Spring Web

◆ Spring整合web环境

- Javaweb三大组件及环境特点

- Spring整合web环境的思路及实现

把ApplicationContext放在ServleContent域【listen组件中】中

ContextLoaderListener ：部分代码写死了

/*** 配置通用的Spring容器的创建，只需要创建一次就可以*/
public class ContextLoaderListener implements ServletContextListener {public void contextDestroyed(ServletContextEvent sce) {//1.创建Spring容器ClassPathXmlApplicationContext app = new ClassPathXmlApplicationContext("application.xml");//2.将容器存储到servletContent域中sce.getServletContext().setAttribute("applicationContext",app);}
}

WebApplicationContextUtils：减少写死代码

public class WebApplicationContextUtils {public static ApplicationContext getWebApplicationContext(ServletContext servletContext){ApplicationContext applicationContext = (ApplicationContext) servletContext.getAttribute("applicationContext.xml");return applicationContext;}
}

- Spring的web开发组件spring-web

使用xml注解

        <dependency><groupId>org.springframework</groupId><artifactId>spring-web</artifactId><version>5.3.7</version></dependency>

<?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_3_1.xsd"version="3.1"><!--定义全局参数--><context-param><param-name>contextConfigLocation</param-name><param-value>classpath:applicationContext.xml</param-value></context-param><!--配置Listener--><listener><listener-class>org.springframework.web.context.ContextLoaderListener</listener-class></listener></web-app>

public class AccountServlet extends HttpServlet {protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {ServletContext servletContext = request.getServletContext();ApplicationContext app = WebApplicationContextUtils.getWebApplicationContext(servletContext);AccountService accountService = app.getBean(AccountService.class);accountService.transferMoney("tom","lucy",500);}}