Example of using Retrofit with digest auth

gistfile1.java

package movida;

import org.apache.http.HttpEntity;
import org.apache.http.auth.AuthScope;
import org.apache.http.auth.Credentials;
import org.apache.http.auth.UsernamePasswordCredentials;
import org.apache.http.client.CredentialsProvider;
import org.apache.http.client.methods.*;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.BasicCredentialsProvider;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
import retrofit.client.Client;
import retrofit.client.Header;
import retrofit.mime.TypedByteArray;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class MovidaClient implements Client {
  private final CloseableHttpClient client;

  public MovidaClient(String user, String pass, String hostname,
                          String scope, int threadCount) {
    Credentials credentials = new UsernamePasswordCredentials(user, pass);
    AuthScope authScope = new AuthScope(hostname, 443, scope);

    HttpClientBuilder clientBuilder = HttpClientBuilder.create();
    CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
    credentialsProvider.setCredentials(authScope, credentials);

    PoolingHttpClientConnectionManager connectionManager = new
        PoolingHttpClientConnectionManager();
    connectionManager.setMaxTotal(threadCount * 2);
    connectionManager.setDefaultMaxPerRoute(threadCount);

    client = clientBuilder
        .setDefaultCredentialsProvider(credentialsProvider)
        .setConnectionManager(connectionManager)
        .build();
  }

  private byte[] toByteArray(HttpEntity entity) throws IOException {
    ByteArrayOutputStream bos = new ByteArrayOutputStream();
    entity.writeTo(bos);
    return bos.toByteArray();
  }

  private List<Header> toRetrofitHeaders(org.apache.http.Header[] headers) {
    List<Header> retrofitHeaders = new ArrayList<>();
    for (org.apache.http.Header header : headers) {
      retrofitHeaders.add(new Header(header.getName(), header.getValue()));
    }
    return retrofitHeaders;
  }

  @Override public retrofit.client.Response execute(
      retrofit.client.Request request) throws IOException {
    // Get body of request.
    ByteArrayOutputStream bos = new ByteArrayOutputStream();
    if (request.getBody() != null) {
      request.getBody().writeTo(bos);
    }
    String body = new String(bos.toByteArray());

    // Which HTTP method are we using?
    HttpUriRequest wrappedRequest;
    String method = request.getMethod();
    switch (method) {
      case "GET":
        wrappedRequest = new HttpGet(request.getUrl());
        break;
      case "POST":
        wrappedRequest = new HttpPost(request.getUrl());
        wrappedRequest.addHeader("Content-Type", "application/xml");
        ((HttpPost) wrappedRequest).setEntity(new StringEntity(body));
        break;
      case "PUT":
        wrappedRequest = new HttpPut(request.getUrl());
        wrappedRequest.addHeader("Content-Type", "application/xml");
        ((HttpPut) wrappedRequest).setEntity(new StringEntity(body));
        break;
      case "DELETE":
        wrappedRequest = new HttpDelete(request.getUrl());
        break;
      default:
        throw new AssertionError("HTTP operation not supported.");
    }

    // Perform the HTTP request.
    CloseableHttpResponse response = null;
    try {
      response = client.execute(wrappedRequest);

      // Return a Retrofit response.
      List<Header> retrofitHeaders = toRetrofitHeaders(
          response.getAllHeaders());
      TypedByteArray responseBody;
      if (response.getEntity() != null) {
        responseBody = new TypedByteArray(MovidaXMLConverter.MIME_TYPE,
            toByteArray(response.getEntity()));
      } else {
        responseBody = new TypedByteArray(MovidaXMLConverter.MIME_TYPE,
            new byte[0]);
      }
      System.out.println("this is the response");
      System.out.println(new String(responseBody.getBytes()));
      return new retrofit.client.Response(request.getUrl(),
          response.getStatusLine().getStatusCode(),
          response.getStatusLine().getReasonPhrase(), retrofitHeaders,
          responseBody);
    } finally {
      if (response != null) {
        response.close();
      }
    }
  }
}