SpringSide4不能获取request

我参考网上这个做法
[code="java"]

org.springframework.web.context.request.RequestContextListener

[/code]
[code="java"]
ServletRequestAttributes reqAttr = (ServletRequestAttributes) RequestContextHolder
.getRequestAttributes();
HttpServletRequest request = reqAttr.getRequest();
[/code]
不能获取request，报的是reqAttr的空指针，我是在我的filter里面用的

RequestContextListener按理说可以，如下是源码
[code="java"]public class RequestContextListener implements ServletRequestListener {

private static final String REQUEST_ATTRIBUTES_ATTRIBUTE =
        RequestContextListener.class.getName() + ".REQUEST_ATTRIBUTES";


public void requestInitialized(ServletRequestEvent requestEvent) {
    if (!(requestEvent.getServletRequest() instanceof HttpServletRequest)) {
        throw new IllegalArgumentException(
                "Request is not an HttpServletRequest: " + requestEvent.getServletRequest());
    }
    HttpServletRequest request = (HttpServletRequest) requestEvent.getServletRequest();
    ServletRequestAttributes attributes = new ServletRequestAttributes(request);
    request.setAttribute(REQUEST_ATTRIBUTES_ATTRIBUTE, attributes);
    LocaleContextHolder.setLocale(request.getLocale());
    RequestContextHolder.setRequestAttributes(attributes);
}[/code]

你试试request.getAttribute(REQUEST_ATTRIBUTES_ATTRIBUTE);能获取吗？

实在不行试试org.springframework.web.filter.RequestContextFilter。