Java quickstart for customers using a service account

AI-generated Key Takeaways

This quickstart guide helps you create a simple Java command-line application that interacts with the zero-touch enrollment customer API using a service account in approximately 10 minutes.
You will need a service account linked to your zero-touch enrollment customer account, Java 1.7 or greater, Gradle 2.3 or greater, and internet access to complete this process.
The guide involves enabling the zero-touch enrollment API, creating a service account, downloading a JSON key file, preparing a Gradle project, and setting up the Java sample code.
The created Java application will interact with the API by listing all the DPCs available using the customer account, showcasing the API's functionality.
After completing the quickstart, there are multiple resources for further reading, including the Google Developers Console help documentation, Google APIs Client for Java documentation, and Google APIs Client Javadocs.

Follow the steps in this quickstart guide, and in about 10 minutes you have a simple Java command-line app that makes requests to the zero-touch enrollment customer API using a service account.

Prerequisites

To run this quickstart, you need:

A service account, that's linked to you zero-touch enrollment customer account. See Get started.
Java 1.7 or greater.
Gradle 2.3 or greater.
Access to the internet and a web browser.

Step 1: Turn on the zero-touch enrollment API

Use this wizard to create or select a project in the Google Developers Console and automatically turn on the API. Click Continue, then Go to credentials .
Set What data will you be accessing? to Application data.
Click Next. You should be prompted to create a service account.
Give a descriptive name for Service account name.
Note the Service account ID (it looks like an email address) because you'll use it later.
Set Role to Service Accounts > Service Account User.
Click Done to finish creating the service account.
Click the email address for the service account that you created.
Click **Keys**.
Click **Add key**, then click **Create new key**.
For **Key type**, select **JSON**.
Click Create and the private key downloads to your computer.
Click **Close**.
Move the file to your working directory and rename it service_account_key.json.

Step 2: Prepare the project

Follow the steps below to set up your Gradle project:

Run the following command to create a new project in the working directory:

gradle init --type basic
mkdir -p src/main/java src/main/resources

Copy the service_account_key.json you downloaded when you created your service account into the src/main/resources/ directory you created above.
Open the default build.gradle file and replace its contents with the following code:

apply plugin: 'java'
apply plugin: 'application'

mainClassName = 'CustomerQuickstart'
sourceCompatibility = 1.7
targetCompatibility = 1.7
version = '1.0'

repositories {
    mavenCentral()
}

dependencies {
    compile 'com.google.api-client:google-api-client:2.2.0'
    compile 'com.google.apis:google-api-services-androiddeviceprovisioning:v1-rev20230509-2.0.0'
    compile 'com.google.auth:google-auth-library-oauth2-http:1.16.1'
    compile 'com.google.auth:google-auth-library-credentials:1.16.1'
    compile 'com.google.http-client:google-http-client:1.43.1'
    compile 'com.google.oauth-client:google-oauth-client-jetty:1.34.1'
}

Step 3: Set up the sample

Create a file named src/main/java/CustomerQuickstart.java and copy in the following code and save the file.

import com.google.api.client.googleapis.javanet.GoogleNetHttpTransport;
import com.google.api.client.http.HttpRequestInitializer;
import com.google.api.client.http.HttpTransport;
import com.google.api.client.json.JsonFactory;
import com.google.api.client.json.gson.GsonFactory;
import com.google.api.services.androiddeviceprovisioning.v1.AndroidProvisioningPartner;
import com.google.api.services.androiddeviceprovisioning.v1.model.Company;
import com.google.api.services.androiddeviceprovisioning.v1.model.CustomerListCustomersResponse;
import com.google.api.services.androiddeviceprovisioning.v1.model.CustomerListDpcsResponse;
import com.google.api.services.androiddeviceprovisioning.v1.model.Dpc;
import com.google.auth.http.HttpCredentialsAdapter;
import com.google.auth.oauth2.GoogleCredentials;
import com.google.auth.oauth2.ServiceAccountCredentials;
import java.io.IOException;
import java.io.InputStream;
import java.util.Arrays;
import java.util.List;

/** This class forms the quickstart introduction to the zero-touch enrollment customer API. */
public class CustomerQuickstart {

  // A single auth scope is used for the zero-touch enrollment customer API.
  private static final List<String> SCOPES =
      Arrays.asList("https://www.googleapis.com/auth/androidworkzerotouchemm");
  private static final String APP_NAME = "Zero-touch Enrollment Java Quickstart";

  // Global shared instances
  private static final JsonFactory JSON_FACTORY = GsonFactory.getDefaultInstance();
  private static HttpTransport HTTP_TRANSPORT;

  static {
    try {
      HTTP_TRANSPORT = GoogleNetHttpTransport.newTrustedTransport();
    } catch (Throwable t) {
      t.printStackTrace();
      System.exit(1);
    }
  }

  /**
   * Creates a GoogleCredentials object with the correct OAuth2 authorization for the service
   * account that calls the reseller API. The service endpoint invokes this method when setting up a
   * new service instance.
   *
   * @return an authorized GoogleCredentials object.
   * @throws IOException
   */
  public static GoogleCredentials authorize() throws IOException {
    // Load service account key.
    InputStream in = CustomerQuickstart.class.getResourceAsStream("/service_account_key.json");

    // Create the credential scoped to the zero-touch enrollment customer APIs.
    GoogleCredentials credential = ServiceAccountCredentials.fromStream(in).createScoped(SCOPES);
    return credential;
  }

  /**
   * Build and return an authorized zero-touch enrollment API client service. Use the service
   * endpoint to call the API methods.
   *
   * @return an authorized client service endpoint
   * @throws IOException
   */
  public static AndroidProvisioningPartner getService() throws IOException {
    GoogleCredentials credential = authorize();
    HttpRequestInitializer requestInitializer = new HttpCredentialsAdapter(credential);
    return new AndroidProvisioningPartner.Builder(HTTP_TRANSPORT, JSON_FACTORY, requestInitializer)
        .setApplicationName(APP_NAME)
        .build();
  }

  /**
   * Runs the zero-touch enrollment quickstart app.
   *
   * @throws IOException
   */
  public static void main(String[] args) throws IOException {

    // Create a zero-touch enrollment API service endpoint.
    AndroidProvisioningPartner service = getService();

    // Get the customer's account. Because a customer might have more
    // than one, limit the results to the first account found.
    AndroidProvisioningPartner.Customers.List accountRequest = service.customers().list();
    accountRequest.setPageSize(1);
    CustomerListCustomersResponse accountResponse = accountRequest.execute();
    if (accountResponse.getCustomers().isEmpty()) {
      // No accounts found for the user. Confirm the Google Account
      // that authorizes the request can access the zero-touch portal.
      System.out.println("No zero-touch enrollment account found.");
      System.exit(-1);
    }
    Company customer = accountResponse.getCustomers().get(0);
    String customerAccount = customer.getName();

    // Send an API request to list all the DPCs available using the customer account.
    AndroidProvisioningPartner.Customers.Dpcs.List request =
        service.customers().dpcs().list(customerAccount);
    CustomerListDpcsResponse response = request.execute();

    // Print out the details of each DPC.
    java.util.List<Dpc> dpcs = response.getDpcs();
    for (Dpc dpcApp : dpcs) {
      System.out.format("Name:%s  APK:%s\n", dpcApp.getDpcName(), dpcApp.getPackageName());
    }
  }
}

Step 4: Run the sample

Use your operating system's help to run the script in the file. On UNIX and Mac computers, run the command below in your terminal:

gradle -q run

Notes

Avoid sharing your service_account_key.json file with anyone. Be careful not to include it in source code repositories. You can read more advice on handling service account secrets.