使用 BAPI_ACC_DOCUMENT_POST 的时候，如果有些字段在 Tables 参数中没有，比如，现在大家都用 Reason code 来作为现金流量表的实现方案。但 BAPI_ACC_DOCUMENT_POST 的 accountgl 参数是没有原因代码这个字段的。这种情况下，如何能在导入凭证的时候，包括这个字段呢？
定义一个结构，包括 POSNR (类型为 POSNR_ACC ) 和 RSTGR (原因代码) 两个字段。POSNR 这个字段必须有，因为 BAPI_ACC_DOCUMENT_POST 包含多个 tables 参数，需要行项目号来关联。比如第一行 #1 的总账科目、金额、extension2 等。
SE19 实现 BADI 增强 ACC_DOCUMENT，这个增强是用来将 BAPI_ACC_DOCUMENT_POST 参数表EXTENSION2 传入系统表 ACCIT。只需要实现 change 方法
在 BAPI_ACC_DOCUMENT_POST 中，启用 extension2 参数，将扩展字段传入
事务码 SE11 定义一个结构 zext2，包括 POSNR (类型为 POSNR_ACC ) 和 RSTGR (原因代码) 两个字段。
SE19，使用 Classical BADI，BADI name 为 ACC_DOCUMENT，点击 Create 按钮。
系统弹出如下对话框，输入 implementation name:
点击确认后，进入如下界面。下面有一个 Filter values，添加一行，选择 BKPFF，表示这个 BADI 实现只适用于会计凭证直接输入。
点击激活按钮，系统提示 migrate 到 New Badi。并弹出如下对话框
我们不选择已有的 Enhancement Implementation，自己新建一个。Composite Enhancement Implementation 留空。
确认后，系统提示 Activate 成功。点击界面上的 Interface 按钮，可以看到，这个 BADI 的实现有两个方法，其中 CHANGE 方法就是我们需要实现的方法。
这个方法可以从 Example implementation class 拷贝，完全不用改动。
method if_ex_acc_document~change.
data: wa_extension type bapiparex,
ext_value(960) type c,
wa_accit type accit,
l_ref type ref to data.
field-symbols: <l_struc> type any,
<l_field> type any.
sort c_extension2 by structure.
loop at c_extension2 into wa_extension.
at new structure.
create data l_ref type (wa_extension-structure).
assign l_ref->* to <l_struc>.
endat.
concatenate wa_extension-valuepart1 wa_extension-valuepart2
wa_extension-valuepart3 wa_extension-valuepart4
into ext_value.
move ext_value to <l_struc>.
assign component 'POSNR' of structure <l_struc> to <l_field>.
read table c_accit with key posnr = <l_field>
into wa_accit.
if sy-subrc is initial.
move-corresponding <l_struc> to wa_accit.
modify c_accit from wa_accit index sy-tabix.
endif.
endloop.
endmethod.
BAPI_ACC_DOCUMENT_POST 使用 extension2 参数接收传入的自定义结构
data: l_extname type string value 'ZEXT2'.
data: extension2 type standard table of bapiparex with header line,
gs_zext2 like zext2.
form populate_extension2.
" first line
clear gs_zext2.
gs_zext2-posnr = '1'.
gs_zext2-rstgr = 'A01'.
clear extension2.
extension2-structure = l_extname.
extension2-valuepart1 = gs_zext2.
append extension2.
" second line
clear gs_zext2.
gs_zext2-posnr = '2'.
gs_zext2-rstgr = 'A01'.
clear extension2.
extension2-structure = l_extname.
extension2-valuepart1 = gs_zext2.
append extension2.
endform.
在 BAPI 中使用 extension2 参数：
call function 'BAPI_ACC_DOCUMENT_POST'
exporting
documentheader = docheader
tables
accountgl = accountgl
currencyamount = currencyamount
extension2 = extension2
return = return.
最后给出完整代码
report zbapi_acc_doc_post_test.
data:
docheader like bapiache09, " structure of document header
accountgl like bapiacgl09 occurs 0 with header line, " internal table for glaccounts
currencyamount like bapiaccr09 occurs 0 with header line, " internal table for currency
return like bapiret2 occurs 0 with header line. " internal table for return
" Extension2
data: extension2 type standard table of bapiparex with header line,
gs_zext2 like zext2.
" Populate required values
data: l_cocd type bukrs value 'Z900',
l_curr type bapiaccr09-currency value 'CNY',
l_doctype type bapiache09-doc_type value 'SA',
l_extname type string value 'ZEXT2'.
start-of-selection.
perform populate_doc_header.
perform populate_gl_accounts.
perform populate_currency_amt.
perform populate_extension2.
perform generate_fi_document.
form populate_doc_header.
clear docheader.
docheader-username = sy-uname.
docheader-header_txt = 'Test FI doc using BAPI'.
docheader-comp_code = l_cocd. " company code
docheader-doc_date = sy-datum.
docheader-pstng_date = sy-datum.
docheader-doc_type = l_doctype.
endform.
form populate_gl_accounts.
clear accountgl.
accountgl-itemno_acc = '1'.
accountgl-gl_account = '0010010100'.
accountgl-comp_code = l_cocd.
accountgl-pstng_date = sy-datum.
accountgl-doc_type = l_doctype.
accountgl-item_text = '银行取现'.
append accountgl.
clear accountgl.
accountgl-itemno_acc = '2'.
accountgl-gl_account = '0010020100'.
accountgl-comp_code = l_cocd.
accountgl-pstng_date = sy-datum.
accountgl-value_date = sy-datum.
accountgl-doc_type = l_doctype.
accountgl-item_text = '银行取现'.
append accountgl.
endform.
form populate_currency_amt.
clear currencyamount.
currencyamount-itemno_acc = '1'.
currencyamount-currency = l_curr.
currencyamount-amt_doccur = '100.00'.
append currencyamount.
clear currencyamount.
currencyamount-itemno_acc = '2'.
currencyamount-currency = l_curr.
currencyamount-amt_doccur = '-100.00'.
append currencyamount.
endform.
form populate_extension2.
clear gs_zext2.
gs_zext2-posnr = '1'.
gs_zext2-rstgr = 'A01'.
clear extension2.
extension2-structure = l_extname.
extension2-valuepart1 = gs_zext2.
append extension2.
clear gs_zext2.
gs_zext2-posnr = '2'.
gs_zext2-rstgr = 'A01'.
clear extension2.
extension2-structure = l_extname.
extension2-valuepart1 = gs_zext2.
append extension2.
endform.
form generate_fi_document.
data: has_error type c,
message_line type string.
has_error = space.
call function 'BAPI_ACC_DOCUMENT_CHECK'
exporting
documentheader = docheader
tables
accountgl = accountgl
currencyamount = currencyamount
extension2 = extension2
return = return.
loop at return.
if return-type = 'E'.
has_error = 'X'.
exit.
endif.
endloop.
if has_error = 'X'.
loop at return.
concatenate return-id return-number ': ' return-message into message_line.
write: / message_line.
clear return.
endloop.
endif.
check has_error = space.
clear return[].
call function 'BAPI_ACC_DOCUMENT_POST'
exporting
documentheader = docheader
tables
accountgl = accountgl
currencyamount = currencyamount
extension2 = extension2
return = return.
if sy-subrc is initial.
call function 'BAPI_TRANSACTION_COMMIT'
exporting
wait = 'X'.
" write messages
loop at return.
concatenate return-id return-number ': ' return-message into message_line.
write: / message_line.
clear return.
endloop.
endif.
if sy-subrc is initial.
write: / 'Successful'.
endif.
endform.