Random简单用法

package com.cp.random;

import java.util.Random;

public class MyRandom {
	public static void main(String[] args) {
		run();
	}
	public static void run() {
		//每次都不同 int
		Random rand = new Random();
		for(int i = 0;i<10;i++) {
			System.out.println(rand.nextInt(100));
		}
		//每次都一样 int
		Random rands = new Random(47);
		for(int i = 0;i<10;i++) {
			System.out.println(rands.nextInt(100));
		}
		//Long
		Random randLong = new Random();
		System.out.println(""+randLong.nextLong());
		//Double
		Random randDouble = new Random();
		System.out.println(""+randDouble.nextDouble());
	}
}
           

如果在创建Random的过程中没有传递任何参数 那么java就会将当前的时间作为随机数生成器的种子