用java编程实现两个定时线程，一个线程每隔1秒显示一次，另一个线程每隔3秒显示一次

public class Test {

Thread th1 = new Thread(new Th1());//定义线程1
Thread th2 = new Thread(new Th2());//定义线程2

public Test() {
this.th1.start();
this.th2.start();
}
public static void main(String[] args) {
new Test();
}
// 线程1
class Th1 implements Runnable {

public void run(){

while(true){
System.out.println("我是线程1");
try {
th1.sleep(1000);//一秒后再此运行
} catch (Exception ex) {
ex.printStackTrace();
}
}
}
}
// 线程2
class Th2 implements Runnable {

public void run(){
while(true){
System.out.println("我是线程2");
try {