Java线程问题

Question

Java中线程对象什么用？有谁知道？

Answer 1

亲，测试例子
[code="java"]
public static void main(String[] args) {

final List singelists = new ArrayList();

    long startTime = System.nanoTime();
    for (int i = 0; i < 900; i++) {
        singelists.add(i);
        System.out.println(i);
    }
    long endTime = System.nanoTime();
    System.out.println("单线程运行时间：" + (endTime - startTime));

    final List lists = new ArrayList();
    final long newStartTime = System.nanoTime();
    new Thread(){
        public void run() {
            for (int i = 0; i < 300; i++) {
                System.out.println(this.getName() + ":" + i);
                lists.add(i);
            }
            if(lists.size() == 900){
                System.out.println(this.getName() + "-多线程运行时间：" + (System.nanoTime() - newStartTime));
            }
        };
    }.start();

    new Thread(){
        public void run() {
            for (int i = 300; i < 600; i++) {
                System.out.println(this.getName()  + ":" + i);
                lists.add(i);
            }
            if(lists.size() == 900){
                System.out.println(this.getName() + "-多线程运行时间：" + (System.nanoTime() - newStartTime));
            }
        };
    }.start();

    new Thread(){
        public void run() {
            for (int i = 600; i < 900; i++) {
                System.out.println(this.getName() + ":" + i);
                lists.add(i);
            }
            if(lists.size() == 900){
                System.out.println(this.getName() + "-多线程运行时间：" + (System.nanoTime() - newStartTime));
            }
        };
    }.start();
}   

[/code]

测试结果：
[code="java"]
单线程运行时间：18768865
Thread-0-多线程运行时间：15046605
[/code]