This is regarding "throw exceptions" in Java

Question

Hi, I have Queue class and a Test drive for the Queue class called QueueDriver. After I run the program I see a number which I have set in the QueueDrive shown up in the terminal window. How can I throw an exception here along with a message? what kind of exception would it be? IOException......OR FileNotFound exception.....OR is there a generic type of exception?
Thanks.

Answer 1

Queue class;
public class Queue
    private Object []items;
    private int max_items;
     private int next_free;
     private int next_full;
     public Queue(int _max_items)
         max_items = _max_items;
          items = new Object[max_items];
          next_free = next_full = 0;
     public void enqueue(Object it)
          items[next_free] = it;
          next_free = (next_free + 1) % max_items;
     // throw exception....
     public Object dequeue()
         Object rtn = items[next_full];
         next_full = (next_full + 1) % max_items;
         return rtn;
     // throw exception....
QueueDriver;
import Queue;
public class QueueDriver
    public static void main(String[] args)throws Exception;
        Queue int_queue = new Queue(50);
        try
            int_queue.enqueue(new Integer(12));
            int_queue.enqueue(new Integer(5));
            System.out.println((Integer) int_queue.dequeue());
           catch(QueueException e)
               System.out.println("Caught QueueException: " + e.getMessage());
}