实现Runnable接口，通过Thread启动多线程

package com.xiner.demo;public class Demo implements Runnable{    boolean flag = false;    public void run(){        for(int i=0;i<10;i++){            System.out.println("-----"+i);        }    }    public void ac(){        Thread th1 = new Thread(Demo.this);        th1.start();    }    public static void main(String[] args){        Demo d1 = new Demo();        Demo d2 = new Demo();        d1.ac();        d2.ac();    }}