In this chapter, we introduced and explained Feign, a declarative HTTP client developed by Netflix. We have learned how Feign simplifies HTTP API clients. We don't need to use a lot of boilerplate code to make the HTTP API clients application to access the microservices. You just simply use an annotated interface while the actual implementation will be created at the runtime.

The reader can learn to use Feign client and Hystrix support with the Feign client. This chapter has also implemented a custom encoder/decoder with exception handling for the Feign requests and responses. We have created some unit test cases to test the Feign client. The reader can also learn to use and customize the configurable options, such as logging and request compression.

In the next chapter, we will explore and implement event-driven systems.