Java多线程生产者消费者实例

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。