• Spring学习总结六——SpringMVC一


    一:什么是springMVC

    MVC,顾名思义,m就是model模型,包括处理业务、访问数据库以及封装数据实体类等,view视图层

    负责和用户进行交互,就是展示给用户的部分,包括jsp页面,html等,c就是控制器,是controller层。

    大致的访问流程是:

    1:浏览器发送请求到服务器,然后服务器将请求分配给dispatcher分发器(在web.xml中配置)

    2:然后dispatcher分发器调用handlerMapping将前台请求地址与controller控制器进行匹配,这里就要

    用到handlerMapping组件

    3:controller控制层调用handlerRequest方法处理请求,当然包括业务以及与数据库交互的部分,然后将

    处理结果以及页面封装到ModelAndView对象中返回给核心分发器

    4:然后分发器调用viewResolver组件将modelandview中返回的视图名称按照viewResolver进行拼接,得到

    访问的视图,然后将数据填充到视图中

    5:将jsp处理结果返回到浏览器展示

    二:示例演示

    下面通过示例来演示:

    1:第一步配置环境,在lib中导入如下jar包

    2:配置spring容器spring-mvc.xml

     1 <?xml version="1.0" encoding="UTF-8"?>
     2 <beans xmlns="http://www.springframework.org/schema/beans"
     3     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
     4     xmlns:jdbc="http://www.springframework.org/schema/jdbc" xmlns:jee="http://www.springframework.org/schema/jee"
     5     xmlns:tx="http://www.springframework.org/schema/tx" xmlns:jpa="http://www.springframework.org/schema/data/jpa"
     6     xmlns:util="http://www.springframework.org/schema/util" xmlns:mvc="http://www.springframework.org/schema/mvc"
     7     xsi:schemaLocation="
     8         http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
     9         http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd
    10         http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.2.xsd
    11         http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.2.xsd
    12         http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd
    13         http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsd     
    14         http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.2.xsd
    15         http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd">
    16     
    17     <!-- 定义请求处理映射 -->
    18     <bean id="handlerMapping" class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
    19         <!-- 指定请求与controller对应关系 -->
    20         <property name="mappings" ref="urlMappings"/>
    21     </bean>
    22     
    23     <!--定义映射关系 -->
    24     <util:properties id="urlMappings">
    25         <prop key="/hello.form">helloController</prop>
    26     </util:properties>
    27     
    28     <bean id="helloController" class="com.hlcui.controller.HelloController"></bean>
    29     
    30     <!-- 定义viewResolver解析器-->
    31     <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
    32         <property name="prefix" value="/WEB-INF/jsp/"/>
    33         <property name="suffix" value=".jsp"/>
    34     </bean>
    35     </beans>
    36     

    3:配置web.xml,dispatcher控制器在这里配置

     1 <?xml version="1.0" encoding="UTF-8"?>
     2 <web-app version="2.5" 
     3     xmlns="http://java.sun.com/xml/ns/javaee" 
     4     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
     5     xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
     6     http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
     7     <servlet>
     8         <servlet-name>springmvc</servlet-name>
     9         <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    10         <!-- 指定配置文件的位置 -->
    11         <init-param>
    12             <param-name>contextConfigLocation</param-name>
    13             <param-value>classpath:spring-mvc.xml</param-value>
    14         </init-param>
    15         <load-on-startup>1</load-on-startup>
    16     </servlet>
    17     <servlet-mapping>
    18         <servlet-name>springmvc</servlet-name>
    19         <url-pattern>*.form</url-pattern>
    20     </servlet-mapping>
    21   <welcome-file-list>
    22     <welcome-file>index.jsp</welcome-file>
    23   </welcome-file-list>
    24 </web-app>

    4:HelloController类

     1 /**
     2  * 
     3  */
     4 package com.hlcui.controller;
     5 
     6 import javax.servlet.http.HttpServletRequest;
     7 import javax.servlet.http.HttpServletResponse;
     8 
     9 import org.springframework.web.servlet.ModelAndView;
    10 import org.springframework.web.servlet.mvc.Controller;
    11 
    12 /**
    13  * @author Administrator
    14  *
    15  */
    16 public class HelloController implements Controller {
    17 
    18     public ModelAndView handleRequest(HttpServletRequest request,
    19             HttpServletResponse response) throws Exception {
    20         System.out.println("处理业务逻辑!");
    21         ModelAndView model = new ModelAndView("hello");
    22         return model;
    23     }
    24 
    25 }

    5:hello.jsp页面

     1 <%@ page language="java" import="java.util.*" pageEncoding="ISO-8859-1"%>
     2 <%
     3 String path = request.getContextPath();
     4 String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
     5 %>
     6 
     7 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
     8 <html>
     9   <head>
    10     <base href="<%=basePath%>">
    11     
    12     <title>My JSP 'hello.jsp' starting page</title>
    13     
    14     <meta http-equiv="pragma" content="no-cache">
    15     <meta http-equiv="cache-control" content="no-cache">
    16     <meta http-equiv="expires" content="0">    
    17     <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    18     <meta http-equiv="description" content="This is my page">
    19     <!--
    20     <link rel="stylesheet" type="text/css" href="styles.css">
    21     -->
    22 
    23   </head>
    24   
    25   <body>
    26     This is my JSP page. <br>
    27   </body>
    28 </html>

    6:启动服务器,然后通过浏览器访问

    访问成功!

    三:使用注解的方式对案例进行重构

    1:在HelloController类中,可以使用@Controller注解在类上,替代实现Controller接口,需要在

    spring容器中配置组件扫描:

    1 <!-- 组件扫描 -->
    2     <context:component-scan base-package="com.hlcui.controller"/>
    3     

    2:在类上或者方法上使用@RequestMapping注解替换在spring容器中配置urlMapping映射bean

    需要在spring容器中配置注解扫描:

    1 <!-- RequestMapping映射配置 -->
    2     <mvc:annotation-driven/>

    3:修改后的类以及配置文件如下

    1     <!-- 组件扫描 -->
    2     <context:component-scan base-package="com.hlcui.controller"/>
    3     
    4     <!-- RequestMapping映射配置 -->
    5     <mvc:annotation-driven/>
     1 @Controller
     2 @RequestMapping("/web")
     3 public class HelloController {
     4 
     5     @RequestMapping("/hello.form")
     6     public String execute(HttpServletRequest request,
     7             HttpServletResponse response) throws Exception {
     8         System.out.println("处理业务逻辑!");
     9         return "hello";
    10     }
    11 
    12 }

    4:启动服务器,使用浏览器进行访问

    访问成功!

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  • 原文地址:https://www.cnblogs.com/warrior4236/p/6120069.html
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