gson最新版本gson2.3.1,源码、文档、开发包一应俱全，需要的朋友可以下载试试，我刚好使用JSON转对象非常好用。
说明：
Provide simple toJson() and fromJson() methods to convert Java objects to JSON and vice-versa
Allow pre-existing unmodifiable objects to be converted to and from JSON
Extensive support of Java Generics
Allow custom representations for objects
Support arbitrarily complex objects (with deep inheritance hierarchies and extensive use of generic types)
