Spring - 无法映射servlet。 它返回404 - Not Found

Question

I am trying to make a simple servlet, but I am getting the error status of 404 Not Found.

This is my servlet code

package servlets;

import javax.servlet.annotation.WebServlet;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;
import java.io.PrintWriter;


@WebServlet(name = "ServletExample", urlPatterns = "/theServlet")
public class ServletExample extends javax.servlet.http.HttpServlet {
    private String message;

    @Override
    public void init() throws ServletException {
        message = "Hello from the servlet";
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //set response type
        response.setContentType("text/html");

        //actual logic goes here.
        PrintWriter out = response.getWriter();
        out.println("<h1>" + message + "</h1>");
    }

    @Override
    public void destroy() {
        //do nothing
    }

}

and this is my web.xml file:

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0">
    <servlet>
        <servlet-name>ServletExample</servlet-name>
        <servlet-class>servlets.ServletExample</servlet-class>
    </servlet>

    <servlet-mapping>
        <servlet-name>ServletExample</servlet-name>
        <url-pattern>/Example</url-pattern>
    </servlet-mapping>
</web-app>

The url's I tried:

http://localhost:8080/Project/Example

http://localhost:8080/Example

http://localhost:8080/theServlet

http://localhost:8080/Project/theServlet

Answer 1

尝试删除web.xml中关于sevlet mapping ..和.. balises的行，因为你已经在类中定义了这个配置，你可以通过http：// localhost：8080 / Project / theServlet调用servlet。

Answer 2

Why you are using both annotations and web.xml. A “best practice” is to try to use one or the other. You can entirely drop web.xml file if you choose to rely on annotations for all of your Servlet configurations. But I still encourage you to keep that file, or at least have one like shown in the example below:

<?xml version="1.0" encoding="UTF-8"?>
<web-app id="WebApp_ID" version="3.0" xmlns="http://java.sun.com/xml/ns/javaee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
    <display-name>Servlet with Annotations Application</display-name>
</web-app>

And try calling http://localhost:8080/Project/theServlet