java-coding-standards_skill

Overview

This skill codifies Java coding standards tailored for Spring Boot services (Java 17+). It focuses on naming, immutability, Optional and stream usage, exception strategy, generics, and project layout to improve readability and maintainability. The guidance is pragmatic and aimed at reviewers and authors working in team services.

How this skill works

The skill inspects code patterns and recommends idiomatic replacements: PascalCase for types, camelCase for members, and UPPER_SNAKE_CASE for constants. It enforces immutability by preferring records and final fields, checks Optional and stream usage for clarity, and flags anti-patterns such as raw generics, deep nesting, and silent catches. It also suggests project layout, logging, null handling, and test conventions to ensure consistent service architecture.

When to use it

• When writing or reviewing Spring Boot service code in Java 17+
• When enforcing naming, immutability, or exception handling conventions
• When evaluating Optional, stream pipelines, or generics for clarity and safety
• When defining package layout, resource placement, or CI test expectations
• When preparing code for maintainability and team handoff

Best practices

• Prefer clarity over cleverness; keep methods short and focused
• Default to immutable state: records and final fields; avoid shared mutable statics
• Use Optional for absent values; map/flatMap and orElseThrow instead of get()
• Keep stream pipelines short; prefer simple loops when pipelines become complex
• Use unchecked domain exceptions with contextual wrapping for technical errors
• Declare generics explicitly and use bounded types for reusable utilities

Example use cases

• Code review checklist for Spring Boot endpoints, services, and repositories
• Refactoring legacy classes into records or final-field domain models
• Replacing nested stream logic with clearer loops and helper methods
• Enforcing project layout and package boundaries in new microservices
• Standardizing exception types and logging patterns across services