This code sample can be used to pull messages that were published to a Pub/Sub Topic using a subscription.
For a comprehensive collection of code samples for the SAP BTP edition of ABAP SDK for Google Cloud, see the code sample repository on GitHub.
For a comprehensive collection of code samples for the on-premises or any cloud edition of ABAP SDK for Google Cloud, see the code samples repository on GitHub.
Code sample
SAP BTP edition
" --------------------------------------------------------------------
" 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.
On-premises or any cloud edition
**********************************************************************
* 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.