使用java语言解决哲学家就餐问题

哲学家就餐问题可以使用Java语言通过线程控制来实现。

具体实现如下：

1. 定义一个Chopstick类表示筷子，其中包含一个标识唯一性的id属性。

class Chopstick {
    private int id;

    public Chopstick(int id) {
        this.id = id;
    }

    public int getId() {
        return id;
    }
}

2. 定义一个Philosopher类表示哲学家，其中包含一个标识唯一性的id属性和两只筷子属性，表示他需要用到的两只筷子。

class Philosopher implements Runnable {
    private int id;
    private Chopstick leftChopstick;
    private Chopstick rightChopstick;

    public Philosopher(int id, Chopstick leftChopstick, Chopstick rightChopstick) {
        this.id = id;
        this.leftChopstick = leftChopstick;
        this.rightChopstick = rightChopstick;
    }

    @Override
    public void run() {
        try {
            while (true) {
                // 哲学家思考
                think();

                // 哲学家拿起左边的筷子
                synchronized (leftChopstick) {
                    System.out.println("Philosopher " + id + " picked up " + leftChopstick.getId() + " chopstick.");

                    // 哲学家拿起右边的筷子
                    synchronized (rightChopstick) {
                        System.out.println("Philosopher " + id + " picked up " + rightChopstick.getId() + " chopstick.");

                        // 哲学家就餐
                        eat();
                    }
                }
            }
        } catch (InterruptedException e) {
            Thread.currentThread().interrupt();
        }
    }

    private void think() throws InterruptedException {
        System.out.println("Philosopher " + id + " is thinking.");
        Thread.sleep(new Random().nextInt(1000));
    }

    private void eat() throws InterruptedException {
        System.out.println("Philosopher " + id + " is eating.");
        Thread.sleep(new Random().nextInt(1000));
        System.out.println("Philosopher " + id + " put down " + rightChopstick.getId() + " chopstick.");
        System.out.println("Philosopher " + id + " put down " + leftChopstick.getId() + " chopstick.");
    }
}

3. 在main方法中创建五个哲学家和五只筷子，并启动每个哲学家的线程。

public class DiningPhilosophers {
    public static void main(String[] args) {
        Chopstick chopstick1 = new Chopstick(1);
        Chopstick chopstick2 = new Chopstick(2);
        Chopstick chopstick3 = new Chopstick(3);
        Chopstick chopstick4 = new Chopstick(4);
        Chopstick chopstick5 = new Chopstick(5);

        Philosopher philosopher1 = new Philosopher(1, chopstick1, chopstick2);
        Philosopher philosopher2 = new Philosopher(2, chopstick2, chopstick3);
        Philosopher philosopher3 = new Philosopher(3, chopstick3, chopstick4);
        Philosopher philosopher4 = new Philosopher(4, chopstick4, chopstick5);
        Philosopher philosopher5 = new Philosopher(5, chopstick5, chopstick1);

        new Thread(philosopher1).start();
        new Thread(philosopher2).start();
        new Thread(philosopher3).start();
        new Thread(philosopher4).start();
        new Thread(philosopher5).start();
    }
}

在程序运行时，哲学家们会不断地思考、拿起筷子、就餐和放下筷子，直到程序被手动终止。