SpringMVC笔记

MVC

 

：模型（dao service）        视图（jsp）        控制器（Servlet）

 jsp本质是Servlet

model2

1. 用户发请求

2. Servlet接收请求数据，并调用对应的业务逻辑方法

3. 业务处理完毕，返回更新后的数据给servlet

4. servlet转向到JSP，由JSP来渲染页面

5. 响应给前端更新后的页面

Controller：控制器

1. 取得表单数据

2. 调用业务逻辑

3. 转向指定的页面

Model：模型

1. 业务逻辑

2. 保存数据的状态

View：视图

servlet回顾

        
            junit
            junit
            4.12
        
        
            org.springframework
            spring-webmvc
            5.1.9.RELEASE
        
        
            javax.servlet
            servlet-api
            2.5
        
        
            javax.servlet.jsp
            jsp-api
            2.2
        
        
            javax.servlet
            jstl
            1.2
        
    

package com.qi.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 HelloServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
       //1.获取前端参数
        String method = req.getParameter("method");
        if (method.equals("add")){
            req.getSession().setAttribute("msg","执行了add方法");
        }
        if (method.equals("delete")){
            req.getSession().setAttribute("msg","执行了delete方法");
        }

        //2.调用业务层

        //3.视图转发或者重定向
        req.getRequestDispatcher("/WEB-INF/jsp/test.jsp").forward(req ,resp);
    }

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

<%--
  Created by IntelliJ IDEA.
  User: V556U
  Date: 2021/10/10
  Time: 10:53
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>


    


${msg}

    
        hello
        com.qi.servlet.HelloServlet
    
    
        hello
        /hello
    

第一个MVC

    
    
        springmvc
        org.springframework.web.servlet.DispatcherServlet
        
        
            contextConfigLocation
            classpath:springmvc-servlet.xml
        
        
        1
    


    
    
    
        springmvc
        /
    

package com.qi.controller;


import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.Controller;

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


public class HelloController implements Controller {
    public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response) throws Exception {
        //ModelAndView 模型和视图
        ModelAndView mv = new ModelAndView();


        //封装对象，放在ModelAndView中。Model
        mv.addObject("msg","HelloSpringMVC!");
        //封装要跳转的视图，放在ModelAndView中
        mv.setViewName("hello"); //: /WEB-INF/jsp/hello.jsp
        return mv;
    }


}

<%--
  Created by IntelliJ IDEA.
  User: V556U
  Date: 2021/10/11
  Time: 9:11
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>


    


  ${msg}

使用注解开发

Meaven项目就要添加这个配置

   
       
           src/main/java
           
               **/*.properties
               **/*.xml
           
           false
       
       
           src/main/resources
           
               **/*.properties
               **/*.xml
           
           false