GIQ: random number range

Given a function which produces a random integer in the range 1 to 5, write a function which produces a random integer in the range 1 to 7.

This is my solution, thrown together quickly, in java of course, bear in mind that the algorithm is simply to loop over the first function (1-5) 7 times, adding in the result to a running total, then do a modulo 7 for the grand result of the second function...

import java.util.Random;
public class rand {

  int A = 5;
  int B = 7;
  int sample = 50;

  public rand(){
  }

  public void init() {
    System.out.println(""+getAppletInfo());
    if (A<=0) throw new IllegalArgumentException("A must be >= 0");
    if (B<=0) throw new IllegalArgumentException("B must be >= 0");
    int[] dist = new int[B];
    for(int j=0; j<B; j++) {
      dist[j] = 0;
    }
    for(int i=0; i<sample; i++) {
      int next = randB();
      dist[next-1] += 1;
      System.out.println(".."+next);
    }
    System.out.println("Distribution...");
    for(int j=0; j<B; j++) {
      System.out.println("j:"+j+",count:"+dist[j]);
    }
  }

  Random random = new Random();
  int randA () {
    return random.nextInt(A) + 1;
  }

  int randB () {
    int r = 0;
    for(int i=0; i<B; i++) {
      r += randA() - 1;
    }
    return r % B + 1;
  }

  public String getAppletInfo() {
    return "randB from randA by Douglas A. Bauman";
  }

  static public void main(String[] args) {
    rand rr = new rand();
    try {
      rr.A = Integer.parseInt(args[0]);
      try {
        rr.B = Integer.parseInt(args[1]);
      } catch (NumberFormatException e) {
      } catch (RuntimeException e) {
      }
    } catch (NumberFormatException e2) {
    } catch (RuntimeException e2) {
    }
    rr.init();
  }
}