Re: can this code be improved

import java.util.ArrayList;
import java.util.Random;
public class SixFourNine {
    ArrayList winningNumbers = null;
    public static int NUM_CHOICES = 6;
    public static int MAX_NUMBER = 49;
    int[][] simulationArray = new int[MAX_NUMBER][2];
    /** creates a new SixFourNine object**/
    public SixFourNine() {
        initializeSimulationArray();
    }
    /** initializes the array for storing the simulation **/
    public void initializeSimulationArray() {
        for (int i=0; i <MAX_NUMBER; i++) {
            simulationArray[i][0] = (i+1);
            simulationArray[i][1] = 0;
        }
    }
    /** default simulation -- 1 million trials **/
    public void runSimulation() {
        runSimulation(1000000);
    }
    /** simulation -- specify # trials **/
    public void runSimulation(int numTrials) {
        if (numTrials <= 0 ) return;
        Random rand = null;
        int number = 0;
        for (int i = 0; i < numTrials; i++ ){
            rand = new Random() ;
            number=rand.nextInt(MAX_NUMBER) + 1;
            simulationArray[number-1][1]++;
        }
    }
    /** get the winning numbers. throws an exception if you have not
run a simulation **/
    public ArrayList getWinningNumbers() throws
SixFourNineSimulationNotRunException {
        if (simulationArray == null) throw new
SixFourNineSimulationNotRunException();
        winningNumbers = new ArrayList();
        for (int i = 0; i < NUM_CHOICES; i++) {
            Integer r = new Integer(findAndRemoveMax());
            winningNumbers.add(r);
        }
        initializeSimulationArray();
        return winningNumbers /*NOT A GUARANTEE*/;
    }
    /** finds the most picked number from the simulations, in the case
of a tie, largest number (index) wins **/
    private int findAndRemoveMax() {
        int max = 0;
        int count = 0;
        for (int i = 0; i < MAX_NUMBER; i++) {
            if (simulationArray[i][1] > count) {
                count = simulationArray[i][1] ;
                max = i;
            }
        }
        simulationArray[max][1] =0;
        return max+1;
    }
    /** program main **/
    public static void main(String[] args) {
        SixFourNine sfn = new SixFourNine();
        sfn.runSimulation(1000000);
        try {
            System.out.println(sfn.getWinningNumbers());
        } catch (SixFourNineSimulationNotRunException sfnnre) { // this
cannot happen in this example but we must catch;
            System.out.println("Sorry, there was a problem; you need to
run a simulation before you can guess the winning numbers!");
            System.exit(42);
        }
        System.exit(0);
    }
    public class SixFourNineSimulationNotRunException extends Exception
{};
}