实现多线程有两种方式，第一种方式，实现runnable接口，第二种方式，继承thread类
重写run方法
public class Runnable1 implements runnable{
public void run(){
for(int i=0;i<5;i++){
System.out.printLn("Thread"+i);
}
}
}
public class Test{
Runnable1 run1 = new Runnable1();
Thread t1 = new Thread(run1);
Thread t2 = new Thread(run1);
t1.start();
}