After you migrate to SAS^® 9.4M9 (TS1M9), REST API calls to the Decision Services endpoint fail with HTTP 400 errors:

curl -v -X POST "http://servername:7980/RTDM/rest/runtime/decisions/Event%20Definition(1)" \
-H "Content-Type: application/vnd.sas.decision.request+json" \
--data-binary @payload.json \
-o respuesta1.json

This error comes from DecisionInputJSONHttpMessageConverter.readInternal(), where an instance of ServletServerHttpRequest fails.

Cause

This issue is caused by the following migration changes:

• SAS^® 9.4M7 (TS1M7): Spring Framework 3.2.18 + Tomcat 9 + javax.servlet
• SAS^® 9.4M9 (TS1M9): Spring Framework 6.1.15 + Tomcat 10 + jakarta.servlet

Specifically, the migration fails because spring 6 introduced a new decorator pattern where HttpInputMessage objects are wrapped in EmptyBodyCheckingHttpInputMessage before being passed to message converters.

This wrapper does as follows:

• Checks if the request body is empty before converter execution.
• Wraps the original ServletServerHttpRequest to provide this functionality.
• Breaks direct instances of ServletServerHttpRequest checks.