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.

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  • 1
    PSLab Android App

    PSLab Android App

    PSLab Android App

    Repository for the PSLab Android App for performing experiments with the Pocket Science Lab open-hardware platform. This repository holds the Android App for performing experiments with PSLab. PSLab is a tiny pocket science lab that provides an array of equipment for doing science and engineering experiments. It can function like an oscilloscope, waveform generator, frequency counter, programmable voltage and current source and also as a data logger. PSLab is a tiny pocket science lab that provides an array of equipment for doing science and engineering experiments.
    Downloads: 2 This Week
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  • 2
    SOFAJRaft

    SOFAJRaft

    A production-grade java implementation of RAFT consensus algorithm

    SOFAJRaft is a production-level, high-performance Java implementation based on the RAFT consistency algorithm that supports MULTI-RAFT-GROUP for high-load, low-latency scenarios. With SOFAJRaft you can focus on your business area. SOFAJRaft handles all RAFT-related technical challenges. SOFAJRaft is very user-friendly, which provides several examples, making it easy to understand and use.
    Downloads: 2 This Week
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  • 3
    SeriesGuide

    SeriesGuide

    Track your favorite TV shows and movies on Android devices

    SeriesGuide highlights shows with new episodes and is backed by the huge TV show catalog of TMDb. It can display movies currently in cinemas or released digitally and offers access to the huge movie catalog of TMDb. It also integrates with Trakt to sync your watched episodes and movies. Connect your Trakt account or sign into SeriesGuide Cloud to sync your watched episodes and movies. Hit the share button to post a link to an awesome episode or movie to any Android app, including WhatsApp, Signal, Facebook and Twitter. Visual indicators make it easy to see remaining episodes and to spot unseen episodes. The statistics tool sums how many hours you have spent watching (and still have to).
    Downloads: 2 This Week
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  • 4
    WebRTC Android

    WebRTC Android

    webrtc VideoCall VideoConference

    WebRTC Android is a sample project that showcases how to implement real-time peer-to-peer communication (audio, video, and data) on Android using WebRTC. It demonstrates a complete pipeline—from signaling and connection setup to media capture and transmission—making it an excellent reference for developers looking to integrate WebRTC into their mobile apps. The project includes UI components and handles network state changes, codec configuration, and ICE negotiation to provide a robust base for real-world applications.
    Downloads: 2 This Week
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  • 5
    fastjson

    fastjson

    A fast JSON parser/generator for Java

    Fastjson is a Java library that can be used to quickly convert Java Objects into their JSON representation or convert JSON strings to their equivalent Java object. Based on benchmarks it provides the best performance in both server side and Android client, and can work with arbitrary Java objects, even those pre-existing objects of which you do not have the source code. Fastjson provides a simple conversion method to turn Java objects to JSON and vice versa, with extensive support of Java Generics and arbitrarily complex objects.
    Downloads: 2 This Week
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  • 6
    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: 2 This Week
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  • 7
    jsoup

    jsoup

    Java library for working with real-world HTML

    jsoup is a Java library for working with real-world HTML. It provides a very convenient API for fetching URLs and extracting and manipulating data, using the best of HTML5 DOM methods and CSS selectors. jsoup implements the WHATWG HTML5 specification, and parses HTML to the same DOM as modern browsers do. jsoup is designed to deal with all varieties of HTML found in the wild; from pristine and validating, to invalid tag-soup; jsoup will create a sensible parse tree. The parser will make every attempt to create a clean parse from the HTML you provide, regardless of whether the HTML is well-formed or not. You have HTML in a Java String, and you want to parse that HTML to get at its contents, or to make sure it's well formed, or to modify it. The String may have come from user input, a file, or from the web.
    Downloads: 2 This Week
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  • 8
    openHAB Distribution

    openHAB Distribution

    The binary distribution of openHAB

    The open Home Automation Bus (openHAB) project aims to provide a universal integration platform for all things around home automation. It is a pure Java solution, fully based on OSGi. It is designed to be vendor-neutral as well as hardware/protocol-agnostic. openHAB brings together different bus systems, hardware devices, and interface protocols by dedicated bindings. These bindings send and receive commands and status updates on the openHAB event bus. This concept allows designing user interfaces with a unique look&feel, but with the possibility to operate devices based on a big number of different technologies. Besides the user interfaces, it also brings the power of automation logic across different system boundaries.
    Downloads: 2 This Week
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  • 9
    Moved to https://github.com/DANS-KNAW/dans-dbf-lib.
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    Downloads: 12 This Week
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  • 10
    AWS Secrets Manager JDBC Library

    AWS Secrets Manager JDBC Library

    The AWS Secrets Manager JDBC Library for Java developers

    The AWS Secrets Manager JDBC Library enables Java developers to easily connect to SQL databases using secrets stored in AWS Secrets Manager. We provide database drivers that intercept calls to real database drivers and swap out secret IDs for actual login credentials. This prevents hard-coding database credentials into your application code. This can be integrated into your app through a few configuration file changes. Change the jdbc url to one that our driver will intercept (starting with jdbc-secretsmanager), Change the c3p0 user to be the secret ID of the secret in secrets manager that has the username and password, and change the driverClass to be our driver wrapper. The secret being used should be in the JSON format we use for our rotation lambdas for RDS databases.
    Downloads: 1 This Week
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  • 11
    Aleph

    Aleph

    Asynchronous streaming communication for Clojure

    Aleph is an asynchronous I/O framework for Clojure built atop Netty, offering efficient, non-blocking network programming with support for HTTP, raw TCP/UDP, and streaming through Manifold streams. Aleph follows the Ring spec fully and can be a drop-in replacement for any existing Ring-compliant server. However, it also allows for the handler function to return a Manifold deferred to represent an eventual response. This feature may not play nicely with synchronous Ring middleware, which modifies the response, but this can be easily fixed by reimplementing the middleware using Manifold's let-flow operator. The aleph.http/wrap-ring-async-handler helper can be used to convert async 3-arity Ring handler to an Aleph-compliant one.
    Downloads: 1 This Week
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  • 12
    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: 1 This Week
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  • 13
    Apache Shiro

    Apache Shiro

    Apache Shiro

    Apache Shiro is a powerful and easy-to-use Java security framework that performs authentication, authorization, cryptography, and session management. With Shiro’s easy-to-understand API, you can quickly and easily secure any application, from the smallest mobile applications to the largest web and enterprise applications.
    Downloads: 1 This Week
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  • 14
    Brave

    Brave

    Java distributed tracing implementation compatible with Zipkin backend

    Brave is a distributed tracing instrumentation library. Brave typically intercepts production requests to gather timing data, correlate and propagate trace contexts. While typically trace data is sent to Zipkin server, third-party plugins are available to send to alternate services such as Amazon X-Ray. This repository includes dependency-free Java libraries and instrumentation for common components used in production services. For example, this includes trace filters for Servlet and log correlation for Apache Log4J. Brave's dependency-free tracer library works against JRE6+. This is the underlying api that instrumentation use to time operations and add tags that describe them. This library also includes code that parses X-B3-TraceId headers.
    Downloads: 1 This Week
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  • 15
    Caffeine

    Caffeine

    A high performance caching library for Java

    Caffeine is a high performance Java caching library providing a near optimal hit rate. A Cache is similar to ConcurrentMap, but not quite the same. The most fundamental difference is that a ConcurrentMap persists all elements that are added to it until they are explicitly removed. A Cache on the other hand is generally configured to evict entries automatically, in order to constrain its memory footprint. In some cases a LoadingCache or AsyncLoadingCache can be useful even if it doesn't evict entries, due to its automatic cache loading. To improve integration, JSR-107 JCache and Guava adapters are provided in extension modules. JSR-107 standardizes a Java 6 based API to minimize vendor specific code at the cost of features and performance. Guava's Cache is the predecessor library and the adapters provide a simple migration strategy. Automatic loading of entries into the cache, optionally asynchronously and size-based eviction when a maximum is exceeded based on frequency and recency.
    Downloads: 1 This Week
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  • 16
    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: 1 This Week
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  • 17
    EasyPermissions

    EasyPermissions

    Simplify Android M system permissions

    EasyPermissions is a wrapper library to simplify basic system permissions logic when targeting Android M or higher. If your app is written in Kotlin consider the easypermissions-ktx library which adds Kotlin extensions to the core EasyPermissions library. To begin using EasyPermissions, have your Activity (or Fragment) override the onRequestPermissionsResult method. If all of the permissions in a given request are granted, all methods annotated with the proper request code will be executed(be sure to have an unique request code). The annotated method needs to be void and without input parameters (instead, you can use onSaveInstanceState in order to keep the state of your suppressed parameters). This is to simplify the common flow of needing to run the requesting method after all of its permissions have been granted. Optionally, for a finer control, you can have your Activity / Fragment implement the PermissionCallbacks interface.
    Downloads: 1 This Week
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  • 18
    FancyToast-Android

    FancyToast-Android

    Make your native android Toasts Fancy

    Make your native Android Fantasy Toasts. A library that takes standard Android toast to the next level with a variety of style options. His style of code toast. Make your native Android Fantasy and Gify dialogue. A library that takes the Android dialog standard to the next level with a variety of style options and the GIF of. Your dialogue style from the code. Make your native Fantasy dialogue android. A library that takes the Android dialog standard to the next level with a variety of style options. Your dialogue style from the code. Fantasy Tutorial is a simple and lightweight library that helps you create fresh and beautiful introduction displays for your applications without having to write dozens of lines of code. As its name describes it, it is an Android library that can be used to display badges that react like facebook.
    Downloads: 1 This Week
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  • 19
    File System Crawler for Elasticsearch

    File System Crawler for Elasticsearch

    Elasticsearch File System Crawler (FS Crawler)

    This crawler helps to index binary documents such as PDF, Open Office, MS Office. Local file system (or a mounted drive) crawling and indexing new files, updating existing ones, and removing old ones. Remote file system over SSH/FTP crawling. REST interface to let you “upload” your binary documents to elastic search.
    Downloads: 1 This Week
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  • 20
    Glide

    Glide

    Android image loading & caching library focused on smooth scrolling

    Glide is a fast and efficient open source image loading and caching library for Android that focuses on smooth scrolling. It supports fetching, decoding and displaying images, video stills as well as animated GIFs, with a simple and easy to use interface and API. Glide offers a performant and extensible resource decoding pipeline and automatic resource pooling, and a flexible API that allows developers to plug in to just about any network stack. It is primarily focused on making any type of a list of images as smooth and fast as possible, and is able to achieve this through smart and automatic downsampling and caching, aggressive re-use of resources and deep lifecycle integration. Apart from smooth and speedy scrolling, it’s also good for any case where fetching, resizing, and displaying of a remote image is needed.
    Downloads: 1 This Week
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  • 21
    Google Cloud Dataflow Template Pipelines

    Google Cloud Dataflow Template Pipelines

    Cloud Dataflow Google-provided templates for solving data tasks

    DataflowTemplates is the source repository for Google-provided Dataflow templates that are intended to solve large-scale in-cloud data processing tasks without requiring users to build everything from scratch in a full development environment. The repository is centered on templated pipelines powered by Google Cloud Dataflow and Apache Beam, making it easier to run common integration and movement jobs such as data import, export, backup, restore, and bulk API operations. Its structure shows support for multiple generations of templates, including v1 and v2 implementations, as well as related metadata, YAML assets, plugins, and Python components that support broader template execution and maintenance. This design makes the project more than a sample set, because it acts as the implementation base for official Google-provided templates used in real cloud data workflows.
    Downloads: 1 This Week
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  • 22
    GraphHopper Routing Engine

    GraphHopper Routing Engine

    Open source routing engine for OpenStreetMap

    GraphHopper invests in an active open source community. Our flagships are the GraphHopper routing engine and jsprit, the toolkit for solving rich vehicle routing problems. We promote a fair & diverse mindset. jsprit is a Java based toolkit for solving rich traveling salesman problems (TSP) and vehicle routing problems (VRP). It is lightweight, flexible, easy-to-use, and based on a single all-purpose meta-heuristic. The GraphHopper routing engine is fast and memory-efficient, using Java. It runs server side, offline on Android and iOS. It uses OpenStreetMap data, but can import other data sources as well. GraphHopper is a fast and memory-efficient routing engine released under Apache License 2.0. It can be used as a Java library or standalone web server to calculate the distance, time, turn-by-turn instructions and many road attributes for a route between two or more points. Beyond this "A-to-B" routing it supports "snap to road", Isochrone calculation, mobile navigation and more.
    Downloads: 1 This Week
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  • 23
    Helidon

    Helidon

    Java libraries for writing microservices

    Helidon is a cloud-native, open‑source set of Java libraries for writing microservices that run on a fast web core powered by Netty. Helidon Níma is the first Java microservices framework based on virtual threads. Helidon is designed to be simple to use, with tooling and examples to get you going quickly. Since Helidon is simply a collection of Java libraries running on a fast Netty core, there is no extra overhead or bloat. Helidon supports MicroProfile and provides familiar APIs like JAX-RS, CDI and JSON-P/B. Our implementation runs on our fast Helidon Reactive WebServer. Helidon Reactive WebServer provides a modern functional programming model and runs on top of Netty. Lightweight, flexible and reactive, the Helidon WebServer provides a simple-to-use and fast foundation for your microservices.
    Downloads: 1 This Week
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  • 24
    JSqlParser

    JSqlParser

    JSqlParser parses an SQL statement and translate it into a hierarchy

    JSqlParser is a SQL statement parser. It translates SQLs in a traversable hierarchy of Java classes. JSqlParser is not limited to one database but provides support for a lot of specials of Oracle, SqlServer, MySQL, PostgreSQL. To name some, it has support for Oracles join syntax using (+), PostgreSQLs cast syntax using ::, relational operators like != and so on. Then the result can be accessed in a structured way. The generated Java class hierarchy can be navigated using the Visitor Pattern.
    Downloads: 1 This Week
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  • 25
    JaCoCo Java Code Coverage Library

    JaCoCo Java Code Coverage Library

    Java Code Coverage Library

    JaCoCo is a free code coverage library for Java, which has been created by the EclEmma team based on the lessons learned from using and integrating existing libraries for many years.
    Downloads: 1 This Week
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