Publish messages to Google Cloud Pub/Sub

On-premises or any cloud edition v1.12 keyboard_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 Programfield, enter a name of your program for example, ZDEMO_PUBSUB .

   3. Click Create.

   4. Specify the program attributes:

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

      2. In the Typefield, 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 Messagestab.

   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 .