whatisgithub

Popular Java repositories on GitHub, each answered in plain English for non-coders: what it is, its tech stack, and how to run it.

• openrefine/openrefineA free desktop app for cleaning and fixing messy spreadsheets and datasets, accessed through your browser loca
• jd-opensource/joyagent-jdgenieA complete, runnable AI agent system from JD.com that takes a plain-language request and delivers a finished r
• frank-lam/fullstack-tutorialA Chinese-language study guide covering the full range of software development topics — from algorithms to dis
• code4craft/webmagicWebMagic is a Java library for building web crawlers that handles page fetching, link following, multi-threadi
• starrocks/starrocksStarRocks is an open-source analytical database built for sub-second queries across billions of rows, and it c
• newbee-ltd/newbee-mallA complete Java e-commerce system built for learning, featuring a customer storefront and admin panel on Sprin
• realm/realm-javaA mobile database for Android that stores data as objects your Java code reads and writes directly, with optio
• gyf-dev/immersionbarAn Android library that controls the status bar and navigation bar appearance in your app with a simple one-li
• careercup/ctci-6th-editionWorking code solutions for every problem in Cracking the Coding Interview 6th Edition, with the official Java
• jhy/jsoupJava library for fetching, parsing, editing, and sanitizing HTML and XML — handles real-world messy web pages
• apple/pklPkl is a configuration-as-code language from Apple that adds types, validation, and reusable templates to conf
• mission-peace/interviewA Java repository of solutions to hundreds of coding interview algorithm and data structure problems, used alo
• apereo/casApereo CAS is a Java-based single sign-on server used mainly in education: users log in once and access many a
• ssssssss-team/spider-flowA no-code web scraping platform where you build scrapers by drawing a flowchart. Handles dynamic pages, proxy
• permissions-dispatcher/permissionsdispatcherAndroid library that cuts out the repetitive code required to ask users for permissions by letting you declare
• daniulive/smarterstreamingA cross-platform SDK for real-time live video streaming with 100–200ms latency on Android, iOS, Windows, and L
• jingmatrix/vectorAn Android framework for rooted phones that lets installable modules change how apps behave at runtime using f
• lingochamp/filedownloaderFileDownloader is an Android library for background file downloads with pause, resume, multi-connection, and b
• h07000223/flycotablayoutFlycoTabLayout is an Android library offering three customizable tab bar styles with sliding indicators, notif
• jwtk/jjwtA Java library for creating, signing, and verifying JSON Web Tokens. Set claims, sign with a key, and get back
• jfeinstein10/slidingmenuAndroid library that adds a slide-out navigation panel to any app — the style made popular by Facebook and You
• androidannotations/androidannotationsA Java framework for Android that uses annotations to automatically generate repetitive setup code, so you wri
• aslody/virtualappAndroid framework that runs other apps inside a sandboxed container, enabling multiple accounts of the same ap
• clojure/clojureThe official source repository for the Clojure programming language. Contains the JVM compiler and runtime wri
• square/javapoetJavaPoet is a deprecated Java library from Square that lets you write code which generates other Java code, au
• tootallnate/java-websocketA pure-Java library for adding WebSocket server or client support to any Java application, with non-blocking c
• zfile-dev/zfileZFile is a self-hosted web app that connects Amazon S3, OneDrive, Google Drive, and other storage in one brows
• alibaba/vlayoutvlayout is an Android library from Alibaba that lets you mix different layout styles — grids, banners, sticky
• resilience4j/resilience4jA Java fault-tolerance library with circuit breakers, retries, rate limiters, and bulkheads. Wraps service cal
• android-async-http/android-async-httpA lightweight Java library for making HTTP requests in Android apps that run entirely in the background, keepi
• jeasonlzy/okhttp-okgoAn Android networking library that simplifies HTTP requests by wrapping OkHttp, adding built-in response cachi
• google/autoA set of four Google-maintained Java code generators that eliminate repetitive boilerplate — automatically pro
• sonarsource/sonarqubeSonarQube is a self-hosted server that continuously scans your codebase for bugs, security vulnerabilities, an
• signalapp/signal-serverThe open-source server software that powers Signal's encrypted private messaging service, handling message del
• activiti/activitiAn open-source Java library that runs business workflows defined as BPMN 2 diagrams — automating multi-step pr
• lipangit/jiaozivideoplayerAn Android video player library in Java you can drop into any app, swap the playback engine with one line of c
• zcshou/gogogoAn Android app that lets you fake your phone's GPS location without root access, using Android developer tools
• tbruyelle/rxpermissionsAn Android library that wraps runtime permission requests (camera, contacts, etc.) in RxJava observables, so y
• awsdocs/aws-doc-sdk-examplesA large collection of working code examples for every major AWS service across 11 programming languages — the
• jessyancoding/mvparmsMVPArms is an Android app framework that bundles Retrofit, RxJava, Dagger2, and other popular libraries into a
• stanfordnlp/corenlpStanford CoreNLP is a Java library from Stanford that extracts structured information from text — named entiti
• crossoverjie/cimAn open-source instant messaging system built for developers to study or extend — supports group and private c
• umano/androidslidinguppanelA Java library for Android that adds a draggable bottom panel — like the info strip in Google Maps — which sli
• justson/agentwebAgentWeb is a Java library for Android that wraps the built-in WebView component to make displaying web pages
• json-path/jsonpathJayway JsonPath is a Java library that lets you extract specific values from JSON documents using short path e
• apache/jmeterAn open-source load testing tool that simulates hundreds or thousands of users hitting your website, API, or d
• huanghaibin-dev/calendarviewAn Android library for adding a fast, customizable calendar to mobile apps — supports monthly, weekly, and yea
• pockethub/pockethubAn open-source Android app for browsing GitHub on your phone — view repos, issues, and pull requests — origina
• gcssloop/androidnoteA personal collection of Android development notes in Chinese covering custom UI views, Canvas drawing, touch
• apache/seatunnelApache SeaTunnel moves large amounts of data between 160+ sources and destinations — databases, cloud storage,
• android/testing-samplesA collection of small Android example projects from Google's Android team, each demonstrating a specific tool
• flowable/flowable-engineFlowable is a Java platform for automating multi-step business processes and workflows using industry standard
• hmcl-dev/hmclA desktop Minecraft launcher written in Java that gives players more control than the official one, with mod m
• wasabeef/android-gpuimageLibrary that lets Android developers apply GPU-accelerated visual filters — blur, sepia, sharpen, edge detecti
• lsposed/lspatchA tool for Android that lets you apply Xposed-style app modifications without rooting your device by injecting
• didi/virtualapkVirtualAPK is an Android framework from Didi that lets a main app dynamically load and run additional APK file
• kunminx/jetpack-mvvm-best-practiceA sample Android music player app that shows Java developers how to correctly use Google Jetpack components li
• pojavlauncherteam/pojavlauncherAn open-source Android app that lets you play Minecraft: Java Edition on your phone, supporting versions up to
• checkstyle/checkstyleCheckstyle automatically scans Java source files against a set of style and formatting rules, flagging violati
• navasmdc/materialdesignlibraryAn Android library that adds Material Design UI components — buttons, sliders, progress bars, and more — to ap
• freelander/android_dataA curated collection of Android development learning resources — books, tools, blogs, and open-source projects
• java-native-access/jnaA Java library that lets you call functions from native operating system libraries written in C without writin
• frohoff/ysoserialA Java security research tool that generates crafted payloads to test whether a Java application is vulnerable
• lauriewired/ghidramcpA plugin that connects the NSA's free reverse engineering tool Ghidra to AI assistants so the AI can automatic
• karatelabs/karateAn all-in-one testing framework for APIs, mock servers, performance testing, and browser automation. Write tes
• cabaletta/baritoneA pathfinding bot for Minecraft that automatically navigates terrain for you. Tell it where to go and it finds
• apache/icebergA table format standard that lets multiple data tools like Spark and Flink safely read and write the same mass
• apache/shenyuApache ShenYu is an open-source API gateway that routes HTTP traffic to multiple backend services with real-ti
• nathanmarz/stormStorm is a distributed system for processing continuous streams of data in real time across a cluster of machi
• iflytek/astron-agentAstron Agent is an open-source enterprise platform from iFlytek for building and running AI agent workflows wi
• laobie/statusbarutilStatusBarUtil is a small Android library that lets you set the color, transparency, or icon style of the Andro
• blankj/awesome-java-leetcodeA curated collection of LeetCode algorithm problem solutions written in Java, organized by difficulty and topi
• spring-projects/spring-aiSpring AI is a Java framework that connects Spring Boot applications to AI models from OpenAI, Anthropic, Goog
• amitshekhariitbhu/android-debug-databaseA one-line Android library that starts a local web server in debug builds so you can view, query, and edit you
• chrisbanes/android-pulltorefreshAn archived Android library that added pull-to-refresh gesture support to lists, grids, web views, and scroll
• ybq/android-spinkitA small Android library that adds 12 animated loading spinner styles — bouncing dots, folding cubes, wave patt
• testcontainers/testcontainers-javaA Java library that spins up real databases, browsers, and other services inside Docker containers during auto
• react-native-image-picker/react-native-image-pickerA React Native module that opens the phone's native camera or photo gallery from JavaScript, letting users cap
• shwenzhang/andresguardAn Android Gradle plugin from the WeChat team that shrinks APK file sizes by renaming resource files to very s
• aeron-io/aeronAeron is a high-performance messaging library for sending data between programs with ultra-low latency. It sup
• apache/beamA framework for writing data processing pipelines once in Java, Python, or Go and running them on your laptop,
• dropwizard/dropwizardDropwizard is a Java toolkit that bundles a web server, REST framework, JSON handling, logging, and database t
• google/tsunami-security-scannerTsunami is an open-source network security scanner from Google that automatically checks networks for serious
• airbnb/epoxyAn Android library from Airbnb that removes RecyclerView boilerplate by auto-generating model classes from ann
• facebook/buckBuck was Facebook's multi-language build system — now deprecated and replaced by Buck2. This repository is arc
• chrisjenx/calligraphyCalligraphy is an Android library (now end-of-life) that made it easy to apply custom fonts across an entire a
• junit-team/junit4JUnit 4 is the classic Java framework for writing and running automated tests, now in maintenance mode with on
• wildfirechat/im-serverWildfire IM Server is a self-hosted instant messaging platform — like Slack or WeChat — that companies run on
• dimuthuupe/androidpdfviewerAn Android library for displaying PDF files inside mobile apps with swipe navigation, pinch-to-zoom, night mod
• hs-web/hsweb-frameworkA Java backend framework built on Spring Boot for enterprise management systems, with fully reactive non-block
• roughike/bottombarA deprecated Android library for adding a Material Design bottom navigation bar to apps — now archived and rep
• pentaho/pentaho-kettlePentaho Data Integration (Kettle/PDI) is a Java ETL tool with a visual drag-and-drop designer for building dat
• bytedeco/javacvA Java library that wraps OpenCV, FFmpeg, and other native computer vision tools so Java developers can proces
• alibaba/transmittable-thread-localA tiny Java library from Alibaba that fixes a common problem: per-request data like trace IDs stored in Thread
• krahets/leetcode-bookA Chinese-language collection of algorithm and data structure solutions in Python, Java, and C++ for three pop
• jakewharton/hugoHugo is an Android debugging tool that automatically logs method inputs, outputs, and execution time when you
• yuanguangxin/leetcodePersonal collection of Java solutions to LeetCode coding problems organized by algorithm type — hash tables, d
• enso-org/ensoA no-code data preparation platform for finance, accounting, and sales teams that lets users clean, transform,
• lenve/vblogVBlog is a multi-user blog platform demo built with Vue and Spring Boot, showing how a modern web frontend con
• gocd/gocdGoCD is an open-source server that automates your software build, test, and deployment pipeline so code change

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