Jsp ServletMapping错误

我试图在我的项目中定义多个servlet，到目前为止，有一个身份验证和一个查询servlet：

<!DOCTYPE web-app PUBLIC
 "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
 "http://java.sun.com/dtd/web-app_2_3.dtd" >

<web-app>
  <display-name>Archetype Created Web Application</display-name>


  <servlet>
    <servlet-name>AuthenticationServlet</servlet-name>
    <servlet-class>applicationsservices.AuthenticationServlet</servlet-class>
    <load-on-startup>1</load-on-startup>
  </servlet>
  <servlet>
    <servlet-name>QueryServlet</servlet-name>
    <servlet-class>applicationsservices.QueryServlet</servlet-class>
    <load-on-startup>2</load-on-startup>
  </servlet>



  <servlet-mapping>
    <servlet-name>AuthenticationServlet</servlet-name>
    <url-pattern>/authServlet</url-pattern>
  </servlet-mapping>
  <servlet-mapping>
    <servlet-name>QueryServlet</servlet-name>
    <url-pattern>/queryServlet</url-pattern>
  </servlet-mapping>

</web-app>

当我尝试调用它时，我得到一个404错误，而AuthServlet工作正常。

---

这有什么问题？

结果表明servlet没有正确显示NullPointerException。我现在就想死，为什么你没有用@WebServlet（“/queryServlet”）映射到你的servlet类上？我正在使用JSP，这似乎是我找不到的最好的方法。如果你详细说明你面临的问题，我们将很容易解决。如果您发布/authServlet，我们就可以发现我发现了，在我的存储库初始化中有一个空指针，但没有显示出来

package applicationsservices;

import domain.IAuthenticationProvider;
import domain.User;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;
import java.util.List;

public class QueryServlet extends HttpServlet {
    private static final long serialVersionUID = 2L;

    private IUserRepository userRepository;
    public QueryServlet(){
        super();
        this.userRepository = new UserRepository();
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String query = request.getParameter("queryString");

        response.getWriter().println(query);

    }
}