topic Re: CL_HTTP_CLIENT strips duplicate parameters from URI in Application Development and Automation Discussions

CL_HTTP_CLIENT strips duplicate parameters from URI

Pyc — Thu, 14 Jun 2012 01:10:13 GMT

G'day all,

I'm having an issue calling a URL which contains duplicate parameters because CL_HTTP_CLIENT is stripping out the duplicates.

The URI is in the form like:

?&action="CREATE"&type="Project"&id="MA-00178"&actype="Vendor"&acid="0000100020"&actype="ProjectAppropriation"&acid="MA00178"

When the request leaves SAP it's in form:

?&action="CREATE"&type="Project"&id="MA-00178"&actype="ProjectAppropriation"&acid="MA00178"

I've debugged down to a level within the class where the parameters are taken from the URI and formatted into a table of name value pairs and is then passed down to a C level routine which I can only assume deletes duplicates from the table before reconstructing the URI.

Is there anyway to prevent this?

Many thanks,
Mark

Re: CL_HTTP_CLIENT strips duplicate parameters from URI

Former Member — Tue, 18 Jun 2013 05:57:30 GMT

Did you ever get to the bottom of this? I think I have debugged into the same bit of code and can see a system-call that seems to overwrite any duplicate/subsequent URL query parameters with the first value.

I can't seem to find a general agreement in "HTTP Land" how duplicate query parameters should be handled but there is a discussion here: http://stackoverflow.com/questions/1746507/authoritative-position-of-duplicate-http-get-query-keys

Cheers,

Simon

Re: CL_HTTP_CLIENT strips duplicate parameters from URI

Pyc — Tue, 18 Jun 2013 07:07:18 GMT

G'day Simon,

Unfortunately the detail of this is lost is a client email system, but in the end I believe the solution was to ensure that parameter names were unique. I was in the fortunate position of designing both sides of the solution and so could work around the limitation.

Given the stripping happens down in C you can't do much other than request SAP's help. Given the variety of responses in your link I can imagine that SAP may do it on purpose 'to be safe' or 'consistent' - i.e. regardless of the receiving system the solution will work consistently, unfortunately consistently with duplicates removed.

Good luck,

Mark

Re: CL_HTTP_CLIENT strips duplicate parameters from URI

UweFetzer_se38 — Tue, 18 Jun 2013 10:11:35 GMT

I was in the fortunate position of designing both sides of the solution

First of all I would change the request from a GET to a POST, because you want to "CREATE" something.

This would also have the advantage, that you can fill the request body with whatever you want (XML, JSON, plain text), even dublicate parameters.

Re: CL_HTTP_CLIENT strips duplicate parameters from URI

Former Member — Tue, 18 Jun 2013 16:11:25 GMT

There is a note about duplicate parameters being overwritten, see SAP note 1856171.

https://service.sap.com/sap/support/notes/1856171