Java Programming

Greetings,

I've been wrestling with this all day, trying to get this program to run. The problem seems to be in the final loop but i've tried everything and need a nudge in the right direction.

Heres the code:

package Lab;
import java.util.Scanner;

public class Shifter {
    
    Scanner input = new Scanner(System.in);
    int data[] = new int [ 15 ];

    public Shifter ( int size )
    {
    for ( int counter = 0; counter < data.length; counter++ )
         data[ counter ] = 1 + counter; 
    }
    
    public int shift( int pos )
    {
    int count = 0;
    
    for(count = 0; count < data.length; count++)
        data[ count ] = data[ count + pos ];
    return data[ count ];
    }
    
    public void display()
    {
    System.out.printf("Array contents: ");
    int pos = 0;
    
        int value = 0;    
        for(value = 0; value < data.length; value++)
        System.out.printf("%d", data[ value ] );
                      
        System.out.println();
        
        System.out.print("Shift how many positions? ");
        pos = input.nextInt();
            
                do{
                    System.out.println();
                    shift( pos );
                        for(value = 0; value < data.length; value++)
                        System.out.printf("%d", data[ value ]); 
                    
                    System.out.print("Shift how many positions? ");
                    pos = input.nextInt();          
            
               }while (! pos.matches("[-]?\\d+"));
       
        
    
    }
}

The final line in the condition statement is where the problem is, I think. I have to use a do/while loop for this assignment, so it can't be a for loop or a while. I want it to exit when something nonnumeric is entered.