1.在src下创建java文件HelloWorld.java  ~~~ package zyw.servlet; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; public class HelloWorld extends HttpServlet { @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { System.out.println("接收到get请求"); } @Override protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { System.out.println("接收到post请求"); } } ~~~ 快捷键 ~~~ sout =>System.out.println(); ~~~ 2.在web》WEB=INF下的web.xml配置servlet信息  ~~~ <?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>HelloServlet</servlet-name> <servlet-class>zyw.servlet.HelloWorld</servlet-class> </servlet> <servlet-mapping> <servlet-name>HelloServlet</servlet-name> <url-pattern>/hi</url-pattern> </servlet-mapping> </web-app> ~~~ 3.为了让访问路径加个层，在tomcat配置的时候加个层  4.启动项目一起正常  5.在路径上加上hi后访问  可在IDEA中看到信息