20220209 Create a basic servlet

Create a class or right-click to create servlet

Form a directory as shown in the figure

Write doGet Method

ServletDemo1.java

package com.helloservlet.hello;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class ServletDemo1 extends HttpServlet{

	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		System.out.println(" receive HTTP Of GET Mode request ");
	}

	@Override
	protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		// TODO Auto-generated method stub
		super.doPost(req, resp);
	}

	@Override
	protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		// TODO Auto-generated method stub
		super.service(req, resp);
	}

}

To configure xml file

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns="http://xmlns.jcp.org/xml/ns/javaee"
	xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
	id="WebApp_ID" version="4.0">
	<display-name>project20220209</display-name>
	<welcome-file-list>
		<welcome-file>index.html</welcome-file>
	</welcome-file-list>
	<!--  To configure servlet -->
	<servlet>
		<!-- servlet Alias  -->
		<servlet-name>demo1</servlet-name>
		<servlet-class>com.helloservlet.hello.ServletDemo1</servlet-class>
	</servlet>
	<!--  To configure servlet mapping  -->
	<servlet-mapping>
		<servlet-name>demo1</servlet-name>
		<url-pattern>/*</url-pattern>
	</servlet-mapping>
</web-app>

according to xml The document welcome page should be index.html, So there will be index.html The content of , But it's set servlet Intercept , So into servlet Of doGet In the method , It will not be displayed index.html The content of