Example program: Executing an HTTP Request

Use

The following ABAP program executes an HTTP request. For testing purposes, the call destination is the sending system itself, so that the Application Server ABAP is used in both the client role and the server role:

Caution

This program shows a simplified sample code. It is not meant as a template for real coding.

                    


                    
report HTTP_Test.
                    
* data declarations
                    
data: client type ref to if_http_client.
                    
…

The following parameters must be entered:

Note

If nothing is entered, the following default values are used: host (default value: current host), service (default value: port 80 for HTTP and port 443 for HTTPS), protocol (default: HTTP/1.0), path to the required service, as described in Implementation (default: /sap/public/ping).

Note

If the connection using the Destination (SM59) is used when the client object is created, these parameters must be set accordingly in the destination.

                    


                    
data: host type string value = 'host.wdf.sap-ag.de',
                    
service type string value = '8080',
                    
path type string value = '/sap/public/ping',
                    
errortext type string. "used for error handling

Step 1

The object of type CL_HTTP_CLIENT is now created. There are two possible procedures for doing this:

In one case, the create method is called. Here, you need to enter the required host and port, and you can also enter the proxy setting. This overrides any configuration that was made in Transaction SICF (see also Configuring Proxies).
In the other case, the destination that was maintained in Transaction SM59 is used (method create_by_destination). Only the name of the destination and the client need be specified here. In both cases, you have to define Exceptions (not shown here) and query the last error code.

Note
SAP recommends that you use a fixed destination, as this reduces the need for configuration of communication parameters.

The object Client can be used to access all data (request, response, header field, and so on).

The scheme determines whether HTTP or HTTPS is to be used.

* create HTTP client object(s)

                      


                      
call method cl_http_client=>create
                      
exporting host = host_str
                      
service = service_str
                      
proxy_host = proxy_host
                      
proxy_service = proxy_service
                      
scheme = scheme
                      
importing client = client
                      
exceptions
                      
argument_not_found = 1
                      
internal_error = 2
                      
plugin_not_active = 3
                      
others = 4.

                      


                      
call method cl_http_client=>create_by_destination
                      
exporting destination = dest
                      
importing client = client
                      
exceptions
                      
destination_not_found = 1
                      
internal_error = 2
                      
argument_not_found = 3
                      
destination_no_authority = 4
                      
plugin_not_active = 5
                      
others = 6.

                      


                      
if sy-subrc <>0.
                      
write: / 'Create failed, subrc = ', sy-subrc.
                      
exit.
                      
endif.

Header fields are then set for the requests. Setting the HTTP request method to GET is optional.

Note

If this field is not set, the system uses GET if the HTTP request does not contain a body. Otherwise, it uses POST.

You must set the request URI unless the whole path was specified as a path prefix using the Destination (SM59). Here you use method set_request_uri of class cl_http_utility.

                      


                      
* set http method GET
                      
call method client-&gtrequest-;&gtset_method;(
                      
if_http_request=&gtco_request_method_get; ).
                      
* set protocol version
                      
if protocol = 'HTTP/1.0'.
                      
client-&gtrequest-;&gtset_version;(
                      
if_http_request=&gtco_protocol_version_1_0; ).
                      
else.
                      
client-&gtrequest-;&gtset_version;(
                      
if_http_request=&gtco_protocol_version_1_1; ).
                      
endif.
                      
* set request uri (/&ltpath;>[?&ltquerystring;>])
                      
cl_http_utility=&gtset_request_uri;( request = client-&gtrequest;
                      
uri = uri ).

Step 2

Any number of fields in the control block can then be filled.

Additional Options

You can deactivate the attributes PROPERTYTYPE_LOGON_POPUP, PROPERTYTYPE_REDIRECT and PROPERTYTYPE_ACCEPT_COMPRESS that have the default value CO_ENABLED (set to CO_DISABLED).
You can set PROPERTYTYPE_ACCEPT_COOKIE to different values. The default value is CO_DISABLED, but values CO_ENABLED (always accept cookies), CO_PROMPT (send a dialog box when cookies are received to ask if the cookie should be accepted) and CO_EVENT (cookie handling using event EVENTKIND_HANDLE_COOKIE of interface IF_HTTP_CLIENT) are also available.
You can set PROPERTYTYPE_ACCEPT_COMPRESS to the value CO_DISABLED so that the partner can send its data in non-compressed form.
Before the request is sent, you can also enter the necessary logon data using the AUTHENTICATE()method of interface IF_HTTP_CLIENT.

Step 3

The request is now sent.

                      


                      
* Send
                      
call method client-&flt;send
                      
exporting timeout = timeout
                      
exceptions http_communication_failure = 1
                      
http_invalid_state = 2
                      
http_processing_failed = 3
                      
others = 4.
                      
if sy-subrc <&flt; 0.
                      
call method client-&flt;get_last_error
                      
importing code = subrc
                      
message = errortext.
                      
write: / 'communication_error( send )',
                      
/ 'code: ', subrc, 'message: ', dummy.
                      
exit.
                      
endif.

Here, the last error must be queried again, using client->get_last_error.

Step 4

The response is now received and the client object is filled with the response data.

                      


                      
* receive
                      
call method client->receive
                      
exceptions http_communication_failure = 1
                      
http_invalid_state = 2
                      
http_processing_failed = 3
                      
others = 4.
                      
if sy-subrc <> 0.
                      
call method client->get_last_error
                      
importing code = subrc
                      
message = errortext.
                      
write: / 'communication_error( receive )',
                      
/ 'code: ', subrc, 'message: ', dummy.
                      
exit.
                      
endif.

Exceptions and error queries must be inserted here too.

If the connection is no longer being used, you must close the client object and the connection as follows:

                      


                      
* close
                      
call method client->close
                      
exceptions http_invalid_state = 1
                      
others = 2.

To document the successful test, the output routine is called at this point.

                      


                      
* output
                      
perform write_document.

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