public static void main(String[] args) {

    Object o1 = new Object();

    Object o2 = new Object();

    Thread thread1 = new Thread(() -> {

        synchronized (o1){
            System.out.println(Thread.currentThread() + " get o1");
            // 线程等待
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            synchronized (o2){
                System.out.println(Thread.currentThread() + " get o2");
            }
        }
    });

    Thread thread2 = new Thread(() -> {

        synchronized (o2){
            System.out.println(Thread.currentThread() + " get o2");
            // 线程等待
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            synchronized (o1){
                System.out.println(Thread.currentThread() + " get o1");
            }
        }
    });

    thread1.start();
    thread2.start();
}