Browse free open source Java Libraries and projects below. Use the toggles on the left to filter open source Java Libraries by OS, license, language, programming language, and project status.

  • Cloud data warehouse to power your data-driven innovation Icon
    Cloud data warehouse to power your data-driven innovation

    BigQuery is a serverless and cost-effective enterprise data warehouse that works across clouds and scales with your data.

    BigQuery Studio provides a single, unified interface for all data practitioners of various coding skills to simplify analytics workflows from data ingestion and preparation to data exploration and visualization to ML model creation and use. It also allows you to use simple SQL to access Vertex AI foundational models directly inside BigQuery for text processing tasks, such as sentiment analysis, entity extraction, and many more without having to deal with specialized models.
    Try for free
  • Infor M3 ERP Icon
    Infor M3 ERP

    Enterprise manufacturers and distributors requiring a solution to manage and execute complex processes

    Efficiently executing the complex processes of enterprise manufacturers and distributors. Infor M3 is a cloud-based, manufacturing and distribution ERP system that leverages the latest technologies to provide an exceptional user experience and powerful analytics in a multicompany, multicountry, and multisite platform. Infor M3 and related CloudSuite™ industry solutions include industry-leading functionality for the chemical, distribution, equipment, fashion, food and beverage, and industrial manufacturing industries. Staying ahead of the competition means staying agile. Our new capabilities bring improved data-driven insights and streamlined workflows to help you make informed decisions and take quick action.
    Learn More
  • 1
    JDA Java Discord API

    JDA Java Discord API

    Java wrapper for the popular chat & VOIP service

    JDA strives to provide a clean and full wrapping of the Discord REST api and its Websocket-Events for Java. This library is a helpful tool that provides the functionality to create a discord bot in java. Discord is currently prohibiting creation and usage of automated client accounts (AccountType.CLIENT). We have officially dropped support for client login as of version 4.2.0! Note that JDA is not a good tool to build a custom discord client as it loads all servers/guilds on startup unlike a client which does this via lazy loading instead. If you need a bot, use a bot account from the Application Dashboard.
    Downloads: 13 This Week
    Last Update:
    See Project
  • 2
    MCProtocolLib

    MCProtocolLib

    A library for communication with a Minecraft client/server

    MCProtocolLib is a simple library for communicating with Minecraft clients and servers. It allows developers to build custom bots, clients, or servers for Minecraft with ease.
    Downloads: 13 This Week
    Last Update:
    See Project
  • 3
    OpenAPI Generator

    OpenAPI Generator

    OpenAPI Generator allows generation of API client libraries

    With 50+ client generators, you can easily generate code to interact with any server which exposes an OpenAPI document. Maintainers of APIs may also automatically generate and distribute clients as part of official SDKs. Each client supports different options and features, but all templates can be replaced with your own Mustache-based templates. Getting started with server development can be tough, especially if you're evaluating technologies. We can reduce the burden when you bring your own OpenAPI document. Some generators support Inversion of Control, allowing you to iterate on design via your OpenAPI document without worrying about blowing away your entire domain layer when you regenerate code. Ever wanted to iteratively design a MySQL database, but writing table declarations was too tedious? OpenAPI documents allow you to convert the metadata about your API into some other format.
    Downloads: 12 This Week
    Last Update:
    See Project
  • 4
    Spoon

    Spoon

    Metaprogramming library to analyze and transform Java source code

    Spoon is an open-source library to analyze, rewrite, transform, transpile Java source code. It parses source files to build a well-designed AST with powerful analysis and transformation API. It supports modern Java versions up to Java 20. Spoon is an official Inria open-source project, and member of the OW2 open-source consortium.
    Downloads: 12 This Week
    Last Update:
    See Project
  • Agentic AI SRE built for Engineering and DevOps teams. Icon
    Agentic AI SRE built for Engineering and DevOps teams.

    No More Time Lost to Troubleshooting

    NeuBird AI's agentic AI SRE delivers autonomous incident resolution, helping team cut MTTR up to 90% and reclaim engineering hours lost to troubleshooting.
    Learn More
  • 5
    red5-server

    red5-server

    Red5 Server core

    Red5 is an Open Source Flash Server written in Java that supports streaming Video (FLV, F4V, MP4, 3GP). Streaming Audio (MP3, F4A, M4A, AAC) Recording Client Streams (FLV and AVC+AAC in FLV container) Shared objects, live stream publishing, remoting, and protocols: RTMP, RTMPT, RTMPS, and RTMPE.
    Downloads: 12 This Week
    Last Update:
    See Project
  • 6
    A Java JNA wrapper for Tesseract OCR API
    Leader badge
    Downloads: 77 This Week
    Last Update:
    See Project
  • 7
    AnLinux

    AnLinux

    AnLinux allow you to run Linux on Android without root access

    AnLinux allow you to run Linux on Android without root access. The bash script downloads the image over the internet, then decompresses the image, and then mounts it using PRoot.
    Downloads: 11 This Week
    Last Update:
    See Project
  • 8
    QR Code generator library

    QR Code generator library

    High-quality QR Code generator library in Java, TypeScript/JavaScript

    This project aims to be the best, clearest library for generating QR Codes. My primary goals are flexible options and absolute correctness. The secondary goals are compact implementation size and good documentation comments. This work is an independent implementation based on reading the official ISO specification documents. I believe that my library has a more intuitive API and shorter code length than competing libraries out there. The library is designed first in Java and then ported to TypeScript, Python, Rust, C++, and C. It is open source under the MIT License. For each language, the codebase is roughly 1000 lines of code and has no dependencies other than the respective language’s standard library.
    Downloads: 11 This Week
    Last Update:
    See Project
  • 9
    Svix

    Svix

    The enterprise-ready webhooks service

    Build a secure, reliable, and scalable webhook platform in minutes using the Svix webhook service. Webhooks require a lot more engineering time, resources and ongoing maintenance than you would first expect. Building a secure, reliable, and scalable webhook service is hard and time-consuming. We built it so you can focus on what matters most, your business. Customer endpoints fail or hang more often than you think. You need automatic retries to ensure deliverability. You need to monitor the deliverability of your webhooks to different endpoints, disable failing ones and notify your customers. Webhooks come with a myriad of security implications, such as SSRF, replay attacks and unauthenticated webhook events. You would need to build a UI for your users to add and remove endpoints, inspect logs and get ongoing reports. Offer your users a great developer experience, including the ability to test, inspect and replay their webhooks.
    Downloads: 11 This Week
    Last Update:
    See Project
  • All Things Performance and Partner Marketing, All in One Place Icon
    All Things Performance and Partner Marketing, All in One Place

    Track calls, leads, and clicks without the manual work

    Automatically tie revenue back to campaigns, channels, publishers, and networks through marketing attribution. Spend less time juggling reports, and more time optimizing for growth by using a single operating solution for partner and performance marketing.
    Learn More
  • 10
    EasyExcel

    EasyExcel

    Lightweight Java library developed by Alibaba for reading and writing

    EasyExcel is a Java library focused on reading and writing Excel files with very low memory usage, making it suitable for large datasets that overwhelm traditional APIs. It uses streaming/event-driven parsing to avoid loading entire workbooks into memory, and it maps rows to Java objects via simple annotations. Writers support multiple sheets, custom styles, merged cells, and template-based filling so production reports remain maintainable. The API emphasizes developer ergonomics: callbacks are straightforward, converters handle common type transformations, and header/column mapping is explicit. It integrates cleanly into Spring/enterprise stacks, often as part of import/export pipelines or scheduled report generation. By optimizing both performance and ease of use, EasyExcel reduces operational risk around big Excel jobs in web services and back-office tools.
    Downloads: 10 This Week
    Last Update:
    See Project
  • 11
    Logbook

    Logbook

    An extensible Java library for HTTP request and response logging

    Logbook is an extensible Java library to enable complete request and response logging for different client- and server-side technologies. It satisfies a special need by a) allowing web application developers to log any HTTP traffic that an application receives or sends b) in a way that makes it easy to persist and analyze it later. This can be useful for traditional log analysis, meeting audit requirements or investigating individual historic traffic issues. Logbook is ready to use out of the box for most common setups. Even for uncommon applications and technologies, it should be simple to implement the necessary interfaces to connect a library/framework/etc. to it.
    Downloads: 10 This Week
    Last Update:
    See Project
  • 12
    JNativeHook

    JNativeHook

    Global keyboard and mouse listeners for Java

    JNativeHook is a library to provide global keyboard and mouse listeners for Java. This will allow you to listen for global shortcuts or mouse motion that would otherwise be impossible using pure Java. To accomplish this task, JNativeHook leverages platform-dependent native code through Java's native interface to create low-level system-wide hooks and deliver those events to your application.
    Downloads: 9 This Week
    Last Update:
    See Project
  • 13
    Zeebe

    Zeebe

    Distributed Workflow Engine for Microservices Orchestration

    Automate processes at scale with unprecedented performance and resilience. Zeebe is the workflow and decision engine that powers Camunda Platform 8. Zeebe’s cloud-native design provides the performance, resilience, and security enterprises need to future-proof their process orchestration efforts. Zeebe distributes data across all brokers in a cluster with storage directly on the server filesystem. If one broker goes down, another can replace it with no data loss. This pre-configured replication mechanism ensures that Camunda Platform 8 can recover from machine or software failure with no human interaction, no data loss and minimal downtime.
    Downloads: 9 This Week
    Last Update:
    See Project
  • 14
    ImGui Java

    ImGui Java

    JNI based binding for Dear ImGui

    imgui-java is a comprehensive Java binding for Dear ImGui, the popular immediate-mode GUI library used for real-time tools and debug interfaces. This binding allows Java applications—including those using LWJGL or JOGL—to leverage ImGui’s fast and flexible GUI features without switching languages. With support for native backends and OpenGL rendering, imgui-java is perfect for game engines, development tools, and editors that need an intuitive GUI system. It includes integrations for multiple platforms and rendering contexts, with regular updates to match upstream ImGui releases.
    Downloads: 8 This Week
    Last Update:
    See Project
  • 15
    Infinity For Reddit

    Infinity For Reddit

    A Reddit client for Android

    A Reddit client on Android written in Java. It does not have any ads and it features a clean UI and smooth browsing experience. Infinity is a beautiful, feature-rich app that offers a smooth Reddit browsing experience. It is completely free and ad-less; you can browse Reddit without interruptions or distractions. Built by a passionate university student, Infinity is open source.
    Downloads: 8 This Week
    Last Update:
    See Project
  • 16
    JMX Exporter

    JMX Exporter

    A process for exposing JMX Beans via HTTP for Prometheus consumption

    JMX to Prometheus exporter: a collector that can configurable scrape and expose mBeans of a JMX target. This exporter is intended to be run as a Java Agent, exposing a HTTP server and serving metrics of the local JVM. It can be also run as a standalone HTTP server and scrape remote JMX targets, but this has various disadvantages, such as being harder to configure and being unable to expose process metrics (e.g., memory and CPU usage). Running the exporter as a Java agent is strongly encouraged.
    Downloads: 8 This Week
    Last Update:
    See Project
  • 17
    Importer library to import assets from different common 3D file formats such as Collada, Blend, Obj, X, 3DS, LWO, MD5, MD2, MD3, MDL, MS3D and a lot of other formats. The data is stored in an own in-memory data-format, which can be easily processed. www.open3mod.com/ is a 3D model viewer and exporter based on Assimp that is also Open Source.
    Downloads: 34 This Week
    Last Update:
    See Project
  • 18
    Alibaba Dragonwell8

    Alibaba Dragonwell8

    Alibaba Dragonwell8 JDK

    Over the years, more than a billion lines of Java code have been written in Alibaba. While adopting OpenJDK to run these applications, we have found a need to customize it specifically for large-scale Java application deployments. Our customization has been well-tested in our environment. We are now contributing some of our work into the Java community. Alibaba Dragonwell, as a downstream version of OpenJDK, is the in-house OpenJDK implementation at Alibaba. It is optimized for online e-commerce, financial and logistics applications running on 100,000+ servers. Alibaba Dragonwell is the engine that runs these distributed Java applications in extreme scaling.
    Downloads: 7 This Week
    Last Update:
    See Project
  • 19
    Booklore

    Booklore

    Digital library with smart shelves

    Booklore is a comprehensive self-hosted digital library platform that helps readers organize, manage, track, and even read their personal collections of books and comics from a centralized web interface. It provides powerful metadata management that automatically fetches rich details like titles, authors, covers, and publication info so your library looks organized and beautiful without manual data entry. Users can create smart shelves with custom filters, build dynamic collections that update automatically, and search through thousands of entries instantly, turning chaotic folders of files into a curated reading experience. Booklore supports multi-user access with granular permission controls, making it suitable for families, book clubs, or shared collections, and its built-in reader can display PDFs, EPUBs, and comic formats directly in a browser.
    Downloads: 7 This Week
    Last Update:
    See Project
  • 20
    MPAndroidChart

    MPAndroidChart

    A powerful Android chart view / graph view library

    MPAndroidChart is a powerful chart library for Android that offers a beautiful and comprehensive range of charts and graphs. Powerful and very easy to use, it supports the creation of bar-, line-, pie-, bubble-, scatter-, radar- and candlestick charts, as well as scaling, dragging and animations. Charts are rendered cleanly and are visually engaging. Visualizing your data exactly how you want is so much easier with MPAndroidChart. To see more great examples of MPAndroidChart, download the MPAndroidChart Example App on Google Play.
    Downloads: 7 This Week
    Last Update:
    See Project
  • 21
    jCasbin

    jCasbin

    An authorization library that supports access control models

    An authorization library that supports access control models like ACL, RBAC, ABAC for Golang, Java, C/C++, Node.js, Javascript, PHP, Laravel, Python, .NET (C#), Delphi, Rust, Ruby, Swift (Objective-C), Lua (OpenResty), Dart (Flutter) and Elixir. In Casbin, an access control model is abstracted into a CONF file based on the PERM metamodel (Policy, Effect, Request, Matchers). So switching or upgrading the authorization mechanism for a project is just as simple as modifying a configuration. Besides memory and file, Casbin policy can be stored into lots of places. Currently, dozens of databases are supported, from MySQL, Postgres, Oracle to MongoDB, Redis, Cassandra, AWS S3. jCasbin is a powerful and efficient open-source access control library for Java projects. It provides support for enforcing authorization based on various access control models.
    Downloads: 7 This Week
    Last Update:
    See Project
  • 22
    iText®, a JAVA PDF library

    iText®, a JAVA PDF library

    PDF Library for Developers

    iText is an open-source PDF library available for Java and .NET (C#). iText allows you to effortlessly generate and manipulate standards-compliant PDF documents with a powerful and feature-rich SDK. With iText, you can create archivable and accessible PDFs, split and merge documents, fill and flatten forms, digitally sign documents, and more. iText add-ons enable additional functionality, such as PDF creation from HTML templates, secure redaction, OCR, and much more. The latest versions of iText build on the success of previous versions and feature an improved document engine, high and low-level programming capabilities, and a more efficient modular structure. iText represents the next level for developers looking to leverage PDF in document workflows. The main project page for iText is now on GitHub, and all the latest releases, code samples, open source add-ons and tools, etc. can be found at https://github.com/itext/.
    Leader badge
    Downloads: 185 This Week
    Last Update:
    See Project
  • 23

    ConcatPDF

    PDF Concatenation Tool

    ConcatPDF is the tool to concatenate PDF files. It can concatenate, extract, encrypt, decrypt, configure PDF files, convert image files to PDF. GUI version and CUI version are both available. iText.NET is iText porting on .NET Framework by J#. This library allows you to generate PDF, (X)HTML, XML, RTF files on Microsoft.NET Framework including ASP.NET.
    Leader badge
    Downloads: 44 This Week
    Last Update:
    See Project
  • 24
    Jackcess
    A pure Java library for reading from and writing to MS Access databases.
    Leader badge
    Downloads: 31 This Week
    Last Update:
    See Project
  • 25
    Java Neural Network Framework Neuroph
    Neuroph is lightweight Java Neural Network Framework which can be used to develop common neural network architectures. Small number of basic classes which correspond to basic NN concepts, and GUI editor makes it easy to learn and use.
    Leader badge
    Downloads: 29 This Week
    Last Update:
    See Project
MongoDB Logo MongoDB