| name | java-patterns |
| description | Java architecture reference - frameworks, design patterns, enterprise architecture, and production best practices for Java 17/21/23-24 (2024-2025). Use when making architectural decisions, reviewing Java code, or selecting libraries. |
| user-invocable | true |
| argument-hint | [frameworks|patterns|architecture|practices|features|all] |
Java Architecture Reference (2024-2025)
Comprehensive reference for Java architectural decisions. Use $ARGUMENTS to focus on a specific area, or browse all sections.
Quick Navigation
- For framework/library selection and comparisons, see frameworks.md
- For design patterns (singleton, builder, strategy, observer), see design-patterns.md
- For architecture patterns (hexagonal, CQRS, DDD, event-driven), see architecture.md
- For best practices (error handling, streams, concurrency, DO/DON'T), see best-practices.md
- For language features (records, sealed classes, virtual threads, pattern matching), see language-features.md
Decision Framework
- Enterprise backend: Default -> Spring Boot 3.x. Cloud-native/GraalVM -> Quarkus. Compile-time DI -> Micronaut
- Persistence: Default ORM -> Hibernate/Spring Data JPA. Type-safe SQL -> jOOQ. Lightweight -> MyBatis
- Testing: Default -> JUnit 5 + Mockito. Integration -> TestContainers. Assertions -> AssertJ
- Messaging: Kafka -> Spring Kafka. AMQP -> Spring AMQP. Integration routing -> Apache Camel
- Build tool: Enterprise/complex -> Maven. Flexible/incremental -> Gradle (Kotlin DSL)
- Observability: Metrics -> Micrometer. Distributed tracing -> OpenTelemetry. Resilience -> Resilience4j
- Security: Default -> Spring Security 6.x. Identity provider -> Keycloak
Java in Production
| Company | Result |
|---|
| Netflix | Microservices backbone, Spring-based platform serving 260M+ subscribers |
| Uber | Backend services handling millions of trips/day, custom Java frameworks |
| LinkedIn | Apache Kafka (written in Java/Scala), processes trillions of messages/day |
| Amazon | AWS SDK for Java, core services, Lambda runtime |
| Goldman Sachs | Low-latency trading systems, Eclipse Collections contributor |
| Airbnb | Backend services, migrated key services from Ruby to Java |
| Twitter/X | JVM-based infrastructure serving 500M+ tweets/day |
Java Evolution
| Version | Key Features |
|---|
| Java 17 (LTS) | Records, Sealed Classes, Pattern Matching instanceof, Text Blocks, Switch Expressions |
| Java 21 (LTS) | Virtual Threads, Pattern Matching Switch, Record Patterns, Sequenced Collections |
| Java 22 | Unnamed Variables (_), Statements before super() (preview) |
| Java 23 | Primitive types in Patterns (preview), Markdown doc comments, Module imports (preview) |
| Java 24 | Structured Concurrency (preview), Scoped Values (preview), Stream Gatherers (preview) |
LTS releases (17, 21) are production defaults. Non-LTS (22, 23, 24) for early adoption of preview features.
Related Skills
