Java Coding Standards

Java Coding Standards

Standards for readable, maintainable Java (17+) code in Spring Boot services.

When to Activate

• Writing or reviewing Java code in Spring Boot projects
• Enforcing naming, immutability, or exception handling conventions
• Working with records, sealed classes, or pattern matching (Java 17+)
• Reviewing use of Optional, streams, or generics
• Structuring packages and project layout

Core Principles

• Prefer clarity over cleverness
• Immutable by default; minimize shared mutable state
• Fail fast with meaningful exceptions
• Consistent naming and package structure

Naming

// ✅ Classes/Records: PascalCase
public class MarketService {}
public record Money(BigDecimal amount, Currency currency) {}

// ✅ Methods/fields: camelCase
private final MarketRepository marketRepository;
public Market findBySlug(String slug) {}

// ✅ Constants: UPPER_SNAKE_CASE
private static final int MAX_PAGE_SIZE = 100;

Immutability

// ✅ Favor records and final fields
public record MarketDto(Long id, String name, MarketStatus status) {}