gson

# 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.

> [!NOTE]\
> 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.

> [!IMPORTANT]\
> Gson's main focus is on Java. Using it with other JVM languages such as Kotlin or Scala might work fine in many cases, but language-specific features such as Kotlin's non-`null` types or constructors with default arguments are not supported. This can lead to confusing and incorrect behavior.\
> When using languages other than Java, prefer a JSON library with explicit support for that language.

> [!IMPORTANT]\
> Gson is not a recommended library for interacting with JSON on Android. The open-ended reflection in the Gson runtime doesn't play nicely with shrinking/optimization/obfuscation passes that Android release apps should perform.\
> If your app or library may be running on Android, consider using [Kotlin Serialization](https://github.com/Kotlin/kotlinx.serialization/blob/master/docs/basic-serialization.md#basics),
> which uses code generation instead of reflection. This avoids Gson's runtime crashes when optimizations are applied (usually due to the fields missing or being obfuscated), and results in faster performance on Android devices.
> If you still want to use Gson and attempt to avoid these crashes, you can see how to do so [here](Troubleshooting.md#proguard-r8).

### 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)

### Download

Gradle:
```gradle
dependencies {
  implementation 'com.google.code.gson:gson:2.15.0'
}
```

Maven:
```xml
<dependency>
  <groupId>com.google.code.gson</groupId>
  <artifactId>gson</artifactId>
  <version>2.15.0</version>
</dependency>
```

[Gson jar downloads](https://central.sonatype.com/artifact/com.google.code.gson/gson) are available from Maven Central.

![Build Status](https://github.com/google/gson/actions/workflows/build.yml/badge.svg)

### Requirements
#### Minim