Spring——集成Web环境

简介

　　Spring集合Web环境：通过Listener自动创建ApplicationContext，并放入ServletContext中。通过这样不用每次都new ApplicationContext()

 

操作

　　1. web.xml中配置ContextLoaderListener监听器，监听Web启动

　　

<!-- 全局初始化参数：让监听器从配置的路径中取得applicationContext.xml  -->
<context-param>
  <param-name>contextConfigLocation</param-name>
  <param-value>classpath:applicationContext.xml</param-value>
</context-param>

<!-- 配置监听器 -->
<listener>
  <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>

 

　　2.使用WebApplicationContextUtils获得应用上下文对象ApplicationContext

WebApplicationContext webApplicationContext = WebApplicationContextUtils.getWebApplicationContext(request.getServletContext());

　使用

  <!-- 全局初始化参数：让监听器从配置的路径中取得applicationContext.xml  -->
  <context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>classpath:applicationContext.xml</param-value>
  </context-param>

  <!-- 配置监听器 -->
  <listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
  </listener>

 

@WebServlet(value = "/userController")
public class UserController extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doPost(request,response);
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        WebApplicationContext webApplicationContext = WebApplicationContextUtils.getWebApplicationContext(request.getServletContext());
    }
}