消費者與生產者

 1 import java.util.concurrent.ExecutorService;
 2 import java.util.concurrent.Executors;
 3 import java.util.concurrent.TimeUnit;
 4 
 5 class Meal{
 6     private final int orderNum;
 7     public Meal(int orderNum){
 8         this.orderNum = orderNum;
 9     }
10     public String toString(){
11         return "Meal" + orderNum;
12     }
13 }
14 
15 class WaitPerson implements Runnable{
16     private Restaurant restaurant;
17     public WaitPerson(Restaurant r){ restaurant = r; }
18     
19     @Override
20     public void run() {
21         // TODO Auto-generated method stub
22         try{
23             while(!Thread.interrupted()){
24                 synchronized(this){
25                     while(restaurant.meal == null){ //餐館沒有菜單就等待，廚師生產出來。
26                         wait();
27                     }
28                 }
29                 System.out.println("服務員得到菜單：" + restaurant.meal);
30                 synchronized(restaurant.chef){
31                     restaurant.meal = null;
32                     restaurant.chef.notifyAll();
33                 }
34             }
35             
36         }catch(InterruptedException e){
37             System.out.println("WaitPerson interrupted");
38         }
39     }
40     
41 }
42 
43 class Chef implements Runnable{
44     private Restaurant restaurant;
45     private int count = 0;
46     public Chef(Restaurant r) { restaurant = r; }
47     
48     @Override
49     public void run() {
50         // TODO Auto-generated method stub
51         try{
52             while(!Thread.interrupted()){
53                 synchronized(this){
54                     while(restaurant.meal != null){  //生產者，當飯店有菜單時，就等待服務員拿走
55                         wait();
56                     }
57                 }
58                 if(++count == 10){
59                     System.out.println("生產的食品超量!");
60                     restaurant.exec.shutdownNow();
61                 }
62                 System.out.println("Order up");
63                 synchronized(restaurant.waitPerson){ //生產餐廳的菜單，這時要保證其間服務員不會介入，而後再通知服務員取菜單
64                     restaurant.meal = new Meal(count);
65                     restaurant.waitPerson.notifyAll();
66                 }
67                 TimeUnit.MILLISECONDS.sleep(100);
68             }
69         }catch(InterruptedException e){
70             System.out.println("Chef interrupted");
71         }
72     }
73 }
74 public class Restaurant {
75     Meal meal;
76     
77     ExecutorService exec = Executors.newCachedThreadPool();
78     
79     WaitPerson waitPerson = new WaitPerson(this);
80     Chef chef = new Chef(this);
81     public Restaurant(){
82         exec.execute(chef);
83         exec.execute(waitPerson);
84         
85     }
86     public static void main(String[] args){
87         new Restaurant();
88     }
89 }

 

 

運行結果：

Order up
服務員得到菜單：Meal1
Order up
服務員得到菜單：Meal2
Order up
服務員得到菜單：Meal3
Order up
服務員得到菜單：Meal4
Order up
服務員得到菜單：Meal5
Order up
服務員得到菜單：Meal6
Order up
服務員得到菜單：Meal7
Order up
服務員得到菜單：Meal8
Order up
服務員得到菜單：Meal9
生產的食品超量!
WaitPerson interrupted
Order up
Chef interrupted