How can I implement a semaphore in Java?

How can I implement a semaphore in Java?

You can implement a semaphore in Java using the Semaphore class from the java.util.concurrent package. Would you like a code example?

Yes, please provide a code example.

Here's a simple example:

import java.util.concurrent.Semaphore;

public class SemaphoreExample {
    private static final Semaphore semaphore = new Semaphore(1);

    public static void main(String[] args) {
        Thread thread1 = new Thread(() -> accessResource("Thread 1"));
        Thread thread2 = new Thread(() -> accessResource("Thread 2"));

        thread1.start();
        thread2.start();
    }

    private static void accessResource(String threadName) {
        try {
            semaphore.acquire();
            System.out.println(threadName + " has acquired the semaphore.");
            // Simulate some work with the resource
            Thread.sleep(1000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            System.out.println(threadName + " is releasing the semaphore.");
            semaphore.release();
        }
    }
}

This code demonstrates how to use a semaphore to control access to a shared resource.

What does the acquire() and release() method do?

The acquire() method is used to acquire a permit from the semaphore, blocking if necessary until a permit is available. The release() method releases a permit, potentially allowing other threads to acquire it.