fileupload ?= cl_htmlb_manager=>get_data(
                       request = runtime->server->request
                       id      = 'myUpload'
                       name    = 'fileUpload' ).

file_name      = fileupload->file_name.
file_mime_type = fileupload->file_content_type.
file_length    = fileupload->file_length.
file_content   = fileupload->file_content.

* преобразуем content из xstring в string.
converted = cl_abap_conv_in_ce=>create(
                  input = file_content
                  encoding = '1504'
                  ignore_cerr = abap_true ).

converted->read( IMPORTING data = content_new ).