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Google Cloud Java Client

Java idiomatic client for Google Cloud Platform services.

Build Status Coverage Status Maven Codacy Badge Dependency Status

This client supports the following Google Cloud Platform services:

  • [Google Cloud BigQuery] (#google-cloud-bigquery-alpha) (Alpha)
  • [Google Cloud Compute] (#google-cloud-compute-alpha) (Alpha)
  • [Google Cloud Datastore] (#google-cloud-datastore)
  • [Google Cloud DNS] (#google-cloud-dns-alpha) (Alpha)
  • [Stackdriver Logging] (#stackdriver-logging-alpha) (Alpha - Not working on App Engine Standard)
  • [Google Cloud Pub/Sub] (#google-cloud-pubsub-alpha) (Alpha - Not working on App Engine Standard)
  • [Google Cloud Resource Manager] (#google-cloud-resource-manager-alpha) (Alpha)
  • [Google Cloud Storage] (#google-cloud-storage)
  • [Google Cloud Translate] (#google-translate) (Alpha)

Note: This client is a work-in-progress, and may occasionally make backwards-incompatible changes.

Where did gcloud-java go?

gcloud-java lives on under a new name, google-cloud. Your code will behave the same, simply change your dependency (see Quickstart).

Quickstart

If you are using Maven, add this to your pom.xml file

<dependency>
  <groupId>com.google.cloud</groupId>
  <artifactId>google-cloud</artifactId>
  <version>0.3.0</version>
</dependency>

If you are using Gradle, add this to your dependencies

compile 'com.google.cloud:google-cloud:0.3.0'

If you are using SBT, add this to your dependencies

libraryDependencies += "com.google.cloud" % "google-cloud" % "0.3.0"

Example Applications

Specifying a Project ID

Most google-cloud libraries require a project ID. There are multiple ways to specify this project ID.

  1. When using google-cloud libraries from within Compute/App Engine, there's no need to specify a project ID. It is automatically inferred from the production environment.
  2. When using google-cloud elsewhere, you can do one of the following:
  • Supply the project ID when building the service options. For example, to use Datastore from a project with ID "PROJECT_ID", you can write:
Datastore datastore = DatastoreOptions.builder().projectId("PROJECT_ID").build().service();
  • Specify the environment variable GOOGLE_CLOUD_PROJECT to be your desired project ID.
  • Set the project ID using the Google Cloud SDK. To use the SDK, download the SDK if you haven't already, and set the project ID from the command line. For example:
gcloud config set project PROJECT_ID

google-cloud determines the project ID from the following sources in the listed order, stopping once it finds a value:

  1. Project ID supplied when building the service options
  2. Project ID specified by the environment variable GOOGLE_CLOUD_PROJECT
  3. App Engine project ID
  4. Project ID specified in the JSON credentials file pointed by the GOOGLE_APPLICATION_CREDENTIALS environment variable
  5. Google Cloud SDK project ID
  6. Compute Engine project ID

Authentication

First, ensure that the necessary Google Cloud APIs are enabled for your project. To do this, follow the instructions on the authentication document shared by all the gcloud language libraries.

Next, choose a method for authenticating API requests from within your project:

  1. When using google-cloud libraries from within Compute/App Engine, no additional authentication steps are necessary.
  2. When using google-cloud libraries elsewhere, there are three options:
  • Generate a JSON service account key. After downloading that key, you must do one of the following:
    • Define the environment variable GOOGLE_APPLICATION_CREDENTIALS to be the location of the key. For example:
    export GOOGLE_APPLICATION_CREDENTIALS=/path/to/my/key.json
    • Supply the JSON credentials file when building the service options. For example, this Storage object has the necessary permissions to interact with your Google Cloud Storage data:
    Storage storage = StorageOptions.builder()
    .authCredentials(AuthCredentials.createForJson(new FileInputStream("/path/to/my/key.json"))
    .build()
    .service();
  • If running locally for development/testing, you can use Google Cloud SDK. Download the SDK if you haven't already, then login using the SDK (gcloud auth login in command line). Be sure to set your project ID as described above.
  • If you already have an OAuth2 access token, you can use it to authenticate (notice that in this case the access token will not be automatically refreshed):
Storage storage = StorageOptions.builder()
    .authCredentials(AuthCredentials.createFor("your_access_token"))
    .build()
    .service();

google-cloud looks for credentials in the following order, stopping once it finds credentials:

  1. Credentials supplied when building the service options
  2. App Engine credentials
  3. Key file pointed to by the GOOGLE_APPLICATION_CREDENTIALS environment variable
  4. Google Cloud SDK credentials
  5. Compute Engine credentials

Google Cloud BigQuery (Alpha)

Preview

Here is a code snippet showing a simple usage example from within Compute/App Engine. Note that you must supply credentials and a project ID if running this snippet elsewhere. Complete source code can be found at CreateTableAndLoadData.java.

import com.google.cloud.bigquery.BigQuery;
import com.google.cloud.bigquery.BigQueryOptions;
import com.google.cloud.bigquery.Field;
import com.google.cloud.bigquery.FormatOptions;
import com.google.cloud.bigquery.Job;
import com.google.cloud.bigquery.Schema;
import com.google.cloud.bigquery.StandardTableDefinition;
import com.google.cloud.bigquery.Table;
import com.google.cloud.bigquery.TableId;
import com.google.cloud.bigquery.TableInfo;

BigQuery bigquery = BigQueryOptions.defaultInstance().service();
TableId tableId = TableId.of("dataset", "table");
Table table = bigquery.getTable(tableId);
if (table == null) {
  System.out.println("Creating table " + tableId);
  Field integerField = Field.of("fieldName", Field.Type.integer());
  Schema schema = Schema.of(integerField);
  table = bigquery.create(TableInfo.of(tableId, StandardTableDefinition.of(schema)));
}
System.out.println("Loading data into table " + tableId);
Job loadJob = table.load(FormatOptions.csv(), "gs://bucket/path");
loadJob = loadJob.waitFor();
if (loadJob.status().error() != null) {
  System.out.println("Job completed with errors");
} else {
  System.out.println("Job succeeded");
}

Google Cloud Compute (Alpha)

Preview

Here are two code snippets showing simple usage examples from within Compute/App Engine. Note that you must supply credentials and a project ID if running this snippet elsewhere.

The first snippet shows how to create a snapshot from an existing disk. Complete source code can be found at CreateSnapshot.java.

import com.google.cloud.compute.Compute;
import com.google.cloud.compute.ComputeOptions;
import com.google.cloud.compute.Disk;
import com.google.cloud.compute.DiskId;
import com.google.cloud.compute.Snapshot;

Compute compute = ComputeOptions.defaultInstance().service();
DiskId diskId = DiskId.of("us-central1-a", "disk-name");
Disk disk = compute.getDisk(diskId, Compute.DiskOption.fields());
if (disk != null) {
  String snapshotName = "disk-name-snapshot";
  Operation operation = disk.createSnapshot(snapshotName);
  operation = operation.waitFor();
  if (operation.errors() == null) {
    // use snapshot
    Snapshot snapshot = compute.getSnapshot(snapshotName);
  }
}

The second snippet shows how to create a virtual machine instance. Complete source code can be found at CreateInstance.java.

import com.google.cloud.compute.AttachedDisk;
import com.google.cloud.compute.Compute;
import com.google.cloud.compute.ComputeOptions;
import com.google.cloud.compute.ImageId;
import com.google.cloud.compute.Instance;
import com.google.cloud.compute.InstanceId;
import com.google.cloud.compute.InstanceInfo;
import com.google.cloud.compute.MachineTypeId;
import com.google.cloud.compute.NetworkId;

Compute compute = ComputeOptions.defaultInstance().service();
ImageId imageId = ImageId.of("debian-cloud", "debian-8-jessie-v20160329");
NetworkId networkId = NetworkId.of("default");
AttachedDisk attachedDisk = AttachedDisk.of(AttachedDisk.CreateDiskConfiguration.of(imageId));
NetworkInterface networkInterface = NetworkInterface.of(networkId);
InstanceId instanceId = InstanceId.of("us-central1-a", "instance-name");
MachineTypeId machineTypeId = MachineTypeId.of("us-central1-a", "n1-standard-1");
Operation operation =
    compute.create(InstanceInfo.of(instanceId, machineTypeId, attachedDisk, networkInterface));
operation = operation.waitFor();
if (operation.errors() == null) {
  // use instance
  Instance instance = compute.getInstance(instanceId);
}

Google Cloud Datastore

Follow the activation instructions to use the Google Cloud Datastore API with your project.

Preview

Here are two code snippets showing simple usage examples from within Compute/App Engine. Note that you must supply credentials and a project ID if running this snippet elsewhere.

The first snippet shows how to create a Datastore entity. Complete source code can be found at CreateEntity.java.

import com.google.cloud.datastore.Datastore;
import com.google.cloud.datastore.DatastoreOptions;
import com.google.cloud.datastore.DateTime;
import com.google.cloud.datastore.Entity;
import com.google.cloud.datastore.Key;
import com.google.cloud.datastore.KeyFactory;

Datastore datastore = DatastoreOptions.defaultInstance().service();
KeyFactory keyFactory = datastore.newKeyFactory().kind("keyKind");
Key key = keyFactory.newKey("keyName");
Entity entity = Entity.builder(key)
    .set("name", "John Doe")
    .set("age", 30)
    .set("access_time", DateTime.now())
    .build();
datastore.put(entity);

The second snippet shows how to update a Datastore entity if it exists. Complete source code can be found at UpdateEntity.java.

import com.google.cloud.datastore.Datastore;
import com.google.cloud.datastore.DatastoreOptions;
import com.google.cloud.datastore.DateTime;
import com.google.cloud.datastore.Entity;
import com.google.cloud.datastore.Key;
import com.google.cloud.datastore.KeyFactory;

Datastore datastore = DatastoreOptions.defaultInstance().service();
KeyFactory keyFactory = datastore.newKeyFactory().kind("keyKind");
Key key = keyFactory.newKey("keyName");
Entity entity = datastore.get(key);
if (entity != null) {
  System.out.println("Updating access_time for " + entity.getString("name"));
  entity = Entity.builder(entity)
      .set("access_time", DateTime.now())
      .build();
  datastore.update(entity);
}

Google Cloud DNS (Alpha)

Follow the activation instructions to use the Google Cloud DNS API with your project.

Preview

Here are two code snippets showing simple usage examples from within Compute/App Engine. Note that you must supply credentials and a project ID if running this snippet elsewhere.

The first snippet shows how to create a zone resource. Complete source code can be found on CreateZone.java.

import com.google.cloud.dns.Dns;
import com.google.cloud.dns.DnsOptions;
import com.google.cloud.dns.Zone;
import com.google.cloud.dns.ZoneInfo;

Dns dns = DnsOptions.defaultInstance().service();
String zoneName = "my-unique-zone";
String domainName = "someexampledomain.com.";
String description = "This is a google-cloud-dns sample zone.";
ZoneInfo zoneInfo = ZoneInfo.of(zoneName, domainName, description);
Zone zone = dns.create(zoneInfo);

The second snippet shows how to create records inside a zone. The complete code can be found on CreateOrUpdateRecordSets.java.

import com.google.cloud.dns.ChangeRequestInfo;
import com.google.cloud.dns.Dns;
import com.google.cloud.dns.DnsOptions;
import com.google.cloud.dns.RecordSet;
import com.google.cloud.dns.Zone;

import java.util.Iterator;
import java.util.concurrent.TimeUnit;

Dns dns = DnsOptions.defaultInstance().service();
String zoneName = "my-unique-zone";
Zone zone = dns.getZone(zoneName);
String ip = "12.13.14.15";
RecordSet toCreate = RecordSet.builder("www.someexampledomain.com.", RecordSet.Type.A)
    .ttl(24, TimeUnit.HOURS)
    .addRecord(ip)
    .build();
ChangeRequestInfo.Builder changeBuilder = ChangeRequestInfo.builder().add(toCreate);

// Verify that the record does not exist yet.
// If it does exist, we will overwrite it with our prepared record.
Iterator<RecordSet> recordSetIterator = zone.listRecordSets().iterateAll();
while (recordSetIterator.hasNext()) {
  RecordSet current = recordSetIterator.next();
  if (toCreate.name().equals(current.name()) &&
      toCreate.type().equals(current.type())) {
    changeBuilder.delete(current);
  }
}

ChangeRequestInfo changeRequest = changeBuilder.build();
zone.applyChangeRequest(changeRequest);

Stackdriver Logging (Alpha)

Follow the activation instructions to use the Stackdriver Logging API with your project.

Preview

Here are two code snippets showing simple usage examples from within Compute Engine/App Engine Flexible. Note that you must supply credentials and a project ID if running this snippet elsewhere.

The first snippet shows how to write and list log entries. Complete source code can be found on WriteAndListLogEntries.java.

import com.google.cloud.MonitoredResource;
import com.google.cloud.Page;
import com.google.cloud.logging.LogEntry;
import com.google.cloud.logging.Logging;
import com.google.cloud.logging.Logging.EntryListOption;
import com.google.cloud.logging.LoggingOptions;
import com.google.cloud.logging.Payload.StringPayload;

import java.util.Collections;
import java.util.Iterator;

LoggingOptions options = LoggingOptions.defaultInstance();
try(Logging logging = options.service()) {

  LogEntry firstEntry = LogEntry.builder(StringPayload.of("message"))
      .logName("test-log")
      .resource(MonitoredResource.builder("global")
          .addLabel("project_id", options.projectId())
          .build())
      .build();
  logging.write(Collections.singleton(firstEntry));

  Page<LogEntry> entries = logging.listLogEntries(
      EntryListOption.filter("logName=projects/" + options.projectId() + "/logs/test-log"));
  Iterator<LogEntry> entryIterator = entries.iterateAll();
  while (entryIterator.hasNext()) {
    System.out.println(entryIterator.next());
  }
}

The second snippet shows how to use a java.util.logging.Logger to write log entries to Stackdriver Logging. The snippet installs a Stackdriver Logging handler using LoggingHandler.addHandler(Logger, LoggingHandler). Notice that this could also be done through the logging.properties file, adding the following line:

com.google.cloud.examples.logging.snippets.AddLoggingHandler.handlers=com.google.cloud.logging.LoggingHandler

The complete code can be found on AddLoggingHandler.java.

import com.google.cloud.logging.LoggingHandler;

import java.util.logging.Logger;

Logger logger = Logger.getLogger(AddLoggingHandler.class.getName());
LoggingHandler.addHandler(logger, new LoggingHandler());
logger.warning("test warning");

Google Cloud Pub/Sub (Alpha)

Preview

Here is a code snippet showing a simple usage example from within Compute Engine/App Engine Flexible. Note that you must supply credentials and a project ID if running this snippet elsewhere. Complete source code can be found at CreateSubscriptionAndPullMessages.java.

import com.google.cloud.pubsub.Message;
import com.google.cloud.pubsub.PubSub;
import com.google.cloud.pubsub.PubSub.MessageConsumer;
import com.google.cloud.pubsub.PubSub.MessageProcessor;
import com.google.cloud.pubsub.PubSubOptions;
import com.google.cloud.pubsub.Subscription;
import com.google.cloud.pubsub.SubscriptionInfo;

try (PubSub pubsub = PubSubOptions.defaultInstance().service()) {
  Subscription subscription =
      pubsub.create(SubscriptionInfo.of("test-topic", "test-subscription"));
  MessageProcessor callback = new MessageProcessor() {
    @Override
    public void process(Message message) throws Exception {
      System.out.printf("Received message \"%s\"%n", message.payloadAsString());
    }
  };
  // Create a message consumer and pull messages (for 60 seconds)
  try (MessageConsumer consumer = subscription.pullAsync(callback)) {
    Thread.sleep(60_000);
  }
}

Google Cloud Resource Manager (Alpha)

Preview

Here is a code snippet showing a simple usage example. Note that you must supply Google SDK credentials for this service, not other forms of authentication listed in the Authentication section. Complete source code can be found at UpdateAndListProjects.java.

import com.google.cloud.resourcemanager.Project;
import com.google.cloud.resourcemanager.ResourceManager;
import com.google.cloud.resourcemanager.ResourceManagerOptions;

import java.util.Iterator;

ResourceManager resourceManager = ResourceManagerOptions.defaultInstance().service();
Project project = resourceManager.get("some-project-id"); // Use an existing project's ID
if (project != null) {
  Project newProject = project.toBuilder()
      .addLabel("launch-status", "in-development")
      .build()
      .replace();
  System.out.println("Updated the labels of project " + newProject.projectId()
      + " to be " + newProject.labels());
}
Iterator<Project> projectIterator = resourceManager.list().iterateAll();
System.out.println("Projects I can view:");
while (projectIterator.hasNext()) {
  System.out.println(projectIterator.next().projectId());
}

Google Cloud Storage

Follow the activation instructions to use the Google Cloud Storage API with your project.

Preview

Here are two code snippets showing simple usage examples from within Compute/App Engine. Note that you must supply credentials and a project ID if running this snippet elsewhere.

The first snippet shows how to create a Storage blob. Complete source code can be found at CreateBlob.java.

import static java.nio.charset.StandardCharsets.UTF_8;

import com.google.cloud.storage.Blob;
import com.google.cloud.storage.BlobId;
import com.google.cloud.storage.BlobInfo;
import com.google.cloud.storage.Storage;
import com.google.cloud.storage.StorageOptions;

Storage storage = StorageOptions.defaultInstance().service();
BlobId blobId = BlobId.of("bucket", "blob_name");
BlobInfo blobInfo = BlobInfo.builder(blobId).contentType("text/plain").build();
Blob blob = storage.create(blobInfo, "Hello, Cloud Storage!".getBytes(UTF_8));

The second snippet shows how to update a Storage blob if it exists. Complete source code can be found at UpdateBlob.java.

import static java.nio.charset.StandardCharsets.UTF_8;

import com.google.cloud.storage.Blob;
import com.google.cloud.storage.BlobId;
import com.google.cloud.storage.Storage;
import com.google.cloud.storage.StorageOptions;

import java.nio.ByteBuffer;
import java.nio.channels.WritableByteChannel;

Storage storage = StorageOptions.defaultInstance().service();
BlobId blobId = BlobId.of("bucket", "blob_name");
Blob blob = storage.get(blobId);
if (blob != null) {
  byte[] prevContent = blob.content();
  System.out.println(new String(prevContent, UTF_8));
  WritableByteChannel channel = blob.writer();
  channel.write(ByteBuffer.wrap("Updated content".getBytes(UTF_8)));
  channel.close();
}

Google Translate

Preview

Here's a snippet showing a simple usage example. The example shows how to detect the language of some text and how to translate some text. The example assumes that the GOOGLE_API_KEY is set and contains a valid API key. Alternatively, you can use the apiKey(String) setter in TranslateOptions.Builder to set the API key. Complete source code can be found at DetectLanguageAndTranslate.java.

import com.google.cloud.translate.Detection;
import com.google.cloud.translate.Translate;
import com.google.cloud.translate.Translate.TranslateOption;
import com.google.cloud.translate.TranslateOptions;
import com.google.cloud.translate.Translation;

Translate translate = TranslateOptions.defaultInstance().service();

Detection detection = translate.detect("Hola");
String detectedLanguage = detection.language();

Translation translation = translate.translate(
    "World",
    TranslateOption.sourceLanguage("en"),
    TranslateOption.targetLanguage(detectedLanguage));

System.out.printf("Hola %s%n", translation.translatedText());

Troubleshooting

To get help, follow the instructions in the shared Troubleshooting document.

Java Versions

Java 7 or above is required for using this client.

Testing

This library provides tools to help write tests for code that uses google-cloud services.

See TESTING to read more about using our testing helpers.

Versioning

This library follows [Semantic Versioning] (http://semver.org/).

It is currently in major version zero (0.y.z), which means that anything may change at any time and the public API should not be considered stable.

Contributing

Contributions to this library are always welcome and highly encouraged.

See google-cloud's CONTRIBUTING documentation and the shared documentation for more information on how to get started.

Please note that this project is released with a Contributor Code of Conduct. By participating in this project you agree to abide by its terms. See Code of Conduct for more information.

License

Apache 2.0 - See LICENSE for more information.