java多线程-生产者消费者模式

 

生产者线程：

如果水果的数量在[0,9]则开始生产，否则转到消费线程。

public class Producer implements Runnable {
    private Fruit fruit;
    
    
    public Producer() {
        super();
    }
    

    public Producer(Fruit fruit) {
        super();
        this.fruit = fruit;
    }


    public Fruit getFruit() {
        return fruit;
    }

    public void setFruit(Fruit fruit) {
        this.fruit = fruit;
    }
    @Override
    public void run() {
        // TODO Auto-generated method stub

        while(true){
            synchronized (fruit) {
                //积压了10个水果未卖出去  停掉生产的线程等待卖出去    
                if(fruit.getNumber()>=10){
                    try {
                        fruit.wait();
                    } catch (InterruptedException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }
                if(fruit.getNumber()>=0&&fruit.getNumber()<10){
                    try {
                        Thread.sleep(200);
                    } catch (InterruptedException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                    
                    System.out.println(fruit.getName()+"被生产出来了");
                    
                    fruit.setNumber(fruit.getNumber()+1);
                    System.out.println("当前水果数量为"+fruit.getNumber());
                    fruit.notify();
                }
            }    
        }

    }

}

消费者线程：

 如果水果的数量在大于0，即可消费，否则转到生产线程

public class Customer implements Runnable {
	private Fruit fruit;
	
	
	public Customer() {
		super();
	}


	public Customer(Fruit fruit) {
		super();
		this.fruit = fruit;
	}


	public Fruit getFruit() {
		return fruit;
	}


	public void setFruit(Fruit fruit) {
		this.fruit = fruit;
	}
	
	@Override
	public void run() {
		while(true){
			//处理并发问题
			synchronized (fruit) {
				//判断水果的数量是否>0;
				if(fruit.getNumber()>0){
					try {
						Thread.sleep(200);
					} catch (InterruptedException e) {
						// TODO Auto-generated catch block
						e.printStackTrace();
					}
					System.out.println(fruit.getName()+"被买走了");
					//减少水果数量
					fruit.setNumber(fruit.getNumber()-1);
					System.out.println("当前水果数量为"+fruit.getNumber());
					fruit.notify();
				}
				else{
					try {
						
						//水果已经卖完拿了 等待生产
						fruit.wait();
					} catch (InterruptedException e) {
						// TODO Auto-generated catch block
						e.printStackTrace();
					}
				}
				
			}
		
		}

	}

}

Fruit类

public class Fruit {
    private int number;
    private String name;

    public Fruit() {
        super();
    }
    public Fruit(int number, String name) {
        super();
        this.number = number;
        this.name = name;
    }
    public int getNumber() {
        return number;
    }
    public void setNumber(int number) {
        this.number = number;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }

    
}

当调用obj.notify()/notifyAl0()l后，调用线程依旧持有obj锁，当调用obj.wait()后，调用线程会释放obj锁，如果将synchronized (fruit)放在while(true)前面，会因为同步锁未及时释放，一直运行到obj.wait()才释放同步锁。