生產者消費者模式

用wait和notifyAll來實現生產者消費者模式（關鍵在於隊列的創建）

import java.util.ArrayList;
import java.util.Date;
import java.util.LinkedList;
import java.util.List;

public class Demo02_生產者消費者模式 {

    public static void main(String[] args) {
        EventStorage storage = new EventStorage();
        Producer producer = new Producer(storage);
        Consumer consumer = new Consumer(storage);
        new Thread(producer).start();
        new Thread(consumer).start();
    }

}

class Producer implements Runnable {
    private EventStorage storage;
    public Producer(EventStorage storage) {
        this.storage = storage;
    }
    @Override
    public void run() {
        for (int i = 0; i < 100; i++) {
            storage.put();
        }
    }
}
class Consumer implements Runnable {
    private EventStorage storage;
    public Consumer(EventStorage storage) {
        this.storage = storage;
    }
    @Override
    public void run() {
        for (int i = 0; i < 100; i++) {
            storage.take();
        }
    }
}

class EventStorage {
    private int maxSize;
    private LinkedList<Date> storage;
    public EventStorage() {
        this.maxSize = 10;
        this.storage = new LinkedList<>();
    }
    public synchronized void put() {
        if (storage.size() == maxSize) {
            try {
                wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        storage.add(new Date());
        System.out.println("倉庫裏有了" + storage.size() + "個產品");
        notify();
    }
    public synchronized void take() {
        if (storage.size() == 0) {
            try {
                wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        System.out.println("消費了" + storage.poll() + "倉庫還剩下" + storage.size() + "個產品");
        notify();
    }

}