spring mvc简介

怼烎@ 2022-08-18 15:15 216阅读 0赞

## 1.1.  spring mvc简介 ##

### 1.1.1.   MVC：Model-View-Control ###

框架性质的C层要完成的主要工作：封装web请求为一个数据对象、调用业务逻辑层来处理数据对象、返回处理数据结果及相应的视图给用户。

### 1.1.2.   简要概述spring mvc ###

Spring C 层框架的核心是 DispatcherServlet，它的作用是将请求分发给不同的后端处理器，也即 使用了一种被称为Front Controller 的模式（后面对此模式有简要说明）。Spring 的C 层框架使用了后端控制器来、映射处理器和视图解析器来共同完成C 层框架的主要工作。并且spring 的C 层框架还真正地把业务层处理的数据结果和相应的视图拼成一个对象，即我们后面会经常用到的ModelAndView 对象。

## 1.2.  Spring MVC入门案例 ##

### 1.2.1.   新建web工程 ###

### 1.2.2.   引入spring jar包和log4j包 ###

文件目录结构

![clip_image0019a5f3d95-3d3a-47c5-9d8a-278b9055e7fc.png][]

### 1.2.3.   配置web.xml ###

<table> 
 <tbody> 
 <tr> 
 <td> &lt;?xml&nbsp;version="1.0"&nbsp;encoding="UTF-8"?&gt; &lt;web-app&nbsp;xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" &nbsp; &nbsp;&nbsp;xmlns="http://java.sun.com/xml/ns/javaee" &nbsp; &nbsp;&nbsp;xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" &nbsp; &nbsp;&nbsp;id="WebApp_ID"&nbsp;version="3.0"&gt; &nbsp; &nbsp;&nbsp;&lt;display-name&gt;HelloSpringMVC&lt;/display-name&gt; &nbsp; &nbsp;&nbsp;&lt;welcome-file-list&gt; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp;&lt;welcome-file&gt;index.jsp&lt;/welcome-file&gt; &nbsp; &nbsp;&nbsp;&lt;/welcome-file-list&gt; &nbsp; &nbsp; &nbsp;&nbsp;&lt;!--&nbsp;配置spring&nbsp;mvc&nbsp;的核心servlet&nbsp;--&gt; &nbsp; &nbsp;&nbsp;&lt;servlet&gt; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp;&lt;servlet-name&gt;spring&lt;/servlet-name&gt; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&lt;servlet-class&gt;org.springframework.web.servlet.DispatcherServlet&lt;/servlet-class&gt; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp;&lt;init-param&gt; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp;&lt;param-name&gt;contextConfigLocation&lt;/param-name&gt; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp;&lt;!--&nbsp;指定spring&nbsp;mvc&nbsp;配置文件的路径 默认为&nbsp;/WEB-INF/&lt;[servlet-name]-servlet.xml&gt;&nbsp;例如此处为/WEB-INF/spring-servlet.xml &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;下面配置的也就是默认值&nbsp;--&gt; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp;&lt;param-value&gt;/WEB-INF/spring-servlet.xml&lt;/param-value&gt; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp;&lt;/init-param&gt; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp;&lt;!--&nbsp;配置随服务器启动自动初始化&nbsp;--&gt; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp;&lt;load-on-startup&gt;1&lt;/load-on-startup&gt; &nbsp; &nbsp; &nbsp;&nbsp;&lt;/servlet&gt; &nbsp; &nbsp;&nbsp;&lt;servlet-mapping&gt; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp;&lt;servlet-name&gt;spring&lt;/servlet-name&gt; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp;&lt;!--&nbsp;过滤所有后缀名为.do的请求&nbsp;--&gt; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp;&lt;url-pattern&gt;*.do&lt;/url-pattern&gt; &nbsp; &nbsp;&nbsp;&lt;/servlet-mapping&gt; &lt;/web-app&gt; </td> 
 </tr> 
 </tbody> 
</table>

### 1.2.4.   新建一个实现了Controller接口的控制器 ###

<table> 
 <tbody> 
 <tr> 
 <td> package com.morris.controller; &nbsp; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; &nbsp; import org.springframework.web.servlet.ModelAndView; import org.springframework.web.servlet.mvc.Controller; &nbsp; public class HelloController&nbsp;implements Controller&nbsp;{ &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; public ModelAndView handleRequest(HttpServletRequest arg0, &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; HttpServletResponse arg1) throws Exception { &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;ModelAndView mav = new ModelAndView("hello.jsp"); &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; mav.addObject("message", "Hello World");&nbsp;&nbsp; &nbsp; &nbsp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return mav; &nbsp; &nbsp; &nbsp;&nbsp; }&nbsp; &nbsp; &nbsp; } </td> 
 </tr> 
 </tbody> 
</table>

### 1.2.5.   配置spring-servlet.xml文件 ###

<table> 
 <tbody> 
 <tr> 
 <td> &lt;?xml&nbsp;version="1.0"&nbsp;encoding="UTF-8"?&gt; &lt;beans&nbsp;xmlns="http://www.springframework.org/schema/beans" &nbsp; &nbsp;&nbsp;xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xmlns:p="http://www.springframework.org/schema/p" &nbsp; &nbsp;&nbsp;xmlns:mvc="http://www.springframework.org/schema/mvc"xmlns:context="http://www.springframework.org/schema/context" &nbsp; &nbsp;&nbsp;xmlns:util="http://www.springframework.org/schema/util" &nbsp; &nbsp;&nbsp;xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.0.xsd"&gt; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&lt;bean&nbsp;id="simpleUrlHandlerMapping" &nbsp; &nbsp; &nbsp; &nbsp;class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping"&gt; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp;&lt;property&nbsp;name="mappings"&gt; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp;&lt;props&gt; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&lt;prop&nbsp;key="/hello.do"&gt;helloControl&lt;/prop&gt; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&lt;!--&nbsp;说明：hello.do的请求将给名为helloControl的bean进行处理。&nbsp;--&gt; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp;&lt;/props&gt; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp;&lt;/property&gt; &nbsp; &nbsp;&nbsp;&lt;/bean&gt; &nbsp; &nbsp;&nbsp;&lt;bean&nbsp;id="helloControl"class="com.morris.controller.HelloController"&gt;&lt;/bean&gt; &lt;/beans&gt; </td> 
 </tr> 
 </tbody> 
</table>

### 1.2.6.   测试 ###

**启动tomcat，在浏览器输入：**[**http://localhost:8080/HelloSpringMVC/hello.do**][http_localhost_8080_HelloSpringMVC_hello.do]

**出现如下的界面**

![clip_image0022e59d363-fd71-4e16-9384-d39ff948226c.png][]

[clip_image0019a5f3d95-3d3a-47c5-9d8a-278b9055e7fc.png]: https://note.wiz.cn/api/document/files/unzip/e7e44252-f257-41d4-8bc1-3960ae3ef7c0/311cbc2b-ba8e-43ee-9eb1-eae9f6854c72.2362/index_files/clip_image0019a5f3d95-3d3a-47c5-9d8a-278b9055e7fc.png
[http_localhost_8080_HelloSpringMVC_hello.do]: http://localhost:8080/HelloSpringMVC/hello.do
[clip_image0022e59d363-fd71-4e16-9384-d39ff948226c.png]: https://note.wiz.cn/api/document/files/unzip/e7e44252-f257-41d4-8bc1-3960ae3ef7c0/311cbc2b-ba8e-43ee-9eb1-eae9f6854c72.2362/index_files/clip_image0022e59d363-fd71-4e16-9384-d39ff948226c.png