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.

• snailclimb/javaguideChinese-language interview prep guide for Java back-end developers, covering fundamentals, databases, distribu
• krahets/hello-algoAn open-source, free interactive book teaching data structures and algorithms to beginners using animated diag
• growinggit/github-chinese-top-chartsCurated leaderboards of the best Chinese-language projects on GitHub, organized by programming language and up
• iluwatar/java-design-patternsA large collection of real, runnable Java examples for classic software design patterns — from creational to b
• macrozheng/mallA complete Java e-commerce platform with customer storefront and admin back-office, built with Spring Boot, My
• spring-projects/spring-bootSpring Boot is a Java framework that sets up a production-ready Spring application with sensible defaults and
• doocs/advanced-javaChinese-language reference guide covering advanced Java backend concepts: message queues, caching, databases,
• elastic/elasticsearchA distributed, RESTful search engine designed to run across multiple servers, handling large datasets and fast
• misterbooo/leetcodeanimationAnimated visual explanations of LeetCode algorithm problems with step-by-step GIFs showing how solutions work,
• nationalsecurityagency/ghidraGhidra is a free, open-source reverse engineering tool from the NSA that lets you analyze compiled programs —
• thealgorithms/javaA collection of classic algorithms and data structures implemented in readable Java code — built for learning
• kdn251/interviewsA study guide for software engineering interviews with explanations of data structures, algorithms, and Java i
• spring-projects/spring-frameworkSpring Framework is the foundational Java platform for building large-scale enterprise applications. It elimin
• termux/termux-appTermux is a free Android app that gives your phone a real Linux terminal and package manager, letting you inst
• google/guavaGuava is Google's battle-tested open-source Java utility library that fills gaps in the standard library — add
• dbeaver/dbeaverFree desktop app that connects to over 100 different databases — MySQL, PostgreSQL, SQLite, Oracle, and more —
• skylot/jadxA tool that converts compiled Android APK files back into readable Java or Kotlin source code, letting you exa
• reactivex/rxjavaA Java library for handling streams of data and events that arrive over time — like network responses or user
• jeecgboot/jeecgbootAI-powered low-code platform that auto-generates enterprise Java applications from plain-language descriptions
• apache/dubboApache Dubbo is a Java framework that lets separate services in a large application call each other over a net
• halo-dev/haloHalo is a self-hosted, open-source website builder and CMS that powers blogs, knowledge bases, company sites,
• philjay/mpandroidchartA Java library for Android that adds interactive charts — line, bar, pie, candlestick, and more — to your app
• teamnewpipe/newpipeNewPipe is a free, open-source Android app for watching YouTube, SoundCloud, Bandcamp, and PeerTube without ad
• eugenp/tutorialsA collection of hundreds of small, runnable Java and Spring code examples organized by topic, designed to teac
• alibaba/arthasArthas is a Java diagnostic tool from Alibaba that attaches to a running application without restarting it, le
• ashishps1/awesome-system-design-resourcesCurated collection of free learning materials for studying system design—how to build large-scale software tha
• yunaiv/ruoyi-vue-proA ready-made Java admin dashboard framework with user login, permissions, file uploads, and optional e-commerc
• geekxh/hello-algorithmVisual algorithm and data structure guide for interview prep, with illustrated LeetCode solutions and tech com
• doocs/leetcodeA massive open-source collection of LeetCode algorithm solutions written in Java, Python, C++, Go, TypeScript,
• airbnb/lottie-androidAn Android library that plays After Effects animations as smooth vector graphics from a JSON file — designers
• bumptech/glideGlide is an Android image loading and caching library that handles fetching, resizing, and caching images from
• netty/nettyNetty is a high-performance Java framework for building servers that handle thousands of simultaneous network
• keycloak/keycloakKeycloak is an open-source identity server that handles login, multi-factor authentication, single sign-on, an
• xkcoding/spring-boot-demoA collection of 66+ working Spring Boot example modules showing Java developers exactly how to connect Spring
• seleniumhq/seleniumSelenium lets you write code that controls a web browser automatically — clicking buttons, filling forms, and
• zxing/zxingZXing is a Java library that reads barcodes and QR codes from images, supporting over a dozen formats includin
• alibaba/easyexcelJava library for reading and writing large Excel files efficiently using streaming, keeping memory usage low r
• blankj/androidutilcodeA Java library of ready-made utility functions for Android apps—date formatting, encryption, file handling, ne
• alibaba/nacosA platform by Alibaba that helps microservices find each other, share configuration settings in real time, and
• binarywang/wxjavaA Java library that makes it easy to build apps on WeChat — handling logins, messaging, payments, mini-program
• apache/kafkaApache Kafka is a distributed platform for moving millions of events per second between services reliably and
• conductor-oss/conductorConductor is an open-source workflow engine that reliably coordinates multi-step processes across distributed
• ityouknow/spring-boot-examplesA collection of hands-on Spring Boot example projects demonstrating specific features like databases, messagin
• chinabugotech/hutoolA Java utility library with hundreds of helper methods for common tasks like string handling, file I/O, HTTP r
• xuxueli/xxl-jobXXL-JOB is a distributed task scheduling framework for Java that automatically runs code on a schedule across
• yuliskov/smarttubeFree, ad-free media player for Android TV that lets you watch videos without ads, Google sign-in, or tracking—
• apolloconfig/apolloCentralized configuration management system for microservices. Edit settings in a web interface and push chang
• alibaba/canalCanal reads MySQL's change log in real time and streams every insert, update, and delete to other systems like
• alibaba/spring-cloud-alibabaA toolkit for Java developers that plugs into Spring Cloud to add service discovery, traffic control, distribu
• drklo/telegramOfficial Android source code for Telegram messaging app. Build your own Telegram-compatible client by compilin
• wuyouzhuguli/springallA collection of hands-on Java code examples for learning Spring Boot, Spring Security, Spring Cloud, and relat
• alibaba/druidDruid is a Java database connection pool library from Alibaba that reuses pre-opened database connections for
• lenve/vhrA web-based HR management system for tracking employees, departments, salaries, and payroll. Built with Spring
• anuken/mindustryMindustry is a free open-source strategy game that combines tower defense with factory automation — build conv
• crossoverjie/jcsproutA curated Chinese-language knowledge base of Java fundamentals, covering collections, multithreading, the JVM,
• kestra-io/kestraKestra is an open-source workflow automation platform where you describe multi-step processes in YAML, then sc
• qiurunze123/miaoshaEducational Java project teaching how to build a high-concurrency flash sale system that handles thousands of
• openapitools/openapi-generatorA tool that reads an API specification file and automatically generates ready-to-use code — client libraries,
• apache/flinkApache Flink is an enterprise-grade open-source framework for processing massive streams of data in real time
• apache/incubator-seataSeata keeps data consistent across multiple Java microservices that each have their own database — if any step
• alibaba/fastjsonFast Java library for converting objects to and from JSON, the standard format for web APIs and data storage.
• codephiliax/chat2dbAI-powered database client that lets you query databases using plain English instead of SQL, with support for
• hollischuang/tobetopjavaerA comprehensive Chinese-language study guide covering 500+ Java interview questions and 60,000+ words on core
• jakewharton/butterknifeButter Knife was an Android library that replaced repetitive UI wiring code with simple annotations — now offi
• bazelbuild/bazelBazel is a fast, reliable build system that only rebuilds code that actually changed, supports multiple progra
• jenkinsci/jenkinsJenkins is an open-source automation server that watches your code repository and automatically builds, tests,
• scwang90/smartrefreshlayoutAndroid library that adds pull-to-refresh and load-more gestures to lists and feeds with automatic detection o
• libgdx/libgdxlibGDX is a free Java game development framework that lets you write a game once and deploy it to Windows, Mac
• apache/skywalkingApache SkyWalking is an open-source monitoring system that collects traces, metrics, and logs from distributed
• proxyee-down-org/proxyee-downAn open-source HTTP download accelerator that acts as a local proxy to speed up file downloads by splitting th
• greenrobot/eventbusEventBus is a tiny Java and Android library that lets different parts of your app send and receive messages wi
• netflix/hystrixA Java library from Netflix that keeps distributed backend systems running when individual services fail, usin
• ibotpeaches/apktoolApktool is a reverse engineering tool for Android APK files that decodes compiled apps into readable resources
• redisson/redissonRedisson is a Java library that wraps Redis and Valkey so your application can share Maps, Sets, Queues, locks
• google/gsonGson is a Google Java library that converts any Java object to JSON and back with a single method call, even o
• dataease/dataeaseSelf-hosted business intelligence tool for building interactive data dashboards without code. Connect database
• ashishps1/awesome-low-level-designA free collection of object-oriented design problems and Java solutions to help software developers prepare fo
• lsposed/lsposedAndroid framework that lets you install modules to modify app behavior and system features at runtime without
• enterprisequalitycoding/fizzbuzzenterpriseeditionA satirical Java implementation of the FizzBuzz programming exercise using absurdly complex enterprise pattern
• doocs/source-code-hunterDeep-dive Chinese-language walkthroughs of how popular Java frameworks (Spring, MyBatis, Netty, Dubbo, Redis,
• alibaba/sentinelA Java library from Alibaba that protects backend microservices from traffic overload using rate limiting, cir
• openjdk/jdkThis is the official source code for the Java Development Kit — the compiler, runtime, and standard library th
• kunal-kushwaha/dsa-bootcamp-javaFree Java bootcamp with code, exercises, and notes for learning data structures, algorithms, and interview pre
• apache/rocketmqApache RocketMQ is a high-throughput messaging platform that reliably delivers events between services in dist
• elunez/eladminA ready-made Java admin panel starter kit with user management, role-based permissions, and a code generator t
• google/exoplayerDeprecated Android media playback library for audio and video. Development has moved to AndroidX Media3; use t
• thingsboard/thingsboardThingsBoard is an open-source IoT platform that collects data from physical devices, stores it, and displays i
• oracle/graalGraalVM is a Java toolkit that compiles applications into standalone binaries before they run, enabling instan
• carguo/gsyvideoplayerAndroid video player library with pluggable playback engines, streaming support, danmaku comments, filters, an
• brettwooldridge/hikaricpA fast, lightweight JDBC connection pool for Java applications — it manages a pool of pre-opened database conn
• apache/shardingsphereApache ShardingSphere adds a smart layer on top of your existing databases so they can scale out, shard data a
• opendataloader-project/opendataloader-pdfAn open-source Java tool that converts PDFs into structured Markdown, JSON, or HTML for AI pipelines, and adds
• didi/dokitA floating debugging panel for mobile apps that gives developers instant access to GPS spoofing, crash logs, n
• mybatis/mybatis-3A Java framework that lets you write your own SQL queries and automatically maps the results to Java objects,
• linlinjava/litemallA complete open-source online shopping mall system with backend, admin panel, WeChat Mini Program, and mobile
• yudaocode/springboot-labsA comprehensive Java learning repository with 50,000+ lines of example code covering Spring Boot, Spring Cloud
• jetbrains/intellij-communityThe open-source codebase behind IntelliJ IDEA and the IntelliJ Platform — the shared foundation for PyCharm, W
• reactivex/rxandroidA small Android library that lets you safely deliver background task results to the UI thread using RxJava — s
• lionsoul2014/ip2regionOffline IP-to-location lookup library that translates IP addresses to country, city, and ISP without network r
• dianping/catReal-time application monitoring platform that tracks errors, slow requests, and performance metrics across di

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