Spring 中任意位置获取 session 和 request

1. 在web.xml中添加监听：

<listener>
	<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>

或者

<listener>  
    <listener-class>org.springframework.web.context.request.RequestContextListener</listener-class>    
</listener> 

2. 写一个静态方法：

import org.springframework.web.context.request.RequestContextHolder;  
import org.springframework.web.context.request.ServletRequestAttributes;  

/**
 * 获取 request
 */
public static HttpServletRequest getRequest() {
	return ((ServletRequestAttributes)RequestContextHolder.getRequestAttributes()).getRequest();
}

/**
 * 获取 session
 */
public static HttpSession getSession(){
	return getRequest().getSession();
}