Building a REST client

So far, we have created a REST API and consumed it in third-party tools such as SoapUI, Postman, or JUnit testing. There might be situations where you will have to consume a REST API using the regular method (service or another controller method) itself like payment API call in service API. It will be useful when you call a third-party API such as PayPal or a weather API in your code. In such situations, having a REST client will be helpful for getting the job done.

Here, we will talk about how to build a REST client to consume another REST API in our method. Before moving onto that, we will talk a little bit about RestTemplate in Spring.

RestTemplate

RestTemplate is a Spring class that is used to consume the REST API from the client side through HTTP. By using RestTemplate, we can keep the REST API consumer in the same application as well, so we don't need a third-party application or another application to consume our API. RestTemplate can be used use to call GET, POST...