SAP ABAP 文件操作函数大全

Working With Files

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Created by Xinpeng Lin, last modified by Gregor Wolf on Feb 09, 2016

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Author: Xinpeng Lin

Submitted: 11.9.2007

This Code Snippets will clarify some general process of working with files when ABAP programmming. Such as,Uploading/Downloading files from/to Application/Presentation server, adding F4 help to file path on the selection-screen,checking file existence.

Check File Existence

Before we process the file which is input on the selection screen by end-user, we need to check whether this file exists or not. If it does not exist, we just give an error message and need not to go into the main

program .This logic should be done within the event 'AT SELECTION-SCREEN'.

presentation server file

For the presentation server file,here intruduce 2 ways, one is Function Module, the other is Class Static Method.

1. Using Funciton Moudle 'DX_FILE_EXISTENCE_CHECK'.

DATA: gdf_file_exist(1) TYPE c.

PARAMETERS p_file TYPE dxfile-filename.

AT SELECTION-SCREEN.

CALL FUNCTION 'DX_FILE_EXISTENCE_CHECK'

EXPORTING

filename = p_file

pc = 'X'

* SERVER =

IMPORTING

file_exists = gdf_file_exist.

IF NOT ( sy-subrc = 0 and gdf_file_exist = 'X' )

MESSAGE 'the input file does not exist.' TYPE 'E'.

ENDIF.

Pay attention to the importing parameter 'pc', it should be set as 'X'.

2. Using Class Static Method 'CL_GUI_FRONTEND_SERVICES=>FILE_EXIST'

DATA: gdf_file_exist(1) TYPE c.

PARAMETERS p_file TYPE dxfile-filename.

AT SELECTION-SCREEN.

CALL METHOD cl_gui_frontend_services=>file_exist

EXPORTING

file = p_file

RECEIVING

result = gdf_file_exist.

IF NOT ( sy-subrc = 0 and gdf_file_exist = 'X' )

MESSAGE 'the input file does not exist.' TYPE 'E'.

ENDIF.

application server file

For application server file, generally we open it first within the event 'AT SELECTION-SCREEN'.If it can be opened successfully, this file exists. After open,do not forget to close it.

PARAMETERS p_file TYPE dxfile-filename.

AT SELECTION-SCREEN.

OPEN DATASET p_file FOR INPUT IN TEXT MODE ENCODING DEFAULT.

IF sy-subrc = 0.

CLOSE DATASET p_file.

ELSE.

MESSAGE 'the input file does not exist.' TYPE 'E'.

ENDIF.

There is also a Function Module can be used, named 'OCS_GET_FILE_INFO'.

DATA: gdt_ocs_file TYPE TABLE OF ocs_file.

PARAMETERS p_file TYPE dxfile-filename.

AT SELECTION-SCREEN.

CALL FUNCTION 'OCS_GET_FILE_INFO'

EXPORTING

dir_name = p_file

file_name = '*'

TABLES

dir_list = gdt_ocs_file. Importing parameter 'file_name' is set as '*' means all the file in the specfied directory will be get and stored in the internal table 'gdt_ocs_file'. If the input file is included in the internal table, this file exists.

Add F4 Help

Adding one F4 Help to the file path on the selection-screen will be very helpful to the end-user.The logic should be under the event 'ON VALUE-REQUEST'.

presentation server file

For the presentation server file,here intruduce 2 ways, one is Function Module, the other is Class Static Method.

1. Using Funciton Module 'F4_FILENAME'.

PARAMETERS p_file TYPE dxfile-filename.

AT SELECTION-SCREEN ON VALUE-REQUEST FOR p_file.

CALL FUNCTION 'F4_FILENAME'

* EXPORTING

* PROGRAM_NAME =

* DYNPRO_NUMBER =

* FIELD_NAME =

IMPORTING

file_name = p_file.

2. Using Class Static Method 'CL_GUI_FRONTEND_SERVICES=>FILE_OPEN_DIALOG'.

DATA: gdt_filetable TYPE filetable.

DATA: gdf_rc TYPE I.

PARAMETERS p_file TYPE dxfile-filename.

AT SELECTION-SCREEN ON VALUE-REQUEST FOR p_file.

CALL METHOD cl_gui_frontend_services=>file_open_dialog

EXPORTING

WINDOW_TITLE = 'Choose a file'

CHANGING

file_table = gdt_filetable

rc = gdf_rc.

IF sy-subrc = 0.

READ TABLE gdt_filetable

INTO gds_filetable INDEX 1.

p_file = gds_filetable-filename.

ENDIF.

gdf_rc is the number of selected file, if it is equal -1, error occured.

application server file

Generally it need not to provide F4 help for application server file. If we want it, there is also a Funciotn Module which can be used.

PARAMETERS p_file TYPE dxfile-filename.

AT SELECTION-SCREEN ON VALUE-REQUEST FOR p_file.

CALL FUNCTION 'F4_DXFILENAME_4_DYNP'

EXPORTING

dynpfield_filename = 'P_FILE'

dyname = sy-repid

dynumb = sy-dynnr

filetype = 'P'

location = 'A'

server = ' '. filetype: 'P' represents Physical file name; 'L' represents Logical file name.

location: 'A' represents Application Server; 'P' represents Presentation server.

Download Files

Sometimes we need to save the internal table data as a file for the further process.For download to

presentation server and download to application server,they are 2 different kinds of process methods.

to presentation server

When storing internal table data as a local file on the presentation server, there are 2 methods we can use.

One is using the function modeule, the other is using the class static method.

1. Using Function Module 'GUI_DOWNLOAD'.

DATA: gdf_filepath type dxfile-filename

DATA: gdt_data type table of gts_data.

START-OF-SELECTION.

gdf_filepath = 'C:\mydata.txt'.

CALL FUNCTION 'GUI_DOWNLOAD'

EXPORTING

filename = gdf_filepath

filetype = 'ASC'

write_field_separator = 'X'

TABLES

data_tab = gdt_data.

filetype is set by 'X' mens separating columns by Tabs in case of ASCII download.

If sy-subrc is equal 0, file downloading is successful.

2. Using class static method 'CL_GUI_FRONTEND_SERVICES =>GUI_DOWNLOAD'

DATA: gdf_filepath type dxfile-filename

DATA: gdt_data type table of gts_data.

START-OF-SELECTION.

gdf_filepath = 'C:\mydata.txt'.

CALL METHOD cl_gui_frontend_services=>gui_download

EXPORTING

filename = gdf_filepath

filetype = 'ASC'

write_field_separator = 'X'

CHANGING

data_tab = gdt_data.

filetype is set by 'X' mens separating columns by Tabs in case of ASCII download.

If sy-subrc is equal 0, file downloading is successful.

to application server

If we want to save the internal table data to the application server, there is no function module or class static

method which we can use, we must wirte the code by ourselves.

DATA: gdf_filepath type dxfile-filename

DATA: gdt_data type table of gts_data.

DATA: ldf_length type i.

FIELD-SYMBOLS: TYPE gts_data

START-OF-SELECTION.

gdf_filepath = 'C:\mydata.txt'.

OPEN DATASET gdf_filepath FOR OUTPUT IN TEXT MODE ENCODING DEFAULT.

LOOP AT prt_data ASSIGNING .

DESCRIBE FIELD LENGTH ldf_length IN BYTE MODE.

TRANSFER TO prf_file LENGTH ldf_length.

ENDLOOP.

CLOSE DATASET gdf_filepath.

The prerequsite is the field of prt_data must be character type.

Using this method, every field column will output as the length defined,without separator.

If we want field columns are separated by tab, we can realize it as below.

DATA: gdf_filepath type dxfile-filename

DATA: gdt_data type table of gts_data.

DATA: ldf_length type i.

FIELD-SYMBOLS: TYPE gts_data

START-OF-SELECTION.

gdf_filepath = 'C:\mydata.txt'.

OPEN DATASET gdf_filepath FOR OUTPUT IN TEXT MODE ENCODING DEFAULT.

LOOP AT prt_data ASSIGNING .

CONCATENATE -BUKRS

...

INTO LDF_OUTDATA

SEPARATED BY

CL_ABAP_CHAR_UTILITIES=>HORIZON

TRANSFER LDF_OUTDATA TO gdf_filepath.

ENDLOOP.

CLOSE DATASET gdf_filepath.

Upload Files

Sometimes we need to upload the file data to the internal table first, and then process it.For upload from

presentation server and upload from application server,they are 2 different kinds of process methods.

from presentation server

When we upload a file data from presentation server to the internal table, there are 2 method that we can choose.One is using the Function Moduel, the other is using the class static method.

1. Using function module 'GUI_UPLOAD'.

DATA: gdt_filedata TYPE TABLE OF gts_filedata.

PARAMETERS p_file TYPE dxfile-filename.

START-OF-SELECTION.

CALL FUNCTION 'GUI_UPLOAD'

EXPORTING

filename = p_file

has_field_separator = 'X'

TABLES

data_tab = gdt_filedata. parameter has_field_separator is set as 'X' means columns separated by tabs in case of ASCII upload.

2. Using the class tatic method 'CL_GUI_FRONTEND_SERVICES =>GUI_UPLOAD'.

DATA: gdt_filedata TYPE TABLE OF gts_filedata.

PARAMETERS p_file TYPE dxfile-filename.

START-OF-SELECTION.

CALL METHOD cl_gui_frontend_services=>gui_upload

EXPORTING

filename = p_file

has_field_separator = 'X'

CHANGING

data_tab = prt_table.

parameter 'has_field_separator' is set as 'X' means columns separated by tabs in case of ASCII upload. from application server

If we want to upload file data from the application server to the internal table, there is no function module or class static method which we can use, we must wirte the code by ourselves.

1. For the file data which has no seperator between field columns.

PARAMETERS p_file TYPE dxfile-filename.

START-OF-SELECTION.

OPEN DATASET p_file IN TEXT MODE ENCODING DEFAULT FOR INPUT.

DO.

READ DATASET p_file INTO gds_data.

IF sy-subrc <> 0.

EXIT.

ENDIF.

APPEND gds_data TO gdt_data.

ENDDO.

CLOSE DATASET p_file.

2. For the file data which has tab separator between field columns.

DATA: gds_field_split type gts_data.

FIELD-SYMBOLS: TYPE gts_data.

PARAMETERS p_file TYPE dxfile-filename.

START-OF-SELECTION.

OPEN DATASET prf_file IN TEXT MODE ENCODING DEFAULT FOR INPUT.

DO.

READ DATASET p_file INTO gds_field.

SPLIT gds_field AT cl_abap_char_utilities=>horizontal_tab

INTO TABLE gdt_field_split.

LOOP AT gdt_field_split into gds_field_split.

gdf_index = gdf_index + 1.

ASSIGN COMPONENT gdf_index OF STRUCTURE

gds_data to .

IF sy-subrc = 0.

= gds_field_split.

ENDIF.

ENDLOOP.

APPEND gds_data TO gdt_data.

ENDDO.

CLOSE DATASET p_file.