Do you know the most popular SpringMVC framework? How do you build it?

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Spring MVC is a web member of Spring family. It is a lightweight Web framework based on Java that implements the request-driven type of Web MVC design idea, that is, it uses the idea of MVC architecture pattern to decouple the responsibilities of The Web layer. Request-based refers to the use of a request-response model. The purpose of the framework is to help simplify development, and Spring MVC is to simplify our daily Web development.

Spring MVC is an implementation of the service-to-worker idea. The front-end controller is DispatcherServlet; The application controller is divided into Handler Mapping for processor management and View Resolver for View management. Support Locale parsing and file uploading. Provides very flexible data validation, formatting, and data binding mechanisms; Provides powerful convention over configuration (convention over convention) programming support by contract.

The way SpringMVC is built

Development environment setup
New Maven webApp
Springmvc environment JAR package dependencies
Configure web.xml (Front-end controller configuration)
The servlet – context. The XML configuration
Page controller writing
Add view page
Start the Jetty server

A case in field

Development environment setup

Eclipse + jdk1.7 + maven + Jetty

New Maven webApp

Establish springmvc01 project and adjust web environment.

Springmvc environment JAR package dependencies

The < project XMLNS = "http://maven.apache.org/POM/4.0.0" XMLNS: xsi = "http://www.w3.org/2001/XMLSchema-instance" Xsi: schemaLocation = "http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd" > The < modelVersion > 4.0.0 < / modelVersion > < groupId > com. XXX < / groupId > < artifactId > springmvc01 < / artifactId > <packaging> War </packaging> <version>0.0.1-SNAPSHOT</version> <name> Springmvc01 Maven Webapp</name> <url>http://maven.apache.org</url> <dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> The < version > 4.12 < / version > < scope > test < / scope > < / dependency > <! -- spring web --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-web</artifactId> < version > 4.3.2. RELEASE < / version > < / dependency > <! -- spring mvc --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> < version > 4.3.2. RELEASE < / version > < / dependency > <! -- web servlet --> <dependency> <groupId>javax.servlet</groupId> <artifactId>javax.servlet-api</artifactId> The < version > 3.0.1 < / version > < / dependency > < / dependencies > <! <build> <finalName> Springmvc01 </finalName> <resources> <resource> <directory>src/main/resources</directory> </resource> </resources> <plugins> <! Plugins </groupId> <artifactId>maven-compiler-plugin</artifactId> <version>2.3.2</version> < Configuration > <source>1.7</source> <target>1.7</target> <encoding>UTF-8</encoding> </configuration> </plugin> <plugin> <groupId>org.mortbay.jetty</groupId> <artifactId>maven-jetty-plugin</artifactId> The < version > 6.1.25 < / version > < configuration > < scanIntervalSeconds > 10 < / scanIntervalSeconds > <contextPath>/springmvc01</contextPath> </configuration> </plugin> </plugins> </build> </project>Copy the code

Configure web.xml (Front-end controller configuration)

<? The XML version = "1.0" encoding = "utf-8"? > < web - app id = "WebApp_ID" version = "3.0" XMLNS = "http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"> <! <context-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:*.xml</param-value> </context-param> <! -- Enable Spring container environment context listening --> <listener> <listener class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> <! Utf-8 --> <filter> <description>char encoding filter</description> <filter-name>encodingFilter</filter-name> <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class> <init-param> <param-name>encoding</param-name> <param-value>UTF-8</param-value> </init-param> </filter> <filter-mapping> <filter-name>encodingFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <! -- Servlet request dispatcher --> <servlet> <servlet-name>springMvc</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:servlet-context.xml</param-value> </init-param> <! <load-on-startup>1</load-on-startup> </ Servlet > <servlet-mapping> <servlet-name>springMvc</servlet-name> <! Do request --> <url-pattern>/</url-pattern> </servlet-mapping> </web-app>Copy the code

To launch our springMvc environment, we have not configured the MVC framework yet. The servlet-context.xml file is referenced above in web.xml.

The servlet – context. The XML configuration

<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:context="http://www.springframework.org/schema/context" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" xsi:schemaLocation=" http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd"> <! <context:component-scan base-package="com.xxx.controller" /> <! MVC request mapping handler and adapter configuration --> < MVC :annotation-driven/> <! <bean id="defaultViewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="viewClass" value="org.springframework.web.servlet.view.JstlView" /> <property name="contentType" value="text/html" /> <property name="prefix" value="/WEB-INF/jsp/" /> <property name="suffix" value=".jsp" /> </bean> </beans>Copy the code

If garble is returned: Configure the message converter

<! < MVC :message-converters register-defaults="true"> <bean class="org.springframework.http.converter.StringHttpMessageConverter"> <property name="supportedMediaTypes" value="text/html; charset=UTF-8"/> </bean> </mvc:message-converters>Copy the code

Page controller writing

@controller public class HelloController {/** * RequestMapping("/hello") public ModelAndView hello(){ ModelAndView mv=new ModelAndView(); mv.addObject("hello", "hello spring mvc"); mv.setViewName("hello"); return mv; }}Copy the code

Add view page

Create a new JSP folder under WEB-INF and create hello.jsp under the file

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; % > <! DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> < HTML > <head> <base href="<%=basePath%>"> <title>My JSP 'hello.jsp' starting page</title> <meta http-equiv="pragma" content="no-cache"> <meta http-equiv="cache-control" content="no-cache"> <meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="This is my page"> </head> <body> <! ${hello} </body> </ HTML >Copy the code

Start the Jetty server

Right-click the project → Run as → Maven build → Goals Enter Jetty :run to start the server.

If it launches successfully, the browser (preferably the powerful Chrome or Firefox, programmers’ favorites!!) To access the address http://localhost:8080/springmvc01/hello

The final effect is as follows:

The SpringMVC environment is now set up.

extension

What can Spring MVC do for us

It makes it very easy to design a clean Web layer;
Developing a cleaner Web layer;
Naturally integrated with the Spring framework (such as IoC container, AOP, etc.);
Provides powerful convention over configuration programming by contract support;
Simple Web layer unit test;
Support flexible URL to page controller mapping;
It is very easy to integrate with other view technologies, such as Velocity, FreeMarker, and so on, because the Model data is not placed in a specific API, but in a Model (Map data structure implementation, therefore easy to use by other frameworks);
Very flexible data validation, formatting, and data binding mechanisms that can be used with any object for data binding without having to implement frame-specific apis;
Support flexible localization and other parsing;
Simpler exception handling;
Support for static resources;

What can G MVC do for us

It makes it very easy to design a clean Web layer;
Developing a cleaner Web layer;
Naturally integrated with the Spring framework (such as IoC container, AOP, etc.);
Provides powerful convention over configuration programming by contract support;
Simple Web layer unit test;
Support flexible URL to page controller mapping;
It is very easy to integrate with other view technologies, such as Velocity, FreeMarker, and so on, because the Model data is not placed in a specific API, but in a Model (Map data structure implementation, therefore easy to use by other frameworks);
Very flexible data validation, formatting, and data binding mechanisms that can be used with any object for data binding without having to implement frame-specific apis;
Support flexible localization and other parsing;
Simpler exception handling;
Support for static resources;
Restful style is supported.