认识Spring MV

工作流程图解析

前端控制器

前端控制器是Spring MVC的核心，负责接受Http请求并协调各个组件请求工作。

<!DOCTYPE web-app PUBLIC
 "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
 "<http://java.sun.com/dtd/web-app_2_3.dtd>" >

<web-app xmlns="<http://xmlns.jcp.org/xml/ns/javaee>"
         xmlns:xsi="<http://www.w3.org/2001/XMLSchema-instance>"
         xsi:schemaLocation="<http://xmlns.jcp.org/xml/ns/javaee>
                                <http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd>"
         version="4.0" metadata-complete="true">

  <display-name>Archetype Created Web Application</display-name>

<!--  声明SpringMVC 核心配置对象：DispatcherServlet,作用是接受所有用户的请求-->
  <servlet>
    <servlet-name>springmvc</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<!--    启动SpringMVC IoC容器（springmvc.xml）-->
    <init-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>classpath:springmvc.xml</param-value>
    </init-param>
<!--    表示web容器启动时，启动DIspatcherServlet（值越小最先启动）-->
    <load-on-startup>0</load-on-startup>
  </servlet>

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

</web-app>

servlet-mappering负责将在<url-pattern>标签标明的url地址转给同 <servlet-name>的servlet处理