code: public static byte getSerializeTypeByContentType(String contentType) throws SofaRpcException {
          if (StringUtils.isNotBlank(contentType)) {
              String ct = contentType.toLowerCase();
              if (ct.contains("text/plain") || ct.contains("text/html") || ct.contains("application/json")) {
                  return getSerializeTypeByName(RpcConstants.SERIALIZE_JSON);
              } else if (ct.contains(RpcConstants.SERIALIZE_PROTOBUF)) {
                  return getSerializeTypeByName(RpcConstants.SERIALIZE_PROTOBUF);
              } else if (ct.contains(RpcConstants.SERIALIZE_HESSIAN)) {
                  return getSerializeTypeByName(RpcConstants.SERIALIZE_HESSIAN2);
              }
          }
          throw new SofaRpcException(RpcErrorType.SERVER_DESERIALIZE, "Unsupported content type " + contentType
              + " in http protocol, please set HTTP HEAD: '" + RemotingConstants.HEAD_SERIALIZE_TYPE + "'.");
      }
docs: Parse serialize type from content type
  
  @param contentType Content-type of http request
  @return serialize code
  @throws SofaRpcException unknown content type