34. Calling REST services

If you need to call remote REST services from your application, you can use Spring Framework’s RestTemplate class. Since RestTemplate instances often need to be customized before being used, Spring Boot does not provide any single auto-configured RestTemplate bean. It does, however, auto-configure a RestTemplateBuilder which can be used to create RestTemplate instances when needed. The auto-configured RestTemplateBuilder will ensure that sensible HttpMessageConverters are applied to RestTemplate instances.

Here’s a typical example:

@Service
public class MyBean {

    private final RestTemplate restTemplate;

    public MyBean(RestTemplateBuilder restTemplateBuilder) {
        this.restTemplate = restTemplateBuilder.build();
    }

    public Details someRestCall(String name) {
        return this.restTemplate.getForObject("/{name}/details", Details.class, name);
    }

}
[Tip]Tip

RestTemplateBuilder includes a number of useful methods that can be used to quickly configure a RestTemplate. For example, to add BASIC auth support you can use builder.basicAuthorization("user", "password").build().