有一个值他无时无刻都在赋值，赋的值也没有规律，怎么让现在的值 和500毫秒以后的值进行比较啊？

Question

有一个值他无时无刻都在赋值，赋的值也没有规律，怎么让现在的值 和500毫秒以后的值进行比较啊？ 
求解！！！

Answer 1

感觉闻到了一丝哲学和物力的味道用个hashmap
保存当前值的值和时间
当过500毫秒后。在保存一个。比较。

Answer 2

package test.test1;public class CompareTest {
    public static int i = 0;
    public static int result = 0;
    public static int a = 0;
    public static int b = 0;
    public static void main(String[] args) {
        new Thread(){
            public void run() {
                while(true){
                    if(i<100000000){
                        i++;
                    }
                    else{
                        i=0;
                    }
                }
            };
        }.start();
        compare();
    }    public static void compare() {
        new Thread() {
            public void run() {
                a = i;
                System.out.println("a = "+a);
                try {
                    Thread.sleep(500);
                }
                catch (InterruptedException e) {
                }
                b = i;
                System.out.println("b = "+b);
                int temp = b-a;
                System.out.println("差值 = " + temp);
            };
        }.start();
    }
}