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.

• yunaiv/yudao-cloudOpen-source enterprise backend platform with microservices, RBAC, multi-tenancy, e-commerce, and code generati
• antlr/antlr4A tool that reads grammar rules you write and automatically generates code that can parse custom languages, fi
• baseflow/photoviewAn Android library that adds pinch-to-zoom and double-tap zoom to image views with a two-line Gradle install —
• dromara/sa-tokenSa-Token is a Java library that adds login, session management, roles, permissions, single sign-on, and OAuth
• williamfiset/algorithmsA comprehensive Java library of algorithms and data structures with clear implementations and video explanatio
• tencent/apijsonA Java library that lets frontend clients query and modify databases directly via JSON requests, eliminating t
• lmax-exchange/disruptorA high-performance Java library for ultra-low-latency inter-thread communication, built by LMAX Exchange for s
• forezp/springcloudlearningChinese-language tutorial repo with runnable Java examples that teach Spring Cloud — the toolkit for building
• ben-manes/caffeineCaffeine is a Java in-memory caching library with size and time-based eviction, async refresh, and removal not
• tencent/tinkerTinker is a Tencent library that lets Android apps patch their compiled code, native libs, and resources at ru
• infinilabs/analysis-ikElasticsearch and OpenSearch plugin that adds Chinese-language tokenization via the IK analyzer, with custom a
• justauth/justauthA Java library that adds social login (GitHub, Google, WeChat, and 40+ more) to your app through a single unif
• openzipkin/zipkinZipkin collects timing data from each service in a multi-service application so you can look up exactly where
• baomidou/mybatis-plusJava toolkit that extends MyBatis with ready-made CRUD methods, pagination, a lambda query API, and a code gen
• gyoogle/tech-interview-for-developerA Korean-language encyclopedia of computer science topics for entry-level developer technical interviews, cove
• material-components/material-components-androidGoogle's official Material Design UI components library for native Android apps. Drop-in replacement for the o
• alibaba/dataxAlibaba's open-source batch data synchronization framework that moves data between databases, warehouses, and
• facebook/frescoMeta's Android library for loading and displaying images. Handles memory, two-level caching, progressive JPEGs
• itwanger/tobebetterjavaerA large free Chinese-language guide to learning Java and backend development, covering everything from Java ba
• questdb/questdbQuestDB is an open-source time-series database optimized for high-speed ingestion and fast SQL queries on time
• heibaiying/bigdata-notesA Chinese-language beginner's guide to big data. Twelve tutorial tracks covering Hadoop, Hive, Spark, Flink, K
• nostra13/android-universal-image-loaderAn archived Android Java library that loads, caches, and displays images from URLs, files, or content provider
• grasscutters/grasscutterAn unofficial private server reimplementation in Java for a certain anime game, letting players run the game l
• winterbe/java8-tutorialA short, code-first walkthrough of every new feature added in Java 8 — lambdas, streams, the new date API, and
• prestodb/prestoA distributed SQL query engine that runs analytical SQL across petabyte-scale data lakes by splitting work acr
• shuzheng/zhengZheng is a Java enterprise application framework built on Spring, SpringMVC, and MyBatis that bundles SSO, CMS
• jeffli1993/springboot-learning-exampleTutorial-style collection of Spring Boot Java code examples covering web, JPA, MyBatis, Redis, Elasticsearch,
• neo4j/neo4jGraph database that stores data as nodes and relationships instead of rows and tables. You query it with Cyphe
• ashishps1/awesome-leetcode-resourcesA hand-picked reading list of the best online resources for learning data structures and algorithms and prepar
• android-hacker/virtualxposedAn Android app that runs Xposed modules inside a virtual sandbox, so you can hook and modify other apps withou
• dyc87112/springboot-learningFree Chinese-language tutorial series for Spring Boot covering 1.x and 2.x, with example projects for MyBatis,
• quarkusio/quarkusJava framework that builds cloud-native and Kubernetes-friendly apps with fast startup, low memory, and native
• android10/android-cleanarchitectureSample Android app in Java that shows how to apply Uncle Bob Clean Architecture with presentation, domain, and
• apache/hadoopApache Hadoop is an open-source Java framework for distributed storage and batch processing of very large data
• konloch/bytecode-viewerBytecode Viewer is a Java reverse-engineering GUI that bundles six decompilers, disassemblers, and APK tooling
• mockito/mockitoMost popular Java mocking framework for unit tests. Lets you create fake versions of dependencies like databas
• apache/dorisApache Doris is an open-source analytical database that runs complex queries across billions of rows in under
• apache/pulsarApache Pulsar is a distributed messaging system — like a postal service for software — that moves millions of
• zaproxy/zaproxyZAP (Zed Attack Proxy) is a free open-source web application security scanner for finding vulnerabilities, use
• cryptomator/cryptomatorDesktop app for Windows, macOS, and Linux that encrypts your files locally before they sync to Dropbox, Google
• java-decompiler/jd-guiJD-GUI is a desktop app that decompiles Java .class and .jar files back into readable source code so you can b
• zhisheng17/flink-learningA Chinese-language learning repo with Java code samples for Apache Flink, covering connectors, concepts like w
• supertokens/supertokens-coreSuperTokens core is a self-hosted Java auth backend for login, sessions, social and passwordless flows, MFA, a
• theonedev/onedevSelf-hosted all-in-one dev platform in Java: Git hosting, code review, CI/CD with a visual editor, Kanban boar
• elastic/logstashServer-side data processing pipeline that ingests logs and events from many sources, transforms them, and ship
• eclipse-vertx/vert.xCore of the Vert.x reactive toolkit for the JVM, providing low-level HTTP, TCP, and file system APIs that othe
• arduino/arduinoSource code for the legacy Arduino IDE 1.x desktop application used to write and upload sketches to Arduino mi
• hdodenhof/circleimageviewA lightweight Android library that displays images as perfect circles — ideal for profile pictures and avatars
• tencent/qmui_androidA ready-made Java UI library for Android from Tencent that provides common interface components and a global s
• alibaba/arouterARouter is an Android routing library from Alibaba that lets modules in a large app jump to any screen using a
• languagetool-org/languagetoolLanguageTool is open-source grammar and style checking software that catches errors beyond basic spell-checkin
• googlecontainertools/jibGoogle's tool for packaging Java applications into Docker container images directly from Maven or Gradle build
• apache/dolphinschedulerAn open-source workflow scheduler for data pipelines — build, run, and monitor multi-step data tasks visually
• deeplearning4j/deeplearning4jEclipse Deeplearning4J is a suite of Java libraries for building and running AI neural network models on the J
• kekingcn/kkfileviewA self-hosted web service that previews over 100 file types—Word, Excel, PDF, images, video, CAD, 3D models, a
• xpipe-io/xpipeA desktop app that centralizes all your server, container, cloud, and VM connections in one place, letting you
• janishar/mit-deep-learning-book-pdfA clean, bookmarked PDF of the Deep Learning textbook by Goodfellow, Bengio, and Courville — the book is free
• netflix/zuulZuul is Netflix's open-source API gateway written in Java that sits in front of your web services and handles
• apache/druidApache Druid is a high-speed analytics database for querying billions of rows of real-time and historical data
• sqshq/piggymetricsPiggymetrics is a sample personal-finance app built as a teaching example to demonstrate microservice architec
• orhanobut/loggerA small Android library that replaces the default Logcat output with visually formatted log messages — borders
• pinpoint-apm/pinpointPinpoint is a self-hosted monitoring tool for large Java systems split across many services — it traces each u
• seaswalker/spring-analysisA collection of personal reading notes in Chinese that walk through how the Spring framework works internally,
• jessyancoding/androidautosizeAndroid library that automatically makes your app look correct on any phone screen size by adjusting layout sc
• lucksiege/pictureselectorAn Android library that adds a fully-featured image, video, and audio picker to your app with cropping, compre
• lgvalle/material-animationsA reference guide for Android's built-in Transition Framework with code samples and animated GIFs showing how
• tink-crypto/tinkA cryptography library from Google that makes encryption, signing, and key management easy to do safely across
• bigkoo/android-pickerviewAndroid-PickerView is a Java library that adds iOS-style scrolling wheel selectors to Android apps for picking
• projectlombok/lombokProject Lombok is a Java library that automatically generates repetitive boilerplate code like getters, setter
• macrozheng/mall-learningA structured Chinese-language tutorial series that walks Java developers through building a production-grade e
• microg/gmscoremicroG Services is a free, open-source replacement for Google Play Services that lets Android apps requiring G
• metersphere/metersphereOpen-source team testing platform covering API tests, test plans, defect tracking, and reports, with an AI ass
• pxb1988/dex2jarA toolkit that converts Android APK and DEX files into readable Java class files or smali text, making it easy
• youth5201314/bannerA Java Android library that adds a smoothly looping image carousel to your app, with built-in transition effec
• plantuml/plantumlA Java tool that turns short plain-text scripts into diagrams — UML, mind maps, Gantt charts, wireframes, and
• alibaba/colaA Java application framework from Alibaba that enforces a standard layered folder structure for backend projec
• macrozheng/mall-swarmA complete e-commerce platform built as Java microservices — covering product management, orders, search, and
• opensearch-project/opensearchAn open-source enterprise search and analytics engine that lets you index millions of documents or log events
• codecentric/spring-boot-adminA web dashboard for monitoring and managing Spring Boot Java services, showing health, memory, logs, and confi
• trinodb/trinoTrino is an open-source SQL engine that lets you query massive amounts of data across multiple databases, data
• lawnchairlauncher/lawnchairA free open-source Android home screen replacement app that adds Material 3 wallpaper-based theming, icon pack
• netflix/conductorA workflow orchestration server originally built at Netflix that sequences multi-step business processes acros
• apache/zookeeperA reliable coordination service for distributed systems that helps clusters of computers agree on shared state
• google/guiceA Google library for Java that automatically wires up the dependencies between parts of your program. You add
• debezium/debeziumA tool that watches databases for every insert, update, and delete, then streams those changes to Apache Kafka
• netflix/eurekaNetflix's service registry that lets backend services find each other on AWS without hardcoded addresses. Serv
• facebook/stethoA Facebook-built Android debugging tool that connects your running Android app to Chrome's developer tools, so
• greenrobot/greendaoAn Android database library (now unmaintained) that maps Java objects to SQLite rows so you can store and retr
• zhihu/matisseA drop-in Android library that adds a polished image and video picker screen to your mobile app, with customiz
• daimajia/androidviewanimationsAndroidViewAnimations is a Java library that lets you add over 60 ready-made visual effects to any element in
• beemdevelopment/aegisAegis is a free, open-source Android app that generates and securely stores two-factor authentication codes in
• daimajia/androidswipelayoutAn Android library that adds swipe-to-reveal hidden buttons or content to any part of your screen — works in l
• pagehelper-org/mybatis-pagehelperA Java plugin that automatically adds pagination to MyBatis database queries, supporting 20+ databases includi
• amitshekhariitbhu/android-interview-questionsA curated collection of hundreds of Android developer interview questions and answers covering Kotlin, corouti
• redis/jedisThe official Java library for connecting to a Redis server — add it to your Maven or Gradle project and store,
• papermc/paperPaper is the most widely used high-performance Minecraft server replacement, offering speed improvements, bug
• team-xmanager/xmanagerxManager is an Android app that lets you install, upgrade, or downgrade specific versions of a popular music s
• tencent/matrixWeChat's open-source performance monitoring framework for iOS and Android apps, detecting crashes, lag, memory
• langchain4j/langchain4jLangChain4j is a Java library that connects your app to over 20 AI providers and adds chat memory, document se
• tencent/vassonicA Tencent framework that makes websites load faster inside mobile apps by pre-fetching page content in paralle

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