@Slf4j
public class TestLock {
    public static void main(String[] args) throws Exception{

        ReentrantLock lock = new ReentrantLock(false);
        String mainThreadName = Thread.currentThread().getName();

        System.out.println("=====BEGIN=====");
        try {
            new Thread(() -> {
                String name 
 
= Thread.currentThread().getName();
                lock.lock(); // 第一次加鎖
                System.out.println("1-1、"+lock.tryLock()); // 第二次加鎖
                System.out.println("1-2、"+lock.tryLock()); // 第三次加鎖

                Thread.currentThread().setName("執行緒A");
                // 未解鎖前，剩餘鎖數量：3
                lock.unlock(); //
 
 解鎖，剩餘鎖數量：2
                lock.unlock(); // 解鎖，剩餘鎖數量：1
                lock.unlock(); // 解鎖，剩餘鎖數量：0
                System.out.println(name + " lock.getHoldCount: " + lock.getHoldCount()); // 列印：0
            }).start();
            new Thread(() -> {
                String name = Thread.currentThread().getName();
                
 
try {
                    Thread.sleep(200);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                System.out.println("2、"+lock.tryLock());
                Thread.currentThread().setName("執行緒B");
                //System.out.println(name);
                if (lock.isLocked()) {
                    System.out.println(name + " =1= lock.getHoldCount: " + lock.getHoldCount());
                    System.out.println(name+"解鎖");
                    lock.unlock();
                    System.out.println(name + " =2= lock.getHoldCount: " + lock.getHoldCount());
                }
            }).start();
            new Thread(() -> {
                String name = Thread.currentThread().getName();
                try {
                    Thread.sleep(200); // 睡眠時間與執行緒B相同，下面lock.unlock()會報IllegalMonitorStateException
                    // Thread.sleep(400); // lock.unlock()不會報IllegalMonitorStateException
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                System.out.println("3、"+lock.tryLock());
                Thread.currentThread().setName("執行緒C");
                if (lock.isLocked()) {
                    // 因為睡眠時間相同，所以可能出現的情況：執行緒B獲取到鎖但還未解鎖，再結合lock.isLocked()原始碼（any thread），
                    // 即鎖還未被釋放，進入判斷後lock.unlock()失敗，因為不符合：If the current thread is the holder of this lock

                    System.out.println(name+"解鎖");
                    lock.unlock();
                }
            }).start();
        } catch (Exception e) {
            log.error(e.getMessage(),e);
        }
        System.out.println(mainThreadName+" lock.isLocked: " + lock.isLocked());
        System.out.println("=====END=====");

    }
}