code: private static String escapeHtmlChars(String s) {
          for (int i = 0; i < s.length(); i++) {
              char ch = s.charAt(i);
              switch (ch) {
                  // only start building a new string if we need to
                  case '<': case '>': case '&':
                      StringBuilder sb = new StringBuilder(s.substring(0, i));
                      for ( ; i < s.length(); i++) {
                          ch = s.charAt(i);
                          switch (ch) {
                              case '<': sb.append("&lt;");  break;
                              case '>': sb.append("&gt;");  break;
                              case '&': sb.append("&amp;"); break;
                              default:  sb.append(ch);      break;
                          }
                      }
                      return sb.toString();
              }
          }
          return s;
      }
docs: Given a string, escape all special html characters and
  return the result.
  
  @param s The string to check.
  @return the original string with all of the HTML characters escaped.