Publish messages to Google Cloud Pub/Sub

On-premises or any cloud edition v1.12keyboard_arrow_down

• SAP BTP edition v1.1
• On-premises or any cloud edition v1.12

This quickstart shows you how to create a program that publishes a "Hello World!" message to a Pub/Sub topic by using the Pub/Sub API.

Before you begin

Before you run this quickstart, make sure that you or your administrators have completed the following prerequisites:

• You have a Google Cloud account and project.

• Billing is enabled for your project. See how to confirm that billing is enabled for your project.

• The on-premises or any cloud edition of ABAP SDK for Google Cloud is installed and configured. See how to install and configure the on-premises or any cloud edition of ABAP SDK for Google Cloud.

• Authentication to access Google Cloud APIs is set up. See how to set up authentication.

• Grant the service account the IAM role roles/pubsub.publisher.

• Make sure the Pub/Sub API is enabled in your Google Cloud project.

  Go to API library

• Create a Pub/Sub topic SAMPLE_TOPIC_01 and add a pull subscription SAMPLE_SUB_TOPIC_01 to the same. For more information, see Create a topic and Create a subscription.

Create a program to publish messages to Google Cloud

1. In the SAP system, create an executable program in your custom namespace (for example, Z or Y) by using transaction SE38.

   1. In the SAP GUI, enter transaction code SE38.

   2. In the Program field, enter a name of your program for example, ZDEMO_PUBSUB.

   3. Click Create.

   4. Specify the program attributes:

      1. In the Title field, enter a title of your program, for example, Publish messages to a Pub/Sub topic.

      2. In the Type field, choose Executable Program.

      3. Click Save.

   5. Save the program as a Local Object.

   6. In the ABAP Editor, add the following code:

      ********************************************************************** * 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_qs_publish_messages. * Data Declaration DATA: lv_p_projects_id TYPE string, lv_p_topics_id TYPE string, ls_input TYPE /goog/cl_pubsub_v1=>ty_023. TRY. * Instantiate the client stub DATA(lo_pubsub) = NEW /goog/cl_pubsub_v1( iv_key_name = 'DEMO_PUBSUB' ). * Pass the relevant input parameters lv_p_topics_id = 'SAMPLE_TOPIC_01'. lv_p_projects_id = lo_pubsub->gv_project_id. APPEND VALUE #( data = cl_http_utility=>encode_base64( 'Hello World!' ) ) to ls_input-messages. * Call the API CALL METHOD lo_pubsub->publish_topics EXPORTING iv_p_projects_id = lv_p_projects_id iv_p_topics_id = lv_p_topics_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). * Handle the output IF lo_pubsub->is_success( lv_ret_code ). MESSAGE 'Message was published!' TYPE 'S'. ELSE. MESSAGE 'Message was not published!' TYPE 'E'. ENDIF. * Close the HTTP Connection lo_pubsub->close( ). CATCH /goog/cx_sdk INTO DATA(lo_exception). MESSAGE lo_exception->get_text( ) TYPE 'E'. ENDTRY. 

      Replace DEMO_PUBSUB with the client key name.

2. Run your application in SE38.

3. To validate the results, follow these steps:

   1. In the Google Cloud console, go to Pub/Sub.

   2. Select the subscription SAMPLE_SUB_TOPIC_01 and go to the Messages tab.

   3. Use the PULL feature to check whether the "Hello World!" message has been published to the topic.

What's next

• Explore other quickstarts available on the GitHub repository, GoogleCloudPlatform/google-cloud-abap/abap-sdk /ZGOOG_SDK_QUICKSTART/.
• Read the guide Application development with the on-premises or any cloud edition of ABAP SDK for Google Cloud.
• View the code samples.
• Ask your questions and discuss ABAP SDK for Google Cloud with the community on Cloud Forums.