full-stack-skills/skills/ddd4j-project-creator/examples/architecture-patterns.md

Architecture Patterns Reference

This document provides detailed structure examples for four DDD architecture patterns.

1. DDD Classic Layered Architecture (DDD 经典分层架构)

Layer Structure

interfaces (接口层)
    ↓ 依赖
application (应用层)
    ↓ 依赖
domain (领域层)
    ↑ 实现接口
infrastructure (基础设施层)

Package Structure

{basePackage}.{module}.interfaces
{basePackage}.{module}.application
{basePackage}.{module}.domain
{basePackage}.{module}.infrastructure

Key Components

• interfaces: Controllers, DTOs, Filters, Exception Handlers
• application: Application Services, Commands, Queries, Event Handlers
• domain: Aggregates, Entities, Value Objects, Domain Services, Repository Interfaces
• infrastructure: Repository Implementations, External Services, Configurations

Reference

See: docs/1、DDD 经典分层架构目录结构.md

2. Hexagonal Architecture (六边形架构)

Layer Structure

adapter (适配器层)
    ↓ 依赖
application (应用层)
    ↓ 依赖
domain (领域层)
    ↑ 实现接口
infrastructure (基础设施层)

Package Structure

{basePackage}.{module}.adapter
{basePackage}.{module}.application
{basePackage}.{module}.domain
{basePackage}.{module}.infrastructure

Key Components

• adapter: Web Controllers, RPC Providers, Message Consumers, Scheduled Jobs
• application: Use Cases, Application Services, Ports (Inbound/Outbound)
• domain: Entities, Value Objects, Domain Services, Domain Events
• infrastructure: Repository Implementations, External Service Adapters, Configurations

Ports and Adapters

• Inbound Ports: Define application services (e.g., IOrderService)
• Outbound Ports: Define external dependencies (e.g., IOrderRepository, IPaymentProvider)
• Inbound Adapters: Web Controllers, CLI, Message Consumers
• Outbound Adapters: Database Repositories, External API Clients, Message Publishers

Reference

See: docs/2、六边形架构详细目录结构参考.md

3. Clean Architecture (整洁架构)

Layer Structure

interfaces (接口适配器层)
    ↓ 依赖
application (应用层/用例层)
    ↓ 依赖
domain (领域层/实体层)
    ↑ 实现接口
infrastructure (基础设施层)

Package Structure

{basePackage}.{module}.interfaces
{basePackage}.{module}.application
{basePackage}.{module}.domain
{basePackage}.{module}.infrastructure

Key Components

• interfaces: Controllers, Presenters, Gateways (Input/Output Ports)
• application: Use Cases, Application Services, Input/Output Ports
• domain: Entities, Value Objects, Domain Services, Repository Interfaces
• infrastructure: Repository Implementations, External Service Adapters, Configurations

Ports

• Input Ports: Define use case interfaces
• Output Ports: Define external dependencies (Repository, External Services)

Reference

See: docs/3、整洁架构详细目录结构参考.md

4. COLA V5 (菱形架构)

Layer Structure

adapter (适配器层)
    ↓ 依赖
app (应用层)
    ↓ 依赖
domain (领域层)
    ↑ 实现接口
infrastructure (基础设施层)

Package Structure

{basePackage}.{module}.adapter
{basePackage}.{module}.app
{basePackage}.{module}.domain
{basePackage}.{module}.infrastructure

Key Components

• adapter: Web Controllers, RPC Providers, Job Schedulers, Message Listeners
• app: Executors (Command/Query), Application Services, Extensions
• domain: Entities, Value Objects, Domain Services, Abilities, Gateways, Repository Interfaces
• infrastructure: Repository Implementations, Gateway Implementations, External Clients

COLA V5 Specific Features

• Executors: Command Executors (CmdExe) and Query Executors (QryExe)
• Extensions: Extension Points for business logic extension
• Abilities: Domain abilities for cross-entity business rules
• Gateways: Domain gateways for external dependencies

Reference

See: docs/4、COLA V5 架构详细目录结构参考.md

Comparison Table

Aspect	DDD Classic	Hexagonal	Clean	COLA V5
Interface Layer	interfaces	adapter	interfaces	adapter
Application Layer	application	application	application	app
Domain Layer	domain	domain	domain	domain
Infrastructure	infrastructure	infrastructure	infrastructure	infrastructure
Port Concept	No	Yes (Inbound/Outbound)	Yes (Input/Output)	Yes (Gateways)
Use Cases	Application Services	Use Cases	Use Cases	Executors
Extension	No	No	No	Yes (Extension Points)
Ability	Domain Services	Domain Services	Domain Services	Abilities

Choosing an Architecture

Choose DDD Classic when:

• Following Eric Evans' DDD book
• Need clear layer separation
• Standard DDD implementation

Choose Hexagonal when:

• Need technology isolation
• Multiple driving adapters (Web, CLI, Message)
• High testability requirements

Choose Clean Architecture when:

• Need concentric circle structure
• High testability requirements
• Business logic complexity

Choose COLA V5 when:

• Need extension mechanism
• Want ability pattern
• Alibaba COLA framework users

Common Principles

All four architectures follow these principles:

1. Dependency Rule: Dependencies point inward, domain layer has no external dependencies
2. Interface Segregation: Domain layer defines interfaces, infrastructure implements them
3. Separation of Concerns: Clear layer responsibilities
4. Testability: Domain layer can be tested independently