PI REST Adapter - How to handle 415 Unsupported format, Special Chars, & HTTP Error messages from 3rd party

[phanikumar_akella]

I am posting this blog post to share some of the challenges I have faced while integrating our SAP system with a REST-based 3^rd party system via SAP PI 7.31 SPS 19 REST adapter.

Scenario:

SAP sends Sync HTTP (GET and POST) requests to the 3^rd Party system (via SAP PI) and expects a response from 3^rd party system.



Issue 1: HTTP  415 Unsupported Media Type exception

All HTTP-GET requests are working fine. HTTP-POST messages triggered from SAP are failing with HTTP  415 Unsupported Media Type exception.

 



Root Cause:

Logs from 3^rd party application suggest POST request from SAP PI REST receiver adapter is failing at 3^rd party as charset is getting appended to the Content-Type HTTP header parameter

i.e. Content-Type = application/json;charset=UTF-8

From the SAP PI point of view, Content-Type is defined as application/json in the REST receiver adapter configuration. Also, PI adapter logs show RESTOUT_HTTP_HEADER Content-Type as application/json.



Solution:

The issue got resolved after implementing SAP Note “2456232 - Cannot send HTTP Content-Type header without charset value”.

 

Issue 2: Special characters in the REST Request

REST requests with special chars like &,’, /, are failing.

e.g. M&S

MARSK & SPENCERS.

Solution:

Implemented 2215187 - Options for URL encoding of query strings with PI REST adapter

Set Module parameter EncodeURL to false.



 

Note: After implementing this fix all the messages with spaces are failing.

i.e. M&S is working fine, but MARKS & SPENCERS is failing.

This issue got resolved after replacing & with %26 and spaces with +.

i.e. MARKS+%26+Spencers.

Pls find below list with more special chars and code used

Special Character	Description	Code Used	Status
£	(pound sign)	%C2%A3	Accepted
}	Right brace	%7D	Accepted
|	Vertical bar	%7C	Accepted
{	Left brace	%7B	Accepted
\	Backward Slash	%5C	Accepted
'	(Apostrophe)	27%	Accepted
&	(ampersand)	26%	Accepted
"	(Inverted Comma)	22%	Accepted
A-Z	(any standard letter)		Accepted
0-9	(any standard numeric)		Accepted
@	(at sign)		Accepted
$	(dollar sign)		Accepted
#	(hash tag)		Accepted
.	(full stop)		Accepted
,	(comma)		Accepted
:	(colon)		Accepted
;	(semi-colon)		Accepted
-	(hyphen)		Accepted
(	Left parenthesis		Accepted
)	Right parenthesis		Accepted
/	Forward Slash		Accepted
+	Plus		Accepted
_	Underscore		Accepted
=	Equals		Accepted
[	Square Bracket Open		Not Accepted
]	Square Bracket Close		Not Accepted
!	Exclamation		Not Accepted
~	Tilde		Not Accepted
`	Grave accent (backtick)		Not Accepted
<	Less Than		Not Accepted
>	Greater Than		Not Accepted
€	(euro sign)		Not Accepted
¥	(yen sign)		Not Accepted

 

Issue 3: HTTP Error Responses from 3^rd are not getting delivered to Source (i.e. SAP)

Non-200 HTTP (error) response messages from 3^rd party like HTTP 415, 503, 500, 404, 403 are failing in SAP PI and not getting delivered to Source (i.e. SAP)

 



Solution:

Test the service via the postman. Get the 3^rd party Error response structure and embed that in the PI response structure (DT).

In the Receiver Adapter configuration -> Error Handling

Source = HTTP Status Code

Select check box “Selection does NOT match”

Message Content = {http_result}

 



 

Conclusion: SAP has released many patches for REST adapter. Its recommended to check the patch levels before starting the development to avoid these issues.