Consume OData Deep Structure In ABAP

[former_member202818]

Recently I have come across a requirement to consume OData service from a different system in our system using ABAP programing. There are some blog post already about how to do this, my blog post is an extension to this.

Business Scenario

Wanted to extract some data from a different system. The source system is having an OData service for exposing the master data. OData output is a deep structured data (Header & Item data together using $expand), converting this data in to an ABAP internal table was little tricky. Would like to share the solution which I implemented.

Code for getting the OData service output and converting the data in to ABAP format.

class Z_CL_ODATA_UTILITY definition

  public

  final

  create public .



public section.

  class-methods GET_RESULT_FROM_ODATA_SRV_DEEP

    importing

      !IV_URI type STRING

      !IV_DESTINATION type C

    exporting

      !E_DATA type DATA

      !ET_MESSAGE type BAL_T_MSG .

ENDCLASS.





CLASS Z_CL_ODATA_UTILITY IMPLEMENTATION.



* <SIGNATURE>---------------------------------------------------------------------------------------+

* | Static Public Method Z_CL_ODATA_UTILITY=>GET_RESULT_FROM_ODATA_SRV_DEEP

* +-------------------------------------------------------------------------------------------------+

* | [--->] IV_URI                         TYPE        STRING

* | [--->] IV_DESTINATION                 TYPE        C

* | [<---] E_DATA                         TYPE        DATA

* | [<---] ET_MESSAGE                     TYPE        BAL_T_MSG

* +--------------------------------------------------------------------------------------</SIGNATURE>

  METHOD get_result_from_odata_srv_deep.

    DATA lv_uri TYPE string.



*-->Create HTTP client object using destination

    TRY.

        CALL METHOD cl_http_client=>create_by_destination

          EXPORTING

            destination              = iv_destination

          IMPORTING

            client                   = DATA(lo_http_client)

          EXCEPTIONS

            argument_not_found       = 1

            destination_not_found    = 2

            destination_no_authority = 3

            plugin_not_active        = 4

            internal_error           = 5

            OTHERS                   = 6.

        IF sy-subrc = 0.

          IF lo_http_client IS BOUND.

            lv_uri = iv_uri.

*-->Always get the output in JSON format. No JSON format if the count is requested

            IF iv_uri NS '/$count' AND iv_uri NS '&$format=json'.

              lv_uri = iv_uri && |&$format=json|.

            ENDIF.

*-->Set URI to be executed in the request object

            CALL METHOD cl_http_utility=>set_request_uri

              EXPORTING

                request = lo_http_client->request

                uri     = lv_uri. 

*-->Set request method as GET

            lo_http_client->request->set_method( if_http_request=>co_request_method_get ).

*-->Send the request

            CALL METHOD lo_http_client->send

              EXCEPTIONS

                http_communication_failure = 1

                http_invalid_state         = 2

                http_processing_failed     = 3

                http_invalid_timeout       = 4

                OTHERS                     = 5.

            IF sy-subrc = 0.

*-->Recive the response

              CALL METHOD lo_http_client->receive

                EXCEPTIONS

                  http_communication_failure = 1

                  http_invalid_state         = 2

                  http_processing_failed     = 3

                  OTHERS                     = 4.

              IF sy-subrc = 0.

*-->Extract data in the form of JSON from the response

                DATA(lv_json_response) = lo_http_client->response->get_cdata( ).

*-->Convert the JSON data in to ABAP format

                IF iv_uri CS '/$count'.

                  TRY.

                      e_data = lv_json_response.

                    CATCH cx_root.

                  ENDTRY.

                ELSE.

                  /ui2/cl_json=>deserialize(

                    EXPORTING

                      json             = lv_json_response

                    CHANGING

                      data             = e_data  ).

                ENDIF.

              ENDIF.

            ENDIF.

          ENDIF.

        ENDIF.

      CATCH cx_root INTO DATA(lo_exception).

    ENDTRY.

  ENDMETHOD.

ENDCLASS.

 

It is important to follow the output structure type (ls_data in below example) definition same as OData structure.

*-->Define the structure for receiving the result

  types:

    BEGIN OF ty_marm,

            results TYPE z_t_marm,

          END OF ty_marm.

  types:

    BEGIN OF ty_marc,

            results TYPE z_t_marc,

          END OF ty_marc.

  types:

    BEGIN OF ty_materials,

            matnr             TYPE  matnr,

            ersda             TYPE  ersda,

            pstat             TYPE  pstat_d,

            mtart             TYPE  mtart,

            navtomarm TYPE ty_marm,

            navtomarc TYPE ty_marc,

          END OF ty_materials .

  types:

    tt_materials TYPE STANDARD TABLE OF ty_materials WITH DEFAULT KEY .

  types:

    BEGIN OF ty_d,

            __count TYPE int4, "Optinal. Needed only if we are getting the inlinecount

            results TYPE tt_materials,

          END OF ty_d .

  types:

    BEGIN OF ty_data,

            d TYPE ty_d,

          END OF ty_data .

  DATA: ls_data  TYPE ty_data.



  z_cl_odata_utility=>get_result_from_odata_srv_deep(

        EXPORTING

          iv_uri         = |MY_SERVICE_SRV/UnpackSet?$filter=(Ersda ge datetime'{ lv_from_ts }' or | &&

                           |Ersda le datetime'{ lv_to_ts }') and Mtart eq 'HALB' | &&

                           |&$expand=navtomarm,navtomarc&$inlinecount=allpages|

          iv_destination = 'MYDES099_HTTP'

        IMPORTING

          e_data        = ls_data

          et_message    = et_message     " Application Log: Table with Messages

      ).

Conclusion

Now you know,
How to consume OData services in ABAP program.
How to receive deep structured data from an OData service and convert it into ABAP data format.
How to consume OData service from a different system.

Questions & Other solutions are welcome! 🙂