CorrelatingRestClient.java

@Component
public class CorrelatingRestClient implements RestClient {

    private RestTemplate restTemplate = new RestTemplate();

    @Override
    public String getForString(String uri) {
        String correlationId = RequestCorrelation.getId();
        HttpHeaders httpHeaders = new HttpHeaders();
        httpHeaders.set(RequestCorrelation.CORRELATION_ID, correlationId);

        LOGGER.info("start REST request to {} with correlationId {}", uri, correlationId);

        //TODO: error-handling and fault-tolerance in production
        ResponseEntity<String> response = restTemplate.exchange(uri, HttpMethod.GET,
                new HttpEntity<String>(httpHeaders), String.class);

        LOGGER.info("completed REST request to {} with correlationId {}", uri, correlationId);

        return response.getBody();
    }
}


//... calling Class
public String exampleMethod() {
        RestClient restClient = new CorrelatingRestClient();
        return restClient.getForString(URI_LOCATION); //correlation id handling completely abstracted to RestClient impl
}