Jackson Vs. Gson

Question

After searching through some existing libraries for JSON, I have finally ended up with these two:

• Jackson
• Google GSon

I am a bit partial towards GSON, but word on the net is that GSon suffers from certain celestial performance issue.

I am continuing my comparison, in the meanwhile I was looking for help to make up my mind.

Answer 1

I did this research the last week and I ended up with the same 2 libraries. As I'm using Spring 3 (that adopts Jackson in its default Json view 'JacksonJsonView') it was more natural for me to do the same. The 2 lib are pretty much the same... at the end they simply map to a json file! :)

Anyway as you said Jackson has a + in performance and that's very important for me. The project is also quite active as you can see from their web page and that's a very good sign as well.

Answer 2

Jackson and Gson are the most complete Java JSON packages regarding actual data binding support; many other packages only provide primitive Map/List (or equivalent tree model) binding. Both have complete support for generic types, as well, as enough configurability for many common use cases.

Since I am more familiar with Jackson, here are some aspects where I think Jackson has more complete support than Gson (apologies if I miss a Gson feature):

• Extensive annotation support; including full inheritance, and advanced "mix-in" annotations (associate annotations with a class for cases where you can not directly add them)
• Streaming (incremental) reading, writing, for ultra-high performance (or memory-limited) use cases; can mix with data binding (bind sub-trees)
• Tree model (DOM-like access); can convert between various models (tree <-> java object <-> stream)
• Can use any constructors (or static factory methods), not just default constructor
• Field and getter/setter access (earlier gson versions only used fields, this may have changed)
• Out-of-box JAX-RS support
• Interoperability: can also use JAXB annotations, has support/work-arounds for common packages (joda, ibatis, cglib), JVM languages (groovy, clojure, scala)
• Ability to force static (declared) type handling for output
• Support for deserializing polymorphic types (Jackson 1.5) -- can serialize AND deserialize things like List correctly (with additional type information)
• Integrated support for binary content (base64 to/from JSON Strings)