Consumer Producer Program In Threading

Consumer Producer program is most popular program in threading. here is the solution of the program. UpdateThread class updating the new stock And ConsumeThread class will get the items from the updated stock. if consumer requerd more than the stock so consumer has to wait untill the update thread class will update the new stock. after updating new stock consumer will get the required stock .




class Stock
{
int stock;
synchronized void update(int n)
{
System.out.println(" updates starts");
stock+=n;
System.out.println(" stock update to "+stock);
notify();
}
synchronized void consume(int n)
{
System.out.println(" consume need  : "+n);
while(n>=stock)
{
System.out.println("stock issue wait for update .....");
try
                    {
Thread.sleep(500);
}
catch(Exception e)
{
System.out.println(" exception found !!!!");
}
try
                     {
wait();
}
catch(Exception e)
{
System.out.println(" Exception occurd !!!!!!");
}
}
stock-=n;
System.out.println(" consumer used :"+n);

}
}

class UpdatedThread implements Runnable
{
Stock s;
int n;
UpdatedThread(Stock s, int n)
{
this.s=s;
this.n=n;
new Thread(this).start();
  }
public void run()
{
s.update(n);
}

 }
class ConsumeThread implements Runnable
{
Stock s;
int n;
ConsumeThread(Stock s, int n)
{
this.s=s;
this.n=n;
new Thread(this).start();

}
public void run()
{
s.consume(n);
}
}

public class DeadlockConsumerProducer
{

public static void main(String[] args)
          {

Stock s=new Stock();

               // consumer required 18 items those are not in producers stock

new ConsumeThread(s,18);

               // producer update the stock after this consumer will get 18 items

new UpdatedThread(s,20);

}

}