-specified number of random bytes. This SecureRandom is a cryptographically secure random number generator (RNG). 1. Random 12 bytes (96 bits) 1.1 Generates a random 12 bytes (96 bits) nonce. HelloCryptoApp.java package com.mkyong.crypto; import java.security.SecureRandom; public class HelloCryptoApp { public static void main(String[] args) { […]

Read more Java – How to generate a random 12 bytes?

Few Java examples to show you how to generate a random alphanumeric String, with a fixed length. 1. Random [a-ZA-Z0-9] 1.1 Generate a random alphanumeric String [a-ZA-Z0-9], with a length of 8. RandomExample.java package com.mkyong; import java.security.SecureRandom; public class RandomExample { private static final String CHAR_LOWER = "abcdefghijklmnopqrstuvwxyz"; private static final String CHAR_UPPER = CHAR_LOWER.toUpperCase(); […]

Read more Java – How to generate a random String

Normally, we are using the following ways to generate a random number in Java. 1. ThreadLocalRandom (JDK 1.7) //Generate number between 0-9 int index = ThreadLocalRandom.current().nextInt(10); 2. Random() //Generate number between 0-9 Random random = new Random(); int index = random.nextInt(10); 3. Math.random() //Generate number between 0-9 int index = (int)(Math.random()*10); Note 1. For single […]

Read more Java : Return a random item from a List