[Spring MVC] Ignore some fields when returning JSONObject from Controller

http://stackoverflow.com/questions/23101260/ignore-fields-from-java-object-dynamically-while-sending-as-json-from-spring-mvc

http://stackoverflow.com/questions/8179986/jackson-change-jsonignore-dynamically

http://www.cowtowncoder.com/blog/archives/2011/02/entry_443.html