/**
* �������ƣ�������Ȩ���ظ�servlet engine��
*/
private void giveUpControl(RequestContext requestContext, FilterChain chain) throws IOException, ServletException {
// 1. �ر�buffering
BufferedRequestContext brc = findRequestContext(requestContext, BufferedRequestContext.class);
if (brc != null) {
try {
brc.setBuffering(false);
} catch (IllegalStateException e) {
// getInputStream��getWriter�Ѿ��������ˣ����ܸ���buffering������
}
}