Trim any of the characters in Java

//  w w  w .  j a  v  a  2  s .c o m
/**
 * Utilities for String formatting, manipulation, and queries. More information
 * about this class is available from <a target="_top" href=
 * "http://ostermiller.org/utils/StringHelper.html">ostermiller.org</a>.
 * 
 * @author Stephen Ostermiller
 *         http://ostermiller.org/contact.pl?regarding=Java+Utilities
 * @since ostermillerutils 1.00.00
 */
public class Main {
  public static void main(String[] argv) {
    System.out.println(trim("test from java2s.com", "a"));
  }

  /**
   * Trim any of the characters contained in the second string from the
   * beginning and end of the first.
   * 
   * @param s
   *            String to be trimmed.
   * @param c
   *            list of characters to trim from s.
   * @return trimmed String.
   * @throws NullPointerException
   *             if s is null.
   * 
   * @since ostermillerutils 1.00.00
   */
  public static String trim(String s, String c) {
    int length = s.length();
    if (c == null) {
      return s;
    }
    int cLength = c.length();
    if (c.length() == 0) {
      return s;
    }
    int start = 0;
    int end = length;
    boolean found; // trim-able character found.
    int i;
    // Start from the beginning and find the
    // first non-trim-able character.
    found = false;
    for (i = 0; !found && i < length; i++) {
      char ch = s.charAt(i);
      found = true;
      for (int j = 0; found && j < cLength; j++) {
        if (c.charAt(j) == ch)
          found = false;
      }
    }
    // if all characters are trim-able.
    if (!found)
      return "";
    start = i - 1;
    // Start from the end and find the
    // last non-trim-able character.
    found = false;
    for (i = length - 1; !found && i >= 0; i--) {
      char ch = s.charAt(i);
      found = true;
      for (int j = 0; found && j < cLength; j++) {
        if (c.charAt(j) == ch)
          found = false;
      }
    }
    end = i + 2;
    return s.substring(start, end);
  }
}

/*
 * Static String formatting and query routines. Copyright (C) 2001-2005 Stephen
 * Ostermiller http://ostermiller.org/contact.pl?regarding=Java+Utilities
 * 
 * This program is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free Software
 * Foundation; either version 2 of the License, or (at your option) any later
 * version.
 * 
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
 * details.
 * 
 * See COPYING.TXT for details.
 */