java programming question

[acer]

So i was wondering...i wrote the following code using regular expressions and i wanted to know if it could be done using substring() and indexOf methods...here is my code.....

Occasionally, backspaces in text are not handled properly, and appear as part of
a String. This question asks you to handle the backspaces in a String. Your input
will be a string which contains upper and lower case letters, spaces and
punctuation, as well as the additional symbol “@”. This symbol represents that
the user typed in a backspace, and that the previous character should be
ignored. So for instance, if the user types in Hej@llo..output would be Hello

import javax.swing.*;
import java.util.regex.Pattern;
import java.util.regex.Matcher;

public class A3Q3
{
    public static void main(String [] args)
         {
    String input;                                                    //The main method of this program only contains the input string which get's
    for(input = getString("Enter a string"); checkForError(input); input = getString("Enter a string"))    //it's value from the method 'getString'. It then
    {                                                                //
        printOutput(fixErrors(input));
    }
    printOutput("This string is error free");
        }
    //Returns true if specified string has an error ('@' in it) and false
    //if it does not.
    public static boolean checkForError(String input)
    {
        Pattern pattern = Pattern.compile("@");
        Matcher matcher = pattern.matcher(input);

        return matcher.find();
    }

    //Prompts the user for a string with the specified input
    //Returns the input string
    public static String getString(String input)
    {
        String tempString = JOptionPane.showInputDialog(input);
        return tempString;
    }

    //Prints the specified message
    public static void printOutput(String tempString)
    {
        System.out.println(tempString);
    }

    //Fixes any errors in the input string
    public static String fixErrors(String tempString)
        {
    Pattern pattern = Pattern.compile("[^@][@?+]");
    Matcher matcher = pattern.matcher(tempString);
    
    while(matcher.find())
    {
        tempString = matcher.replaceAll("");
        matcher = pattern.matcher(tempString);
    }

    pattern = Pattern.compile("@");                //This block gets rid of any extra @'s left over.
    matcher = pattern.matcher(tempString);
    tempString = matcher.replaceAll("");

    return tempString;
      }
}