如何获取http体 不带参数载体的

public static String getPacket(HttpServletRequest request, String logFlag) {
String packet = request.getParameter(Constants.PACKET);
if (packet == null) {
try {
InputStream is = request.getInputStream();
BufferedInputStream bis = new BufferedInputStream(is);
List byteList = new ArrayList();
byte[] temp = new byte[1];
while (bis.read(temp) != -1) {
byteList.add(temp[0]);
}
int size = byteList.size();
            if (size > 0) {
                byte[] b = new byte[size];
                for (int i = 0; i < size; i++) {
                    b[i] = byteList.get(i);
                }
                packet = new String(b, Constants.ENCODE);
            } else {
                LOGGER.info("[" + logFlag + "] 从request中获取请求数据流中获取为空 ");
            }
        } catch (Exception e) {
            LOGGER.error("[" + logFlag + "] 从request中获取请求数据流异常: " + e.toString(), e);
        }
    }
    LOGGER.info(orgLog(logFlag, "获取请求报文", "uri[#0]packet[#1]", request.getRequestURI(), packet));
    return packet;
}