java多线程——生产者和消费者 保证生产者先生产20个再消费

package ls0526;

public class Run2
{
//  产品
	public static class Product
	{
		public int count=0;
	}
//  生产者
	public static class Producer implements Runnable
	{
        private Product product;
        
		public Producer(Product product)
		{
			super();
			this.product = product;
		}

		public void run()
		{
			while(true)
			{
				synchronized (product)
				{
					if(product.count<20)
					{
						product.count++;
						System.out.println(Thread.currentThread().getName()+"生产了"+product.count);
						
						try
						{
							Thread.sleep(500);
						}
						catch (InterruptedException e)
						{
							// TODO Auto-generated catch block
							e.printStackTrace();
						}
					}
				}
			}
			
		}
		
	}
//  消费者
	public static class Customer implements Runnable
	{
		private Product product;
		
		public Customer(Product product)
		{
			super();
			this.product = product;
		}

		public void run()
		{
			while(true)
			{
				synchronized (product)
				{
					if(product.count>0)
					{
						System.out.println(Thread.currentThread().getName()+"消费了"+product.count);
						product.count--;
						try
						{
							Thread.sleep(500);
						}
						catch (InterruptedException e)
						{
							// TODO Auto-generated catch block
							e.printStackTrace();
						}
					}
				}
			}
		}
	}
	public static void main(String[] args)
	{
		Product product=new Product();
		Producer producer=new Producer(product);
		Customer customer=new Customer(product);
		Thread p1=new Thread(producer,"华为");
		Thread p2=new Thread(producer,"联想");
		Thread p3=new Thread(producer,"小米");
		Thread p4=new Thread(producer,"OPPO");
		Thread p5=new Thread(producer,"一加");
		Thread p6=new Thread(producer,"魅族");
		Thread c1=new Thread(customer,"张三");
		Thread c2=new Thread(customer,"李四");
		p1.start();
		p2.start();
		p3.start();
		p4.start();
		p5.start();
		p6.start();
		c1.start();
		c2.start();
	}
}

运行结果：