gistfile1.java

 /**
        * Substitute sub-strings in side of a string.
        *
        * @param buff    Stirng buffer to use for substitution (buffer is not reset)
        * @param from    String to substitute from
        * @param to      String to substitute to
        * @param string  String to look for from in
        * @return        Substituted string
        */
       public static String subst(final StringBuffer buff, final String from, final String to, final String string)
       {
          int begin = 0, end = 0;

          while ((end = string.indexOf(from, end)) != -1)
          {
             // append the first part of the string
             buff.append(string.substring(begin, end));

             // append the replaced string
             buff.append(to);

             // update positions
             begin = end + from.length();
             end = begin;
          }

          // append the rest of the string
          buff.append(string.substring(begin, string.length()));

          return buff.toString();
       }