How to download a file from application server in webdynpro

Question

Hi Experts,
                   I am trying to download a file through Web Dynpro file download UI element..The file is stored in application server in binary format ..in my code i am reading the file in binary mode,converting Binary File into Xstring(Using FM SCMS_BINARY_TO_XSTRING) ..getting its Mime type and binding the UI element properties (data with XString, Mime type and file name) with respective context attributes..But the problem is file is getting opened but Junk data is getting displayed on it..Not sure where i am making the mistake.

Answer 1

Hi Lukas,thanks for the reply..please find the code
here '/tmp/accenturedocs'  is the folder name on application server,and zdocs_list_tab is the table that contains file URL.File upload is on the BSP page (custom logic to upload the file ) where they are storing local file path in ztable.Same i am extracting in my code to get File URL.
DATA: i_file TYPE rlgrap-filename .
  DATA:v_path TYPE zlist.
  DATA:i_datatab TYPE STANDARD TABLE OF tbl1024,
       wa_datatab TYPE   tbl1024.
  DATA  file TYPE  string.
  DATA dot_offset TYPE i.
  DATA extension TYPE mimetypes-extension.
  DATA mimetype TYPE mimetypes-type.
  SELECT SINGLE description
    FROM  zdocs_list_tab
    INTO v_path.
  CONCATENATE '/tmp/accenturedocs' v_path INTO i_file.
  FIELD-SYMBOLS <hex_container> TYPE x.
  OPEN DATASET i_file FOR INPUT IN LEGACY BINARY MODE.
  IF sy-subrc NE 0.
    MESSAGE e999(00) WITH 'Error opening file' .
  ENDIF.
  ASSIGN  wa_datatab TO <hex_container> CASTING.
  DO.
    READ DATASET i_file INTO <hex_container>.
    IF sy-subrc = 0.
      APPEND wa_datatab TO i_datatab.
    ELSE.
      EXIT.
    ENDIF.
  ENDDO.
  CLOSE DATASET i_file.
  DATA:l_count TYPE i,
        l_len TYPE i.
  DESCRIBE TABLE i_datatab LINES l_count.
  READ TABLE i_datatab INTO wa_datatab INDEX l_count.
  l_len = XSTRLEN( wa_datatab-line ).
  l_len = l_len + ( l_count - 1 ) * 1022.
DATA: v_xstring TYPE xstring.
  CALL FUNCTION 'SCMS_BINARY_TO_XSTRING'
    EXPORTING
      input_length = l_len
    IMPORTING
      buffer       = v_xstring
    TABLES
      binary_tab   = i_datatab
    EXCEPTIONS
      failed       = 1
      OTHERS       = 2.
  IF sy-subrc <> 0.
  ENDIF.
file = i_file.
  " Find out file name extension
  FIND FIRST OCCURRENCE OF REGEX '\.[^\.]+$' IN file MATCH OFFSET
  dot_offset.
  ADD 1 TO dot_offset.
  extension = file+dot_offset.
  " Get mime type
  CALL FUNCTION 'SDOK_MIMETYPE_GET'
    EXPORTING
      extension = extension
    IMPORTING
      mimetype  = mimetype.
DATA lv_file_content TYPE wd_this->element_context-file_content.
get element via lead selection
  lo_el_context = wd_context->get_element( ).
set single attribute
  lo_el_context->set_attribute(
    name =  `FILE_CONTENT`
    value =  v_xstring ).
same way i am assigning file name and file mime type to context attributes.
please suggest where is the mistake.