Improve response messages and implement meaningful error messages

[jannisjung]

As a developer or API user, I want the API to provide clear and meaningful error responses so that I can understand whether a feature is not implemented or there is an issue with the backend, and take appropriate action.

Rules

• When a feature is not implemented for an endpoint but the spec/interface includes it, the response when using it should reflect this
• When there is a problem in the backend, the response should include a meaningful response (not just internal server error 500 response)
• analyze, where exceptions are "just" passing the the stack trace, try throwing a more specific exception or if it is a runtime exception, add a more specific Error description

Entry Points

• aas-repository
• submodel-repository
• conceptdescription-repository
• AASXFileServer
• discovery-service
• submodel-service

Acceptance Criteria

For each endpoint all known errors are handled with meaningful error messages and http status

Risks and Assumptions

• Message handling for error responses should be part of common
• Error messages should be meaningful, but should not provide insight into the codebase
• how would just an exception be decoded to a useful message -> providing the message is more problematic -> mapping between exception and Message needed
  • Http status is translated to its actual meaning
  • Error Message that is provided by java is enough in the first place
  • (Translation from Java error message to meaningful error message is out of scope)

References & Notes

• How this could be achieved:
  https://github.com/eclipse-basyx/basyx-java-server-sdk/blob/main/basyx.aasregistry/basyx.aasregistry-service/src/main/java/org/eclipse/digitaltwin/basyx/aasregistry/service/errors/BasyxControllerAdvice.java
• identify Exceptions that are not considering the stack trace
• See also https://github.com/eclipse-basyx/basyx-java-server-sdk/blob/main/basyx.common/basyx.http/src/main/java/org/eclipse/digitaltwin/basyx/http/BaSyxExceptionHandler.java

This is the package for messages: org.eclipse.digitaltwin.basyx.aasregistry.model.Message

Dependencies and Blockers