选择两个城市作为预选旅游目标，实现两个独立的线程分别显示10次城市名，每次显示后休眠一段随机时间（1000毫秒以内），哪个先显示完毕，就决定去哪个城市。请用Runnable接口或Thread类实现。
下面是用Thread类的实现，参考程序如下,用Runable接口实现方法类似。
public class Ex82 {
public static void main(String[] args){
String[] citys = {"合肥","淮南"};
ThreadCity1 thread1 = new ThreadCity1(citys);
ThreadCity2 thread2 = new ThreadCity2(citys);
thread1.start();
thread2.start();
/*
* 请在下面补充几行代码，保证thread1和thread2都允许结束再执行后面的if语句。
*/
While(thread1.isAlive() || thread2.isAlive()){
}
if(thread1.getTime()<thread2.getTime()){
System.+
out.println("决定去:"+citys[0]);
}
else{
System.out.println("决定去:"+citys[1]);
}
}
}
class ThreadCity1 extends Thread{
private String[] citys;
private long time;
public long getTime(){
return time;
}
ThreadCity1(String[] citys){
this.citys=citys;
}
public void run(){
long start = System.currentTimeMillis();
for(int i=0;i<10;i++){
try{
System.out.println("Thread1:"+citys[0]);
Thread.sleep((int)(Math.random()*1000));
}
catch(Exception e){
}
}
time = System.currentTimeMillis() - start;
System.out.println("Thread1 Ends!");
}
}
class ThreadCity2 extends Thread{
private String[] citys;
private long time;
public long getTime(){
return time;
}
ThreadCity2(String[] citys){
this.citys=citys;
}
public void run(){
long start = System.currentTimeMillis();
for(int i=0;i<10;i++){
try{
System.out.println("Thread2:"+citys[1]);
Thread.sleep((int)(Math.random()*1000));
}
catch(Exception e){
}
}
time = System.currentTimeMillis() - start;
System.out.println("Thread2 Ends!");
}
}
