ad5cd31498
* Add shrinker-test examples with never-referenced constructors R8 can do some optimizations that assume values of types whose constructors are never referenced are `null`. (A bit confused why the rules here are sufficient to avoid that optimization in the case of a class whose sole constructor has arguments and is unreferenced, since the keep rule only refers to `<init>()` instead of `<init>(...)`. Does R8 have special behavior for `<init>()` where attempting to keep that makes it assume a class is constructable even if it doesn't have a no-args constructor?) Also rename some test classes/names to refer to `NoArgs` instead of `Default` constructors. The examples here care about whether a no-argument constructor is present. While a no-argument constructor (explicitly defined or not) is used by default in some circumstances, the Java documentation consistently uses "default constructor" to refer only to constructors whose implementation is implicitly provided by the complier (all default constructors are no-argument constructors, but not vice versa). * Update shrinker-test/src/main/java/com/example/ClassWithNoArgsConstructor.java Accept review suggestion Co-authored-by: Marcono1234 <Marcono1234@users.noreply.github.com> * Update shrinker-test/src/main/java/com/example/NoSerializedNameMain.java Accept review suggestion Co-authored-by: Marcono1234 <Marcono1234@users.noreply.github.com> * Further adjust test class/method names for consistency * Update shrinker-test/src/main/java/com/example/NoSerializedNameMain.java Co-authored-by: Marcono1234 <Marcono1234@users.noreply.github.com> --------- Co-authored-by: Marcono1234 <Marcono1234@users.noreply.github.com> |
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.github | ||
.mvn | ||
examples/android-proguard-example | ||
extras | ||
graal-native-image-test | ||
gson | ||
lib | ||
metrics | ||
proto | ||
shrinker-test | ||
.gitignore | ||
CHANGELOG.md | ||
GsonDesignDocument.md | ||
LICENSE | ||
pom.xml | ||
README.md | ||
ReleaseProcess.md | ||
Troubleshooting.md | ||
UserGuide.md |
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.
ℹ️ 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.
Goals
- Provide simple
toJson()
andfromJson()
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:
dependencies {
implementation 'com.google.code.gson:gson:2.10.1'
}
Maven:
<dependency>
<groupId>com.google.code.gson</groupId>
<artifactId>gson</artifactId>
<version>2.10.1</version>
</dependency>
Gson jar downloads are available from Maven Central.
Requirements
Minimum Java version
- Gson 2.9.0 and newer: Java 7
- Gson 2.8.9 and older: Java 6
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 classsun.misc.Unsafe
(optional)
When this module is present, Gson can use theUnsafe
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, seeGsonBuilder.disableJdkUnsafe()
.
Minimum Android API level
- Gson 2.11.0 and newer: API level 21
- Gson 2.10.1 and older: API level 19
Older Gson versions may also support lower API levels, however this has not been verified.
Documentation
- API Javadoc: Documentation for the current release
- User guide: This guide contains examples on how to use Gson in your code
- Troubleshooting guide: Describes how to solve common issues when using Gson
- Releases and change log: Latest releases and changes in these versions; for older releases see
CHANGELOG.md
- Design document: 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 or the google-gson Google group to discuss Gson or to post questions.
Related Content Created by Third Parties
- Gson Tutorial by
StudyTrails
- Gson Tutorial Series by
Future Studio
- Gson API Report
Building
Gson uses Maven to build the project:
mvn clean verify
JDK 11 or newer is required for building, JDK 17 is recommended.
Contributing
See the contributing guide.
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.
License
Gson is released under the Apache 2.0 license.
Copyright 2008 Google Inc.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
Disclaimer
This is not an officially supported Google product.