DefaultResponseErrorHandler wastes the body of a response with an unknown status [SPR-16604]

[spring-projects-issues]

Milos Cubrilo opened SPR-16604 and commented

RestTemplate.handleResponse calls ResponseErrorHandler.hasError(response) to check if it should delegate error handling to ResponseErrorHandler instance.

In case of an unknown status code, DefaultResponseErrorHandler.hasError swallows the exception thrown by DefaultResponseErrorHandler.getHttpStatusCode(response) and returns false.

This causes RestTemplate code to proceed with standard response handling, but without possibility to read message body, which has already been consumed during UnknownHttpStatusCodeException creation in DefaultResponseErrorHandler.getHttpStatusCode(response) call.

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Affects: 4.3.14

Issue Links:

• RestTemplate doesn't consistently tolerate unknown HTTP status codes [SPR-15978] #20529 RestTemplate doesn't consistently tolerate unknown HTTP status codes
• DefaultResponseErrorHandler.hasError doesn't tolerate unknown status codes [SPR-16108] #20656 DefaultResponseErrorHandler.hasError doesn't tolerate unknown status codes
• DefaultResponseErrorHandler should have its methods protected [SPR-15329] #19892 DefaultResponseErrorHandler should have its methods protected
• DefaultResponseErrorHandler does not handle status values outside of HttpStatus enum [SPR-17461] #21993 DefaultResponseErrorHandler does not handle status values outside of HttpStatus enum
• RestTemplate does not throw exception for custom error codes [SPR-17439] #21971 RestTemplate does not throw exception for custom error codes

Referenced from: pull request #1742, and commits 3b3f27d, d95bbb6

[spring-projects-issues]

Juergen Hoeller commented

Indeed, for hasError purposes, we should locally resolve the status code and catch the IllegalArgumentException instead. I'll revise this for 4.3.15.

Note that this has been resolved for 5.0 already where HTTP status code resolution has been streamlined in several places.

[spring-projects-issues]

Denys Ivano commented

I also faced difficulties with unknown status codes. We have some logic based on catching and processing RestClientResponseException, especially it's subclass - UnknownHttpStatusCodeException. But in 4.3.12 new approach was introduced, so we can't even get response data w/o providing custom ResponseErrorHandler. Maybe it would be better to make hasError() method work the same way as it works in Spring Framework 5. I've submitted pull request which is able to resolve this issue. I hope this will help.
#1742

[spring-projects-issues]

Juergen Hoeller commented

Resolved through direct enum value comparisons in hasError (without an intermediate exception and therefore as analogous as possible to the 5.0 code).