線程：a，b
資源：1，2
簡單說就是線程a持有資源1需要資源2，線程b持有資源2需要資源1，產(chǎn)生死鎖。

public class DeadLock {
    public static void main(String[] args) {
        ReentrantLock alock = new ReentrantLock();
        ReentrantLock block = new ReentrantLock();

        new Thread(()->{
            alock.lock();
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            block.lock();
            block.unlock();


            alock.lock();
        }).start();

        new Thread(()->{
            block.lock();
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            alock.lock();
            alock.unlock();


            block.lock();
        }).start();
    }
}