Haifa

A multi-module Maven workspace for exploring the Java ecosystem—from core language features to frameworks, middleware, distributed systems, and AI integrations. Each haifa-* module is a self-contained demo or study note that documents experiments, patterns, and lessons learned while revisiting technologies used in day-to-day development.

Repository Overview

• Parent build: single pom.xml at the root orchestrates 40+ modules, all targeting Java 25.
• Naming: modules follow the haifa-<topic> convention (e.g., haifa-concurrent, haifa-springframework).
• Source layout: primary packages live under org.wrj with accompanying resources in src/main/resources.
• License: MIT; retain the copyright header when extending.

Module Landscape

• Foundations & language internals: haifa-base, haifa-java-library, haifa-my-library, haifa-jvm-internal, haifa-legacy, haifa-block, haifa-vs.
• Concurrency & coordination: haifa-concurrent, haifa-scheduler, haifa-coordinate, haifa-reactor.
• Framework deep dives: haifa-springframework, haifa-springboot, haifa-springcloud-nacos, haifa-springsecurity, haifa-dubbo, haifa-java-ee, haifa-web-container, haifa-template-engine, haifa-markup-language.
• Integration & middleware: haifa-mq (Kafka/RabbitMQ/RocketMQ demos), haifa-cache, haifa-httpclient, haifa-aws, haifa-websocket, haifa-grpc, haifa-netty.
• Data, search & blockchain: haifa-mongodb, haifa-search, haifa-json, haifa-nlp, haifa-web3j.
• Big data & streaming: haifa-flink, haifa-flink13.
• Patterns, testing & algorithms: haifa-design-pattern, haifa-junit5, haifa-leetcode.
• AI experiments: haifa-ai-alibaba, haifa-ai-spring.
• Tooling & CI: haifa-ci-cd, haifa-empty.

Tip: Not every module has a README yet—scan package names or tests for context when exploring a new area.

Technology Highlights

• Java 25 toolchain with Maven 3.x builds.
• Spring ecosystem (Framework, Boot, Cloud, Security), Netty, Dubbo, Reactor, Akka, Flink, and more.
• Messaging stacks (Kafka, RocketMQ, RabbitMQ) and database clients (MongoDB, Lucene, Web3j).
• Occasional Python helpers (e.g., simple Netty integrations) alongside Java code.

Getting Started

Prerequisites

• Java Development Kit 25+
• Apache Maven 3.8+ (wrapper not included)
• Optional: Docker/locally installed services for middleware demos (Kafka, RabbitMQ, MongoDB, Redis, Nacos, etc.)

Clone & Build Everything

git clone <repo-url>
cd haifa
mvn -T1C clean install

Build or Test a Single Module

mvn -pl haifa-<module> -am clean test

Use -pl (project list) to narrow the scope; add -DskipTests when exploring compile-only changes.

Running Samples

• Many modules expect local infrastructure—consult source comments before running.
• Legacy experiments pin older dependencies (e.g., Tomcat 7, Jetty 8); keep them isolated unless you need compatibility updates.
• Generated content lives in target/; ignore it in version control.

Working With Modules

• Prefer adding focused demos instead of sweeping refactors; the repository is intentionally a playground for isolated studies.
• When introducing a new topic, follow the naming convention (haifa-<topic>) and add the module to the parent pom.xml.
• Document external prerequisites and configuration in the module itself (consider adding a module-level README).
• Validate changes with mvn -pl <module> -am verify to avoid rebuilding the whole tree.

Documentation Map

• AGENTS.md – automation-oriented notes for coding assistants.
• README-zh.md – Chinese version of this document.
• Module READMEs (where available) – topic-specific instructions.

Contributing

• Keep experiments reproducible: check in only source/configuration needed to rebuild examples.
• Leave TODO comments or issues for follow-up work rather than half-complete migrations.
• Respect existing code style (org.wrj.<topic> packages, descriptive class names, minimal annotations unless required).

License

This project is released under the MIT License. See LICENSE for details.