code: private void readHttpDataChunkByChunk(HttpPostRequestDecoder decoder) {
          try {
              while (decoder.hasNext()) {
                  InterfaceHttpData data = decoder.next();
                  if (data != null) {
                      // check if current HttpData is a FileUpload and previously set as partial
                      if (partialContent == data) {
                          partialContent = null;
                      }
                      try {
                          // new value
                          writeHttpData(data);
                      } finally {
                          data.release();
                      }
                  }
              }
              // Check partial decoding for a FileUpload
              InterfaceHttpData data = decoder.currentPartialHttpData();
              if (data != null) {
                  if (partialContent == null) {
                      partialContent = (HttpData) data;
                  }
              }
          } catch (HttpPostRequestDecoder.EndOfDataDecoderException e1) {
              // end
          }
      }
docs: Example of reading request by chunk and getting values from chunk to chunk