content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you under the Apache License, Version 2.0 (the
   * "License"); you may not use this file except in compliance
   * with the License.  You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.apache.beam.sdk.extensions.gcp.auth;
  
  import com.google.api.client.http.HttpRequest;
  import com.google.api.client.http.HttpRequestInitializer;
  import com.google.api.client.http.HttpResponse;
  import com.google.api.client.http.HttpUnsuccessfulResponseHandler;
  import java.io.IOException;
  
  /**
   * A {@link HttpRequestInitializer} for requests that don't have credentials.
   *
   * <p>When the access is denied, it throws {@link IOException} with a detailed error message.
   */
  public class NullCredentialInitializer implements HttpRequestInitializer {
    private static final int ACCESS_DENIED = 401;
    private static final String NULL_CREDENTIAL_REASON =
        "Unable to get application default credentials. Please see "
            + "https://developers.google.com/accounts/docs/application-default-credentials "
            + "for details on how to specify credentials. This version of the SDK is "
            + "dependent on the gcloud core component version 2015.02.05 or newer to "
            + "be able to get credentials from the currently authorized user via gcloud auth.";
  
    @Override
    public void initialize(HttpRequest httpRequest) throws IOException {
      httpRequest.setUnsuccessfulResponseHandler(new NullCredentialHttpUnsuccessfulResponseHandler());
    }
  
    private static class NullCredentialHttpUnsuccessfulResponseHandler
        implements HttpUnsuccessfulResponseHandler {
  
      @Override
      public boolean handleResponse(
          HttpRequest httpRequest, HttpResponse httpResponse, boolean supportsRetry)
          throws IOException {
        if (!httpResponse.isSuccessStatusCode() && httpResponse.getStatusCode() == ACCESS_DENIED) {
          throwNullCredentialException();
        }
        return supportsRetry;
      }
    }
  
    public static void throwNullCredentialException() {
      throw new RuntimeException(NULL_CREDENTIAL_REASON);
    }
  }
  