使用类if_http_client基本可以解决大多数ABAP调用http服务的问题。在调用服务前可以先用postman来测试服务，确定可输入的参数。
通用代码如下：
代码语言：javascript复制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再举一个例子
以post方式为例，request的参数都是通过body来传输的。正常服务发起比较简单，通过if_http_client->request->set_data设置传输值，if_http_client->request->set_header_field设置header的content-type。如果服务端对body的数据字符集有要求，比如gbk，则需要先将body数据进行jbk转码，然后在if_http_client->request->set_content_type中设置content-type，示例代码如下：
代码语言：javascript复制 "设定传输请求内容格式以及编码格式
lo_http_client->request->set_content_type( content_type = 'application/XML; charset=GBK' ).
"设定调用服务
lo_http_client->request->set_method( if_http_request=>co_request_method_post ).
CLEAR:lv_result_xstring.
lv_result_xstring = cl_abap_codepage=>convert_to(
source = uv_reqxml
codepage = 'GBK'
).
lv_len = xstrlen( lv_result_xstring ).
lo_http_client->request->set_data(
EXPORTING
data = lv_result_xstring
offset = 0
length = lv_len ).
lo_http_client->send(
EXCEPTIONS
http_communication_failure = 1
http_invalid_state = 2 ).
lo_http_client->receive(
EXCEPTIONS
http_communication_failure = 1
http_invalid_state = 2
http_processing_failed = 3 ).
* lv_result_string = lo_http_client->response->get_cdata( ).
CLEAR:lv_result_xstring,lv_result_string.
lv_result_xstring = lo_http_client->response->get_data( ).
lv_result_string = cl_abap_codepage=>convert_from(
source = lv_result_xstring
codepage = 'GBK' ).
