language:java topic:hexagonal-architecture created:2021-01-01..2021-12-31
JpaOrderRepository.java (Implements OrderRepository ).
What or external services must your application integrate with? The Domain (The Center) package com
The architecture relies on a strict separation of concerns, divided into three distinct layers: the Domain, Ports, and Adapters. The Domain (The Center)
package com.bank.ports.inbound; import java.math.BigDecimal; import java.util.UUID; public interface TransferUseCase void transfer(UUID sourceId, UUID targetId, BigDecimal amount); Use code with caution. Requires mapping data between multiple architectural layers
Coined by Alistair Cockburn, the goal of hexagonal architecture is to create systems that can be driven by users, programs, automated tests, or batch scripts, and to be developed and tested in isolation from their eventual run-time devices and databases.
We define an inbound port for the use case and an outbound port for persistence. The Domain (The Center) package com.bank.ports.inbound
Requires mapping data between multiple architectural layers.
com.mybankapp/ ├── domain/ (No dependencies) │ ├── model/ (Account, Customer) │ └── exception/ (DomainRuleViolation) ├── application/ (Use cases & Ports) │ ├── port/in/ (Input ports: CreateAccountUseCase) │ ├── port/out/ (Output ports: LoadAccountPort) │ └── service/ (Implements the Use Cases) ├── infrastructure/ (Adapters) │ ├── web/ (RestControllers) │ ├── persistence/ (JPA Repositories) │ └── messaging/ (Kafka/RabbitMQ listeners) └── shared/ (Helpers, Annotations)
: Rich domain objects that encapsulate data and behavior.
Teams can build frontend integrations and database schemas simultaneously by adhering to port definitions.