11 Consuming REST endpoints
This chapter covers
- Calling REST endpoints using Spring Cloud OpenFeign
- Calling REST endpoints using RestTemplate
- Calling REST endpoints using WebClient
In chapter 10, we discussed implementing REST endpoints. REST services are a common way to implement the communication between two system components. Not only the client of a web app may call the backend, but also two backend components may communicate one with the other to accomplish their responsibilities. In a backend solution composed of multiple services (see appendix A), these components need to “speak” to exchange data. So when you implement such a service using Spring, you need to know how to call a REST endpoint exposed by another service (figure 11.1).
Figure 11.1 Often, a backend app needs to act as a client for another backend app and call exposed REST endpoints to work with specific data.
In this chapter, you’ll learn three ways to call REST endpoints from a Spring app: