Application log（应用日志）是SAP内部用于记录application运行的事件日志，通常可用作message collector。 - 在Package SZAL下，SAP提供了一系列的标准函数，通过复用这些函数，可以轻松地根据项目需求，实现application log的创建、保存、查询、删改等功能。通常，在3.0 release的版本中的SAP的application log相关的Function Modle 以APPL_LOG_*开始；Function Module以BAL_*为前缀从Release 4.6开始。
常用的transaction -
SLG0: 创建Application Log的Object 和sub-object, 一个object下，可以有多个sub-object。在程序中保存log时，会指定具体保存在哪个object上。 SLG1: 查看Application log SLGD: 查看Application log（详细的筛选条件）
常用的的3个function module：
BAL_LOG_CREATE：创建 BAL_LOG_MSG_ADD: 写入一条log BAL_DSP_LOG_DISPLAY: 显示log 常用的demo程序：
SBAL_DEMO_06 (最简单的create，save, delete) SBAL_DEMO_04 (花式display log): log可以display成不同的样式，例如单条log，多条log，树状显示，层级显示等等。 显示多条Log
多层级记录Log
在某个sub-screen中显示Log
***********************************************************************
******************** SELECTION SCREEN *********************************
***********************************************************************
PARAMETERS:
p_create RADIOBUTTON GROUP par,
p_disp RADIOBUTTON GROUP par,
p_delete RADIOBUTTON GROUP par.
***********************************************************************
******************** CONSTANTS, TYPES, DATA ***************************
***********************************************************************
SET EXTENDED CHECK OFF.
INCLUDE sbal_constants.
SET EXTENDED CHECK ON.
TABLES:
bal_indx.
CONSTANTS:
const_example_object TYPE bal_s_log-object VALUE 'BCT1',
const_example_extnumber TYPE bal_s_log-extnumber VALUE 'BAL_INDX',
const_name_msg_ident(9) TYPE c VALUE 'MSG_IDENT'.
DATA:
g_identifier(10) TYPE n,
g_lognumber TYPE balhdr-lognumber.
* these are our own data we want to save with the application log:
DATA:
g_my_header_data TYPE bal_s_ex05 OCCURS 0 WITH HEADER LINE,
BEGIN OF g_my_message_data OCCURS 0,
identifier LIKE g_identifier,
t_my_data TYPE bal_s_ex06 OCCURS 0,
END OF g_my_message_data.
***********************************************************************
******************** MAIN PROGRAM *************************************
***********************************************************************
END-OF-SELECTION.
* create log
IF NOT p_create IS INITIAL.
PERFORM log_create.
ENDIF.
* display log
IF NOT p_disp IS INITIAL.
PERFORM log_display.
ENDIF.
* delete log
IF NOT p_delete IS INITIAL.
PERFORM log_delete.
ENDIF.
***********************************************************************
************** FORMS FOR CREATION OF THE LOG *************************
***********************************************************************
*--------------------------------------------------------------------
* FORM log_create.
*--------------------------------------------------------------------
FORM log_create.
DATA:
l_log_handle TYPE balloghndl.
* create log header with information about the carriers and
* connection which are calculated in this transaction
PERFORM log_header_create
CHANGING
l_log_handle.
* create the message
PERFORM log_message_create
USING
l_log_handle.
* save the application log and our data
PERFORM log_save
USING
l_log_handle.
ENDFORM.
*--------------------------------------------------------------------
* FORM log_header_create
*--------------------------------------------------------------------
FORM log_header_create
CHANGING
c_log_handle TYPE balloghndl.
DATA:
l_s_log TYPE bal_s_log.
* create log header data
CLEAR l_s_log.
l_s_log-object = const_example_object.
l_s_log-extnumber = const_example_extnumber.
* define callback routine
l_s_log-params-callback-userexitp = sy-repid.
l_s_log-params-callback-userexitf = 'CALLBACK_LOG_DETAIL'.
l_s_log-params-callback-userexitt = const_callback_form.
* create the log header
CALL FUNCTION 'BAL_LOG_CREATE'
EXPORTING
i_s_log = l_s_log
IMPORTING
e_log_handle = c_log_handle
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.
* we want to store some information in the log header
* to describe which carriers and flight were handled in this log
g_my_header_data-carrid = 'AB'. "#EC NOTEXT
g_my_header_data-txt_carrid = 'Airways AB'. "#EC NOTEXT
g_my_header_data-connid = '0003'."#EC NOTEXT
g_my_header_data-txt_connid = 'Hamburg - New York'(001).
APPEND g_my_header_data.
g_my_header_data-carrid = 'XY'. "#EC NOTEXT
g_my_header_data-txt_carrid = 'XY Lines'. "#EC NOTEXT
g_my_header_data-connid = '0002'."#EC NOTEXT
g_my_header_data-txt_connid = 'Walldorf - Tokio'(002).
APPEND g_my_header_data.
g_my_header_data-carrid = 'ZZ'. "#EC NOTEXT
g_my_header_data-txt_carrid = 'ZZ Wings'. "#EC NOTEXT
g_my_header_data-connid = '0014'."#EC NOTEXT
g_my_header_data-txt_connid = 'Paris - Frankfurt'(003).
APPEND g_my_header_data.
ENDFORM.
*--------------------------------------------------------------------
* FORM log_message_create
*--------------------------------------------------------------------
FORM log_message_create
USING
i_log_handle TYPE balloghndl.
DATA:
l_s_msg TYPE bal_s_msg,
l_s_par TYPE bal_s_par,
l_s_my_data TYPE bal_s_ex06.
* create a message
* 327(BL): "&1 customers were allowed to fly for free (see detail)"
CLEAR l_s_msg.
l_s_msg-msgty = 'E'.
l_s_msg-msgid = 'BL'.
l_s_msg-msgno = '327'.
l_s_msg-msgv1 = '3'.
* define callback routine
l_s_msg-params-callback-userexitp = sy-repid.
l_s_msg-params-callback-userexitf = 'CALLBACK_MSG_DETAIL'.
l_s_msg-params-callback-userexitt = const_callback_form.
* define an identifer. This is used to establish the link between
* the message and its additional data
ADD 1 TO g_identifier.
* put his identifier into the parameters of the message
l_s_par-parname = const_name_msg_ident.
l_s_par-parvalue = g_identifier.
APPEND l_s_par TO l_s_msg-params-t_par.
* create the message
CALL FUNCTION 'BAL_LOG_MSG_ADD'
EXPORTING
i_log_handle = i_log_handle
i_s_msg = l_s_msg
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.
* we want to store information for this message about the customers
* which were allowed to fly for free:
g_my_message_data-identifier = g_identifier.
l_s_my_data-id = '00000002'.
l_s_my_data-txt_id = 'Peter Smith'. "#EC NOTEXT
APPEND l_s_my_data TO g_my_message_data-t_my_data.
l_s_my_data-id = '00000013'.
l_s_my_data-txt_id = 'Paula Jones'. "#EC NOTEXT
APPEND l_s_my_data TO g_my_message_data-t_my_data.
l_s_my_data-id = '00001345'.
l_s_my_data-txt_id = 'Jane Meyer'. "#EC NOTEXT
APPEND l_s_my_data TO g_my_message_data-t_my_data.
APPEND g_my_message_data.
ENDFORM.
*--------------------------------------------------------------------
* FORM log_save
*--------------------------------------------------------------------
FORM log_save
USING
i_log_handle TYPE balloghndl.
DATA:
l_t_log_handle TYPE bal_t_logh,
l_s_new_lognumber TYPE bal_s_lgnm,
l_t_new_lognumbers TYPE bal_t_lgnm.
* save this log
INSERT i_log_handle INTO TABLE l_t_log_handle.
CALL FUNCTION 'BAL_DB_SAVE'
EXPORTING
i_t_log_handle = l_t_log_handle
IMPORTING
e_new_lognumbers = l_t_new_lognumbers
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.
* find out the lognumber of this saved log
READ TABLE l_t_new_lognumbers INTO l_s_new_lognumber
WITH KEY log_handle = i_log_handle.
CHECK sy-subrc = 0.
g_lognumber = l_s_new_lognumber-lognumber.
* also save our own, complex data:
EXPORT g_my_header_data g_my_message_data
TO DATABASE bal_indx(al)
ID g_lognumber.
ENDFORM.
***********************************************************************
************** FORMS FOR DISPLAY OF THE LOG **************************
***********************************************************************
*--------------------------------------------------------------------
* FORM log_display
*--------------------------------------------------------------------
FORM log_display.
DATA:
l_s_log_filter TYPE bal_s_lfil,
l_s_obj TYPE bal_s_obj,
l_s_extn TYPE bal_s_extn,
l_t_log_header TYPE balhdr_t.
* create filter to search for this log on db
CLEAR l_s_log_filter-object.
CLEAR l_s_obj.
l_s_obj-sign = 'I'.
l_s_obj-option = 'EQ'.
l_s_obj-low = const_example_object.
APPEND l_s_obj TO l_s_log_filter-object.
CLEAR l_s_extn.
l_s_extn-sign = 'I'.
l_s_extn-option = 'EQ'.
l_s_extn-low = const_example_extnumber.
APPEND l_s_extn TO l_s_log_filter-extnumber.
* search for this log
CALL FUNCTION 'BAL_DB_SEARCH'
EXPORTING
i_s_log_filter = l_s_log_filter
IMPORTING
e_t_log_header = l_t_log_header
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.
* load these messages into memory
CALL FUNCTION 'BAL_DB_LOAD'
EXPORTING
i_t_log_header = l_t_log_header
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.
* show this log:
* - we do not specify the display profile I_DISPLAY_PROFILE since
* we want to use the standard profile
* - we do not specify any filter (like I_S_LOG_FILTER, ...,
* I_T_MSG_HANDLE) since we want to display all messages available
CALL FUNCTION 'BAL_DSP_LOG_DISPLAY'
* EXPORTING
* I_S_LOG_FILTER =
* I_T_LOG_CONTEXT_FILTER =
* I_S_MSG_FILTER =
* I_T_MSG_CONTEXT_FILTER =
* I_T_LOG_HANDLE =
* I_T_MSG_HANDLE =
* I_S_DISPLAY_PROFILE =
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.
ENDFORM.
*--------------------------------------------------------------------
* FORM CALLBACK_LOG_DETAIL
*--------------------------------------------------------------------
FORM callback_log_detail "#EC CALLED
TABLES
i_params STRUCTURE spar.
* load my specififc data from database
PERFORM load_my_data
TABLES
i_params.
* display header data
CALL FUNCTION 'REUSE_ALV_LIST_DISPLAY'
EXPORTING
i_structure_name = 'BAL_S_EX05'
i_screen_start_column = 1
i_screen_start_line = 1
i_screen_end_column = 80
i_screen_end_line = 10
TABLES
t_outtab = g_my_header_data
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.
ENDFORM.
*--------------------------------------------------------------------
* FORM CALLBACK_MSG_DETAIL
*--------------------------------------------------------------------
FORM callback_msg_detail "#EC CALLED
TABLES
i_params STRUCTURE spar.
DATA:
l_my_message_data TYPE bal_s_ex06 OCCURS 0.
* load my specififc data from database
PERFORM load_my_data
TABLES
i_params.
* find out the identifier for this message
READ TABLE i_params WITH KEY param = const_name_msg_ident.
CHECK sy-subrc = 0.
g_identifier = i_params-value.
* search for those entries which belong to thgis message
READ TABLE g_my_message_data WITH KEY identifier = g_identifier.
CHECK sy-subrc = 0.
l_my_message_data = g_my_message_data-t_my_data.
* display header data
CALL FUNCTION 'REUSE_ALV_LIST_DISPLAY'
EXPORTING
i_structure_name = 'BAL_S_EX06'
i_screen_start_column = 1
i_screen_start_line = 1
i_screen_end_column = 80
i_screen_end_line = 10
TABLES
t_outtab = l_my_message_data
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.
ENDFORM.
*--------------------------------------------------------------------
* FORM LOAD_MY_DATA
*--------------------------------------------------------------------
FORM load_my_data
TABLES
i_params STRUCTURE spar.
DATA:
l_lognumber TYPE balhdr-lognumber.
* find out the log number of this log which is displayed
* (this number is automatically added by the display module)
READ TABLE i_params WITH KEY param = bal_param_lognumber.
IF sy-subrc = 0.
l_lognumber = i_params-value.
ENDIF.
* when number has changed, load these data
IF g_lognumber NE l_lognumber.
g_lognumber = l_lognumber.
IMPORT g_my_header_data g_my_message_data
FROM DATABASE bal_indx(al)
ID g_lognumber.
IF sy-subrc NE 0.
CLEAR:
g_my_header_data[],
g_my_message_data[].
ENDIF.
ENDIF.
ENDFORM.
***********************************************************************
************** FORMS FOR DELETION OF THE LOG *************************
***********************************************************************
*--------------------------------------------------------------------
* FORM log_delete
*--------------------------------------------------------------------
FORM log_delete.
DATA:
l_s_log_filter TYPE bal_s_lfil,
l_s_obj TYPE bal_s_obj,
l_s_extn TYPE bal_s_extn,
l_t_log_header TYPE balhdr_t.
* create filter to search for this log on db
CLEAR l_s_log_filter-object.
CLEAR l_s_obj.
l_s_obj-sign = 'I'.
l_s_obj-option = 'EQ'.
l_s_obj-low = const_example_object.
APPEND l_s_obj TO l_s_log_filter-object.
CLEAR l_s_extn.
l_s_extn-sign = 'I'.
l_s_extn-option = 'EQ'.
l_s_extn-low = const_example_extnumber.
APPEND l_s_extn TO l_s_log_filter-extnumber.
* search for this log
CALL FUNCTION 'BAL_DB_SEARCH'
EXPORTING
i_s_log_filter = l_s_log_filter
IMPORTING
e_t_log_header = l_t_log_header
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.
* delete these logs
CALL FUNCTION 'BAL_DB_DELETE'
EXPORTING
i_t_logs_to_delete = l_t_log_header
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.
ENDFORM.
