request.getRealPath的替代

public class TestServlet extends HttpServlet ...{

    /** *//** serialVersionUID. */
    private static final long serialVersionUID = 5222793251610509039L;

    @Override
    protected void service(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException ...{
        String realPath = this.getServletContext().getRealPath("/");
        System.out.println(realPath);
    }

}