package com.my.demo;
import java.util.Arrays;
import java.util.LinkedList;
import java.util.Random;
import java.util.Scanner;

public class ProducerConsumerDemo {
    public static void main(String args[]) {
        LinkedList<Integer> buffer = new LinkedList<>();
        new Producer(buffer, "P1").start();
        new Consumer(buffer, "C1").start();
        new Consumer(buffer, "C2").start();
        new Consumer(buffer, "C3").start();
    }
}

class Producer extends Thread {
    private LinkedList<Integer> list;

    public Producer(LinkedList<Integer> list, String name) {
        super(name);
        this.list = list;
    }

    @Override
    public void run() {
        try {
            Scanner scanner = new Scanner(System.in);
            while (true) {
                String line = scanner.nextLine();
                if (line.startsWith("p")) {//produce. example: p8->produce 8 items
                    fillList(Integer.parseInt(line.substring(1)));
                } else if (line.startsWith("b")) {//break producer.
                    break;
                }
            }
            scanner.close();
            System.out.println(getName() + " exit.");
        } catch (Exception e) {
            System.out.println(getName() + " Producer exception.");
        }
    }
    
    private void fillList(int count) {
        synchronized (list) {
            for (int n = 0; n < count; n++) {
                //如果list已满，则等待
                if (list.size() >= 20) {
                    try {
                        System.out.println(getName() + " List is full, Producer wait.");
                        list.wait();
                    } catch (Exception ex) {
                        ex.printStackTrace();
                    }
                }
                
                //如果list没有满，则继续生产
                Random random = new Random();
                int i = random.nextInt(90) + 10;
                list.add(i);
                list.notifyAll();
            }
        }
    }
}

class Consumer extends Thread {
    private LinkedList<Integer> list;

    public Consumer(LinkedList<Integer> list, String name) {
        super(name);
        this.list = list;
    }

    @Override
    public void run() {
        while (true) {
            synchronized (list) {
                if (list.isEmpty()) {
                    System.out.println(getName() + " List is empty, Consumer wait.");
                    try {
                        list.wait();
                    } catch (Exception ex) {
                        ex.printStackTrace();
                    }
                }
                System.out.println(getName() + " Consuming: " + list.removeLast() + ", list.size=" + list.size() + ", list=" + Arrays.toString(list.toArray()));
                list.notifyAll();
            }
            try {
                Thread.sleep(200);
            } catch (InterruptedException e) {
                System.out.println(getName() + " Consumer interrupted");
            }
        }
    }
}