org.apache.http.NoHttpResponseException: The target server failed to respond
at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:95)
at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:62)

@Bean
public RestTemplate restTemplate() {
  RestTemplate restTemplate = new RestTemplate();
  restTemplate.setMessageConverters(ImmutableList.of(messageConverter));
  restTemplate.setErrorHandler(errorHandler);

  HttpHost host = URIUtils.extractHost(new URI("http://127.0.0.1:8080"));
  HttpComponentsDigestRequestFactory requestFactory = new HttpComponentsDigestRequestFactory(host,new AuthProperties("user", "password", "realm"))
  requestFactory.setConnectTimeout(5000);
  requestFactory.setReadTimeout(30000);
  restTemplate.setRequestFactory(requestFactory);
}

class HttpComponentsDigestRequestFactory  extends HttpComponentsClientHttpRequestFactory {    

 public HttpComponentsDigestRequestFactory(@NotNull HttpHost host, @NotNull AuthProperties auth) {
   DefaultHttpClient httpClient = (DefaultHttpClient) getHttpClient();
   httpClient.getCredentialsProvider().setCredentials(new AuthScope(host, auth.getRealm(), "DIGEST"),
        new UsernamePasswordCredentials(auth.getUsername(), auth.getPassword()));
  }

@Override
protected HttpContext createHttpContext(HttpMethod httpMethod, URI uri) {
  AuthCache authCache = new BasicAuthCache();
  DigestScheme digestScheme = new DigestScheme();
  digestScheme.overrideParamter("realm", realm);
  authCache.put(host, digestScheme);
  BasicHttpContext context = new BasicHttpContext();
  context.setAttribute(ClientContext.AUTH_CACHE, authCache);
  return context;
  }

public void post(@NotNull String relativeUrl, @NotNull Object body,     @NotNull Map<String, ?> uriVariables) {
  String url = gateway + relativeUrl;
  restTemplate.postForEntity(url, body, MyError.class, uriVariables);
}

private String json(Object body) {
 return gson.toJson(body);
}