What are the ways to implement thread locking in Java?

There are several ways to implement thread locks in Java.

1. The synchronized keyword: Using the synchronized keyword can synchronize code blocks or methods, achieving mutual exclusion access of threads. When a thread accesses a synchronized method or code block of an object, other threads must wait for the current thread to release the lock before they can continue executing.
2. ReentrantLock class: ReentrantLock is a reentrant lock provided by Java that can be used as an alternative to the synchronized keyword for synchronization. Use the lock() and unlock() methods of ReentrantLock to control access to critical sections.
3. ReadWriteLock interface: ReadWriteLock is a lock used to control read and write operations, including read locks that can be held by multiple threads simultaneously, and write locks that can only be held by one thread.
4. The Condition interface is used in conjunction with the Lock interface to perform waiting and signaling operations on a condition, similar to the wait() and notify() methods of the Object class.
5. Semaphore class: Semaphore is a counting semaphore that can control the number of threads accessing a specific resource simultaneously. Permissions can be obtained and released using the acquire() and release() methods.
6. The CountDownLatch class is a synchronous utility class used to wait for other threads to complete. It can be used with the await() method to wait for other threads to finish and with the countDown() method to notify the CountDownLatch to decrease its counter.