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java併發程式設計:如何實現生產者消費者模式?

package concurrent;

import java.util.LinkedList;
import java.util.Queue;

public class ProducerConsumer {
	
	public static class Storage{
		
		private static final int MAX_ITEM = 5;
		
		private Queue<Integer> queue = new LinkedList<>();
		
		public synchronized void put(Integer item){
			while(queue.size() >= MAX_ITEM){
				try {
					wait();
				} catch (InterruptedException e) {
					e.printStackTrace();
				}
			}
			
			try {
				Thread.sleep(100);
			} catch (InterruptedException e) {
				e.printStackTrace();
			}
			
			queue.add(item);
			System.out.println("produce product:" + item);
			notifyAll();
		}
		
		public synchronized Integer take(){
			Integer item = 0;
			while(queue.isEmpty()){
				try {
					wait();
				} catch (InterruptedException e) {
					e.printStackTrace();
				}
			}
			
			try {
				Thread.sleep(100);
			} catch (InterruptedException e) {
				e.printStackTrace();
			}
			
			item = queue.poll();
			System.out.println("consume product:" + item);
			notifyAll();
			return item;
		}
		
	}
	
	public static class ProducerThread implements Runnable{

		private Storage storage;
		
		ProducerThread(Storage storage){
			this.storage = storage;
		}
		
		@Override
		public void run() {
			int num = 20;
			for(int i = 0; i < num; i++){
				storage.put(i);
			}
		}
	}
	
	public static class ConsumerThread implements Runnable{

		private Storage storage;
		
		ConsumerThread(Storage storage){
			this.storage = storage;
		}
		
		@Override
		public void run() {
			int num = 20;
			for(int i = 0; i < num; i++){
				storage.take();
			}
		}
	}

	public static void main(String[] args) {
		Storage storage = new Storage();
		Thread consumerThread = new Thread(new ConsumerThread(storage));
		Thread productThread = new Thread(new ProducerThread(storage));
		consumerThread.start();
		productThread.start();
	}
}

結果如下圖所示: