阻塞队列的写法

基于linkedList的BlockingQueue的书写

    //java中阻塞队列的应用
public class BlockingQueue {
    private List queue = new LinkedList<>();
    private int limit = 10;
    public BlockingQueue(int limit){
        this.limit = limit;
    }
    public synchronized void enqueue(Object item) throws Exception{
        while(this.queue.size() == this.limit){
            wait();
        }
        if(this.queue.size()==0){
            notify();
        }
        this.queue.add(item);
    }
    public synchronized void dequeue(Object item) throws Exception{
        while(this.queue.size() == this.limit){
            notify();
        }
        if(this.queue.size()==0){
            wait();
        }
        this.queue.remove(0);
    }
}

异步消息队列

原始数据类

public class PCData {
    private final int intData;
    public PCData (int d ){
        intData=d;
    }
    public PCData (String d ){
        intData=Integer.valueOf(d);
    }
    public int getData(){
        return intData;
    }
    @Override
    public String toString() {
        return "data: "+intData;
    }
    
}

消费者

public class Consumer  implements Runnable{
    private BlockingQueue queue;
    private static final int SLEEPTIME = 1000;
    public Consumer(BlockingQueue queue){
        this.queue = queue;
    }
    
    @Override
    public void run() {
        System.out.println("start Consumer id :"+Thread.currentThread().getId());
        Random r = new Random();
        try{
            while(true){
                //注意：take()都remove()都是删除元素并返回队列的头，但是take()操作为空不报错
                PCData data = queue.take();
                if(data != null)
                {
                    int re = data.getData() * data.getData();
                    System.out.println("消费者消耗的数值：  "+MessageFormat.format("{0}*{1}={2}", data.getData(),data.getData(),re));
                    Thread.sleep(r.nextInt(SLEEPTIME));
                }
            }
        }catch (InterruptedException e) {
            e.printStackTrace();
            Thread.currentThread().interrupt();
        }
    }
}

生产者

public class Producer implements Runnable{
    private volatile boolean isRunning = true;
    private BlockingQueue queue;
    private static AtomicInteger count = new AtomicInteger();
     private static final int SLEEPTIME = 1000;
    public Producer( BlockingQueue queue){
        this.queue = queue;
    }
    @Override
    public void run() {
        PCData data = null;
        Random random = new Random();
         System.out.println("start producting id:" + Thread.currentThread().getId());
         try {
            while(isRunning){
                Thread.sleep(random.nextInt(SLEEPTIME));
                data = new PCData(count.incrementAndGet());
                System.out.println(data + "加入队列");
                if(!queue.offer(data, 2, TimeUnit.SECONDS)){
                    System.out.println("加入队列失败");
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
            Thread.currentThread().interrupt();
        }
    }
    public void stop(){
        isRunning = false;
    }
    
}

主测试方法

public class Main {
    public static void main(String[] args) throws Exception {
        BlockingQueue queue = new LinkedBlockingDeque<>(10);
        Producer p1 = new Producer(queue);
        Producer p2 = new Producer(queue);
        Producer p3 = new Producer(queue);
        Consumer c1 = new Consumer(queue);
        Consumer c2 = new Consumer(queue);
        Consumer c3 = new Consumer(queue);
        ExecutorService service = Executors.newCachedThreadPool();
        service.execute(p1);
        service.execute(p2);
        service.execute(p3);
        service.execute(c1);
        service.execute(c2);
        service.execute(c3);
        Thread.sleep(10*1000);
        p1.stop();
        p2.stop();
        p3.stop();
        Thread.sleep(3000);
        service.shutdown();
    }
}