通过xml配置

<servlet>
    <servlet-name>MyServlet</servlet-name>
    <servlet-class>MyServlet</servlet-class>
</servlet>
<servlet-mapping>
    <servlet-name>MyServlet</servlet-name>
    <url-pattern>/MyServlet</url-pattern>
</servlet-mapping>

这段配置的含义是将一个名为 “MyServlet” 的 Servlet 映射到一个URL为"/MyServlet"路径上，以便在浏览器中访问该路径时能够调用该 Servlet。

注解

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

@WebServlet("/my-servlet")
public class MyServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException {
        response.getWriter().write("Servlet Demo");
    }
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws IOException {
        this.doGet(request, response);
    }
}