尚硅谷面试第一季-10SpringMVC的工作流程

目录结构：

关键代码：

web.xml

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
 3          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 4          xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
 5          version="4.0">
 6     <welcome-file-list>
 7        <welcome-file>index.jsp</welcome-file>
 8     </welcome-file-list>
 9     <!-- 设置CharacterEncodingFilter -->
10     <filter>
11         <filter-name>CharacterEncodingFilter</filter-name>
12         <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
13         <!-- 设置请求的字符集 -->
14         <init-param>
15             <param-name>encoding</param-name>
16             <param-value>UTF-8</param-value>
17         </init-param>
18         <!-- 设置响应的字符集 -->
19         <init-param>
20             <param-name>forceEncoding</param-name>
21             <param-value>true</param-value>
22         </init-param>
23     </filter>
24     <filter-mapping>
25         <filter-name>CharacterEncodingFilter</filter-name>
26         <url-pattern>/*</url-pattern>
27     </filter-mapping>
28     <servlet>
29         <servlet-name>springDispatcherServlet</servlet-name>
30         <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
31         <init-param>
32             <param-name>contextConfigLocation</param-name>
33             <param-value>WEB-INF/springmvc.xml</param-value>
34         </init-param>
35         <load-on-startup>1</load-on-startup>
36     </servlet>
37 
38     <servlet-mapping>
39         <servlet-name>springDispatcherServlet</servlet-name>
40         <url-pattern>/</url-pattern>
41     </servlet-mapping>
42 
43     <!-- 注册HiddenHttpMethodFilter，目的是为了将一个POST请求转换为PUT或者DELETE请求 -->
44     <filter>
45         <filter-name>HiddenHttpMethodFilter</filter-name>
46         <filter-class>org.springframework.web.filter.HiddenHttpMethodFilter</filter-class>
47     </filter>
48     <filter-mapping>
49         <filter-name>HiddenHttpMethodFilter</filter-name>
50         <url-pattern>/*</url-pattern>
51     </filter-mapping>
52 </web-app>

SpringMVCHandler.java

 1 package SpringMVC的工作流程.handler;
 2 
 3 import java.util.Map;
 4 
 5 import SpringMVC的工作流程.entities.Department;
 6 import SpringMVC的工作流程.entities.Employee;
 7 import org.springframework.stereotype.Controller;
 8 import org.springframework.web.bind.annotation.RequestMapping;
 9 import org.springframework.web.servlet.ModelAndView;
10 
11 
12 
13 @Controller
14 public class SpringMVCHandler {
15     
16     public static final String SUCCESS="success";
17 
18     //1.简单的谈一下SpringMVC的工作流程
19     
20     //处理模型数据方式一：将方法的返回值设置为ModelAndView
21     @RequestMapping("/testModelAndView")
22     public ModelAndView testModelAndView() {
23         //1.创建ModelAndView对象
24         ModelAndView mav = new ModelAndView();
25         //2.设置模型数据，最终会放到request域中
26         mav.addObject("user", "admin");
27         //3.设置视图
28         mav.setViewName("success");
29         return mav;
30     }
31     /*
32      * ★处理模型数据方式二：方法的返回值仍是String类型，在方法的入参中传入Map、Model或者ModelMap
33      *     不管将处理器方法的返回值设置为ModelAndView还是在方法的入参中传入Map、Model或者ModelMap，
34      *  SpringMVC都会转换为一个ModelAndView对象
35      */
36     @RequestMapping("/testMap")
37     public String testMap(Map<String , Object> map) {
38         //向Map中添加模型数据，最终会自动放到request域中
39         map.put("user", new Employee(1, "韩总", "hybing@atguigu.com", new Department(101, "教学部")));
40         return SUCCESS;
41     }
42     
43 }

运行结果：

完整代码：

https://gitee.com/ZhangShunHai/interview_atguigu_seasonone/tree/master/ssm_springmvc%20workflow

课堂重点:

SpringMVC工作流程图：