Declarative HTTP Interface Clients (Boot 4)

Declarative HTTP Interface Clients (Boot 4)

Define a remote API as an interface with @HttpExchange methods. Boot 4 registers the proxy with @ImportHttpServices, so do not create a manual factory for every client.

Define and register the interface

@HttpExchange("/orders")
public interface OrderApiClient {
    @GetExchange("/{id}")
    OrderDto get(@PathVariable UUID id);

    @PostExchange
    OrderDto create(@RequestBody CreateOrderRequest request);
}

@SpringBootApplication
@ImportHttpServices(group = "orders", basePackages = "com.example.client.orders")
public class Application { }

Inject OrderApiClient like any other bean. The interface needs no @Component and no implementation class.

Configure groups and transport

spring:
  http:
    clients:
      connect-timeout: 2s
      read-timeout: 5s
    serviceclient:
      orders:
        base-url: https://orders.internal.example.com
        read-timeout: 10s

spring.http.clients.* contains global transport defaults. spring.http.serviceclient.<group>.*