Java Guide

Applies to: Java 17+, Spring Boot, Maven/Gradle, Enterprise Applications

Core Principles

1. Immutability by Default: Prefer records, final fields, and unmodifiable collections
2. Explicit Over Implicit: Clear type declarations, no raw types, no unchecked casts
3. Fail Fast: Validate inputs at boundaries, use Objects.requireNonNull liberally
4. Composition Over Inheritance: Favor delegation and interfaces over deep class hierarchies
5. Standard Library First: Use java.util, java.time, java.nio before adding dependencies

Guardrails

Version & Dependencies

• Use Java 17+ (LTS) with preview features disabled in production
• Manage dependencies with Maven (pom.xml) or Gradle (build.gradle.kts)
• Pin dependency versions explicitly (no dynamic versions like 1.+)