How can locks be implemented in Java?

In Java, locks can be implemented by using either the synchronized keyword or the ReentrantLock class.

1. Using the synchronized keyword:

Using the synchronized keyword on a code block or method allows for locking an object or class. For example:

public class Table {
    private static final Object lock = new Object();
    
    public void updateTable() {
        synchronized (lock) {
            // 更新表的操作
        }
    }
}

1. Use the ReentrantLock class.

“ReentrantLock is a reentrant lock provided in Java, used to lock access to data tables, for example.”

import java.util.concurrent.locks.ReentrantLock;

public class Table {
    private final ReentrantLock lock = new ReentrantLock();
    
    public void updateTable() {
        lock.lock();
        try {
            // 更新表的操作
        } finally {
            lock.unlock();
        }
    }
}

By using the two methods mentioned above, it is possible to implement table locking in Java to ensure that operations on the table are safe in a multi-threaded environment. It is important to choose the appropriate locking method based on the specific situation.