初识SpringMVC


Spring的web框架围绕DispatcherServlet [ 调度Servlet ] 设计

下面我们快速使用SpringMVC来实现一段代码!!

  1.新建module

  2.添加web框架支持

  3.配置web.xml。同时注册DispatcherServlet


   <servlet>
       <servlet-name>springmvcservlet-name>
       <servlet-class>org.springframework.web.servlet.DispatcherServletservlet-class>
       
       <init-param>
           <param-name>contextConfigLocationparam-name>
           <param-value>classpath:springmvc-servlet.xmlparam-value>
       init-param>
       
       <load-on-startup>1load-on-startup>
   servlet>

   
   
   <servlet-mapping>
       <servlet-name>springmvcservlet-name>
       <url-pattern>/url-pattern>
   servlet-mapping>

  4.用到了springmvc-servlet.xml,来编写SpringMVC的配置文件。名称就是:springmvc-servlet.xml  放在resources路径下即可

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans.xsd">

beans>

  5.在SpringMVC配置文件中添加处理映射器

<bean class="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping"/>

  6.在SpringMVC配置文件中添加处理适配器

<bean class="org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter"/>

  7.在SpringMVC配置文件中添加视图解析器


    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" id="InternalResourceViewResolver">
        
        <property name="prefix" value="/WEB-INF/jsp/"/>
        
        <property name="suffix" value=".jsp"/>
    bean>

  8.编写我们要操作业务Controller ,实现Controller接口。需要返回一个ModelAndView,装数据,封视图

package com.chen.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 httpServletRequest, HttpServletResponse httpServletResponse) 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!");
        //封装要跳转的视图也就是页面,放在ModelAndView中。告诉前台要展示哪个页面了!
        mv.setViewName("hello"); //: /WEB-INF/jsp/hello.jsp
        return mv;
    }
}

  9.将Controller类交给Spring容器,注册bean

class="com.chen.controller.HelloController"/>

  10.写出要跳转的jsp页面,显示ModelandView存放的数据

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
   <title>Kuangshentitle>
head>
<body>
${msg}
body>
html>

  11.配置tomcat,并启动,访问/hello

   12.报错排查:

    查看控制台输出,看一下是不是缺少了什么jar包。

    如果jar包存在,显示无法输出,就在IDEA的项目发布中,添加lib依赖!【项目结构,找到对应的module,在WEB-INF下新建lib,并导入依赖】

    重启Tomcat

  13.我们实际开发中并不这么来!!以上提供思路!!

  要用注解来实现!!