Java ThreadLocalRandom example 2017-11-24 07:59

ThreadLocalRandom is less contention and better performance than Random. If you need to use random number in multi-thread environment. The example code is here.

public class ThreadLocalRandomClient {
    public static void main(String[] args) {
        for (int i = 0; i < 10; i++) {
            int randomInt = ThreadLocalRandom.current().nextInt();
            int randomIntLessThan2 = ThreadLocalRandom.current().nextInt(2);
            int randomIntBiggerOrEqualThen2LessThan5 = ThreadLocalRandom.current().nextInt(2, 5);
            System.out.println("randomInt:" + randomInt);
            System.out.println("randomIntLessThan2:" + randomIntLessThan2);
            System.out.println("randomIntBiggerOrEqualThen2LessThan5:" + randomIntBiggerOrEqualThen2LessThan5);
        }
    }
}

output

randomInt:927733376
randomIntLessThan2:1
randomIntBiggerOrEqualThen2LessThan5:4
randomInt:-1210126526
randomIntLessThan2:0
randomIntBiggerOrEqualThen2LessThan5:3
randomInt:-359089879
randomIntLessThan2:0
randomIntBiggerOrEqualThen2LessThan5:3
randomInt:-2112033180
randomIntLessThan2:0
randomIntBiggerOrEqualThen2LessThan5:4
randomInt:-1410394207
randomIntLessThan2:1
randomIntBiggerOrEqualThen2LessThan5:3
randomInt:-1745100708
randomIntLessThan2:0
randomIntBiggerOrEqualThen2LessThan5:4
randomInt:-487542546
randomIntLessThan2:1
randomIntBiggerOrEqualThen2LessThan5:3
randomInt:-1435869749
randomIntLessThan2:0
randomIntBiggerOrEqualThen2LessThan5:2
randomInt:1015078975
randomIntLessThan2:1
randomIntBiggerOrEqualThen2LessThan5:2
randomInt:-76514204
randomIntLessThan2:1
randomIntBiggerOrEqualThen2LessThan5:4

summary

• nextInt() return random int value
• nextInt(int num) return the random value between 0 and num(exclude).
• nextInt(int num1,int num2) return the random value between num1 and num2(exclude).

EOF