Java优学网Semaphore入门解析：轻松掌握信号量并发控制技巧

// 基本用法示例 semaphore.acquire(); try {

// 访问共享资源
doSomething();

} finally {

semaphore.release();

}

public class ParkingLot {

private Semaphore parkingSpots = new Semaphore(3);

public void parkCar(String carId) {
    try {
        parkingSpots.acquire();
        System.out.println(carId + " 成功停入车位");
        // 模拟停车时间
        Thread.sleep(2000);
    } catch (InterruptedException e) {
        Thread.currentThread().interrupt();
    } finally {
        System.out.println(carId + " 离开车位");
        parkingSpots.release();
    }
}

}