What is feign?

Feign is a lightweight Java HTTP client framework used to simplify the RESTful web service consumption. It is a declarative REST client that allows developers to write HTTP client code with minimum effort. Feign generates API clients at compile time based on declared interfaces, and it uses annotations such as @RequestMapping to define the endpoints.

Feign provides easy integration with other libraries like Ribbon and Hystrix, thus making it an excellent choice for microservice architectures. With Ribbon load balancer, it helps in distributing the traffic to different endpoints based on user-defined policies, and with Hystrix circuit breaker, it helps in preventing network failures from impacting other parts of the system.

Feign provides several features such as request compression, automatic URL encoding, and support for various HTTP methods - GET, PUT, POST, DELETE, among others. It also has support for custom request/response interceptors, logging and error handling, and content decoding.

Overall, Feign is a fantastic tool that simplifies RESTful web service consumption in Java applications and makes it easier for developers to write client-side logic to interact with various RESTful services.