HttpServletResponse对象获取头信息，报错找不到方法 ?报错

源码：

            JSONObject returnJson = JSONObject.fromObject(json);
      response.setContentType("text/html;charset=utf-8");
            if(!"0".equals(returnJson.get("code"))){
                response.setHeader("McAuditResult", "W");
                response.containsHeader("McAuditResult");//返回true
                response.getHeader("McAuditResult");//报错，找不到getHeader方法
            }
            response.getWriter().write(returnJson.toString());

response.getHeader("McAuditResult")
这一行报错：

2015-7-2 12:24:58 org.apache.catalina.core.StandardWrapperValve invoke
严重: Servlet.service() for servlet rest threw exception
java.lang.AbstractMethodError: org.apache.catalina.connector.ResponseFacade.getHeader(Ljava/lang/String;)Ljava/lang/String;