What is Feign Client and how does it simplify inter-service communication? Feign Client क्या है और यह इंटर-सर्विस कम्युनिकेशन को कैसे आसान बनाता है?

OpenFeign is a declarative HTTP client: instead of manually building HTTP requests with RestTemplate or WebClient, you define a Java interface annotated with the target service's endpoints, and Spring generates the implementation at runtime — calling another microservice looks like calling a local method.

Feign integrates with Eureka for service discovery (using the service's registered name instead of a hardcoded URL) and with Resilience4j or Hystrix for automatic circuit breaking, and supports custom encoders, decoders, and interceptors for things like propagating an auth header on every outgoing call.

@FeignClient(name = "inventory-service")
public interface InventoryClient {
    @GetMapping("/api/inventory/{productId}")
    Inventory getStock(@PathVariable String productId);
}

@Service
public class OrderService {
    private final InventoryClient inventoryClient;
}