servlet中init方法可以执行，但是doGet方法不能执行解决办法

public class TestServlet extends HttpServlet {    private static final long serialVersionUID = 1L;    /**     * Default constructor.      */    public TestServlet() {         TODO Auto-generated constructor stub        super();    }    /**     * @see Servlet#init(ServletConfig)     */    public void init(ServletConfig config) throws ServletException {        // TODO Auto-generated method stub        System.out.println("Hello!");    }    /**     * @see Servlet#destroy()     */    public void destroy() {        // TODO Auto-generated method stub    }    /**     * @see Servlet#getServletConfig()     */    public ServletConfig getServletConfig() {        // TODO Auto-generated method stub        return null;    }    /**     * @see Servlet#getServletInfo()     */    public String getServletInfo() {        // TODO Auto-generated method stub        return null;     }    /**     * @see HttpServlet#service(HttpServletRequest request, HttpServletResponse response)     */    protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        // TODO Auto-generated method stub    }    /**     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)     */    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        // TODO Auto-generated method stub            System.out.println("doGet");    }    /**     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)     */    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        // TODO Auto-generated method stub    }}