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.
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.
:information_source: Gson is currently in maintenance mode; existing bugs will be fixed, but large new features will likely not be added. If you want to add a new feature, please first search for existing GitHub issues, or create a new one to discuss the feature and get feedback.
Despite supporting older Java versions, Gson also provides a JPMS module descriptor (module name `com.google.gson`) for users of Java 9 or newer.
#### JPMS dependencies (Java 9+)
These are the optional Java Platform Module System (JPMS) JDK modules which Gson depends on.
This only applies when running Java 9 or newer.
-`java.sql` (optional since Gson 2.8.9)
When this module is present, Gson provides default adapters for some SQL date and time classes.
-`jdk.unsupported`, respectively class `sun.misc.Unsafe` (optional)
When this module is present, Gson can use the `Unsafe` class to create instances of classes without no-args constructor.
However, care should be taken when relying on this. `Unsafe` is not available in all environments and its usage has some pitfalls,
see [`GsonBuilder.disableJdkUnsafe()`](https://javadoc.io/doc/com.google.code.gson/gson/latest/com.google.gson/com/google/gson/GsonBuilder.html#disableJdkUnsafe()).
* [Releases and change log](https://github.com/google/gson/releases): Latest releases and changes in these versions; for older releases see [`CHANGELOG.md`](CHANGELOG.md)
* [Design document](GsonDesignDocument.md): This document discusses issues we faced while designing Gson. It also includes a comparison of Gson with other Java libraries that can be used for Json conversion
Please use the ['gson' tag on StackOverflow](https://stackoverflow.com/questions/tagged/gson) or the [google-gson Google group](https://groups.google.com/group/google-gson) to discuss Gson or to post questions.
Please perform a quick search to check if there are already existing issues or pull requests related to your contribution.
Keep in mind that Gson is in maintenance mode. If you want to add a new feature, please first search for existing GitHub issues, or create a new one to discuss the feature and get feedback.