Java线程：并发协作-生产者消费者模型

/** 
* Java线程：并发协作-生产者消费者模型 
* 
* @author leizhimin 2009-11-4 14:54:36 
*/ 
public  class Test { 
         public  static  void main(String[] args) { 
                Godown godown =  new Godown(30); 
                Consumer c1 =  new Consumer(50, godown); 
                Consumer c2 =  new Consumer(20, godown); 
                Consumer c3 =  new Consumer(30, godown); 
                Producer p1 =  new Producer(10, godown); 
                Producer p2 =  new Producer(10, godown); 
                Producer p3 =  new Producer(10, godown); 
                Producer p4 =  new Producer(10, godown); 
                Producer p5 =  new Producer(10, godown); 
                Producer p6 =  new Producer(10, godown); 
                Producer p7 =  new Producer(80, godown); 

                c1.start(); 
                c2.start(); 
                c3.start(); 
                p1.start(); 
                p2.start(); 
                p3.start(); 
                p4.start(); 
                p5.start(); 
                p6.start(); 
                p7.start(); 
        } 
} 

/** 
* 仓库 
*/ 
class Godown { 
         public  static  final  int max_size = 100;  //最大库存量 
         public  int curnum;      //当前库存量 

        Godown() { 
        } 

        Godown( int curnum) { 
                 this.curnum = curnum; 
        } 

         /** 
         * 生产指定数量的产品 
         * 
         * @param neednum 
         */ 
         public  synchronized  void produce( int neednum) { 
                 //测试是否需要生产 
                 while (neednum + curnum > max_size) { 
                        System.out.println( "要生产的产品数量" + neednum +  "超过剩余库存量" + (max_size - curnum) +  "，暂时不能执行生产任务!"); 
                         try { 
                                 //当前的生产线程等待 
                                wait(); 
                        }  catch (InterruptedException e) { 
                                e.printStackTrace(); 
                        } 
                } 
                 //满足生产条件，则进行生产，这里简单的更改当前库存量 
                curnum += neednum; 
                System.out.println( "已经生产了" + neednum +  "个产品，现仓储量为" + curnum); 
                 //唤醒在此对象监视器上等待的所有线程 
                notifyAll(); 
        } 

         /** 
         * 消费指定数量的产品 
         * 
         * @param neednum 
         */ 
         public  synchronized  void consume( int neednum) { 
                 //测试是否可消费 
                 while (curnum < neednum) { 
                         try { 
                                 //当前的生产线程等待 
                                wait(); 
                        }  catch (InterruptedException e) { 
                                e.printStackTrace(); 
                        } 
                } 
                 //满足消费条件，则进行消费，这里简单的更改当前库存量 
                curnum -= neednum; 
                System.out.println( "已经消费了" + neednum +  "个产品，现仓储量为" + curnum); 
                 //唤醒在此对象监视器上等待的所有线程 
                notifyAll(); 
        } 
} 

/** 
* 生产者 
*/ 
class Producer  extends Thread { 
         private  int neednum;                 //生产产品的数量 
         private Godown godown;             //仓库 

        Producer( int neednum, Godown godown) { 
                 this.neednum = neednum; 
                 this.godown = godown; 
        } 

         public  void run() { 
                 //生产指定数量的产品 
                godown.produce(neednum); 
        } 
} 

/** 
* 消费者 
*/ 
class Consumer  extends Thread { 
         private  int neednum;                 //生产产品的数量 
         private Godown godown;             //仓库 

        Consumer( int neednum, Godown godown) { 
                 this.neednum = neednum; 
                 this.godown = godown; 
        } 

         public  void run() { 
                 //消费指定数量的产品 
                godown.consume(neednum); 
        } 
}

已经生产了10个产品，现仓储量为40 
已经生产了10个产品，现仓储量为50 
已经消费了50个产品，现仓储量为0 
已经生产了80个产品，现仓储量为80 
已经消费了30个产品，现仓储量为50 
已经生产了10个产品，现仓储量为60 
已经消费了20个产品，现仓储量为40 
已经生产了10个产品，现仓储量为50 
已经生产了10个产品，现仓储量为60 
已经生产了10个产品，现仓储量为70 

Process finished with exit code 0