Sottoscrizioni pull

Questo esempio di codice può essere utilizzato per eseguire il pull dei messaggi pubblicati in un argomento Pub/Sub utilizzando una sottoscrizione.

Per una raccolta completa di esempi di codice per Versione SAP BTP dell'SDK ABAP per Google Cloud, consulta il repository di codice di esempio su GitHub.

Per una raccolta completa di esempi di codice per on-premise o su qualsiasi versione cloud dell'SDK ABAP per Google Cloud, consulta il repository di esempi di codice su GitHub.

Esempio di codice

Versione SAP BTP

" --------------------------------------------------------------------
"  Copyright 2024 Google LLC                                         -
"                                                                    -
"  Licensed under the Apache License, Version 2.0 (the "License");   -
"  you may not use this file except in compliance with the License.  -
"  You may obtain a copy of the License at                           -
"      https://www.apache.org/licenses/LICENSE-2.0                   -
"  Unless required by applicable law or agreed to in writing,        -
"  software distributed under the License is distributed on an       -
"  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,      -
"  either express or implied.                                        -
"  See the License for the specific language governing permissions   -
"  and limitations under the License.                                -
" --------------------------------------------------------------------
CLASS zcl_cs_pull_subscriptions DEFINITION
  PUBLIC FINAL
  CREATE PUBLIC.

  PUBLIC SECTION.
    INTERFACES if_oo_adt_classrun.
ENDCLASS.


CLASS zcl_cs_pull_subscriptions IMPLEMENTATION.
  METHOD if_oo_adt_classrun~main.
    " Data Declarations
    DATA lv_p_projects_id      TYPE string.
    DATA lv_p_subscriptions_id TYPE string.
    DATA ls_input              TYPE /goog/cl_pubsub_v1=>ty_026.
    DATA ls_input_ack          TYPE /goog/cl_pubsub_v1=>ty_001.

    TRY.

        " Open HTTP Connection
        DATA(lo_pubsub) = NEW /goog/cl_pubsub_v1( iv_key_name = 'PUBSUB_DEMO' ).

        " Populate relevant parameters
        " Derive project id from the client object
        lv_p_projects_id = lo_pubsub->gv_project_id.
        " Name of the subscription from where we want to pull data
        lv_p_subscriptions_id = 'SAMPLE_SUBSCRIPTION'.
        " Max number of messages that will be received in 1 API call
        ls_input-max_messages = 1.

        " Call API method
        lo_pubsub->pull_subscriptions( EXPORTING iv_p_projects_id      = lv_p_projects_id
                                                 iv_p_subscriptions_id = lv_p_subscriptions_id
                                                 is_input              = ls_input
                                       IMPORTING es_output             = DATA(ls_output)
                                                 ev_ret_code           = DATA(lv_ret_code)
                                                 ev_err_text           = DATA(lv_err_text)
                                                 es_err_resp           = DATA(ls_err_resp) ).

        IF /goog/cl_http_client=>is_success( lv_ret_code ).
          IF ls_output-received_messages IS NOT INITIAL.
            " Messages published to Pub/Sub should be base-64 encoded
            " Therefore in order to get the exact message, we need to decode the data field.
            " However, attributes published to Pub/Sub should be accessible without any additional logic.
            DATA(lv_msg) = | MESSAGE Received: { cl_http_utility=>decode_base64(
                                                     encoded = ls_output-received_messages[ 1 ]-message-data ) }|.
            APPEND ls_output-received_messages[ 1 ]-ack_id TO ls_input_ack-ack_ids.

            " Call API method: pubsub.projects.subscriptions.acknowledge
            " Acknowledge the messages so it is not pulled again.
            lo_pubsub->acknowledge_subscriptions( EXPORTING iv_p_projects_id      = lv_p_projects_id
                                                            iv_p_subscriptions_id = lv_p_subscriptions_id
                                                            is_input              = ls_input_ack
                                                  IMPORTING es_output             = DATA(ls_output_ack)
                                                            ev_ret_code           = lv_ret_code
                                                            ev_err_text           = lv_err_text
                                                            es_err_resp           = ls_err_resp ).

            IF lo_pubsub->is_success( lv_ret_code ).
              out->write( | Error occurred: { lv_msg }| ).
            ELSE.
              out->write( | Error occurred: { lv_err_text }| ).
            ENDIF.
          ELSE.
            out->write( | No Messages were received!| ).
          ENDIF.
        ELSE.
          out->write( | Error occurred: { lv_err_text }| ).
        ENDIF.

        " Close HTTP Connection
        lo_pubsub->close( ).

      CATCH /goog/cx_sdk INTO DATA(lo_exception).
        lv_err_text = lo_exception->get_text( ).
        out->write( |Exception occurred: { lv_err_text } | ).
    ENDTRY.
  ENDMETHOD.
ENDCLASS.

Versione on-premise o qualsiasi versione cloud

**********************************************************************
*  Copyright 2023 Google LLC                                         *
*                                                                    *
*  Licensed under the Apache License, Version 2.0 (the "License");   *
*  you may not use this file except in compliance with the License.  *
*  You may obtain a copy of the License at                           *
*      https://www.apache.org/licenses/LICENSE-2.0                   *
*  Unless required by applicable law or agreed to in writing,        *
*  software distributed under the License is distributed on an       *
*  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,      *
*  either express or implied.                                        *
*  See the License for the specific language governing permissions   *
*  and limitations under the License.                                *
**********************************************************************

REPORT zr_pull_subscriptions.

DATA:
  lv_p_projects_id      TYPE string,
  lv_p_subscriptions_id TYPE string,
  ls_input              TYPE /goog/cl_pubsub_v1=>ty_026,
  ls_input_ack          TYPE /goog/cl_pubsub_v1=>ty_001.

TRY.

* Open HTTP Connection
    DATA(lo_client) = NEW /goog/cl_pubsub_v1( iv_key_name = 'CLIENT_KEY' ).

* Populate relevant parameters
    " Derive project id from the client object
    lv_p_projects_id = lo_client->gv_project_id.
    " Name of the subscription from where we want to pull data
    lv_p_subscriptions_id = 'SAMPLE_SUBSCRIPTION'.
    " Max number of messages that will be received in 1 API call
    ls_input-max_messages = 1.

* Call API method
    CALL METHOD lo_client->pull_subscriptions
      EXPORTING
        iv_p_projects_id      = lv_p_projects_id
        iv_p_subscriptions_id = lv_p_subscriptions_id
        is_input              = ls_input
      IMPORTING
        es_output             = DATA(ls_output)
        ev_ret_code           = DATA(lv_ret_code)
        ev_err_text           = DATA(lv_err_text)
        es_err_resp           = DATA(ls_err_resp).

    IF /goog/cl_http_client=>is_success( lv_ret_code ).
      IF ls_output-received_messages IS NOT INITIAL.
        "Messages published to Pub/Sub should be base-64 encoded, hence in order to get the exact message, we need to decode the data field.
        "However, attributes published to Pub/Sub should be accessible without any additional logic.
        DATA(lv_msg) = | Message Received: { cl_http_utility=>decode_base64( encoded = ls_output-received_messages[ 1 ]-message-data ) }|.
        APPEND ls_output-received_messages[ 1 ]-ack_id TO ls_input_ack-ack_ids.

* Call API method: pubsub.projects.subscriptions.acknowledge
        "Acknowledge the messages so it is not pulled again.
        CALL METHOD lo_client->acknowledge_subscriptions
          EXPORTING
            iv_p_projects_id      = lv_p_projects_id
            iv_p_subscriptions_id = lv_p_subscriptions_id
            is_input              = ls_input_ack
          IMPORTING
            es_output             = DATA(ls_output_ack)
            ev_ret_code           = lv_ret_code
            ev_err_text           = lv_err_text
            es_err_resp           = ls_err_resp.

        IF lo_client->is_success( lv_ret_code ).
          MESSAGE lv_msg TYPE 'S'.
        ELSE.
          MESSAGE lv_err_text TYPE 'E'.
        ENDIF.
      ELSE.
        MESSAGE 'No Messages were received!' TYPE 'S'.
      ENDIF.
    ELSE.
      MESSAGE lv_err_text TYPE 'E'.
    ENDIF.

* Close HTTP Connection
    lo_client->close( ).

  CATCH /goog/cx_sdk INTO DATA(lo_exception).
    MESSAGE lo_exception->get_text( ) TYPE 'E'.
ENDTRY.