Outputting BigInteger Results one line at a time

Question

hi all,
im new to this. im havin problems with my code. i was to read into two Bigintegers and multi[ply them.. but with the multiplication i want to show each line as it is being done and send it to the screen. as u can see from the code i was hopin to do it in two parts. the first gettin the result and the second just workin it out line by line. is this a good way to do it?  i was tryin to read the last digit and work up to the work up to the first but i cant do it. here is a snippet of the calucatations.. i really hope someone can help cause im really stuck at this point
thanks a million
al.
BigInteger num1 = new BigInteger(textAreaNum1.getText());
    BigInteger num2 = new BigInteger(textAreaNum2.getText());
    result = num1.multiply(num2);
    totalDigit = num2;
    currDigit= num2;
    for (BigInteger ix = BigInteger.ZERO; ix.compareTo(totalDigit) < 0; ix = currDigit.add(BigInteger.ONE))
      currResult = currDigit.multiply(num1);
      textAreaCalculation.setText("" + num1 + "" + zeroAdder);
textAreaResult.setText(""+ result);
// the resultin screen should look like
// 234
// *123
// 702
// 4680
// 23400
// 28782

Answer 1

this is my program as it stands but with another class callin the frame.. so u want me to change the textfield to jtextfield?
package Mulitply;
import java.awt.*;
import java.awt.event.*;
import java.math.BigInteger;
import javax.swing.JTextArea.*;
* Title: Mulitplier of Large Numbers
* Description: This class extends the application class and add all
* all the data below to it. it basically sets up the frame
* in terms of look,feel and action.
* Copyright: Copyright (c) 2004
* Company:
* author
* version 1.0
class CalcFrame extends Frame implements ActionListener{
Button btnMult;
TextField textAreaNum1, textAreaNum2, textAreaCalculation, textAreaResult;
public CalcFrame() {
addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
setSize(1000, 300);
setTitle("Mulitpler");
setLayout(new FlowLayout());
setBackground(Color.lightGray);
Panel pnlNums = new Panel();
Panel pnlBtns = new Panel();
Panel pnlCalculation = new Panel();
Panel pnlResult = new Panel();
setLayout(new GridLayout(3, 1));
textAreaNum1 = new TextField(50);
textAreaNum2 = new TextField(50);
pnlNums.add(textAreaNum1);
pnlNums.add(textAreaNum2);
btnMult = new Button("*");
btnMult.addActionListener(this);
pnlBtns.add(btnMult);
textAreaCalculation = new TextField(50);
textAreaResult = new TextField(50);
pnlResult.add(textAreaResult);
pnlCalculation.add(textAreaCalculation);
add(pnlNums);
add(pnlBtns);
add(pnlCalculation);
add(pnlResult);
public void actionPerformed(ActionEvent e) {
String str1 = textAreaNum1.getText().trim();
String str2 = textAreaNum2.getText().trim();
int len1 = str1.length();
int len2 = str2.length();
if ( (len1 == 0) || (len2 == 0))
return;
BigInteger num1 = new BigInteger(str1);
BigInteger num2 = new BigInteger(str2);
BigInteger result = num1.multiply(num2);
String resultStr = result.toString();
int resultLen = resultStr.length();
textAreaCalculation.setText("");
textAreaCalculation.append(str1 + "\n");
textAreaCalculation.append("*" + str2 + "\n");
textAreaCalculation.append(pad(resultLen, "--") + "\n");
BigInteger ten = new BigInteger("10");
for (int i = (len2 - 1); i >= 0; i--) {
BigInteger curNum = new BigInteger(str2.substring(i, i + 1));
BigInteger curRes = curNum.multiply(num1);
for (int j = 0; j < len2 - 1 - i; j++)
curRes = curRes.multiply(ten);
String curResStr = curRes.toString();
int curResLen = curResStr.length();
textAreaCalculation.append(pad(resultLen - curResLen, "--") + curResStr + "\n");
textAreaCalculation.append(pad(resultLen, "--") + "\n");
textAreaCalculation.append(resultStr + "\n");
String pad(int n, String s) {
String ret = "";
for (int i = 0; i < n; i++)
ret += s;
return ret;
}