Hi All, We are in the middle of a ongoing discussion about how to handle REST exceptions.
Response Content type : JSON
Two solutions we have:
1) Throw all the unchecked exceptions as a JSON response.
2) Send Request Invalid Response code.
Arguments:
When its a error, why return JSON? Just send a invalid response code.
Counter Argument:
Response code are too technical to handle for normal developers.
Whats your say??
For a JSON API I recently developed I do both. I always respond with valid JSON (well, assuming I respond at all). If I detect an invalid request, I use status 400. If I detect a server error (which I don't believe is caused by an invalid request), I use a 5xx status. The JSON object contains a special key that is only set for errors, with a string value.
I think this is a good solution that respects REST principles, and can be used in multiple ways. The same solution is used by some other JSON APIs, such as Yahoo Search. Try http://search.yahooapis.com/ImageSearchService/V1/imageSearch?appid=YahooDemo&output=json .
Use error codes like for HTTP. So 50* for any exception cause by some internal problem. And 40* for . Avoid using your own defined codes as far as its possible. The idea is to have a "uniform" interface.
In general. 201 for success without sending any content 200 for success with a json representation of the resource And if its not a successful operation return appropriate response code. You can choose to optionally return a json. To simplify things you can have a common format (json) for all error responses.
http://en.wikipedia.org/wiki/REST is a must read before you freeze on your api specs.