思想为：定义两个ArrayList,将他们都加上锁A,B，线程1,2，1拿住了锁A ，请求锁B，2拿住了锁B请求锁A，在等待对方释放锁的过程中谁也不让出已获得的锁。

public class DeadLock {

    public static void main(String[] args) {

        final List<Integer> list1 = Arrays.asList(1, 2, 3);

        final List<Integer> list2 = Arrays.asList(4, 5, 6);

        new Thread(new Runnable() {

            @Override

            public void run() {

                synchronized (list1) {

                    for (Integer i : list1) {

                        System.out.println(i);

                    }

                    try {

                        Thread.sleep(1000);

                    } catch (InterruptedException e) {

                        e.printStackTrace();

                    }

                    synchronized (list2) {

                        for (Integer i : list2) {

                            System.out.println(i);

                        }

                    }

                }

            }

        }).start();