ApplicationContext是Spring的容器环境，通过ApplicationContext对象可以访问所有配置的bean.
在Web开发开发中，常常需要从JSP或者Servlet或者Action中获取ApplicationContext对象，这时候，就无法使用new关键字通过查找配置文件来实例化ApplicationContext这个对象了。Spring通过WebApplicationContextUtils可以方便实现您的需求。下面看个例子：
一、Spring2.5+Struts2环境下
1、配置web.xml，通过这个配置来获取的。
| <?xml version="1.0" encoding="UTF-8"?> <web-app 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_2_5.xsd" version="2.5"> <context-param> <param-name>contextConfigLocation</param-name> <param-value>/WEB-INF/applicationContext.xml</param-value> </context-param> <filter> <filter-name>struts2</filter-name> <filter-class>org.apache.struts2.dispatcher.FilterDispatcher</filter-class> </filter> <filter-mapping> <filter-name>struts2</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> <servlet> <servlet-name>dispatcher</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>dispatcher</servlet-name> <url-pattern>*.form</url-pattern> </servlet-mapping> </web-app> |
2、在JSP、Servlet、Action中获取ApplicationContext
| <%@ page import="lavasoft.service.TestService" %> <%@ page import="org.springframework.context.ApplicationContext" %> <%@ page import="org.springframework.web.context.support.WebApplicationContextUtils" %> <%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head><title>Simple jsp page</title></head> <body> <% // ApplicationContext ctx = WebApplicationContextUtils.getWebApplicationContext(request.getSession().getServletContext()); ApplicationContext ctx = WebApplicationContextUtils.getWebApplicationContext(session.getServletContext()); TestService service = (TestService) ctx.getBean("testService"); String s = service.test(); out.print(s); %> </body> </html> |
二、Spring+JSP的环境
在此环境下web.xml配置会有些变化：
| <?xml version="1.0" encoding="UTF-8"?> <web-app 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_2_5.xsd" version="2.5"> <context-param> <param-name>contextConfigLocation</param-name> <param-value>/WEB-INF/applicationContext.xml</param-value> </context-param> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> <servlet> <servlet-name>dispatcher</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>dispatcher</servlet-name> <url-pattern>*.form</url-pattern> </servlet-mapping> </web-app> |
获取的方式和上述完全一样。
下面给出本例子的工程源码，参看附件。
下载附件：
testspringweb2
testspringweb
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