Detailed explanation of Spring MVC: in-depth analysis of this powerful framework
- WBOYOriginal
- 2023-12-29 08:09:561065browse
Spring MVC is a very popular Java Web development framework, which is widely welcomed for its powerful functions and flexibility. Its design idea is based on the MVC (Model-View-Controller) architectural pattern, which achieves decoupling and modularization of the application by dividing the application into three parts: model, view and controller.
In this article, we will delve into various aspects of the Spring MVC framework, including request processing and forwarding, model and view processing, page rendering, etc. At the same time, we will combine specific code examples to help readers better understand and use this powerful framework.
First, we need to configure the Spring MVC environment. Add the following content to the web.xml file:
<servlet>
<servlet-name>dispatcher</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>/WEB-INF/spring-mvc.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>dispatcher</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>In the above configuration, we specified the location of the DispatcherServlet class and configuration file. Next we create the spring-mvc.xml file and configure some important parsers and processors:
<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: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/context
http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc.xsd">
<context:component-scan base-package="com.example.controller" />
<mvc:annotation-driven />
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/views/" />
<property name="suffix" value=".jsp" />
</bean>
</beans>In the above configuration, we use context:component-scan to specify the scanned controller package, mvc:annotation -driven is used to support annotation-based request processing. At the same time, we configured the InternalResourceViewResolver to specify the position and suffix of the view.
Next, we need to create a simple Controller class to handle requests. For example, we create a HomeController class with the following code:
package com.example.controller;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;
@Controller
public class HomeController {
@RequestMapping("/")
public ModelAndView home() {
ModelAndView modelAndView = new ModelAndView("home");
modelAndView.addObject("message", "Hello, Spring MVC!");
return modelAndView;
}
}In the above code, we use the @Controller annotation to mark the class as a Controller, and the @RequestMapping annotation specifies the path of the request. In the home() method, we create a ModelAndView object, set the name of the view to "home", and add a "message" attribute.
Finally, we need to create a folder named "views" in the WEB-INF directory, and create a JSP file named "home.jsp" in it, the code is as follows:
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Spring MVC Home</title>
</head>
<body>
<h1>${message}</h1>
</body>
</html> In the above code, we use JSP's EL expression to output the value of the "message" attribute.
Now, we can run our application. When the root path is accessed, the request will be handled by the home() method in HomeController and the view will be rendered and returned to the user.
To summarize, this article introduces some important aspects of the Spring MVC framework in detail, including request processing and forwarding, model and view processing, page rendering, etc. Through specific code examples, we help readers better understand and use this powerful framework. I hope this article can be helpful to readers and make them more comfortable when using Spring MVC.
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