Sample app

This page presents a sample app that demonstrates how to provision a dedicated device, and send it a reboot command. The app uses the Android Management API Java client library.

Before you begin

  1. Download the Android Management API Java client library and add all the jar files to the classpath.
  2. Create or select a Google Cloud project that will own the created enterprise.
  3. Enable the Android Management API in the project.
  4. Create or select a service account that has the owner or editor role on the project.
  5. Select a Google Account to sign up for a new enterprise. The account cannot be the admin for any pre-existing enterprise.
  6. Set the PROJECT_ID and SERVICE_ACCOUNT_CREDENTIAL_FILE constants in the code sample.
  7. Change the APP_PACKAGE_NAME constant in the code sample to install the app of your choice.

Code

package sample;

import com.google.api.client.googleapis.javanet.GoogleNetHttpTransport;
import com.google.api.client.http.HttpRequestFactory;
import com.google.api.client.http.javanet.NetHttpTransport;
import com.google.api.client.json.gson.GsonFactory;
import com.google.api.services.androidmanagement.v1.AndroidManagement;
import com.google.api.services.androidmanagement.v1.model.ApplicationPolicy;
import com.google.api.services.androidmanagement.v1.model.Command;
import com.google.api.services.androidmanagement.v1.model.Device;
import com.google.api.services.androidmanagement.v1.model.EnrollmentToken;
import com.google.api.services.androidmanagement.v1.model.Enterprise;
import com.google.api.services.androidmanagement.v1.model.ListDevicesResponse;
import com.google.api.services.androidmanagement.v1.model.PersistentPreferredActivity;
import com.google.api.services.androidmanagement.v1.model.Policy;
import com.google.api.services.androidmanagement.v1.model.SignupUrl;
import com.google.auth.http.HttpCredentialsAdapter;
import com.google.auth.oauth2.GoogleCredentials;
import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.security.GeneralSecurityException;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;

public class SampleApp {
  /** The id of the Google Cloud Platform project. */
  private static final String PROJECT_ID = "YOUR_PROJECT_ID";

  /** The JSON credential file for the service account. */
  private static final String SERVICE_ACCOUNT_CREDENTIAL_FILE =
      "/PATH/TO/YOUR_FILE";

  /** The id of the policy for the dedicated device. */
  private static final String POLICY_ID = "samplePolicy";

  /** The package name of the app. */
  private static final String APP_PACKAGE_NAME =
      "com.google.android.apps.youtube.gaming";

  /** The OAuth scope for the Android Management API. */
  private static final String OAUTH_SCOPE =
      "https://www.googleapis.com/auth/androidmanagement";

  /** The name of this app. */
  private static final String APP_NAME = "Android Management API sample app";

  /** The Android Management API client. */
  private final AndroidManagement androidManagementClient;

  public static void main(String[] args)
      throws IOException, GeneralSecurityException {
    new SampleApp(getAndroidManagementClient()).run();
  }

  public SampleApp(AndroidManagement androidManagementClient) {
    this.androidManagementClient = androidManagementClient;
  }

  /** Runs the app. */
  public void run() throws IOException {
    // Create an enterprise. If you've already created an enterprise, the
    // createEnterprise call can be commented out and replaced with your
    // enterprise name.
    String enterpriseName = createEnterprise();
    System.out.println("Enterprise created with name: " + enterpriseName);

    // Set the policy to be used by the device.
    setPolicy(enterpriseName, POLICY_ID, getDedicatedDevicePolicy());

    // Create an enrollment token to enroll the device.
    String token = createEnrollmentToken(enterpriseName, POLICY_ID);
    System.out.println("Enrollment token (to be typed on device): " + token);

    // List some of the devices for the enterprise. There will be no devices for
    // a newly created enterprise, but you can run the app again with an
    // existing enterprise after enrolling a device.
    List<Device> devices = listDevices(enterpriseName);
    for (Device device : devices) {
      System.out.println("Found device with name: " + device.getName());
    }

    // If there are any devices, reboot one.
    if (devices.isEmpty()) {
      System.out.println("No devices found.");
    } else {
      rebootDevice(devices.get(0));
    }
  }

  /** Builds an Android Management API client. */
  private static AndroidManagement getAndroidManagementClient()
      throws IOException, GeneralSecurityException {
    try (FileInputStream input = new FileInputStream(SERVICE_ACCOUNT_CREDENTIAL_FILE)) {
      final GoogleCredentials credential =
          GoogleCredentials.fromStream(input).createScoped(Collections.singleton(OAUTH_SCOPE));

      final HttpCredentialsAdapter credentialsAdapter = new HttpCredentialsAdapter(credential);
      final HttpRequestFactory requestFactory =
          new NetHttpTransport().createRequestFactory(credentialsAdapter);

      return new AndroidManagement.Builder(
              GoogleNetHttpTransport.newTrustedTransport(),
              GsonFactory.getDefaultInstance(),
              requestFactory.getInitializer())
          .setApplicationName(APP_NAME)
          .build();
    }
  }

  /** Creates a new enterprise. Returns the enterprise name. */
  private String createEnterprise() throws IOException {
    // Initiate signup process.
    System.out.println("Creating signup URL...");
    SignupUrl signupUrl =
        androidManagementClient
            .signupUrls()
            .create()
            .setProjectId(PROJECT_ID)
            .setCallbackUrl("https://localhost:9999")
            .execute();
    System.out.print(
        "To sign up for a new enterprise, open this URL in your browser: ");
    System.out.println(signupUrl.getUrl());
    System.out.println(
        "After signup, you will see an error page in the browser.");
    System.out.print(
        "Paste the enterpriseToken value from the error page URL here: ");
    String enterpriseToken =
        new BufferedReader(new InputStreamReader(System.in)).readLine();

    // Create the enterprise.
    System.out.println("Creating enterprise...");
    return androidManagementClient
        .enterprises()
        .create(new Enterprise())
        .setProjectId(PROJECT_ID)
        .setSignupUrlName(signupUrl.getName())
        .setEnterpriseToken(enterpriseToken)
        .execute()
        .getName();
  }

  /** Gets a Policy for a dedicated device. */
  private Policy getDedicatedDevicePolicy() {
    List<String> categories = Arrays.asList(
        "android.intent.category.HOME",
        "android.intent.category.DEFAULT"
    );

    return new Policy()
        .setApplications(
            Collections.singletonList(
                new ApplicationPolicy()
                    .setPackageName(APP_PACKAGE_NAME)
                    .setInstallType("FORCE_INSTALLED")
                    .setDefaultPermissionPolicy("GRANT")
                    .setLockTaskAllowed(true)))
        .setPersistentPreferredActivities(
            Collections.singletonList(
                new PersistentPreferredActivity()
                    .setReceiverActivity(APP_PACKAGE_NAME)
                    .setActions(
                        Collections.singletonList("android.intent.action.MAIN"))
                    .setCategories(categories)))
        .setKeyguardDisabled(true)
        .setStatusBarDisabled(true);
  }

  /** Sets the policy of the given id to the given value. */
  private void setPolicy(String enterpriseName, String policyId, Policy policy)
      throws IOException {
    System.out.println("Setting policy...");
    String name = enterpriseName + "/policies/" + policyId;
    androidManagementClient
        .enterprises()
        .policies()
        .patch(name, policy)
        .execute();
  }

  /** Creates an enrollment token. */
  private String createEnrollmentToken(String enterpriseName, String policyId)
      throws IOException {
    System.out.println("Creating enrollment token...");
    EnrollmentToken token =
        new EnrollmentToken().setPolicyName(policyId).setDuration("86400s");
    return androidManagementClient
        .enterprises()
        .enrollmentTokens()
        .create(enterpriseName, token)
        .execute()
        .getValue();
  }

  /** Lists the first page of devices for an enterprise. */
  private List<Device> listDevices(String enterpriseName) throws IOException {
    System.out.println("Listing devices...");
    ListDevicesResponse response =
        androidManagementClient
            .enterprises()
            .devices()
            .list(enterpriseName)
            .execute();
    return response.getDevices() == null
        ? Collections.emptyList() : response.getDevices();
  }

  /** Reboots a device. Note that reboot only works on Android N+. */
  private void rebootDevice(Device device) throws IOException {
    System.out.println(
        "Sending reboot command to " + device.getName() + "...");
    Command command = new Command().setType("REBOOT");
    androidManagementClient
        .enterprises()
        .devices()
        .issueCommand(device.getName(), command)
        .execute();
  }
}