使用多线程通信技术编程实现拿水果

爸爸往盘子里放苹果，妈妈往盘子里放桔子，每次只能放一样水果。爸爸放苹果后，叫儿子拿走吃，妈妈放桔子后，叫女儿拿走吃。水果被拿走后，爸爸妈妈又可以往盘子里放水果。利用多线程通信技术编程实现。

import java.util.List;
//爸爸线程
public class Father implements Runnable {
    List<String> list;

    public Father(List<String> list) {
        this.list = list;
    }

    @Override
    public void run() {
        while(true){
            synchronized (list){
                if (list.contains("苹果")){
                    try {
                        list.wait();
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }else{
                    System.out.println("我正在放苹果，题主快来吃！！");
                    list.add("苹果");
                    list.notify();
                }
            }
        }
    }
}



import java.util.List;
/*
   妈妈线程 
 */
public class Mather implements Runnable{
    List<String> list;

    public Mather(List<String> list) {
        this.list = list;
    }

    @Override
    public void run() {
        while(true){
            synchronized (list){
                if (list.contains("桔子")){
                    try {
                        list.wait();
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }else{
                    System.out.println("妈妈正在放桔子，女儿来拿！！");
                    list.add("桔子");
                    list.notify();
                }
            }
        }
    }
}



import java.util.List;
/*
    儿子线程
 */
public class Son implements Runnable{
    List<String> list;

    public Son(List<String> list) {
        this.list = list;
    }

    @Override
    public void run() {
        while(true){
            synchronized (list){
                if (!list.contains("苹果")){
                    try {
                        list.wait();
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }else{
                    System.out.println("题主吃完了苹果，答主快来放！！");
                    list.remove("苹果");
                    list.notify();
                }
            }
        }
    }
}



import java.util.List;
/*
    女儿线程
 */
public class Daughter implements Runnable{
    List<String> list;

    public Daughter(List<String> list) {
        this.list = list;
    }

    @Override
    public void run() {
        while(true){
            synchronized (list){
                if (!list.contains("桔子")){
                    try {
                        list.wait();
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }else{
                    System.out.println("女儿吃完了桔子，妈妈快来放！！");
                    list.remove("桔子");
                    list.notify();
                }
            }
        }
    }
}


import java.util.ArrayList;
import java.util.List;
/*
    测试类
 */
public class Test {
    public static void main(String[] args) {
        List<String> list = new ArrayList<>();
        Thread th1 = new Thread(new Father(list));
        th1.start();
        Thread th2 = new Thread(new Mather(list));
        th2.start();
        Thread th3 = new Thread(new Son(list));
        th3.start();
        Thread th4 = new Thread(new Daughter(list));
        th4.start();



    }
}

运行效果