博客

<?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">

<!--   在web中启动spring两项：如下-->
    
<!--    2、指定配置文件的位置-->
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:applicationContext.xml</param-value>
    </context-param>
    
<!--    1、配置启动Spring框架的监听器-->
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
</web-app>

业务层：

创建servlet：

package com.hhh.web.servlet;

import com.hhh.service.UsersService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationContext;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;

import javax.servlet.ServletException;
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(urlPatterns = "/addUsers.do")
public class UsersServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        this.doPost(req, resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//        获得SpringIOC的容器的方式一：
//        WebApplicationContext webApplicationContext =(WebApplicationContext) this.getServletContext().getAttribute(WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE);
//        UsersService usersService = (UsersService)webApplicationContext.getBean("usersServiceImpl");
//        usersService.addUsers();
//        resp.getWriter().print("hello world");

//        方式二：
        WebApplicationContext webApplicationContext = WebApplicationContextUtils.getWebApplicationContext(this.getServletContext());
        UsersService usersService = (UsersService)webApplicationContext.getBean("usersServiceImpl");
        resp.getWriter().print("hello...");
    }
}