java生产者消费者模式之2个生产者

0 0

java生产者消费者模式之2个生产者3

现在的需求，有2个生产者a和b，一个消费者c
每个轮回需要等待生产者a和b依次生产1个产品（该产品有id和value）后，通知消费者c取走queue中的2个product。
网上找的所有例子都是一个生产者，一个消费者的。。。自己做了一个代码。。。但是也只能1个生产者一个消费者，原因在addProduct里不知道怎么区分。。以及notifyAll的时候会在第一个生产者添加完product后，让第二个生产者也陷入等待。。

public class Consumer extends Thread {
    private ProductTable productTable;

    public Consumer(ProductTable productTable) {
        this.productTable = productTable;
    }

    public void run() {
        for (int i = 1; i <= 10; i++) {
            try {
                // wait for a random time
                Thread.sleep((int) (Math.random() * 3000));
            }
            catch (InterruptedException e) {
                e.printStackTrace();
            }
            productTable.getProduct();
        }
    }
}

public class Producer extends Thread {
    private ProductTable productTable;
    private Product p;

    public Producer(ProductTable productTable, Product p) {
        this.productTable = productTable;
        this.p = p;
    }

    public void run() {
        for (int product = 1; product <= 10; product++) {
            productTable.addProduct(p);
        }
    }
}

public class Product {
    private int id;
    private String value;

    public Product(int it,String value){
        this.id=id;
        this.value=value;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getValue() {
        return value;
    }

    public void setValue(String value) {
        this.value = value;
    }
}

public class ProductTable {
    private LinkedList products = new LinkedList();

    public synchronized void addProduct(Product product) {
        while(products.size() >= 2) { // 容量限制為 2
            try {
                wait();
            }
            catch(InterruptedException e) {}
        }

        products.addLast(product);
        System.out.println(product.getId()+" added");
        notifyAll();
    }

    public synchronized Product getProduct() {
        while(products.size() <= 0) {
            try {
                wait();
            }
            catch(InterruptedException e) {}
        }

        Product product = (Product) products.removeFirst();
        System.out.println(product.getId()+" removed");
        notifyAll();

        return product;
    }
}

public class Main {

    public static void main(String[] args) {
        Product a = new Product(1, "a");
        Product b = new Product(2, "b");
        ProductTable queue = new ProductTable();
        Producer producera = new Producer(queue, a);
        Consumer consumer = new Consumer(queue);
        new Thread(producera).start();
        new Thread(consumer).start();
    }
}

设计模式

2008年11月25日 15:43

dreamramon
0
0 0 0

2个答案按时间排序按投票排序

0 0

public class Producer extends Thread {   
    private ProductTable productTable;   
    private Product p;   
  
    public Producer(ProductTable productTable, Product p) {   
        this.productTable = productTable;   
        this.p = p;   
    }   
  
    public void run() {   
         productTable.addProduct(p);   
    }   
}

public class Consumer extends Thread {   
    private ProductTable productTable;   
  
    public Consumer(ProductTable productTable) {   
        this.productTable = productTable;   
    }   
  
    public void run() {   
           productTable.getProducts();          
    }   
}

public class Main {   
  
    public static void main(String[] args) {   
        Product a = new Product(1, "a");   
        Product b = new Product(2, "b");   
        ProductTable queue = new ProductTable(); 
  
        for(int i=0; i<10; i++) {
             Producer producerA = new Producer(queue, a); 
             Producer producerB = new Producer(queue, b); 
             Consumer consumer = new Consumer(queue);   
             
             new Thread(producerA).start();
             new Thread(producerB).start();   
             new Thread(consumer).start();
   
    }   
}

2008年12月02日 15:26

lookingfor
32
0 0 0

添加评论

0 0

这是改后的代码，看下合符你的要求吗？

public class Product {   
    private int id;   
    private String value;   
  
    public Product(int it,String value){   
        this.id=id;   
        this.value=value;   
    }   
  
    public int getId() {   
        return id;   
    }   
  
    public void setId(int id) {   
        this.id = id;   
    }   
  
    public String getValue() {   
        return value;   
    }   
  
    public void setValue(String value) {   
        this.value = value;   
    }   
}

public class ProductTable {   
    private LinkedList products = new LinkedList();   
  
    public synchronized void addProduct(Product product) {   
        while(products.size() >= 2) { // 容量限制為 2   
            try {   
                wait();   
            }   
            catch(InterruptedException e) {}   
        }   
  
        products.addLast(product);   
        System.out.println(product.getId()+" added");   
        notifyAll();   
    }   
  
   [color=blue] public synchronized Product[] getProducts() {   
        while(products.size() <= 0) {   
            try {   
                wait();   
            }   
            catch(InterruptedException e) {}   
        }   
 
        // remove two products every time
        Product[] products= new Product[2];
        products[0] = (Product) products.removeFirst();   
        System.out.println(products[0].getId()+" removed");  
        products[1]= (Product) products.removeFirst();
        System.out.println(products[1].getId()+" removed"); 

        // notify all the producers waiting for producing
        notifyAll();   
  
        return products;   
    }   [/color]}

2008年12月02日 15:20

lookingfor
32
0 0 0