Spring MVC入门例子

梦里梦外; 2022-05-18 09:00 264阅读 0赞

参考总结自[易百教程][Link 1]

springMVC工作流程：

浏览器------>请求request---------->核心分发控制器DispatcherServlet(在/WEB-INF/web.xml中配置)

--------匹配相应的处理器handle或控制器controller(在/WEB-INF/\[serlvet-name\]-servlet.xml中定义注解扫描器，扫描控制器类包)

------>该处理器处理请求(调用模型层model，通过业务逻辑数据库操作完成model数据封装)  
      
    --------返回ModelAndView------->DispatcherServlet前端控制器---------->视图层(获得数据渲染视图)

--------返回到-------->DispatcherServlet前端控制器------通过视图解析器(在/WEB-INF/\[serlvet-name\]-servlet.xml中配置)

-------匹配完整响应路径----------->响应response----->浏览器

1、新建JavaWeb工程

2、导入spring支持包建立path，可以通过IDE部署spring开发能力自动完成导包，需取消勾选生成applicationContext.xml

3、在/WEB-INF/下新建web.xml 和 \[(在web.xml中配置的)servlet-name\]-servlet.xml (如: hello-servlet.xml)

4、控制器：新建com.controller包，编写一个普通java文件，如：HelloController.java添加@Controller注解，

类体中编写请求处理方法，如pulbic String hello()\{\}添加@RequsetMapping(…)注明该方法处理的请求内容或类型，返回的是

视图文件字符串如return "index";（前置路径“/jsp/”,后置文件名“.jsp”）[http://localhost:8080/][http_localhost_8080]项目名[/][http_localhost_8080][i][http_localhost_8080]ndex最终配置映射

为“http://localhost:8080/项目名/jsp/index.jsp”

5、视图：在Web-Root/下新建jsp文件夹添加一个jsp文件，如：index.jsp

![70][]

web.xml

<?xml version="1.0" encoding="UTF-8"?>
    <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xmlns="http://xmlns.jcp.org/xml/ns/javaee"
      xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee 
      http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
       id="WebApp_ID" version="3.1">
      
      <display-name>springMVC_hello</display-name>
      
      <servlet>
      	<servlet-name>dispatcher</servlet-name>
      	<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
     	<init-param>
      		<param-name>contextConfigLocation</param-name>
      		<param-value>/WEB-INF/dispatcher-servlet.xml</param-value>
      	</init-param>
      </servlet>
    
    	<servlet-mapping>
    		<servlet-name>dispatcher</servlet-name>
    		<url-pattern>/</url-pattern>
    	</servlet-mapping>
      	
    </web-app>

disparcher-servlet.xml

<?xml version="1.0" encoding="UTF-8"?>
    <beans xmlns="http://www.springframework.org/schema/beans"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xmlns:context="http://www.springframework.org/schema/context"
        xmlns:mvc="http://www.springframework.org/schema/mvc"
        xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
            http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.1.xsd
            http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.1.xsd">  
           
           
           <context:component-scan base-package="com.controller" />
    
           <mvc:default-servlet-handler /> 
           
           <mvc:annotation-driven />
    
           
           <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" id="internalResourceViewResolver">
                  
                  <property name="prefix" value="/jsp/" />
                  
                  <property name="suffix" value=".jsp" />
           </bean>
           
    </beans>

HelloController.java

package com.controller;
    
    import org.springframework.stereotype.Controller;
    import org.springframework.ui.ModelMap;
    import org.springframework.web.bind.annotation.RequestMapping;
    
    @Controller		//注明此类为控制器，配置bean到上下文中
    public class HelloController {
    	
    	@RequestMapping(value="/hello")	//映射该路径下的访问请求到此方法下处理
    	public String hello(ModelMap model){
    		
    		System.out.println("hello controller");
    		
    		//业务处理逻辑编写，调用model层操作
    		/* …… */
    		
    		model.addAttribute("paramName","Hello,This is my first spring MVC programe!");
    		
    		return "index";	//返回相应的视图文件
    	} 
    }

index.jsp

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
    <%
    String path = request.getContextPath();
    String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
    %>
    
    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
    <html>
      <head>
        <base href="<%=basePath%>">
        
        <title>My JSP 'index.jsp' starting page</title>
        
    	<meta http-equiv="pragma" content="no-cache">
    	<meta http-equiv="cache-control" content="no-cache">
    	<meta http-equiv="expires" content="0">    
    	<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    	<meta http-equiv="description" content="This is my page">
    	
    
      </head>
      
      <body>
        <h2>${paramName}</h2>
      </body>
    </html>

结果

![70 1][]

[Link 1]: https://www.yiibai.com/spring_mvc/springmvc_hello_world_example.html
[http_localhost_8080]: http://localhost:8080/springMVC_hello/hello
[70]: /images/20220518/0284bdc76a8e4b289cd66d56841e02ac.png
[70 1]: /images/20220518/1fd92c6307b44a5cb93a190a08276ec4.png