@Repository

@Repository() marks a class as a bean that stores and loads data.

Why

It does exactly what @Component does. The name tells the reader that the class is the data-access layer: a database, a file, a remote API, an in-memory map.

Keeping data access in its own beans lets a test or a profile replace it with a fake one, without touching the services that use it.

Example

import 'package:spring_core_dart/spring_core_dart.dart';

class Order {
  Order(this.id, this.total);
  final int id;
  final double total;
}

// The interface the services depend on.
abstract interface class Orders {
  Order? findById(int id);
  void save(Order order);
}

// In-memory storage. Another implementation could use a database;
// the services do not change.
@Repository()
class InMemoryOrders implements Orders {
  final _orders = <int, Order>{};

  @override
  Order? findById(int id) => _orders[id];

  @override
  void save(Order order) => _orders[order.id] = order;
}

The bean is registered under InMemoryOrders and under Orders, so a service can ask for Orders.

Parameters

In Spring (Java)

@Repository
class InMemoryOrders implements Orders {
  public Order findById(int id) { ... }
}

Spring also translates database exceptions of @Repository beans into its DataAccessException hierarchy. This package does not.

See also

• @Component
• @Service
• @Profile: swap the repository by environment
• @Primary