Java HTML character conversion method

Here's the source code for a Java method that converts a given String into an equivalent new String, where characters that cause problems when rendered as HTML have been converted to their ISO Latin equivalent:

  /**
   * Convert extended characters to ISO-Latin equivalents.
   * Might be improved by using a HashMap to map the key/values.
   * However, I'm currently limited to a JDK1.1.x environment, not JDK2.
   */
  public static String convertExtendedCharactersToIsoLatin(String input)
  {
    StringBuffer buffer = new StringBuffer(input);
    StringBuffer output = new StringBuffer();
    int length = buffer.length();
    for (int i = 0; i < length; i++)
    {
      if (buffer.charAt(i) == '"')
        output.append(""");
      else if (buffer.charAt(i) == '!')
        output.append("!");
      else if (buffer.charAt(i) == '#')
        output.append("#");
      else if (buffer.charAt(i) == '&')
        output.append("&");
      else if (buffer.charAt(i) == '\'')
        output.append("'");
      else if (buffer.charAt(i) == '(')
        output.append("(");
      else if (buffer.charAt(i) == ')')
        output.append(")");
      else if (buffer.charAt(i) == '*')
        output.append("*");
      else if (buffer.charAt(i) == '+')
        output.append("+");
      else if (buffer.charAt(i) == ',')
        output.append(",");
      else if (buffer.charAt(i) == '-')
        output.append("-");
      else if (buffer.charAt(i) == '.')
        output.append(".");
      else if (buffer.charAt(i) == '/')
        output.append("/");
      else if (buffer.charAt(i) == ':')
        output.append(":");
      else if (buffer.charAt(i) == ';')
        output.append(";");
      else if (buffer.charAt(i) == '<')
        output.append("<");
      else if (buffer.charAt(i) == '=')
        output.append("=");
      else if (buffer.charAt(i) == '>')
        output.append(">");
      else if (buffer.charAt(i) == '?')
        output.append("?");
      else if (buffer.charAt(i) == '@')
        output.append("@");
      else if (buffer.charAt(i) == '[')
        output.append("[");
      else if (buffer.charAt(i) == '\\')
        output.append("\");
      else if (buffer.charAt(i) == ']')
        output.append("]");
      else if (buffer.charAt(i) == '^')
        output.append("^");
      else if (buffer.charAt(i) == '_')
        output.append("_");
      else if (buffer.charAt(i) == '`')
        output.append("`");
      else if (buffer.charAt(i) == '{')
        output.append("{");
      else if (buffer.charAt(i) == '|')
        output.append("|");
      else if (buffer.charAt(i) == '}')
        output.append("}");
      else if (buffer.charAt(i) == '~')
        output.append("~");
      else
        output.append(buffer.charAt(i));
    }
    return output.toString();
  }

Note: Looking at this code a few year's later I don't know why I didn't write this using a 2D array and a simpler loop, but in the end, it works, and performance hasn't been an issue.