在 SAP 常用的接口技术中，大多是外部系统主动请求，比如外部系统调用 RFC 函数，如果需要 SAP 侧主动推送数据，RFC 则不能实现，需要 iDoc 之类的技术才行。本文介绍在 ABAP 中提交 http post 请求的方式，实现 SAP 侧主动推送数据，外部只需要有 web server，能接收到数据就行。这种方法比较简单，而且也没有编程语言的限制。
本例实现的功能：ABAP 调用 Z_BAPI_GLACCPERIODBALANCES 自定义函数 (z 函数的代码在之前的博文中有提供)，把数据从 internal table 转换为 json 格式的字符串，发送到 web server，并接收服务器返回的信息。
ABAP 发送 http post 请求
report z_http_post.
" data to post
data: gt_accbal like standard table of zglaccbalance with header line.
data: lv_json_str type string. "发送报文
data: gr_serializer type ref to zcl_trex_json_serializer.
start-of-selection.
" get data
call function 'Z_BAPI_GLACCPERIODBALANCES'
exporting
companycode = 'Z900'
fiscalyear = '2020'
fiscalperiod = '10'
tables
acc_balances = gt_accbal.
" 序列化
create object gr_serializer
exporting
data = gt_accbal[] .
call method gr_serializer->serialize( ) .
lv_json_str = gr_serializer->get_data( ).
" 发送http post请求
perform http_post.
*&---------------------------------------------------------------------*
*& Form HTTP_POST
*&---------------------------------------------------------------------*
form http_post .
data: lv_url type string. "http 服务接口地址
data: lo_http_client type ref to if_http_client.
data: lv_len type i."发送报文长度
data: lv_resp type string.
data: lv_message type string.
data: lv_mtype type bapi_mtype.
data: lv_code type sysubrc.
" 设置http接口地址
lv_url = 'http://192.168.3.14:5000/testpost/'.
"创建客户端请求
call method cl_http_client=>create_by_url
exporting
url = lv_url
importing
client = lo_http_client
exceptions
argument_not_found = 1
plugin_not_active = 2
internal_error = 3
others = 4.
if sy-subrc <> 0.
"lv_subrc = sy-subrc.
message id sy-msgid type sy-msgty number sy-msgno with
sy-msgv1 sy-msgv2 sy-msgv3 sy-msgv4.
exit.
endif.
" 设置content type和character set
lo_http_client->request->set_content_type( content_type = 'application/json; charset=utf-8' ).
" 设置方法为 post
lo_http_client->request->set_method( if_http_request=>co_request_method_post ).
" 设置待传输内容
lv_len = strlen( lv_json_str ).
call method lo_http_client->request->set_cdata
exporting
data = lv_json_str
offset = 0
length = lv_len .
" 发送请求
lo_http_client->send( exceptions http_communication_failure = 1
http_invalid_state = 2 ).
if sy-subrc <> 0.
"操作失败，获取失败原因
lo_http_client->get_last_error( importing message = lv_message code = lv_code ).
lv_mtype = 'E'.
exit.
endif.
" 读取远程服务返回的结果消息。
lo_http_client->receive( exceptions http_communication_failure = 1
http_invalid_state = 2
http_processing_failed = 3 ).
if sy-subrc <> 0 .
" lv_subrc = sy-subrc.
lo_http_client->get_last_error( importing message = lv_message code = lv_code ).
lv_mtype = 'E'.
write: lv_message, lv_code.
exit.
else.
" 读取返回返回内容
clear lv_resp.
lv_resp = lo_http_client->response->get_cdata( ).
endif.
write:lv_resp.
* MESSAGE LV_MESSAGE TYPE LV_MTYPE .
endform. "HTTP_POST
web server 接收 json 消息并下载为本地文件
使用 python 的 flask 框架来实现。
from flask import Flask, jsonify, request
import json
app = Flask(__name__)
@app.route("/")
def index():
return "Index page"
@app.route("/testpost/", methods = ["GET","POST"])
def process_http_post():
if request.method == "POST":
data = request.get_json()
print(data)
# write data to file
with open('output.txt', mode='w', encoding='utf-8') as f:
json.dump(data, f, ensure_ascii=False)
return str(len(data)) + ' lines of data was received from SAP successfully.'
if __name__ == "__main__":
app.run(host='0.0.0.0')