在sap里有GUI_DOWNLOAD 函数将sap的数据下载到客户端机器(presentation server),而Dataset则是将数据传输到应用服务器(Application server)。然而在有些时候需要将数据传输到第三方其他系统(3rd Party System),这是我们就可以使用FTP命令来完成数据传输。
1、相关函数
HTTP_SCRAMBLE
FTP_CONNECT
FTP_R3_TO_SERVER
FTP_DISCONNECT
RFC_CONNECTION_CLOSE 
2、函数说明
HTTP_SCRAMBLE: 将密码转化为SAP的格式
样例代码
l_pwd = p_pwd.
l_slen = STRLEN( l_pwd ).
CALL FUNCTION 'HTTP_SCRAMBLE'
exporting
  source = l_pwd
  sourcelen = l_slen
  key = c_key
importing
  destination = l_pwd.
FTP_CONNECT : 连接其他系统
* To Connect to the Server using FTP
样例代码
CALL FUNCTION 'FTP_CONNECT'
EXPORTING
  user = p_user
  password = l_pwd
  host = p_host
  rfc_destination = c_dest 
IMPORTING
  handle = w_hdl
EXCEPTIONS
  OTHERS = 1.
IF sy-subrc <> 0.
  MESSAGE ID sy-msgid TYPE sy-msgty NUMBER sy-msgno
  WITH sy-msgv1 sy-msgv2 sy-msgv3 sy-msgv4.
ENDIF.
FTP_R3_TO_SERVER: 将SAP的内表数据按字符方式传输到其他系统.
样例代码
CALL FUNCTION 'FTP_R3_TO_SERVER'
EXPORTING
  handle = w_hdl
  fname = <file path of destination system>
  character_mode = 'X'
TABLES
  text = <internal table data>
EXCEPTIONS
  tcpip_error = 1
  command_error = 2
  data_error = 3
OTHERS = 4.
IF sy-subrc <> 0.
  MESSAGE ID sy-msgid TYPE sy-msgty NUMBER sy-msgno
  WITH sy-msgv1 sy-msgv2 sy-msgv3 sy-msgv4
  RAISING invalid_output_file.
ENDIF.
FTP_DISCONNECT: 关闭SAP与其他系统的连接.
样例代码
* To disconnect the FTP
CALL FUNCTION 'FTP_DISCONNECT'
EXPORTING
  handle = w_hdl.
RFC_CONNECTION_CLOSE:关闭SAP与其他系统的RFC连接.
样例代码
CALL FUNCTION 'RFC_CONNECTION_CLOSE'
EXPORTING
  destination = c_dest
EXCEPTIONS
OTHERS = 1.
3、SAP的样例代码
report rsftp004.
parameters: suser(30) type c lower case,
            spwd(30) type c lower case,
            shost(64) type c lower case,
            duser(30) type c lower case,
            dpwd(30) type c lower case,
            dhost(64) type c lower case,
            lines type i default 1000,
            pasv.
selection-screen skip 1.
parameters: dest like rfcdes-rfcdest default 'SAPFTP'.
types: begin of text,
       line(120) type c,
       end of text.
types: begin of blob,
       line(80) type x,
       end of blob.
data: shdl type i,
      dhdl type i,
      key type i value 26101957,
      slen type i,
      bline(80) type x,
      sdocid like sysuuid-c,
      ddocid like sysuuid-c,
      blob_length type i,
      cmd(120),
      error.
data: result type table of text with header line,
      bindata type table of blob with header line.
* Create data
set extended check off.
error = 0.
bline = '0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F' &
        '0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F' &
        '0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F' &
        '0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F'.
do lines times.
  bindata-line = bline.
  append bindata.
enddo.
call function 'SYSTEM_UUID_C_CREATE'
  importing
    uuid = sdocid.
call function 'SYSTEM_UUID_C_CREATE'
  importing
    uuid = ddocid.
* connect to ftp server - source
slen = strlen( spwd ).
call function 'HTTP_SCRAMBLE'
  exporting
    source      = spwd
    sourcelen   = slen
    key         = key
  importing
    destination = spwd.
call function 'SAPGUI_PROGRESS_INDICATOR'
  exporting
    text = 'Connect to FTP Server - Source'.
call function 'FTP_CONNECT'
  exporting
    user            = suser
    password        = spwd
    host            = shost
    rfc_destination = dest
  importing
    handle          = shdl.
* connect to ftp server - destination
slen = strlen( dpwd ).
call function 'HTTP_SCRAMBLE'
  exporting
    source      = dpwd
    sourcelen   = slen
    key         = key
  importing
    destination = dpwd.
call function 'SAPGUI_PROGRESS_INDICATOR'
  exporting
    text = 'Connect to FTP Server - Destination'.
call function 'FTP_CONNECT'
  exporting
    user            = duser
    password        = dpwd
    host            = dhost
    rfc_destination = dest
  importing
    handle          = dhdl.
if not pasv is initial.
  refresh result.
  call function 'FTP_COMMAND'
    exporting
      handle        = shdl
      command       = 'set passive on'
    tables
      data          = result
    exceptions
      tcpip_error   = 1
      command_error = 2
      data_error    = 3.
  if sy-subrc eq 0.
    write: / 'Set passive mode - Source'.
  endif.
refresh result.
  call function 'FTP_COMMAND'
    exporting
      handle        = dhdl
      command       = 'set passive on'
    tables
      data          = result
    exceptions
      tcpip_error   = 1
      command_error = 2
      data_error    = 3.
  if sy-subrc eq 0.
    write: / 'Set passive mode - Destination'.
  endif.
  skip 1.
endif.
* Create file on Source
blob_length = lines * 80.
call function 'SAPGUI_PROGRESS_INDICATOR'
  exporting
    text = 'Create File on Source'.
call function 'FTP_R3_TO_SERVER'
  exporting
    handle      = shdl
    fname       = sdocid
    blob_length = blob_length
  tables
    blob        = bindata.
* Copy Files
call function 'SAPGUI_PROGRESS_INDICATOR'
  exporting
    text = 'Copy File to Destination'.
refresh result.
call function 'FTP_COPY'
  exporting
    handle_source      = shdl
    handle_destination = dhdl
    file_source        = sdocid
    file_destination   = ddocid
  tables
    data               = result
  exceptions
    tcpip_error        = 1
    command_error      = 2
    data_error         = 3
    others             = 4.
if sy-subrc ne 0. error = 1. endif.
loop at result.
  write / result-line.
endloop.
* compare content
if error eq 0.
  call function 'SAPGUI_PROGRESS_INDICATOR'
    exporting
      text = 'Compare Content'.
  skip 1.
  refresh bindata.
  call function 'FTP_SERVER_TO_R3'
    exporting
      handle      = shdl
      fname       = sdocid
    importing
      blob_length = blob_length
    tables
      blob        = bindata.
slen = lines * 80.
  if slen ne blob_length.
    error = 1.
    write: / 'Length error - expected',slen,'received',blob_length.
  else.
    loop at bindata.
      if bindata-line ne bline.
        slen = sy-tabix * 80.
        write: / 'Content error at',slen,bindata-line.
        error = 1.
        exit.
      endif.
    endloop.
  endif.
refresh bindata.
  call function 'FTP_SERVER_TO_R3'
    exporting
      handle      = dhdl
      fname       = ddocid
    importing
      blob_length = blob_length
    tables
      blob        = bindata.
slen = lines * 80.
  if slen ne blob_length.
    error = 1.
    write: / 'Length error - expected',slen,'received',blob_length.
  else.
    loop at bindata.
      if bindata-line ne bline.
        slen = sy-tabix * 80.
        write: / 'Content error at',slen,bindata-line.
        error = 1.
        exit.
      endif.
    endloop.
  endif.
  if error eq 0.
    write: / 'Content compare OK'.
  else.
    write: / 'Content compare error'.
  endif.
  skip 1.
endif.
* Delete
concatenate 'del' sdocid into cmd separated by ' '.
refresh result.
call function 'SAPGUI_PROGRESS_INDICATOR'
  exporting
    text = 'Delete Files'.
call function 'FTP_COMMAND'
  exporting
    handle        = shdl
    command       = cmd
  tables
    data          = result
  exceptions
    tcpip_error   = 1
    command_error = 2
    data_error    = 3.
loop at result.
  write / result-line.
endloop.
concatenate 'del' ddocid into cmd separated by ' '.
refresh result.
call function 'FTP_COMMAND'
  exporting
    handle        = dhdl
    command       = cmd
  tables
    data          = result
  exceptions
    tcpip_error   = 1
    command_error = 2
    data_error    = 3.
loop at result.
  write / result-line.
endloop.
* Disconnect
call function 'FTP_DISCONNECT'
  exporting
    handle = shdl.
call function 'FTP_DISCONNECT'
  exporting
    handle = dhdl.
call function 'RFC_CONNECTION_CLOSE'
  exporting
    destination = dest
  exceptions
    others = 1.
if error ne 0.
  format color col_negative.
  write: / 'Error im Test'.
else.
  format color col_positive.
  write: / ' Test OK'.
endif.
* password not visible
at selection-screen output.
  loop at screen.
    if screen-name = 'SPWD' or screen-name = 'DPWD'.
      screen-invisible = '1'.
      modify screen.
    endif.
  endloop.