Need Help Replace Random Array with Read in from file

package main;

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.io.File;
import java.util.Scanner;

public class Launch extends AlgorithmAnimator {

    protected SortAlgorithm theAlgorithm;
    protected AlgorithmFactory algorithmFactory;

    protected void initAnimator() {

        //Get Algorithm Choice From User
        System.out.println("Please select your Algorithm: "
                + "[1] BubbleSort   [2] QuickSort   [3] SelectionSort");
        Scanner scanner = new Scanner(System.in);
        String inputAlgorithm = scanner.nextLine();


        if ("1".equals(inputAlgorithm)) {
            algName = "BubbleSort";
        } else if ("2".equals(inputAlgorithm)) {
            algName = "QuickSort";
        } else if ("3".equals(inputAlgorithm)) {
            algName = "SelectionSort";
        }else {
            algName = "BubbleSort";
        }
        System.out.println("Your selection is: " + algName);

        //Set Algorithm Type
        String at = getParameter("alg");
        if (at != null) {
            algName = at;
        }

        algorithmFactory = new StaticAlgoFactory(this);
        theAlgorithm = algorithmFactory.makeSortAlgorithm(algName);

        setDelay(20);
        scramble();

    }

    protected void algorithm() {
        if (theAlgorithm != null)
            theAlgorithm.sort(arr);
    }

    //scramble()
    protected void scramble() {

        arr = new int[getSize().height /2];
        for (int i = arr.length; --i >= 0;) {
            arr[i] = i;
        }
        for (int i = arr.length; --i >=0;) {
            int j = (int)(i * Math.random());
            swap(arr, i , j);
        }
    }

    protected void paintFrame(Graphics g) {
          Dimension d = getSize();
          g.setColor(Color.black);
          g.fillRect(0, 0, d.width, d.height);
          g.setColor(Color.green);
          int y = d.height - 1;
          double f = d.width / (double) arr.length;
          for (int i = arr.length; --i >= 0; y -= 2) {
                  g.drawLine(0, y, (int)(arr[i] * f), y);
          }

        }

     //swap()
     private void swap(int a[], int i, int j) {
           int temp = a[i]; a[i] = a[j]; a[j] = temp;
        }

    protected int arr[];
    protected String algName;

}