Thread: Try/Catch exception so i can return an array and print out an exception too

Hi i am writing a lottery method where the user has to enter in two numbers, n and k, as arguments. The lottery gets filled with a randomized queue that goes up to k. so if i put in k=10 the queue would hold 1,2,3,4,5,6,7,8,9,10. The argument n is the number of items that has to be removed randomly. so if i chose 3 then it could return 4,6,8 or it could be 1,3,10.

Now if n is greater than k it has to throw an error saying that there is not enough items in the queue to pull. So if i put n=5 and k=3, there are still 3 items in the queue but i can't select 5.

Now my problem is i have to return the items that are still in the queue. so n=5 and k=3 would return 1,3,2 or 2,3,1 and so forth. But i have to print an exception after i return that array. So far i am able to return the array but i can not get the try catch exception to work. Is there another method i can try that will return the array and then print out the exception after that so it looks like this:

%java Lottery 5 2
2  1
java.lang.Exception: Not enough items in your queue.
at Lottery.pickNumbers(Lottery.java:29)
at Lottery.main(Lottery.java:56)

Here is my code

import java.util.*;
import java.math.*;
public class Lottery{
    RandomizedQueue rq;
    Random Rnum = new Random();
    int [] Larray;
 
    // constructs a Lottery class
    public Lottery(){
    }
 
 
    // picks the numbers and store them in an array of integers
    // int n: number of items to pick
    // int k: maximum integer to be picked
    public int [] pickNumbers(int n, int k) throws Exception{
 
    	rq = new RandomizedQueue();
 
    	int [] remainQueue = new int [k];
 
 
    	if(n>k) 
    	{
    		for(int i=1; i<=remainQueue.length;i++)
    		{
    			rq.enqueue(i);
    		}
	    		for(int i =0; i<remainQueue.length;i++)
	    		{
	    			try{
	    			remainQueue[i] = rq.dequeue();
	    			}
	    			catch (Exception e)
	    			{
	    				System.out.println("not enough items in the queue");
	    			}
	    		}
	    		return remainQueue;	
    	}  
 
    	for(int i =1;i<=k;i++)
    	{
    		rq.enqueue(i);
    	}
 
    	Larray = new int[n];
    	for(int i = 0;i< Larray.length;i++)
    	{
    		Larray[i] = rq.dequeue();
    	}
 
    	return Larray;
 
 
    }
 
 
 
    // Do not change main().
    public static void main(String [] args) throws Exception{
    	if (args.length<2){
	       System.out.println("Please enter your input values.");
	       System.out.println("e.g. java Lottery [number of integers to pick] [Maximum integer to be picked]");
	   }else{
	       int n = Integer.parseInt(args[0]);
	       int k = Integer.parseInt(args[1]);
	       Lottery l = new Lottery();
	       try{
		   int [] picked = l.pickNumbers(n,k);
		   for (int i = 0; i< picked.length; i++){
		       System.out.print(picked[i]+" ");
		   }
		   System.out.println();
	       }catch (Exception e){
		   e.printStackTrace();
	       }
	   }
 
 
 
    } 
 
}