与BlockingQueue息息相关的一个话题就是:生产者-消费者模型。
- 生产者持续生产,直道缓冲区满,阻塞
- 消费者持续消费,直到缓冲区空,阻塞
- 生产,消费 并发
接下来,我们就要用BlockingQueue去实现生产消费。
分别定义生产,消费接口。请注意定义中的阻塞。
public interface Consumer{
void consume() throws InterruptedException;
}
public interface Producer{
void produce() throws InterruptedException;
}
注意生产者,消费者可以并发。可以对接口进行进一步封装
abstract class AbsConsumer implements Consumer, Runnable{
@Override
public void run() {
try{
consume();
} catch(InterruptedException e) {
}
}
}
abstract class AbstractProducer implements Producer, Runnable {
@Override
public void run() {
try {
produce();
} catch (InterruptedException e) {
}
}
}
生产者,消费者消费的个体单位是:
public class Task {
public int no;
public Task(int no) {
this.no = no;
}
}
最后,模型就是:
public class BlockingQueueModel {
private final BlockingQueue<Task> queue;
//这里使用AtomicInteger,保证并发的生产的个体的标记唯一
private final AtomicInteger increTaskNo = new AtomicInteger(0);
public BlockingQueueModel(int cap) {
this.queue = new LinkedBlockingQueue<>(cap);
}
public Runnable newRunnableConsumer() {
return new ConsumerImpl();
}
public Runnable newRunnableProducer() {
return new ProducerImpl();
}
private class ConsumerImpl extends AbstractConsumer {
@Override
public void consume() throws InterruptedException {
Task task = queue.take();
// 固定时间范围的消费,模拟相对稳定的服务器处理过程
Thread.sleep(500 + (long) (Math.random() * 500));
System.out.println("consume: " + task.no);
}
}
private class ProducerImpl extends AbstractProducer implements Producer, Runnable {
@Override
public void produce() throws InterruptedException {
// 不定期生产,模拟随机的用户请求
Thread.sleep((long) (Math.random() * 1000));
Task task = new Task(increTaskNo.getAndIncrement());
System.out.println("produce: " + task.no);
queue.put(task);
}
}
public static void main(String[] args) {
Model model = new BlockingQueueModel(3);
for (int i = 0; i < 2; i++) {
new Thread(model.newRunnableConsumer()).start();
}
for (int i = 0; i < 5; i++) {
new Thread(model.newRunnableProducer()).start();
}
}
}