The user makes a request, and the Dispatcher Servlet receives and intercepts the request.

Let's assume the requested URL is: http://localhost:8080/sm/hello

As above, the URL is split into three parts:

• http://localhost:8080 Represents a server domain name

• sm represents a web site deployed on a server

• hello representation controller

Through analysis, as indicated by the URL above:

1. The hello controller for the sm site located on server localhost:8080 is requested, and the user makes the request.

2. HandlerMapping is a processor mapping.

   Dispatcher Servlet calls Handler Mapping, which looks for Handler based on the request url.

3. Handler Execution represents a specific handler.

   The main purpose is to find the controller based on the url, such as hello.

4. HandlerExecution passes parsed information to Dispatcher Servlet, such as resolving controller mappings.

5. A Handler Adapter represents a processor adapter that executes a Handler according to specific rules.

6. Handler lets the specific Controller execute.

7. Controller returns specific execution information to the Handler Adapter, such as ModelAndView.

8. HandlerAdapter passes the view logical name or model to Dispatcher Servlet.

9. Dispatcher Servlet calls ViewResolver to resolve the logical view name passed by Handler Adapter.

10. The view parser passes the parsed logical view name to Dispatcher Servlet.

11. Dispatcher Servlet calls a specific view based on the result of the view parsed by the view parser.

12. The final view is presented to the user.

xml Configuration Edition

==========================================================================

The xml configuration version is just a try. It will not be used in development, but will be more annotated.

1. Create a Web project

Create a new Moudle, springmvc-hello, to add web support.

2. pom. Dependency on Importing SpringMVC in XML

<dependencies>

    <dependency>

        <groupId>org.springframework</groupId>

        <artifactId>spring-webmvc</artifactId>

        <version>5.2.6.RELEASE</version>

    </dependency>

    <dependency>

        <groupId>javax.servlet</groupId>

        <artifactId>servlet-api</artifactId>

        <version>2.5</version>

    </dependency>

    <dependency>

        <groupId>javax.servlet.jsp</groupId>

        <artifactId>jsp-api</artifactId>

        <version>2.2</version>

    </dependency>

    <dependency>

        <groupId>javax.servlet</groupId>

        <artifactId>jstl</artifactId>

        <version>1.2</version>

    </dependency>

</dependencies> 

3. Configure the web.xml, register Dispatcher Servlet

<?xml version="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">



   <!--1.register DispatcherServlet-->

   <servlet>

       <servlet-name>springmvc</servlet-name>

       <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>

       <!--Associate one springmvc Profile:[servlet-name]-servlet.xml-->

       <init-param>

           <param-name>contextConfigLocation</param-name>

           <param-value>classpath:springmvc-servlet.xml</param-value>

       </init-param>

       <!--Startup Level-1-->

       <load-on-startup>1</load-on-startup>

   </servlet>



   <!--/ Match all requests; (excluding.jsp)-->

   <!--/* Match all requests; (Includes.jsp)-->

   <servlet-mapping>

       <servlet-name>springmvc</servlet-name>

       <url-pattern>/</url-pattern>

   </servlet-mapping>



</web-app> 

4. Write the configuration file for SpringMVC: springmvc-servlet.xml

Create the configuration file springmvc-servlet under resources. XML to which you add the following configuration:

• Processing Mapper (BeanNameUrlHandlerMapping)

• Processing adapter (SimpleController HandlerAdapter)

• View Resolver

<?xml version="1.0" encoding="UTF-8"?>

<beans xmlns="http://www.springframework.org/schema/beans"

       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

       xsi:schemaLocation="http://www.springframework.org/schema/beans

       http://www.springframework.org/schema/beans/spring-beans.xsd">



    <!--Add Processing Mapper-->

    <bean class="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping"/>

    <!--Add Processing Adapter-->

    <bean class="org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter"/>



    <!--view resolver:DispatcherServlet For him ModelAndView-->

    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" id="InternalResourceViewResolver">

        <!--prefix-->

        <property name="prefix" value="/WEB-INF/jsp/"/>

        <!--Suffix-->

        <property name="suffix" value=".jsp"/>

    </bean>



    <!--Handler-->

    <bean id="/hello" class="com.yusael.controller.HelloController"/>



</beans> 

5. Write Operational Business Controller

Controller either implements the Controller interface or uses the @Controller annotation;

• Implementing Controller requires returning a ModelAndView, encapsulating data and views;

package com.yusael.controller;



import org.springframework.web.servlet.ModelAndView;

import org.springframework.web.servlet.mvc.Controller;



import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;



// Implement Controller interface

public class HelloController implements Controller {



   public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response) throws Exception {

       // ModelAndView Model and View

       ModelAndView mv = new ModelAndView();



       // Encapsulate the object and place it in ModelAndView

       mv.addObject("msg", "HelloSpringMVC!");

       // Encapsulate the view you want to jump to and place it in ModelAndView

       mv.setViewName("hello"); // Automatically stitch into/WEB-INF/jsp/hello according to the view parser. JSP

       return mv;

  }

} 

6. Register bean s in configuration files

Springmvc-servlet. Give your class to the SpringIOC container in XML to register the bean s:

<!--Handler-->

<bean id="/hello" class="com.yusael.controller.HelloController"/> 

7. Create a view layer hello.jsp

Write a shell to jump to. JSP page, showing the data stored in ModelandView, as well as our normal page;

<%@ page contentType="text/html;charset=UTF-8" language="java" %>

<html>

<head>

   <title>yusael</title>

</head>

<body>

${msg}

</body>

</html> 

8. Configure Tomcat to start the test!

URL: http:localhost:8080/hello

Probable problem: 404 visits

Add lib dependencies to IDEA project publishing!

• Restart Tomcat to solve!

Annotation Version

======================================================================

1. Create a Web project

Create a new Moudle, springmvc-hello-annotation, and add web support.

2. pom. Dependency on Importing SpringMVC in XML

There are mainly Spring Framework Core Library, Spring MVC, servlet, JSTL and so on.

<dependencies>

    <dependency>

        <groupId>org.springframework</groupId>

        <artifactId>spring-webmvc</artifactId>

        <version>5.2.6.RELEASE</version>

    </dependency>

    <dependency>

        <groupId>javax.servlet</groupId>

        <artifactId>servlet-api</artifactId>

        <version>2.5</version>

    </dependency>

    <dependency>

        <groupId>javax.servlet.jsp</groupId>

        <artifactId>jsp-api</artifactId>

        <version>2.2</version>

    </dependency>

    <dependency>

        <groupId>javax.servlet</groupId>

        <artifactId>jstl</artifactId>

        <version>1.2</version>

    </dependency>

</dependencies> 

Resource filtering issues

Because Maven may have resource filtering problems, pom.xml adds the following configuration:

<build>

   <resources>

       <resource>

           <directory>src/main/java</directory>

           <includes>

               <include>**/*.properties</include>

               <include>**/*.xml</include>

           </includes>

           <filtering>false</filtering>

       </resource>

       <resource>

           <directory>src/main/resources</directory>

           <includes>

               <include>**/*.properties</include>

               <include>**/*.xml</include>

           </includes>

           <filtering>false</filtering>

       </resource>

   </resources>

</build> 

3. Configure the web.xml, register Dispatcher Servlet

<?xml version="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">



   <!--1.register servlet-->

   <servlet>

       <servlet-name>SpringMVC</servlet-name>

       <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>

       <!--Specify by initialization parameters SpringMVC Configuration file location, associated-->

       <init-param>

           <param-name>contextConfigLocation</param-name>

           <!-- Relation SpringMVC configuration file -->

           <param-value>classpath:springmvc-servlet.xml</param-value>

       </init-param>

       <!-- Start sequence, the smaller the number, the earlier to start -->


# summary

Other content can be familiar, learned, digested one by one according to the knowledge points sorted out in the roadmap. It is not recommended that you go to a book to learn. It is best to watch more videos and read them repeatedly where you don't understand them. You must review a video content the next day and summarize it into a mind map to form a tree-like knowledge network structure for easy review in the future.

There's also a good copy of " Java Foundation Core Summary Notes, shared with you intentionally,[Click here for free if you need it](https://gitee.com/vip204888/java-p7)

**Catalog:**

![](https://img-blog.csdnimg.cn/img_convert/a4a11d0df0fec352c3b4f0241e9111a7.png)

**Partial screenshots of content:**

![](https://img-blog.csdnimg.cn/img_convert/3ffae7f576071b8680a9eba29656b739.png)

![](https://img-blog.csdnimg.cn/img_convert/fc1f6b5418d20b201120056dcf08ab6b.png)

     <init-param>

           <param-name>contextConfigLocation</param-name>

           <!-- Relation SpringMVC configuration file -->

           <param-value>classpath:springmvc-servlet.xml</param-value>

       </init-param>

       <!-- Start sequence, the smaller the number, the earlier to start -->


# summary

Other content can be familiar, learned, digested one by one according to the knowledge points sorted out in the roadmap. It is not recommended that you go to a book to learn. It is best to watch more videos and read them repeatedly where you don't understand them. You must review a video content the next day and summarize it into a mind map to form a tree-like knowledge network structure for easy review in the future.

There's also a good copy of " Java Foundation Core Summary Notes, shared with you intentionally,[Click here for free if you need it](https://gitee.com/vip204888/java-p7)

**Catalog:**

[Outer Chain Picture Transfer in Progress...(img-I3J1mYXw-1628600322209)]

**Partial screenshots of content:**

[Outer Chain Picture Transfer in Progress...(img-KEMBRNJC-1628600322212)]

[Outer Chain Picture Transfer in Progress...(img-fn38q2xq-1628600322213)]