在servlet、filter、Taglib中获取Spring Bean

在servlet、filter、Taglib中获取Spring Bean
This entry was posted by kingapex on 星期天, 20 九月, 2009 at
在servlet容器中使用spring框架时spring的上下文（WebApplicationContext）被在保存在ServletContext中。在servlet、filter或jsp标签中获取spring bean的关键在于如何获取ServletContext。

servlet中：

public void init(ServletConfig config){
servletContext= config.getServletContext();
}
filter中：
public void init(FilterConfig config) throws ServletException {
ServletContext  servletContext  =config.getServletContext();
}
jsp taglib中：
ServletContext servletContext = this.pageContext.getServletContext();
spring的上下文（WebApplicationContext）存在ServletContext以WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE为key的属性中，可通过如下方式获取：

Object ob = servletContext
.getAttribute(WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE);
 
WebApplicationContext context = (WebApplicationContext) ob;
在WebApplicationContext中获取bean:

protected Object getBean(String name){
 
return this.getWebApplicationContext().getBean(name);
}

 

ｂｅａｎ中：

　 private static ApplicationContext ctx;

ctx = SysConstants.AppContext;
    if(ctx!=null){
     fpSysParaService = (FpSysParaService) ctx.getBean("fpSysParaService");

}
    

 

一个抽像的servlet基类：

package com.enation.core.servlet;
import javax.servlet.ServletContext;
import javax.servlet.ServletConfig;
import javax.servlet.Servlet;
 
import org.springframework.web.context.WebApplicationContext;
 
/**
 * @author kingapex
 * @version 1.0
 * @created 20-九月-2009 11:52:26
 */
public abstract class BaseServlet implements Servlet {
 
 protected ServletContext servletContext;
 
 /**
  *
  * @param o0
  */
 public void init(ServletConfig config){
  servletContext= config.getServletContext();
 }
 
 public ServletContext getServletContext(){
  return servletContext;
 }
 
 public void destroy(){
 
 }
 
 public String getServletInfo(){
  return "";
 }
 
 protected WebApplicationContext getWebApplicationContext()throws RuntimeException{
 
  Object ob = servletContext
    .getAttribute(WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE);
 
  WebApplicationContext context = (WebApplicationContext) ob;
 
  return context;
 
 }
 
 protected Object getBean(String name){
 
  return this.getWebApplicationContext().getBean(name);
 }
 
 public ServletConfig getServletConfig(){
  return null;
 }
 
}