Create an HTTP Service in SAP BTP ABAP Environment

Requires Customer/Partner License

Beginner

15 min.

ABAP Development, Beginner, SAP BTP, ABAP environment, Tutorial, SAP Business Technology Platform

Create an HTTP service in SAP BTP ABAP environment that can be called from the browser.

You will learn

How to create an HTTP service that can be accessed from a browser
How to return system data using a (whitelisted) ABAP utility class
How to expose the service for external consumption, by defining the necessary inbound communication artifacts

Julie PlummerOctober 19, 2022

Created bySeptember 12, 2018

Contributors

Prerequisites

IMPORTANT: This tutorial cannot be completed on a trial account
You have set up SAP Business Technology Platform (BTP), ABAP Environment, for example by using the relevant booster: Using a Booster to Automate the Setup of the ABAP Environment
Tutorial: Create Your First Console Application, for a licensed user, steps 1-2
You have installed ABAP Development Tools, latest version

Important: If you are working in SAP S/4HANA:
ICF services are direct entry points into the ABAP system via the HTTP protocol. Implementing ICF services is a security-critical task with implications on the system and landscape configuration.

Therefore, to follow the best practices adopted by SAP internally, consider implementing your service as an OData service.

More Information

SAP Help Portal: HTTP Communication
SAP Help Portal: Components of SAP Communication Technology - HTTP Service
SAP ABAP Keyword Documentation: Calling an HTTP Service: Search for ICF, Subject

Step 1
Select a package and choose New > Other Repository Object from the context menu:
Enter the filter text HTTP and choose Next:
Enter a Name:Z_GET_DATE_HTTP_XXX and Description:Get system date for your service and choose Next:
Choose or create a transport request:
The new HTTP service is displayed on a new tab. The handler class and URL are generated automatically, in the form:
https://<server:port>/sap/bc/http/sap/<service_name>?sap-client=100
Step 2
Now, you will implement the handler class, starting with a simple text output.
Open the handler class by clicking on the hyperlink:
The structure of the class and the interfaces statement for IF_HTTP_SERVICE_EXTENSION are generated automatically.
Go to the class implementation section and insert the following statement in the method:
response->set_text('Hello!').
Step 3
Save (Ctrl+S) and Activate (Ctrl+F3) your class.
Step 4
Go back to your HTTP Service. Test your service in the browser by clicking the URL link:
If necessary, log in again. The preview open automatically in a new tab and display something like this:
Step 5
Now you will add a method to get system data and format this in HTML
In the ABAP environment, you can only use whitelisted APIs. Therefore, for example, you cannot use SY-UNAME. Instead, you call the appropriate method of the class CL_ABAP_CONTEXT_INFO.
In your class definition, add the following statement:
ABAP
Copy
METHODS: get_html RETURNING VALUE(ui_html) TYPE string.
You will get the error “Implementation missing…”. Resolve this by choosing Quick Assist ( Ctrl+1 ) and choosing Add implementation…. Ignore the two warnings for now.
ABAP
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DATA(user_formatted_name) = cl_abap_context_info=>get_user_formatted_name( ). DATA(system_date) = cl_abap_context_info=>get_system_date( ). ui_html = |<html> \n| && |<body> \n| && |<title>General Information</title> \n| && |<p style="color:DodgerBlue;"> Hello there, { user_formatted_name } </p> \n | && |<p> Today, the date is: { get_system_date }| && |<p> | && |</body> \n| && |</html> | .
Now change the method implementation of the method handle_request
ABAP
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response->set_text( get_html( ) ).
Now select the warning for the method get_html and choose Quick Assist ( Ctrl + 1 ). (You cannot resolve the warning for the method handle_request).
Choose Add raising declaration, then choose Finish.
Format, save, and activate the class ( Shift + F1, Ctrl + S, Ctrl + F3 ).
Test the service again using the URL. Your page should look roughly like this:

Step 6

Your code should look like this:

ABAP

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CLASS Z_GET_DATE_HTTP_XXX DEFINITION
  PUBLIC
  CREATE PUBLIC .

  PUBLIC SECTION.

    INTERFACES if_http_service_extension .

    METHODS: get_html RETURNING VALUE(ui_html) TYPE string
    RAISING
        cx_abap_context_info_error.

  PROTECTED SECTION.
  PRIVATE SECTION.
ENDCLASS.



CLASS Z_GET_DATE_HTTP_XXX IMPLEMENTATION.


  METHOD if_http_service_extension~handle_request.
    response->set_text( get_html(  ) ).
  ENDMETHOD.

  METHOD get_html.

    DATA(user_formatted_name) = cl_abap_context_info=>get_user_formatted_name( ).
    DATA(system_date) = cl_abap_context_info=>get_system_date( ).

    ui_html =  |<html> \n| &&
    |<body> \n| &&
    |<title>General Information</title> \n| &&
    |<p style="color:DodgerBlue;"> Hello there, { user_formatted_name } </p> \n | &&
    |<p> Today, the date is:  { get_system_date }| &&
    |<p> | &&
    |</body> \n| &&
    |</html> | .

  ENDMETHOD.

ENDCLASS.

Step 7
You will now create the artifacts you need to allow other systems to call your service compliantly. This involves some overhead for one consumer; however, the advantage is that you can add several consumer systems, or users (for example, with different authentication) pointing to the same HTTP service, wrapped in the same Communication Scenario.
First, create the Communication Scenario.
Select your package, then choose New > Other Repository Object… from the context menu.
Add the filter scen, then choose Communication Scenario, then choose Next.
Add a Name: Z_WRAP_HTTP_INBOUND_XXX and Description, choose a transport request, then choose Finish.
Your Communication Scenario appears.
Step 8
On the Inbound tab, choose Add….
IMPORTANT: Choose Browse. You cannot simply enter the name. Then add a filter, such as Z_HTTP, select your service, then choose Finish.
Your service appears. Choose Publish Locally.
Step 9
Open the dashboard for your system. You can find the URL for the dashboard by selecting your system (that is, ABAP Project in Project Explorer), then choosing Properties > ABAP Development from the context menu.
From Communication Management, choose Communication Arrangement. Then choose New.
Choose your scenario, Z_WRAP_HTTP_INBOUND_XXX from the drop-down list. Accept the default (identical) Arrangement name.
Step 10
From the Dashboard Home screen, choose Communication Systems.
Enter the name of your Communication Arrangement, then for Communication System, choose New.
Enter a System ID and Accept the default (identical) System name, then choose Create.
In Technical Data > General > Host Name, enter Dummy. Leave the other defaults and choose Save.
Step 11
Scroll down to Users for Inbound Communication, then create a new user by choosing the + icon.
Choose New User and the Authentication Method: User name and password.
Enter a name and description, then choose Propose password, then choose Create > OK > Save.
Step 12
Step 13
What is the correct syntax to Implement the method `IF_HTTP_SERVICE_EXTENSION~HANDLE_REQUEST`
so that it returns the current user name (`UNAME`), not the system date. Choose only one option.
DATA() = CL_ABAP_CONTEXT_INFO=>get_user_formatted_name( user_name )
DATA(user_name) = CL_ABAP_CONTEXT_INFO->get_user_formatted_name( );
DATA(user_name) = CL_ABAP_CONTEXT_INFO=>get_user_formatted_name( ).