线程-模拟死锁问题

public class DeadLockTest implements Runnable{
private int flag;
public DeadLockTest(int flag){
this.flag = flag;
}

static Object o1 = new Object(),o2 = new Object();

@Override
public void run() {
if(flag == 1) {
synchronized(o1) {
try {
System.out.println(Thread.currentThread().getName() + " 占据o1");
Thread.sleep(100);
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println(Thread.currentThread().getName() + " 等待t2释放o2");
synchronized(o2) {
System.out.println("flag == 1");
}
}
}

if(flag == 2) {
synchronized(o2) {
try {
System.out.println(Thread.currentThread().getName() + " 占据o2");
Thread.sleep(100);
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println(Thread.currentThread().getName() + " 等待t1释放o1");
synchronized(o1) {
System.out.println("flag == 2");
}
}
}
// 上面2个线程死锁 执行不到此处
System.out.println("ok");
}

public static void main(String[] args) {
Thread t1 = new Thread(new DeadLockTest(1), "t1");
Thread t2 = new Thread(new DeadLockTest(2), "t2");
t1.start();
t2.start();
}
}