Java生产者消费者实例

设计：涉及到的类有食物、厨师、服务员、顾客以及测试类。厨师负责生产食物，服务员服务于顾客，顾客负责点餐以及吃饭。

技术点：Java多线程，线程安全(synchronized)，wait()/notify()线程之间通信。

食物类：

/**  * @Author: liudq  * @Description:食物类  * @Date: create in 2017/11/4 17:28  */ public class Food {     private int num;    //食物的数量，这个为公共资源，多个线程竞争     private String name;         public Food(int num, String name) {         this.num = num;         this.name = name;     }      public synchronized boolean add(){         if (!max()){             num++;             return true;         }else {             return false;         }     }      public synchronized boolean sub(){         if (!min()){             num--;             return true;         }else {             return false;         }     }      public boolean max(){         if (num >= 10){             return true;         }         return false;     }      public boolean min(){         if (num <= 0){             return true;         }         return false;     }      public int getNum() {         return num;     }      public void setNum(int num) {         this.num = num;     }      public String getName() {         return name;     }      public void setName(String name) {         this.name = name;     } }

厨师类：

/**  * 厨师类  * @Author: liudq  * @Description:厨师生产食物  * @Date: create in 2017/11/4 17:35  */ public class Cook {     private String name;     private Food food;      public Cook(String name, Food food) {         this.name = name;         this.food = food;     }      /**      * 厨师生产食物      */     public void produce()  {             while (true){                 try {                     synchronized (food){                         boolean isAdd = food.add();                         if (!isAdd){                             System.out.println(food.getName()+"已经到达最大值了，不能再生成了！数量为："+food.getNum());                             food.wait();                         }else {                             System.out.println(food.getName()+"已经做好了，数量为："+food.getNum());                             Thread.sleep(1000);                             food.notifyAll();                         }                     }                 } catch (InterruptedException e) {                     e.printStackTrace();                 }             }     }      public String getName() {         return name;     }      public void setName(String name) {         this.name = name;     }      public Food getFood() {         return food;     }      public void setFood(Food food) {         this.food = food;     } }

顾客类：

/**  * @Author: liudq  * @Description: 顾客类  * @Date: create in 2017/11/4 17:43  */ public class Customer {      private int id; //顾客编号     private Food food;  //顾客点的食物      public Customer(int id, Food food) {         this.id = id;         this.food = food;     }      public void order(){         System.out.println(id+"号顾客点了"+food.getName());     }      public void eat(){         System.out.println(id+"号顾客正在吃"+food.getName());     }       public Food getFood() {         return food;     }      public void setFood(Food food) {         this.food = food;     }      public int getId() {         return id;     }      public void setId(int id) {         this.id = id;     } }

服务员类：

/**  * @Author: liudq  * @Description: 服务员  * @Date: create in 2017/11/4 17:55  */ public class Waiter {     private List<Customer> customers;     private Cook cook;     private Food food;      public Waiter(List<Customer> customers, Cook cook, Food food) {         this.customers = customers;         this.cook = cook;         this.food = food;     }      public void server() {         for (Customer customer : customers){             synchronized (food){                 System.out.println("欢迎光临!");                 System.out.println(customer.getId()+"号客人开始点餐");                 customer.order();                 if (customer.getFood().min()){                     food.notifyAll();                     try {                         food.wait();                     } catch (InterruptedException e) {                         e.printStackTrace();                     }                 }                 System.out.println(customer.getId()+"号客人的"+food.getName()+"好了！");                 customer.getFood().sub();                 customer.eat();                 try {                     Thread.sleep(1000);                 } catch (InterruptedException e) {                     e.printStackTrace();                 }             }         }     }      public Food getFood() {         return food;     }      public void setFood(Food food) {         this.food = food;     }      public List<Customer> getCustomers() {         return customers;     }      public void setCustomers(List<Customer> customers) {         this.customers = customers;     }      public Cook getCook() {         return cook;     }      public void setCook(Cook cook) {         this.cook = cook;     } }

测试类：两种食物，两个厨师，两个服务员，多个顾客，每个顾客点一种食物，每个服务员服务点专门的一种食物的顾客

/**  * 测试类  *  */ public class App  {     public static void main( String[] args ) {         Food food1 = new Food(0,"包子");         Food food2 = new Food(0,"馒头");         final Cook cook1 = new Cook("王师傅",food1);         final Cook cook2 = new Cook("李师傅",food2);         List<Customer> customers1 = new ArrayList<Customer>();         List<Customer> customers2 = new ArrayList<Customer>();         for (int i = 1; i <= 5; i++){             Customer customer = new Customer(i,food1);             customers1.add(customer);         }         for (int i = 6; i <= 10; i++){             Customer customer = new Customer(i,food2);             customers2.add(customer);         }         final Waiter waiter1 = new Waiter(customers1,cook1,food1);         final Waiter waiter2 = new Waiter(customers2,cook2,food2);         Thread thread1 = new Thread() {             public void run() {                 cook1.produce();             }         };         Thread thread2 = new Thread() {             public void run() {                 cook2.produce();             }         };         Thread thread3 = new Thread() {             public void run() {                 waiter1.server();             }         };         Thread thread4 = new Thread() {             public void run() {                 waiter2.server();             }         };         thread1.start();         thread2.start();         thread3.start();         thread4.start();     } }

程序写的不是很好，还有很多可以改进的地方，比如一个顾客可以点多种食物，一个服务员可以服务于任意一个顾客。这里的主要目的是实现生产者和消费者模式。

推荐一本Java多线程的书籍：《Java多线程编程核心技术》，这本书比较注重实践，对我理解Java的多线程有很大帮助。