求大神啊，哪位大神对java重入锁比较理解求教

这是分段锁的代码
public class SegementLock<T> {

     

    private int segementCount=16;

    

    private final Map<Integer, ReentrantLock> lockMap=new HashMap<>();

    

    public SegementLock() {

        init(null, false);

    }

    

    

    public SegementLock(Integer count,boolean fair){

        init(count, fair);

    }

    

    

    private void init(Integer count,boolean fair){

        if(count!=null){

            segementCount=count;

        }

        for(int i=0;i<segementCount;i++){

            lockMap.put(i, new ReentrantLock(fair));

        }

    }

    

    public boolean lock(T key){

        ReentrantLock lock = lockMap.get(Math.abs(key.hashCode() % segementCount));

        System.out.println("获取"+Math.abs(key.hashCode() % segementCount)+"号锁");

        if(lock.tryLock()){

            lock.lock();

            return true;

        }

        

            return false;

    }

    

    public void unlock(T key){

        ReentrantLock lock = lockMap.get(Math.abs(key.hashCode() % segementCount));

        System.out.println("释放+"+Math.abs(key.hashCode() % segementCount)+"号锁");

        lock.unlock();

    }

}

这是测试代码

public static void main(String[] args) throws InterruptedException {

         final SegementLock<String> lock=new SegementLock<>();

         lock.lock("1234");

         lock.unlock("1234");

         new Thread(new Runnable() {

            @Override

            public void run() {

                if(lock.lock("12345")){

                System.out.println("线程获取锁");

                lock.unlock("12345");

                }

            }

        }).start();

        

         if(lock.lock("1234")){

             System.out.println("main 获取" );

             lock.unlock("1234");

         }

         Thread.sleep(3000);

            if(lock.lock("12345")){

                System.out.println("main获取锁 12345");

                lock.unlock("12345");

            }

    }



理应是key=1234的锁主线程获取并释放 然后其它线程获取key=12345的锁然后释放，最后线程休眠3秒，然后在获取key=12345的锁，但就是获取不了啊，锁都释放了啊，谁知道啊啊

这是控制台输出代码

获取2号锁

释放+2号锁

获取2号锁

main 获取

释放+2号锁

获取3号锁

线程获取锁

释放+3号锁

获取3号锁  -===应该紧接着获取锁之后 输出main获取锁12345 但是就是不能获取到