java死锁问题

public class app12{
    public static void main(String[] args){
        Runner r1 = new Runner();
        Runner r2 = new Runner();
        r1.flag = 0;
        r2.flag = 1;
        Thread t1 = new Thread(r1);
        Thread t2 = new Thread(r2);
        t1.start();
        t2.start();
    }
}

class Runner implements Runnable{
    int flag = 1;
    Object o1 = new Object();
    Object o2 = new Object();
    public void run(){
        System.out.println("flag---"+flag);
        if(flag==1){
            synchronized(o1){
                try{
                    Thread.sleep(5000);
                }catch(InterruptedException e){
                    e.printStackTrace();
                }
            }
            synchronized(o2){
                    System.out.println("true");
                }
        }
        if(flag==0){
            synchronized(o2){
                try{
                    Thread.sleep(3000);
                }catch(InterruptedException e){
                    e.printStackTrace();
                }
            }
            synchronized(o1){
                System.out.println("false");
            }
        }
    }
}


为什么没有死锁！！
----------------解决方案--------------------------------------------------------
synchronized(o2)应该包含在synchronized(o1)的花括号中，该成下面就可以了。if(flag==1){
            synchronized(o1){
                try{
                    Thread.sleep(5000);
                }catch(InterruptedException e){
                    e.printStackTrace();
                }
            
            synchronized(o2){
                    System.out.println("true");
                }
        }
}
----------------解决方案--------------------------------------------------------
这个怎么会死锁呢，r1和r2是两个不同的资源啊，不可能死锁的
----------------解决方案--------------------------------------------------------
谢2楼
----------------解决方案--------------------------------------------------------
vasdjcgb
----------------解决方案--------------------------------------------------------