使用GSON反序列化时如何记录丢弃的字段？

Question

I am using JSON as a save format.

If I change the field names of my object GSON will silently discard the original fields upon loading the older version, because they no longer match the new names.

I would like to be able to get some notification if I do this accidentally through refactoring, ie "Warning: variableName not found in ObjectType during deserialization." There is a @Version annotation but it isn't exactly what I'm looking for.

Has anyone written a custom deserializer or custom type converter that will throw an error when a field in the JSON does not exist in the type? Is there another serialization library that does this?

Edit: I would still be interested in a GSON deserializer that does this as well, if anyone has one.

Answer 1

Jackson can be used to fail on unexpected JSON elements. Jackson can also be configured to gather (and log) all unbound JSON elements, as described at http://www.cowtowncoder.com/blog/archives/2010/09/entry_414.html (search for "any setter").

If you're already familiar with Gson, I documented how to use Jackson to do the same things covered in the Gson User Guide at http://programmerbruce.blogspot.com/2011/07/gson-v-jackson-part-6.html .