public class RestClient {

    private final String API_A = "http://api.somecompany.com/a";
    private final String API_B = "http://api.somecompany.com/b";

    RestTemplate restTemplate;

    public ResponseA postA(RequestA request) {
        HttpHeaders headers = getHeaders();
        HttpEntity<RequestA> request = new HttpEntity<>(request, headers);
        return postForObject(API_A, request, ResponseA.class);
    }

    public ResponseB postB(RequestB request) {
        HttpHeaders headers = getHeaders();
        HttpEntity<RequestB> request = new HttpEntity<>(request, headers);
        return postForObject(API_B, request, ResponseB.class);
    }

    private HttpHeaders getHeaders() {
        HttpHeaders headers = new HttpHeaders();
        headers.setContentType(MediaType.APPLICATION_JSON);
        headers.setAccept(Collections.singletonList(MediaType.APPLICATION_JSON));
        return headers;
    }
}