Java HacktoberFest

Open-source Java projects categorized as HacktoberFest

Top 23 Java HacktoberFest Projects

HacktoberFest
  1. Design Patterns

    Design patterns implemented in Java

    Project mention: ๐ŸŒŸ Unlock Your Developer Potential: Top 5 Must-Explore GitHub Repositories ๐Ÿš€ | dev.to | 2025-01-14

    design-patterns

  2. CodeRabbit

    CodeRabbit: AI Code Reviews for Developers. Revolutionize your code reviews with AI. CodeRabbit offers PR summaries, code walkthroughs, 1-click suggestions, and AST-based analysis. Boost productivity and code quality across all major languages with each PR.

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  3. Java

    All Algorithms implemented in Java

    Project mention: Algorithms Implemented in Java | news.ycombinator.com | 2024-12-01
  4. termux-app

    Termux - a terminal emulator application for Android OS extendible by variety of packages.

    Project mention: How do you backup your Android? | news.ycombinator.com | 2025-01-09
  5. Jenkins

    Jenkins automation server

    Project mention: Top DevOps Tools You Need to Know in 2025 | dev.to | 2025-02-07

    Jenkins remains a favorite for continuous integration and deployment. It provides:

  6. openapi-generator

    OpenAPI Generator allows generation of API client libraries (SDK generation), server stubs, documentation and configuration automatically given an OpenAPI Spec (v2, v3)

    Project mention: 7 SDK Generator Tools for APIs in 2025 | dev.to | 2025-01-15

    OpenAPI Generator

  7. JHipster

    JHipster, much like Spring initializr, is a generator to create a boilerplate backend application, but also with an integrated front end implementation in React, Vue or Angular. In their own words, it "Is a development platform to quickly generate, develop, & deploy modern web applications & microservice architectures."

    Project mention: Mill: A fast JVM build tool for Java and Scala | news.ycombinator.com | 2024-10-27

    Interesting that you ended up going all the way to Rust land instead of just using one of the multiple tools that have been created to help with this, like:

    * Spring Boot (it has a UI to create projects where you pick Java version, DB, build tool, some libs etc): https://spring.io/guides/gs/spring-boot

    * JHipster - the nuclear option, pick what you want a la carte: https://www.jhipster.tech/

    * JBang - a cute CLI for this: https://www.jbang.dev/

    * Maven Archetypes - the old fashioned way (existed before "create-app" kind of tools appeared): https://maven.apache.org/guides/introduction/introduction-to...

    And most IDEs also have "new project" wizzards.

  8. Apache RocketMQ

    Apache RocketMQ is a cloud native messaging and streaming platform, making it simple to build event-driven applications.

    Project mention: RocketMQ: A Cloud-Native Messaging Platform for Event-Driven Apps | news.ycombinator.com | 2024-08-08
  9. SaaSHub

    SaaSHub - Software Alternatives and Reviews. SaaSHub helps you find the best software and product alternatives

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  10. shardingsphere

    Empowering Data Intelligence with Distributed SQL for Sharding, Scalability, and Security Across All Databases.

  11. QuestDB

    QuestDB is a high performance, open-source, time-series database

    Project mention: QuestDB is an open source time-series database for fast ingest and SQL queries | news.ycombinator.com | 2024-08-31
  12. bytecode-viewer

    A Java 8+ Jar & Android APK Reverse Engineering Suite (Decompiler, Editor, Debugger & More)

  13. Quarkus

    Quarkus: Supersonic Subatomic Java.

    Project mention: Java Can Be Serverless Too: Using GraalVM for Fast Cold Starts | dev.to | 2025-01-06

    It wasnโ€™t long before I ran into several other blog posts about developers successfully using GraalVM and frameworks such as Quarkus to address this very problem. And so Iโ€™ve decided to try it out for myself.

  14. SuperTokens Community

    Open source alternative to Auth0 / Firebase Auth / AWS Cognito

    Project mention: Auth Pricing Wars: Cognito vs Auth0 vs Firebase vs Supabase | dev.to | 2024-12-19

    For B2C, Supabase will get you most of the way for small to medium MAU applications. You might need additional services for analytics and monitoring. If you are building a boom-or-bust B2C company (ex. social media platform, video game, media publication) you should consider using an open-source self-hosted solution like SuperTokens.

  15. ZAP

    The ZAP by Checkmarx Core project

    Project mention: Show HN: Kate's App | news.ycombinator.com | 2025-01-09
  16. Apache ZooKeeper

    Apache ZooKeeper

    Project mention: Mastering Apache Kafka: Powering Modern Data Pipelines | dev.to | 2025-01-16

    Zookeeper is a distributed coordination service used in older versions of Kafka to manage cluster metadata, leader election, and configuration. It ensures consistency and synchronization across Kafka brokers.

  17. jjwt

    Java JWT: JSON Web Token for Java and Android

  18. Paper

    The most widely used, high performance Minecraft server that aims to fix gameplay and mechanics inconsistencies

    Project mention: PaperMC/Paper: The most widely used, high performance Minecraft server | news.ycombinator.com | 2024-03-10
  19. kafka-ui

    Open-Source Web UI for Apache Kafka Management

    Project mention: How to Get Remote Code Execution in Kafka UI | news.ycombinator.com | 2024-07-22
  20. datahub

    The Metadata Platform for your Data and AI Stack

    Project mention: Guided Data Access Patterns: A Deal Breaker for Data Platforms | dev.to | 2024-05-15

    There are several commercial providers, but I would definitely recommend Data Hub Project. DataHub Project is an open-source metadata platform that serves as an extensible data catalog and supports data discovery, data observability, and federated governance to address the complexity of the data ecosystem. The data catalog enables the combination of technical, operational and business metadata to provide a 360-degree view of data entities. DataHub makes it possible to pre-enrich important metadata using shift-left practices and respond to changes in real time.

  21. OpenSearch

    ๐Ÿ”Ž Open source distributed and RESTful search engine.

    Project mention: OpenSearch vs. Elasticsearch: Why OpenSearch is the Better Choice for AWS Users | dev.to | 2024-09-25

    OpenSearch Project on GitHub

  22. Aegis

    A free, secure and open source app for Android to manage your 2-step verification tokens.

    Project mention: Twilio says hackers identified cell phone numbers of two-factor app Authy users | news.ycombinator.com | 2024-07-03

    Personally I'm a fan of Aegis: https://getaegis.app/

    It's open source, doesn't try to lock you in. The app has a number of options for backup, but there's no cloud component.

    I've seen some love for Ente Auth as well, also open source. Ultimately it's a very simple app so there's a number of good open source options.

  23. android-gif-drawable

    Views and Drawable for displaying animated GIFs on Android

  24. Checkstyle

    Checkstyle is a development tool to help programmers write Java code that adheres to a coding standard. By default it supports the Google Java Style Guide and Sun Code Conventions, but is highly configurable. It can be invoked with an ANT task and a command line program.

    Project mention: Contribution Instructions: Formate Code and Linting | dev.to | 2024-11-01

    We had a list of suggested code formation tools, as my code was written in Java I decided to use suggested formatter GoogleJavaFormat. However, I didn't decide to pick suggested tool for Linter. I picked Checkstyle; for the reason, that SpotBugs wasn't available for JDK 22.

  25. Testcontainers

    Testcontainers is a Java library that supports JUnit tests, providing lightweight, throwaway instances of common databases, Selenium web browsers, or anything else that can run in a Docker container.

    Project mention: Top Resources to Learn Testcontainers | dev.to | 2024-10-15

    Repository

  26. SaaSHub

    SaaSHub - Software Alternatives and Reviews. SaaSHub helps you find the best software and product alternatives

    SaaSHub logo
NOTE: The open source projects on this list are ordered by number of github stars. The number of mentions indicates repo mentiontions in the last 12 Months or since we started tracking (Dec 2020).

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Java HacktoberFest related posts

  • Apache Accumulo 4.0 Feature Preview

    1 project | news.ycombinator.com | 24 Jan 2025
  • Introducing Kafbat UI: Simplify Kafka Management with a Modern UI

    1 project | dev.to | 17 Jan 2025
  • 7 SDK Generator Tools for APIs in 2025

    3 projects | dev.to | 15 Jan 2025
  • Show HN: Kafbat UI for Apache Kafka v1.1 is out

    1 project | news.ycombinator.com | 13 Jan 2025
  • JOOQ Is Not a Replacement for Hibernate. They Solve Different Problems

    1 project | dev.to | 11 Jan 2025
  • "Escapando" de IntelliJ

    5 projects | dev.to | 3 Jan 2025
  • A Beginnerโ€™s Guide to Java: 10 Must-Know Development Tools๐ŸŽ‰๐ŸŽ‰

    4 projects | dev.to | 31 Dec 2024
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Index

What are some of the best open-source HacktoberFest projects in Java? This list will help you:

# Project Stars
1 Design Patterns 90,652
2 Java 60,762
3 termux-app 38,735
4 Jenkins 23,570
5 openapi-generator 22,652
6 JHipster 21,720
7 Apache RocketMQ 21,496
8 shardingsphere 20,025
9 QuestDB 14,851
10 bytecode-viewer 14,835
11 Quarkus 14,074
12 SuperTokens Community 13,768
13 ZAP 13,014
14 Apache ZooKeeper 12,366
15 jjwt 10,474
16 Paper 10,471
17 kafka-ui 10,237
18 datahub 10,231
19 OpenSearch 10,161
20 Aegis 9,733
21 android-gif-drawable 9,570
22 Checkstyle 8,446
23 Testcontainers 8,123

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