R/3 HTTP GET to external supplier - what are the options

Question

Hello all
Our scenario is that we have to connect to an external supplier using HTTP GET to get our order responses in the return structure. I was wondering what the best/easiest way is to do this.
We cannot use the HTTP adapter since that only supports HTTP-POST. Additionally the RFC that lies behind it does not allow query strings in the definition, something we need to use.
we could make use of the HTTP_GET function module in the SFTP function group but how to do it then?
-we cannot create an abap proxy for this since the outbound WSDL contains invalid keywords (choice keyword not supported)
-we probably could use BPM that calls the HTTP_GET.
-we could write an ABAP that calls the HTTP_GET and puts the output into a directory where XI can pick it up.
-I also read that you could write a small java function that does the HTTP_GET . But i have no experience with this.
So what is the best option to accomplish this?
thanks
Tom

Answer 1

From SP15 you may use Adapter-Specific Message Attributes.
To evaluate adapter attributes in the message header of the XI message, set the Use Adapter-Specific Message Attributes indicator.
œ     If you want missing message attributes to trigger an error message, set the Fail If Adapter-Specific Message Attributes Missing indicator. If the indicator is set and the header for adapter-specific message attributes or one of the set attributes is missing from the message, this leads to a system error (red flag).
If you do not set the indicator, and message attributes are missing, the adapter accesses information from the adapter configuration.
œ     If you want to use an HTTP destination or URL set by the mapping, set the URL or HTTP Destination indicator. (The indicator displayed depends on the Addressing Type you selected above). If you set the indicator, the URL or HTTP destination set dynamically is called by HTTP.
If the message header does not contain the URL or the HTTP destination, and you have set the Fail If Adapter-Specific Message Attributes Missing indicator, the XI message is set to status System Error. If you do not set the indicator, the URL or HTTP destination defined statically in the communication channel is used.
œ     If you want to use HTTP Header Fields, set the indicator and enter the fields in Field 1 to Field 6. The fields are embedded in the HTTP request under the names you enter here.
The technical names of the fields are HeaderFieldOne, .... HeaderFieldSix.
œ     If you want to use URL Parameters, set the indicator and enter the parameters in the fields Parameter 1 to Parameter 6. The parameters are embedded in the HTTP request under the names you enter here.
The technical names of the fields are URLParamOne, c, URLParamSix.
The attribute namespace for the adapter is http://sap.com/xi/XI/System/HTTP.
http://help.sap.com/saphelp_nw04/helpdata/en/43/64dbb0af9f30b4e10000000a11466f/content.htm
/Otto