# 123 Java Design Patterns > Use when you need to select, review, or implement Java design and integration patterns — including classic Java design patterns, REST API patterns, Kafka and event-driven patterns, database and persistence patterns, and cross-cutting integration patterns. This should trigger for requests such as Apply Java design patterns; Review REST API patterns; Design Kafka event-driven patterns; Improve data… - **Type:** Skill - **Install:** `agentstack add skill-jabrena-cursor-rules-java-123-java-design-patterns` - **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior - **Seller:** [jabrena](https://agentstack.voostack.com/s/jabrena) - **Installs:** 0 - **Category:** [Databases](https://agentstack.voostack.com/c/databases) - **Latest version:** 0.1.0 - **License:** Apache-2.0 - **Upstream author:** [jabrena](https://github.com/jabrena) - **Source:** https://github.com/jabrena/cursor-rules-java/tree/main/skills/123-java-design-patterns - **Website:** https://jabrena.github.io/cursor-rules-java/ ## Install ```sh agentstack add skill-jabrena-cursor-rules-java-123-java-design-patterns ``` Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent. ## About # Java Design and Integration Patterns Guide Java developers in selecting patterns by problem signal, implementation context, and trade-off rather than by pattern name alone. **What is covered in this Skill?** - Classic Java design patterns for application code: creational, structural, and behavioral patterns - REST API patterns for resource design, contracts, idempotency, versioning, and error handling - Kafka and event-driven patterns for event schemas, partitioning, idempotency, retries, outbox, and sagas - Database and persistence patterns for repositories, transactions, aggregates, locking, migrations, and read models - Cross-cutting integration patterns for anti-corruption layers, resilience, observability, and reliable message boundaries **Scope:** Use this skill to explain, review, and implement practical patterns in Java systems. Prefer simple code first; introduce a pattern only when it reduces real complexity, protects a boundary, improves testability, or makes change safer. ## Constraints Pattern guidance must be problem-led, concrete, and safe to apply in Java projects. - **PROBLEM FIRST**: Identify the design pressure before naming or applying a pattern - **NO PATTERN SHOPPING**: Do not add abstractions only because a pattern exists; prefer simple code when variation is not present - **BUILD SAFETY**: For code changes, run `./mvnw compile` or `mvn compile` before refactoring and `./mvnw clean verify` or `mvn clean verify` after changes - **REFERENCE SELECTION**: Read the relevant reference before acting: Java code patterns, REST API patterns, Kafka/event-driven patterns, database/persistence patterns, or cross-cutting integration patterns - **TRADE-OFFS REQUIRED**: Explain the benefit, cost, and when-not-to-use guidance for any recommended pattern ## When to use this skill - Apply Java design patterns - Review Java code for design patterns - Choose REST API patterns - Design Kafka event-driven patterns - Improve database persistence patterns - Add resilient integration patterns ## Workflow 1. **Identify the design pressure** Clarify the concrete problem: object creation, behavior variation, API contract evolution, event delivery, persistence consistency, integration reliability, or another recurring design force. 2. **Select the relevant reference** Read only the matching reference(s): `references/123-java-design-patterns.md`, `references/123-rest-api-patterns.md`, `references/123-kafka-event-driven-patterns.md`, `references/123-database-persistence-patterns.md`, or `references/123-cross-cutting-integration-patterns.md`. 3. **Recommend the smallest useful pattern** Choose the simplest pattern that addresses the design pressure. Show how it changes responsibilities, boundaries, tests, operations, or evolution safety. 4. **Implement or document the pattern** When code changes are requested, make focused Java or configuration changes following the project conventions. When design advice is requested, provide diagrams, examples, request/response shapes, event shapes, or transaction flows as appropriate. 5. **Validate the outcome** Verify that the resulting design remains understandable, testable, and operationally safe. Run the project build for code changes and name any remaining trade-offs. ## Reference For detailed guidance, examples, and constraints, see: - [references/123-java-design-patterns.md](references/123-java-design-patterns.md) - [references/123-rest-api-patterns.md](references/123-rest-api-patterns.md) - [references/123-kafka-event-driven-patterns.md](references/123-kafka-event-driven-patterns.md) - [references/123-database-persistence-patterns.md](references/123-database-persistence-patterns.md) - [references/123-cross-cutting-integration-patterns.md](references/123-cross-cutting-integration-patterns.md) ## Source & license This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code. - **Author:** [jabrena](https://github.com/jabrena) - **Source:** [jabrena/cursor-rules-java](https://github.com/jabrena/cursor-rules-java) - **License:** Apache-2.0 - **Homepage:** https://jabrena.github.io/cursor-rules-java/ Install and usage instructions live in the source repository linked above. ## Pricing - **Free** — Free ## Security capabilities Automated source analysis of v0.1.0 — what this tool can access: - **Network access:** no - **Filesystem access:** no - **Shell / process execution:** no - **Environment & secrets:** no - **Dynamic code execution:** no *"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.* ## Versions - **0.1.0** — security scan: passed — Imported from the upstream source. ## Links - Listing page: https://agentstack.voostack.com/l/skill-jabrena-cursor-rules-java-123-java-design-patterns - Seller: https://agentstack.voostack.com/s/jabrena - Browse the marketplace: https://agentstack.voostack.com/browse --- Listed on AgentStack — the marketplace for AI agent skills and MCP servers. Every listing is security-reviewed. Creators keep 70%.