Issue
It seems that the JSON default encoding is UTF-8 and Spring MVC returns application/json; charset=utf-8
by default, which is hard to change.
Solution
According to RFC 4627
JSON text SHALL be encoded in Unicode. The default encoding is UTF-8.
It goes on to describe how the different UTF-* encoding are to be detecting, suggesting that no other encodings are supported.
"SHALL" represents an absolute requirement here (see RFC 2119).
And there really is no reason to use a non-UTF encoding with JSON (as anything that can handle JSON can definitely handle UTF-8).
Answered By - Joachim Sauer