死锁

/**
 * 一共有两个人和两份资源，
 * 一人手中有一份，
 *但是，tang想得到对方的资源后，才后放手自己的资源(给对方享用)，
 *对方（dou）也是这样想的，两者都不让步，
 */
public class DeadIockThread {

    /**
     * 死锁
     * @param args
     */
    public static void main(String[] args) {
        Object zi = new Object();
        Object yuan = new Object();
        Thread t = new Thread(new tang(zi, yuan));
        Thread t1 = new Thread(new dou(zi,yuan));
    
        System.out.println("aaaa");
        t.start();
        t1.start();
    
    }
}
class tang implements Runnable{
    Object zi;
    Object yuan;
    public tang(Object zi, Object yuan) {
        this.zi = zi;
        this.yuan = yuan;
    }
    @Override
    public void run() {
        /*tang拥有“资”，但还想拥有“源”
         * 拥有“源”后，才会分享“资”
         */
        synchronized(zi){
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            synchronized(yuan){
                System.out.println("还想拥有“源”");
            }
        }    
    }
}
class dou implements Runnable{
    Object zi;
    Object yuan;
    
    public dou(Object zi, Object yuan) {
        this.zi = zi;
        this.yuan = yuan;
    }
    //同理
    public void run() {
        
        synchronized(yuan){
            
            synchronized(zi){
            System.out.println("还拥有“资”");