java.util.Scanner 和 Random

1.java util包下的Scanner类，为java的终端输入提供了极大的便利。下面是一个简单的例子。

package com.java.util;

import java.util.Scanner;

public class CLASSES {
	public static void testLocale(){
	public static void main(String[] args) throws Exception{
		Scanner cin = new Scanner(System.in);
		String input = "";
		while(!(input = cin.next()).equals("end")){
			System.out.println(input);
		}
	}
}

2.java util包下的Random类，使得实现随机数相当容易（虽然是伪随机数）。java.lang.Math.random()相当于未显示设置种子而得到的一个Random实例。即 new java.util.Random();
相同的随机数种子，会使用相同的方法调用序列。如：

package com.java.math;

import java.util.Random;

public class CLASSES {
	public static void print(){
		Random random1 = new Random(100);
		System.out.println(random1.nextDouble());
		System.out.println(random1.nextDouble());

		
		Random random2 = new Random(100);
		System.out.println(random2.nextDouble());
		System.out.println(random2.nextDouble());
	}
	
	public static void main(String[] args) {
		System.out.println("--------------------- The First Time ---------------------");
		print();
		System.out.println("--------------------- The Second Time ---------------------");
		print();
	}
}

结果：
--------------------- The First Time ---------------------
0.7220096548596434
0.19497605734770518
0.7220096548596434
0.19497605734770518
--------------------- The Second Time ---------------------
0.7220096548596434
0.19497605734770518
0.7220096548596434
0.19497605734770518