Find maximum positive integer using String concatenation - Java Full Code

/**
 * $Id: FindMaxIntegerForGivenDigitsUsingStrings.java 5 2009-11-25 14:58:29Z oneyour $
 * 
 * This is an accompanying program for the article
 * <a href="http://www.1your.com/drupal/findmaxintegerinjavausingstringconcatenation
" title="http://www.1your.com/drupal/findmaxintegerinjavausingstringconcatenation
">http://www.1your.com/drupal/findmaxintegerinjavausingstringconcatenation
</a> * 
 * Copyright (c) 2009 - 2010 <a href="http://www.1your.com" title="www.1your.com">www.1your.com</a>.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
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 *     contributors may be used to endorse or promote products derived
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 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
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import java.math.BigInteger;
import java.text.ParseException;
 
/**
 * A Java  program to find the maximum possible Integer with the given number of digits.
 * For example this program will find the number 9999 for 4 digits and 999999 for 6 digits.
 */
public class FindMaxIntegerForGivenDigitsUsingStrings {
 
  private FindMaxIntegerForGivenDigitsUsingStrings()
 
  {
    // Private constructor as the only method provided by this class is
    // a static method.
  }
 
  /**
   * The main method which is the entry point of this program.
   */
  public static void main(String[] args)
  {
    for (int count = 1; count < 100; count++)
    {
      try
      {
        String maxNumberByString = findMaxPositiveIntegerByStringConcatenation(count);
 
        System.out.println("Digits - '" + count + "' -- Max Number - '" + maxNumberByString + "'");
      }
      catch (ParseException parseException)
      {
        System.err.println("Problems encountered.");
        parseException.printStackTrace();
      }
    }
  }
 
  /**
   *
   * @param digits
   *            The number of digits for which the maximum possible integer will be found.
   * @return
   *            The maximum number (integer) for the given number of digits.
   * @throws ParseException
   *            Problems while finding the maximum maximum number (integer) for the given number of digits.
   */
  private static String findMaxPositiveIntegerByStringConcatenation(int digits) throws ParseException
  {
    if (digits <= 0)
    {
      // Error condition
      return "-1";
    }
 
    StringBuilder maxNumberString = new StringBuilder();
    for (int count =0; count < digits; count++)
    {
      maxNumberString.append(9);
    }
 
    return new BigInteger((maxNumberString.toString())).toString();
  }
}