线程通信问题，实在不知道错哪儿

[会飞的大萝卜]

//经典的生产者与消费者问题，线程的通讯知识点
class product1{//定义一个产品类
	String name="apple";
	double price;
	int number;
	 boolean flag=false;
	
}
class producer1 extends Thread{//定义一个生产者类
	product1 p;//定义一个产品对象的饮用

	public producer1(product1 p) {
	// TODO Auto-generated constructor stub
		this.p=p;
}

	@Override
	public void run() {
		int number=0;
	while(true){
		synchronized(p){
			if(p.flag=false){
		if(number%2==0){
			p.name="apple";
			p.price=2.5;
		}
		else{
			p.name="blanana";
			p.price=1.5;
		}
		System.out.println("生产的产品："+p.name+"价格："+p.price);
		System.out.println("生产后的商品数量："+number);
		p.flag=true;
		number++;
		p.notifyAll();
			} else
				try {
					p.wait();
				} catch (InterruptedException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
	    }
	 }
  }
}
class custumer extends Thread{
	product1 p;//定义一个产品对象的饮用
	public custumer(product1 p) {
		// TODO Auto-generated constructor stub
		this.p=p;
	}
	
	@Override
	public void run(){
		while(true){
			synchronized (p) {
				if(p.flag=true)
				{

			System.out.println("消费： "+p.name+"价格是："+p.price);
		
			p.flag=false;
			p.notifyAll();
				} else{
					try {
						p.wait();
					} catch (InterruptedException e) {
						// TODO Auto-generated catch block
						e.printStackTrace();
					}		}
		}
	  }
	}
}

	public class demo1{
		public static void main(String[]args) throws InterruptedException{
			product1 p=new product1();
			producer1 thread1=new producer1(p);
			custumer thread2=new custumer(p);
			thread1.start();
			thread2.start();
			
		}
		
		
		
	}
	
	
	
	
	
	
	
	
	

[peter_xizi]

package ProducerAndConsumer; public class demo { private static volatile product p =null; static class product { String name = "apple"; double price=1.0; int number=0; boolean flag = false; } static class producer extends Thread { product p;// 定义一个产品对象的饮用 public producer(product p) { // TODO Auto-generated constructor stub this.p = p; } @Override public void run() { int number = 0; while (true) { synchronized (p) { if (p.flag == false) { if (number % 2 == 0) { p.name = "apple"; p.price = 2.5; } else { p.name = "blanana"; p.price = 1.5; } System.out.println("Produce Product:" + p.name + " --Price:" + p.price); System.out.println("Product Number:" + number); p.flag = true; number++; p.notifyAll(); } else try { p.wait(); } catch (InterruptedException e) { e.printStackTrace(); } } } } } static class custumer extends Thread { product p;// 定义一个产品对象的饮用 public custumer(product p) { this.p = p; } @Override public void run() { while (true) { synchronized (p) { if (p.flag == true) { System.out.println("Consumber: " + p.name + " -- Price:" + p.price); p.flag = false; p.notifyAll(); } else { try { p.wait(); } catch (InterruptedException e) { e.printStackTrace(); } } } } } } public static void main(String[] args) throws InterruptedException { p = new product(); producer thread1 = new producer(p); custumer thread2 = new custumer(p); thread1.start(); thread2.start(); } } 把你的代码稍微改造了一下，见红色部分, 1. volatile保证多线程的可见性，2.if条件判断 以上代码已测试通过： Produce Product:apple --Price:2.5 Product Number:28642 Consumber: apple -- Price:2.5 Produce Product:blanana --Price:1.5 Product Number:28643 Consumber: blanana -- Price:1.5 Produce Product:apple --Price:2.5 Product Number:28644 Consumber: apple -- Price:2.5 Produce Product:blanana --Price:1.5 Product Number:28645 Consumber: blanana -- Price:1.5 Produce Product:apple --Price:2.5 Product Number:28646 Consumber: apple -- Price:2.5 Produce Product:blanana --Price:1.5 Product Number:28647 Consumber: blanana -- Price:1.5 ......

[会飞的大萝卜]

@peter_xizi 感谢

[会飞的大萝卜]

@peter_xizi 刚才百度了一下，一直没发现还有这种安全机制在，实在是感谢

[迷林]

引用 3 楼 qq_15310795 的回复:

@peter_xizi 刚才百度了一下，一直没发现还有这种安全机制在，实在是感谢

楼主可以结贴了

[peter_xizi]

结贴