Worker Thread模式

工人线程Worker thread会逐个取回工作并进行处理，当所有工作全部完成后，工人线程会等待新的工作到来

5个工人线程从传送带取数据，3个传送工人线程将数据放入传送带

public class Channel {

    private final static int MAX_REQUEST = 100;

    private final Request[] requestQueue;

    private int head;

    private int tail;

    private int count;

    private final WorkerThread[] workerPool;

    public Channel(int workers) {
        this.requestQueue = new Request[MAX_REQUEST];
        this.head = 0;
        this.tail = 0;
        this.count = 0;
        this.workerPool = new WorkerThread[workers];
        this.init();
    }

    private void init() {
        for (int i = 0; i < workerPool.length; i++) {
            workerPool[i] = new WorkerThread("【工人:"+i+"】", this);
        }
    }

    /**
     * push switch to start all of worker to work.
     */
    public void startWorker() {
        Arrays.asList(workerPool).forEach(WorkerThread::start);
    }

    public synchronized void put(Request request) {
        while (count >= requestQueue.length) {
            try {
                this.wait();
            } catch (Exception e) {
            }
        }

        this.requestQueue[tail] = request;
        this.tail = (tail + 1) % requestQueue.length;
        this.count++;
        this.notifyAll();
    }

    public synchronized Request take() {
        while (count <= 0) {
            try {
                this.wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }

        Request request = this.requestQueue[head];
        this.head = (this.head + 1) % this.requestQueue.length;
        this.count--;
        this.notifyAll();
        return request;
    }
}

public class Request {

    private final String name;

    private final int number;

    public Request(final String name, final int number) {
        this.name = name;
        this.number = number;
    }

    public void execute() {
        System.out.println(Thread.currentThread().getName() + " executed " + this);
    }

    @Override
    public String toString() {
        return " Request=> No." + number + " Name." + name;
    }
}

public class TransportThread extends Thread {
    private final Channel channel;

    private static final Random random = new Random(System.currentTimeMillis());

    public TransportThread(String name, Channel channel) {
        super(name);
        this.channel = channel;
    }

    @Override
    public void run() {
        try {
            for (int i = 0; true; i++) {
                Request request = new Request(getName(), i);
                //向channel中放入request对象（谁放的，编号是多少）
                this.channel.put(request);
                Thread.sleep(random.nextInt(1_000));
            }
        } catch (Exception e) {
        }
    }
}

public class WorkerThread extends Thread {

    private final Channel channel;

    private static final Random random = new Random(System.currentTimeMillis());

    public WorkerThread(String name, Channel channel) {
        super(name);
        this.channel = channel;
    }

    @Override
    public void run() {
        while (true) {
            //取出request，执行里面的方法
            channel.take().execute();
            try {
                Thread.sleep(random.nextInt(1_000));
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
}

public class Test {
    public static void main(String[] args) {
        
        final Channel channel = new Channel(5);
        channel.startWorker();

        new TransportThread("Mark", channel).start();
        new TransportThread("Jack", channel).start();
        new TransportThread("Irish", channel).start();
    }
}