Spring - 无法映射 servlet.它返回 404 - 未找到

Question

我正在尝试制作一个简单的servlet，但是我得到的错误状态为404 Not Found。

这是我servlet代码

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
}
}

这是我web.xml文件：

<?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>

我尝试过的网址：

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 中的行.xml关于 sevlet 映射 .. 和 .. balises 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

为什么同时使用注释和网络.xml。"最佳实践"是尝试使用其中一个。如果您选择依赖所有 Servlet 配置的注释，则可以完全删除 web.xml 文件。但我仍然鼓励你保留该文件，或者至少有一个如下例所示的文件：

<?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>

并尝试致电 http://localhost:8080/Project/theServlet