Java Java Hub
The complete Java encyclopedia — 1,600+ articles from language fundamentals and algorithms to enterprise frameworks, cloud native Java, and interview preparation.
Core Foundations
Master the Java language, build tooling, testing practices, and classic design patterns.
Java SE
The Java platform from syntax and OOP to generics, streams, concurrency, JVM internals, API reference, cookbook recipes, and Java 8–21 features. 400+ articles.
Build Tools
Maven and Gradle — project structure, dependency management, plugins, version catalogs, and multi-module builds for modern Java projects.
Testing
JUnit 5, Mockito, and Testcontainers — unit testing, mocking, parameterized tests, and integration testing with real Docker services.
Design Patterns
23 design patterns with Java implementations — Singleton, Factory, Builder, Adapter, Decorator, Observer, Strategy, and more.
Data Access & Web Development
Connect to databases, build web applications, and design RESTful APIs.
Database
JDBC, JPA/Hibernate, MyBatis, connection pooling with HikariCP, and NoSQL clients for Redis and MongoDB.
Web Development
Servlet, JSP, and RESTful API design — the building blocks of Java web applications from classic to modern architectures.
Enterprise Frameworks
Spring ecosystem, security frameworks, and message-driven architectures for production applications.
Spring Framework
Spring Core, Spring Boot, Spring Cloud, and Spring Data — dependency injection, auto-configuration, microservices, and data access.
Security
Spring Security, Apache Shiro, JAAS, OAuth2, and JWT — authentication, authorization, and token-based security for Java apps.
Message Queues
JMS, Apache Kafka, and RabbitMQ — asynchronous messaging, event streaming, and message-driven architecture patterns.
Algorithms, DevOps & Cloud
Computer science fundamentals, CI/CD pipelines, and cloud platform integration for Java applications.
Algorithms
Sorting, searching, graphs, dynamic programming, and string algorithms — with Java implementations and complexity analysis.
DevOps
GitHub Actions, Jenkins, Docker, Kubernetes, and deployment automation for Java applications.
Cloud Native
AWS, Azure, and Google Cloud SDK integration — Lambda, S3, Cloud Run, and managed services for Java.
Jakarta EE
CDI, Servlet, JPA, JAX-RS, and enterprise specifications — the standard platform for Java enterprise applications.
Reactive
Project Reactor, Spring WebFlux, and reactive streams — build non-blocking, high-throughput Java applications.
Code Quality
SonarQube, Checkstyle, SpotBugs, SOLID principles, and refactoring — maintain high code quality standards.
Advanced Topics
Microservices, distributed systems, performance tuning, interview preparation, and the broader Java ecosystem.
Microservices
Microservice architecture principles, Apache Dubbo for RPC, and gRPC for high-performance service communication.
Distributed Systems
Distributed caching, distributed locks, and distributed transactions — patterns for building reliable large-scale systems.
Performance & Tuning
JVM heap and GC tuning, profiling with JFR and async-profiler — optimize your Java applications for production.
Interview Guide
Curated Java SE, Spring, JVM, system design, and 200+ LeetCode coding problems — prepare for technical interviews with confidence.
Java Ecosystem
Popular libraries beyond the JDK — Project Lombok, Google Guava, and Netty for high-performance network programming.