(续)SSM整合之springmvc笔记(SpringMVC简介)（P119-123）还没完

此配置作用下， SpringMVC 的配置文件默认位于 WEB-INF 下，默认名称为 -

servlet.xml ，例如，以下配置所对应 SpringMVC 的配置文件位于 WEB-INF 下，文件名为 springMVC-servlet.xml

"1.0" encoding="UTF-8"?>
<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">
 
    
    <servlet>
        <servlet-name>springMVCservlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServletservlet-class>
    servlet>
 
               
    <servlet-mapping>
        <servlet-name>springMVCservlet-name>
        <url-pattern>/url-pattern>
    servlet-mapping>
 
web-app>

②扩展配置方式

"1.0" encoding="UTF-8"?>
<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">
 
    
    <servlet>
        <servlet-name>springMVCservlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServletservlet-class>
 
        
        <init-param>
            
            <param-name>contextConfigLocationparam-name>
            
            <param-value>classpath:springmvc.xmlparam-value>
        init-param>
    servlet>
 
          
    <servlet-mapping>
        <servlet-name>springMVCservlet-name>
        <url-pattern>/url-pattern>
    servlet-mapping>
 
 
 
web-app>

重新测试

如果报错 可以先clean 在打包

DispatcherServlet是框架帮我们创建出来的  他的初始化里面会做很多操作  接下来我们来简单的看下DispatcherServlet的源码：

单击DispatcherServlet   按住Ctrl+鼠标左健

DispatcherServlet extends FrameworkServlet 

单击FrameworkServlet  按住Ctrl+鼠标左健

FrameworkServlet extends HttpServletBean

 单击HttpServletBean  按住Ctrl+鼠标左健

HttpServletBean extends HttpServlet

 单击HttpServlet  按住Ctrl+鼠标左健

HttpServlet extends GenericServlet

 单击GenericServlet  按住Ctrl+鼠标左健

GenericServlet implements Servlet

 单击Servlet  按住Ctrl+鼠标左健

总结：

DispatcherServlet extends FrameworkServlet

FrameworkServlet extends HttpServletBean

HttpServletBean extends HttpServlet

HttpServlet extends GenericServlet

GenericServlet implements Servlet

 然后Alt+7 查看类的内容结构

 

 

具体源码分析 这里面不讲 总结一句话在DispatcherServlet 在初始化的过程中执行了非常多的操作

所以我们最好不要让DispatcherServlet第一次访问的时候进行初始化  因为初始化要花很多时间还要进行接收请求  很慢  所以我们这里面加上1  将当前Servlet初始化时间提前到服务器启动的时候  因为如果不设置 第一次防问的时候  不但要来处理请求  还要进行很长时间的一个初始化过程 

"1.0" encoding="UTF-8"?>
<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">
 
    
    <servlet>
        <servlet-name>springMVCservlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServletservlet-class>
 
        
        <init-param>
            
            <param-name>contextConfigLocationparam-name>
            
            <param-value>classpath:springmvc.xmlparam-value>
        init-param>
 
        
        <load-on-startup>1load-on-startup>
 
 
    servlet>
 
          
    <servlet-mapping>
        <servlet-name>springMVCservlet-name>
        <url-pattern>/url-pattern>
    servlet-mapping>
 
 
 
web-app>

com.atguigu.controller.HelloController

package com.atguigu.controller;
 
import org.springframework.stereotype.Controller;
 
@Controller
public class HelloController {
 
 
}

springMVC-servlet.xml

"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"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd">
 
    
 
 
    <context:component-scan base-package="com.atguigu.controller">context:component-scan>
 
    
    <bean id="viewResolver"
          class="org.thymeleaf.spring5.view.ThymeleafViewResolver">
        <property name="order" value="1"/>
        <property name="characterEncoding" value="UTF-8"/>
        <property name="templateEngine">
            <bean class="org.thymeleaf.spring5.SpringTemplateEngine">
                <property name="templateResolver">
                    <bean
                            class="org.thymeleaf.spring5.templateresolver.SpringResourceTemplateResolver">
                        
                        <property name="prefix" value="/WEB-INF/templates/"/>
                        
                        <property name="suffix" value=".html"/>
                        <property name="templateMode" value="HTML5"/>
                        <property name="characterEncoding" value="UTF-8" />
                    bean>
                property>
            bean>
        property>
    bean>
 
 
 
 
 
beans>