google-gson

Gson is a Java library that can be used to convert Java Objects into their JSON representation. It can also be used to convert a JSON string to an equivalent Java object. Gson can work with arbitrary Java objects including pre-existing objects that you do not have source-code of.

There are a few open-source projects that can convert Java objects to JSON. However, most of them require that you place Java annotations in your classes; something that you can not do if you do not have access to the source-code. Most also do not fully support the use of Java Generics. Gson considers both of these as very important design goals.

Gson Goals

• 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)

Gson Downloads

• Gson 2.5 Download downloads at Maven Central

Gson Documentation

• Gson API: Javadocs for the current Gson release
• Gson user guide: This guide contains examples on how to use Gson in your code.
• Gson Roadmap: Details of changes in the recent versions
• Gson design document: This document discusses issues we faced while designing Gson. It also include a comparison of Gson with other Java libraries that can be used for Json conversion

Please use the google-gson Google group to discuss Gson, or to post questions.

Gson-related Content Created by Third Parties

• Gson Tutorial by StudyTrails