springMVC 01 ------- springMVC entry and environmental structures

A, springMVC entry

SpringMVC Introduction
MVC is the Web application is divided into three, namely:
- A controller (Controller): is responsible for receiving and processing the request, the response client;
- Model (Model): data model, the business logic;
- View (View): Presentation Model, interact with the user;
SpringMVC corresponds to a sub-frame of the spring, so the spring can be naturally SpringMVC used in combination without integration.

Access process:
SpringMVC core components

Package	name	effect
DispatcherServlet	Front Controller	Used to control execution of other components, a unified scheduling, reduce coupling of the various components
Handler	processor	Complete the specific business logic
Handler Mapping		Maps the request to Handler
HandlerInterceptor	Processor interceptors	It is an interface to intercept processing
HandlerExecutionChain	Processor execution chain	Including a Handler and a except
Handler Adapter	Processor Adapter	DispatcherServlet perform different Handler by HandlerAdapter
ModelAndView		Loading model data and view (logical view) as the processing result information returned to the Handler DispatcherServlet
ViewResolver	View resolvers	The logical view resolved into a physical view, and then return the results to the client

SpringMVC workflow
- Client requests submitted to DispatcherServlet
- Looking from the one or more HandlerMapping DispatcherServlet controller, to find a processing request Controller
- DispatcherServlet submit requests to Controller
- After Controller call business logic processing returns ModelAndView
- DispatcherServlet looking for one or more ViewResolver view resolver, find the specified view ModelAndView
- View is responsible for displaying the results to the client

Second, to achieve a springMVC

Xml-based way to achieve springMVC

Creating a Maven project

Import dependencies required springMVC

<dependencies>
	<dependency>
		<groupId>junit</groupId>
		<artifactId>junit</artifactId>
		<version>4.11</version>
		<scope>test</scope>
	</dependency>

	<dependency>
		<groupId>org.springframework</groupId>
		<artifactId>spring-webmvc</artifactId>
		<version>5.1.6.RELEASE</version>
	</dependency>
</dependencies>

In web.xmlthe configurationDispatcherServlet

<!--配置springMVC的servlet：DispatcherServlet-->
<servlet>
	<servlet-name>springMVC</servlet-name>
	<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
	
	<!--指定springMVC文件的路径-->
	<init-param>
		<param-name>contextConfigLocation</param-name>
		<param-value>classpath:springMVC.xml</param-value>
	</init-param>
</servlet>

<!--拦截所有的请求-->
<servlet-mapping>
		<servlet-name>springMVC</servlet-name>
		<url-pattern>/</url-pattern>
</servlet-mapping>

Achieve a Handler

/**
* 自己去实现Handler
* 要继承 Controller 类
*/
public class MyHandler implements Controller {
	@Override
	public ModelAndView handleRequest(javax.servlet.http.HttpServletRequest httpServletRequest, javax.servlet.http.HttpServletResponse httpServletResponse) throws Exception {

		//装载模型数据和逻辑视图
		ModelAndView modelAndView = new ModelAndView();

		//添加模型数据
		modelAndView.addObject("name","tom");

		//添加逻辑视图，这里由视图解析器将逻辑视图进行解析，所以不需要加前后缀
		modelAndView.setViewName("show");
		return modelAndView;
	}
}

ConfigurationSpringMVC.xml

<?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">

	<!--配置一个HandlerMapping，将URL请求映射到-->
	<bean id="HandlerMapping" class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
		<property name="mappings">
    		<props>
        		<!--配置 /test 请求对应的Handler-->
        		<prop key="/test">testHandler</prop>
    		</props>
		</property>
	</bean>

	<!--配置Handler-->
	<bean id="testHandler" class="MyHandler"></bean>

	<!--配置视图解析器-->
	<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
		<property name="prefix" value="/"></property>
		<property name="suffix" value=".jsp"></property>
	</bean>
</beans>

Implementation view show.jsp
Run the project, access / test

SpringMVC achieve a comment on the way

Add an automated scan the springMVC.xml

<!--将AnnotationHandler自动扫描到IOC容器中-->
<context:component-scan base-package="com.springdemo.controller"></context:component-scan>

Achieve Handler

@Controller
public class AnotationHandler {

	@RequestMapping("/test")
	public ModelAndView test(){
	
		//装载模型数据和逻辑视图
		ModelAndView modelAndView = new ModelAndView();

		//添加模型数据
		modelAndView.addObject("name","tom");

		//添加逻辑视图，这里由视图解析器将逻辑视图进行解析，所以不需要加前后缀
		modelAndView.setViewName("show");
		return modelAndView;
	}
}

Other business methods can also be used two ways:

Use Model by value, String parsed view

@Controller
public class AnotationHandler {

	@RequestMapping("/test")
	public String  test(Model model){
	
		model.addAttribute("name", "Tom");
		return "show";
		
	}
}

Use Map by value, String parsed view

@Controller
public class AnotationHandler {

	@RequestMapping("/test")
	public String  test(Map<String,String> map){
		map.put("name", "Tom");
		return "show";
	}
}

Original Address: SpringMVC frame 01 -------- use IDEA to build SpringMVC environment Panya's blog

springMVC 01 ------- springMVC entry and environmental structures

A, springMVC entry

Second, to achieve a springMVC

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