Background

Just knowing spring, it gives me the feeling that the encapsulated tool class will make our development easier, more energy will be put on business logic, of course, some excellent ideas of spring, what control inversion, face-to-face and so on. I don't know exactly how it works. Later, slowly understand.. try to build a spring framework, here is a record.

II. Construction

The project is relatively simple, using only spring core and webMvc packages, which is enough for requests to return to the page ____________.

Environment: idea+maven

Configuring the pom.xml file

This is the name of several nodes that need to be entered manually when creating a project

  <! - Project Package - >
  <groupId>com.huimin</groupId>
  <! - Project name - >
  <artifactId>first_spring</artifactId>
  <! - Packed files are in war format - >
  <packaging>war</packaging>
  <! - Version - >
  <version>1.0-SNAPSHOT</version>

<!--Unified Management Version-->
  <properties>
    <!--Coding format-->
    <project.build.sourceEncoding>utf-8</project.build.sourceEncoding>
    <!--spring format-->
    <spring.version>4.3.5.RELEASE</spring.version>
    <!--Store the version number of some packages-->
  </properties>

  <dependencies>
    <!--Dependence on unit testing-->
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
    <!--mvc-->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-webmvc</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <!--spring Core package-->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-core</artifactId>
      <version>${spring.version}</version>
    </dependency>
  </dependencies>

After the introduction of spring framework, the whole project is built on spring, so spring configuration should be loaded at the entrance of the program, so it should be configured in web.xml first.

(1) Configure a spring listener first. When a web project starts, start loading the spring configuration file through this listener.

    <!--spring Monitor ApplicationContext Loading-->
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

    <!--To configure applicationContext.xml Global Name-->
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>WEB-INF/applicationContext.xml</param-value>
    </context-param>

  <servlet>
      <servlet-name>SpringMVC</servlet-name>
      <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
      <!--Definition spring Separate configuration, servlet Relevant content in spring-servlet In separate management-->
      <init-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>WEB-INF/spring-servlet.xml</param-value>
      </init-param>
      <load-on-startup>1</load-on-startup>
  </servlet>
    <!--Set the mapping relationship by spring Administration-->
    <servlet-mapping>
        <servlet-name>SpringMVC</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

(4) spring-servlet configuration content

<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:aop="http://www.springframework.org/schema/aop"
       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/aop
       http://www.springframework.org/schema/aop/spring-aop-2.5.xsd
       http://www.springframework.org/schema/context
       http://www.springframework.org/schema/context/spring-context-2.5.xsd
       http://www.springframework.org/schema/mvc
       http://www.springframework.org/schema/mvc/spring-mvc-4.1.xsd">
    <!--Open Annotation Driver-->
    <mvc:annotation-driven></mvc:annotation-driven>
    <!--Scanning Pack-->
    <context:component-scan base-package="com.huimin.*"></context:component-scan>


    <!--jsp Page Designated Location    optional content-->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <!--File path-->
        <property name="prefix" value="/WEB-INF/jsp/"/>
        <!--file extension-->
        <property name="suffix" value=".jsp"/>
    </bean>
</beans>

       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xmlns:mvc="http://www.springframework.org/schema/mvc"

Just remember that he's a namespace.

The.xsd file in schemaLocation is a specification of xml. Introducing the xsd file of context, the context tag can be written in the configuration.

The xsd of beans is introduced, so the beans tag can be introduced into the configuration.

There must be two configurations in the spring configuration file: open annotation driver and scan package

java code (annotations)

@Controller
public class RegistController {
    @RequestMapping("/regist")
    public String regist(){

        return "firstJsp";
    }
}

Summary

As for why to use spring framework, I don't know much about it yet. I've talked about how good spring is, but I haven't personally realized it yet. Everyone uses it first. If you know more, you will realize the benefits of spring.