Calling an external RESTful service from ABAP - HTTP Method GET

[former_member204528]

HTTP POST  method: http://scn.sap.com/community/abap/connectivity/blog/2014/11/09/calling-an-external-restful-service-f...

I have made inline code explanation. Please go through step by step description.

Scenario: GET operation to access: http://hostname.com:55400/vendavo/rest/agreements/XYZ

1) Create a RFC destination of type (HTTP Connections to External Server)

content-type: application/json

DATA: lo_http_client     TYPE REF TO if_http_client,

         lo_rest_client     TYPE REF TO cl_rest_http_client,

         lv_url             TYPE        string,

         lv_body            TYPE        string,

         token              TYPE        string,

         agreements         TYPE        string,

         "Create a structure(or deep) that exactly matches your JSON response

         abap_response      TYPE        zca_serno_ln,

         lo_response    TYPE REF TO     if_rest_entity.

* Create HTTP intance using RFC restination created

* You can directly use the REST service URL as well

   cl_http_client=>create_by_destination(

    EXPORTING

      destination              = 'VENDAVO'    " Logical destination (specified in function call)

    IMPORTING

      client                   = lo_http_client    " HTTP Client Abstraction

    EXCEPTIONS

      argument_not_found       = 1

      destination_not_found    = 2

      destination_no_authority = 3

      plugin_not_active        = 4

      internal_error           = 5

      OTHERS                   = 6

  ).

* If you are using cl_http_client=>create_by_url use this code to supress and pass your

 * HTTP basic authenication 

 *  lo_http_client->propertytype_logon_popup = lo_http_client->co_disabled.

 *  DATA l_username TYPE string.

 *  DATA l_password TYPE string.

 *  l_username = 'user'.

 *  l_password = 'password'.

 *  CALL METHOD lo_http_client->authenticate

 *    EXPORTING

 *      username = l_username

 *      password = l_password.

* Create REST client instance

   CREATE OBJECT lo_rest_client

     EXPORTING

       io_http_client = lo_http_client.

* Set HTTP version

   lo_http_client->request->set_version( if_http_request=>co_protocol_version_1_0 ).

   IF lo_http_client IS BOUND AND lo_rest_client IS BOUND.

     DATA(id) = 'XYZ'.

     CONCATENATE 'agreements/' id INTO lv_url.

* Set the URI if any

     cl_http_utility=>set_request_uri(

       EXPORTING

         request = lo_http_client->request    " HTTP Framework (iHTTP) HTTP Request

         uri     = lv_url                     " URI String (in the Form of /path?query-string)

     ).

* Set request header if any

     CALL METHOD lo_rest_client->if_rest_client~set_request_header

       EXPORTING

         iv_name  = 'auth-token'

         iv_value = token.

* HTTP GET

     lo_rest_client->if_rest_client~get( ).

  

* HTTP response   

     lo_response = lo_rest_client->if_rest_client~get_response_entity( ).

  

* HTTP return status   

     DATA(http_status)   = lo_response->get_header_field( '~status_code' ).

  

* HTTP JSON return string   

     DATA(json_response) = lo_response->get_string_data( ).

* Class to convert the JSON to an ABAP sttructure

    DATA lr_json_deserializer TYPE REF TO cl_trex_json_deserializer.

    CREATE OBJECT lr_json_deserializer.

    lr_json_deserializer->deserialize( EXPORTING json = json_response IMPORTING abap = abap_response ).