关于Java Web servlet 404 问题

 public class loginServlet extends HttpServlet {

public void doPost(HttpServletRequest request, HttpServletResponse response)

        throws ServletException, IOException {

    request.setCharacterEncoding("utf-8");

    response.setContentType("text/html");

    PrintWriter out = response.getWriter();

    String name = new String(request.getParameter("user").getBytes("ISO8859_1"), "utf-8");

    String pwd = new String(request.getParameter("pwd").getBytes("ISO8859_1"), "UTF-8");

    User user = new User();

    user.setUser(name);

    user.setPwd(pwd);

    Dao dao = new Dao();

    boolean isLogin;

    try

    {

        isLogin = dao.logoin(user);

        if (isLogin) {
            HttpSession session=request.getSession();   
            session.setAttribute("sessionname", user.getUser());
            response.sendRedirect("index.jsp");

        } else {
            response.sendRedirect("dologin.jsp");
        }
    } catch (SQLException e)

    {

        e.printStackTrace();

    }

}

public void doGet(HttpServletRequest request, HttpServletResponse response)

        throws ServletException, IOException {

    doPost(request, response);

}

public void init() throws ServletException {

}

}

我看网上说还要配置web.xml什么的，但是配置正确之后依然是404......

servlet3.0使用注解的方式：@WebServlet(name="firstServlet",urlPatterns={"/firstServlet"})。以下用web.xml配置的方式：

 <servlet>
    <servlet-name>firstServlet</servlet-name>
    <servlet-class>包名.FirstServlet</servlet-class>
</servlet>
<servlet-mapping>
    <servlet-name>firstServlet</servlet-name>
    <url-pattern>/firstServlet</url-pattern>
</servlet-mapping>

web.xml配置会覆盖servlet中注解的配置，我个人觉得应该是配置问题，要么就是整个web工程没有导入对应的java EE 容器中，也就是没有部署成功，你可以试试web根目录的路径，试一下能够访问