ABAP 调用外部接口

1、JSON转换
DATA: json_ser TYPE REF TO cl_trex_json_serializer.

2、http客户端访问
DATA: lo_http_client  TYPE REF TO if_http_client.

3、定义传入参数结构
{
    head:...
    detail:[
        xxx:xxx.
    ]
}

4、定义接收参数结构

5、定义传入参数string
DATA: lv_json_str TYPE string.

6、将内表转成JSON
lv_json_str = /ui2/cl_json=>serialize( data = ls_json assoc_arrays = abap_true ).

7、创建请求
  CALL METHOD cl_http_client=>create_by_url
    EXPORTING
      url                = lv_url  "外部接口地址
    IMPORTING
      client             = lo_http_client
    EXCEPTIONS
      argument_not_found = 1
      plugin_not_active  = 2
      internal_error     = 3
      OTHERS             = 4.

8、认证
lo_http_client->propertytype_logon_popup = lo_http_client->co_disabled.

  CALL METHOD lo_http_client->authenticate(
    EXPORTING
*     client   = ''
*     proxy_authentication = 'X'
      username = '用户名'
      password = '密码'
*                            LANGUAGE
*     =        =
*     'E'      =
  ).

*设置header
    CALL METHOD lo_http_client->request->set_header_field
      EXPORTING
        name  = 'username'
        value = lv_username.

    CALL METHOD lo_http_client->request->set_header_field
      EXPORTING
        name  = 'password'
        value = lv_password.

  "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/json; charset=utf-8' ).

  "设定调用服务
  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 = message ).
    code = 0.
    EXIT.
  ENDIF.

  "读取远程服务返回的处理过结果。
  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 = message ).
    code = 0.
    EXIT.
  ELSE.
    "读取返回返回内容
    CLEAR lv_respon.
    code = 1.
    lv_respon = lo_http_client->response->get_cdata( ).

    /ui2/cl_json=>deserialize( EXPORTING json = lv_respon assoc_arrays = abap_true          
 CHANGING data = ls_exp ). "ls_exp是返回参数结构
  ENDIF.