solid-java

Original：🇺🇸 English

Translated

SOLID principles for Java 21+. Files < 100 lines, interfaces separated, modular architecture. Modules MANDATORY.

1installs

Added on2026-02-28

NPX Install

npx skill4agent add fusengine/agents solid-java

Before ANY implementation, use

TeamCreate

to spawn 3 agents:

Before writing ANY new code:

Check shared locations:

modules/core/services/

,

modules/core/interfaces/

Layer	Location	Max Lines
Controllers	`modules/[feature]/controllers/`	50
Services	`modules/[feature]/services/`	100
Repositories	`modules/[feature]/repositories/`	100
Interfaces	`modules/[feature]/interfaces/`	30
Models/DTOs	`modules/[feature]/models/`	50
Shared	`modules/core/{services,interfaces,models}/`	-

NEVER use flat
src/
structure - always
modules/[feature]/

Rule	Value
File limit	100 lines (split at 90)
Controllers	< 50 lines, delegate to services
Interfaces	`modules/[feature]/interfaces/` ONLY
Javadoc	Every public method documented
Records	Use for DTOs (Java 16+)
Sealed	Use for restricted hierarchies (Java 17+)

Anti-Pattern	Fix
Files > 100 lines	Split at 90
Interfaces in impl files	Move to `interfaces/` directory
`new ConcreteClass()` in services	Use dependency injection
Flat `src/` structure	Use `modules/[feature]/`
God classes	Split by responsibility