package com.itheima.web;

import com.itheima.service.UserService;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;

import javax.servlet.ServletContext;
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 UserServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        /*ApplicationContext app = new ClassPathXmlApplicationContext("applicationContext.xml");
        //  ServletContext servletContext = this.getServletContext();
        //ApplicationContext app = (ApplicationContext) servletContext.getAttribute("app");
        //ApplicationContext app = WebApplicationContextUtils.getWebApplicationContext(servletContext);
        //ApplicationContext app = WebApplicationContextUtils.getWebApplicationContext(servletContext);*/
        ServletContext servletContext = this.getServletContext();
//        ApplicationContext app = (ApplicationContext) servletContext.getAttribute("app");
//        ApplicationContext app = com.itheima.listener.WebApplicationContextUtils.getWebApplicationContext(servletContext);
        ApplicationContext app = WebApplicationContextUtils.getWebApplicationContext(servletContext);
        UserService userService = app.getBean(UserService.class);
        userService.save();
    }
}

package com.itheima.web;

import com.itheima.service.UserService;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;

import javax.servlet.ServletContext;
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 UserServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        /*ApplicationContext app = new ClassPathXmlApplicationContext("applicationContext.xml");
        //  ServletContext servletContext = this.getServletContext();
        //ApplicationContext app = (ApplicationContext) servletContext.getAttribute("app");
        //ApplicationContext app = WebApplicationContextUtils.getWebApplicationContext(servletContext);
        //ApplicationContext app = WebApplicationContextUtils.getWebApplicationContext(servletContext);*/
        ServletContext servletContext = this.getServletContext();
//        ApplicationContext app = (ApplicationContext) servletContext.getAttribute("app");
//        ApplicationContext app = com.itheima.listener.WebApplicationContextUtils.getWebApplicationContext(servletContext);
        ApplicationContext app = WebApplicationContextUtils.getWebApplicationContext(servletContext);
        UserService userService = app.getBean(UserService.class);
        userService.save();
    }
}