Java is an object-oriented programming language used for building mobile, desktop, web and embedded applications.

Java has a quite amazing open-source presence with over 1,302,333 repository results on which happens to be twice that of javascript.

As a Developer, contributing to an open-source project is good to scale faster. Events like Hacktoberfest even give out prices to encourage open source contribution.

Let’s have a look at some Amazing Java Opensource Projects, You might love to contribute too. Note: These listings are randomly arranged hence the first isn’t necessarily the best of all.

1. Guava: Google Core Libraries for Java

Guava is a set of core libraries that includes new collection types (such as multimap and multiset), immutable collections, a graph library, and utilities for concurrency, I/O, hashing, primitives, strings, and more!

2. MPAndroidChart

A powerful 🚀 Android chart view / graph view library, supporting line- bar- pie- radar- bubble- and candlestick charts as well as scaling, dragging and animations.

3. Butter Knife


Field and method binding for Android views which uses annotation processing to generate boilerplate code for you.

4. Apache Dubbo

Apache Dubbo (incubating) is a high-performance, java based RPC framework open-sourced by Alibaba.

5. AndroidUtilCode

AndroidUtilCode is a powerful & easy to use library for Android. This library encapsulates the functions that commonly used in Android development which have complete demo and unit tests. 

6. Picasso

A powerful image downloading and caching library for Android (Java).

7. Fresco

Fresco is a powerful system for displaying images in Android applications. It is created by Facebook.

8. LibGDX

LibGDX is a cross-platform Java game development framework based on OpenGL (ES) that works on Windows, Linux, Mac OS X, Android, your WebGL enabled browser and iOS.

9. Fastjson

Java Opensource Projects

Fastjson is a Java library that can be used to convert Java Objects into their JSON representation. It is created Alibaba

10. Jenkins

Java Opensource Projects

Jenkins is the leading open-source automation server. Built with Java, it provides over 1000 plugins to support automating virtually anything, so that humans can actually spend their time doing things machines cannot.

11. ExoPlayer

Java Opensource Projects

An extensible media player for Android (Java) created by Google.

12. Realm

Realm is a mobile database that runs directly inside phones, tablets or wearables.

13. Bazel

Java Opensource Projects

A fast, scalable, multi-language and extensible build system.

14. MyBatis

MyBatis SQL mapper framework for Java.

15. Dagger

Java Opensource Projects

A fast dependency injector for Android and Java by Square.

16. Guice

Java Opensource Projects

Guice (pronounced ‘juice’) is a lightweight dependency injection framework for Java 6 and above, brought to you by Google.

17. Auto

Java Opensource Projects

A collection of source code generators for Java.

18. JUnit 4

Java Opensource Projects

A programmer-oriented testing framework for Java.

19. Mockito

Java Opensource Projects

Popular Mocking framework for unit tests written in Java.

20. Rebound

Java Opensource Projects

A Java library that models spring dynamics and adds real-world physics to your app by Facebook.


Java Opensource Projects

A modern JSON library for Android and Java by Square.


I hope you enjoyed my article, Do well to leave a comment, tell us your opinions and share with us other open-source java projects you find.

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