CL_HTTP_CLIENT

Make HTTP/HTTPS requests from ABAP to external REST APIs or web services.

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Purpose

CL_HTTP_CLIENT is ABAP's built-in HTTP client. It supports GET, POST, PUT, DELETE, custom headers, basic auth, and SSL/TLS. Use it to call REST APIs, webhooks, or any HTTP endpoint reachable from the SAP application server.

SM59 destinations (recommended for production)

CREATE_BY_DESTINATION reads host, port, SSL settings, and credentials from an SM59 HTTP destination. This keeps configuration out of code and is the preferred approach for production systems. CREATE_BY_URL is convenient for prototyping.

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Key methods

Method	Called on	Description
CREATE_BY_URL	CL_HTTP_CLIENT (static)	Create client from a literal URL
CREATE_BY_DESTINATION	CL_HTTP_CLIENT (static)	Create client from SM59 destination name
set_method	client->request	Set HTTP verb: 'GET', 'POST', 'PUT', 'DELETE'
set_header_field	client->request	Set a request header (name / value)
set_cdata	client->request	Set text request body (string — UTF-8)
set_data	client->request	Set binary request body (xstring)
send	client	Send the request
receive	client	Receive the response (blocks until complete)
get_status	client->response	Read HTTP status code into integer
get_header_field	client->response	Read a response header value
get_cdata	client->response	Read text response body (string)
get_data	client->response	Read binary response body (xstring)
close	client	Close TCP connection — always call in FINALLY

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Examples

GET request

DATA lo_client  TYPE REF TO if_http_client.
DATA lv_url     TYPE string VALUE 'https://api.example.com/items/42'.
DATA lv_body    TYPE string.
DATA lv_status  TYPE i.
DATA lv_reason  TYPE string.

cl_http_client=>create_by_url(
  EXPORTING
    url                = lv_url
  IMPORTING
    client             = lo_client
  EXCEPTIONS
    argument_not_found = 1
    plugin_not_active  = 2
    internal_error     = 3
    OTHERS             = 4 ).

IF sy-subrc <> 0.
  RAISE EXCEPTION TYPE cx_static_check.  " or MESSAGE
ENDIF.

TRY.
  lo_client->request->set_method( if_http_request=>co_request_method_get ).
  lo_client->request->set_header_field(
    name  = 'Accept'
    value = 'application/json' ).

  lo_client->send(
    EXCEPTIONS
      http_communication_failure = 1
      http_invalid_state         = 2
      OTHERS                     = 3 ).
  lo_client->receive(
    EXCEPTIONS
      http_communication_failure = 1
      http_invalid_state         = 2
      http_processing_failed     = 3
      OTHERS                     = 4 ).

  lo_client->response->get_status(
    IMPORTING
      code   = lv_status
      reason = lv_reason ).

  lv_body = lo_client->response->get_cdata( ).

  IF lv_status = 200.
    " process lv_body (JSON string)
  ELSE.
    MESSAGE |HTTP { lv_status }: { lv_reason }| TYPE 'E'.
  ENDIF.

FINALLY.
  lo_client->close( ).
ENDTRY.

POST with JSON body

DATA lv_json TYPE string.
lv_json = '{"name":"Test Item","qty":5}'.

lo_client->request->set_method( if_http_request=>co_request_method_post ).
lo_client->request->set_header_field(
  name  = 'Content-Type'
  value = 'application/json' ).
lo_client->request->set_header_field(
  name  = 'Accept'
  value = 'application/json' ).
lo_client->request->set_cdata( lv_json ).

lo_client->send(
  EXCEPTIONS
    http_communication_failure = 1
    http_invalid_state         = 2
    OTHERS                     = 3 ).
lo_client->receive(
  EXCEPTIONS
    http_communication_failure = 1
    http_invalid_state         = 2
    http_processing_failed     = 3
    OTHERS                     = 4 ).

lo_client->response->get_status(
  IMPORTING
    code   = lv_status
    reason = lv_reason ).

lv_body = lo_client->response->get_cdata( ).

Using an SM59 destination

cl_http_client=>create_by_destination(
  EXPORTING
    destination        = 'MY_REST_API'   " defined in SM59
  IMPORTING
    client             = lo_client
  EXCEPTIONS
    argument_not_found = 1
    destination_not_found = 2
    internal_error     = 3
    OTHERS             = 4 ).

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Common pitfalls

• SSL / HTTPS: the server certificate must be imported into the SAP trust store via STRUST (SSL client identity ANONYM or a dedicated one). Without it, send() raises HTTP_COMMUNICATION_FAILURE.
• Always close: call lo_client->close() in a FINALLY block. Unclosed connections exhaust the HTTP connection pool.
• Text vs. binary: use get_cdata() / set_cdata() for JSON and XML (character data). Use get_data() / set_data() for binary payloads (images, PDFs, etc.).
• Basic auth via URL: embedding credentials in the URL (http://user:pass@host) works but is insecure. Store credentials in SM59 or use set_header_field with a Base64-encoded Authorization header.
• Proxy: if the SAP system accesses the internet via a proxy, configure it in SICF / SM59 HTTP settings or use lo_client->propertytype_proxy_host.

Response body encoding

get_cdata() returns the body re-encoded to ABAP's internal UTF-16. If the API returns a charset other than UTF-8 and the conversion fails, use get_data() and handle the raw bytes manually.

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See also

• Tutorial: calling a REST API from ABAP
• Transaction SM59 — HTTP/HTTPS destination configuration
• Transaction STRUST — SSL certificate management
• IF_HTTP_CLIENT, IF_HTTP_REQUEST, IF_HTTP_RESPONSE — underlying interfaces

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