Awesome
Google Cloud Storage Client for Java
Java idiomatic client for Cloud Storage.
Quickstart
If you are using Maven with BOM, add this to your pom.xml file:
<dependencyManagement>
<dependencies>
<dependency>
<groupId>com.google.cloud</groupId>
<artifactId>libraries-bom</artifactId>
<version>26.49.0</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<dependencies>
<dependency>
<groupId>com.google.cloud</groupId>
<artifactId>google-cloud-storage</artifactId>
</dependency>
<dependency>
<groupId>com.google.cloud</groupId>
<artifactId>google-cloud-storage-control</artifactId>
</dependency>
</dependencies>
If you are using Maven without the BOM, add this to your dependencies:
<dependency>
<groupId>com.google.cloud</groupId>
<artifactId>google-cloud-storage</artifactId>
<version>2.44.1</version>
</dependency>
<dependency>
<groupId>com.google.cloud</groupId>
<artifactId>google-cloud-storage-control</artifactId>
<version>2.44.1</version>
</dependency>
If you are using Gradle 5.x or later, add this to your dependencies:
implementation platform('com.google.cloud:libraries-bom:26.49.0')
implementation 'com.google.cloud:google-cloud-storage'
If you are using Gradle without BOM, add this to your dependencies:
implementation 'com.google.cloud:google-cloud-storage:2.44.1'
If you are using SBT, add this to your dependencies:
libraryDependencies += "com.google.cloud" % "google-cloud-storage" % "2.44.1"
Authentication
See the Authentication section in the base directory's README.
Authorization
The client application making API calls must be granted authorization scopes required for the desired Cloud Storage APIs, and the authenticated principal must have the IAM role(s) required to access GCP resources using the Cloud Storage API calls.
Getting Started
Prerequisites
You will need a Google Cloud Platform Console project with the Cloud Storage API enabled.
You will need to enable billing to use Google Cloud Storage.
Follow these instructions to get your project set up. You will also need to set up the local development environment by
installing the Google Cloud Command Line Interface and running the following commands in command line:
gcloud auth login
and gcloud config set project [YOUR PROJECT ID]
.
Installation and setup
You'll need to obtain the google-cloud-storage
library. See the Quickstart section
to add google-cloud-storage
as a dependency in your code.
About Cloud Storage
Cloud Storage is a durable and highly available object storage service. Google Cloud Storage is almost infinitely scalable and guarantees consistency: when a write succeeds, the latest copy of the object will be returned to any GET, globally.
See the Cloud Storage client library docs to learn how to use this Cloud Storage Client Library.
About Storage Control
The Storage Control API lets you perform metadata-specific, control plane, and long-running operations.
The Storage Control API creates one space to perform metadata-specific, control plane, and long-running operations apart from the Storage API. Separating these operations from the Storage API improves API standardization and lets you run faster releases.
If you are using Maven with BOM, add this to your pom.xml file:
<dependencyManagement>
<dependencies>
<dependency>
<groupId>com.google.cloud</groupId>
<artifactId>libraries-bom</artifactId>
<version>26.44.0</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<dependencies>
<dependency>
<groupId>com.google.cloud</groupId>
<artifactId>google-cloud-storage-control</artifactId>
</dependency>
</dependencies>
If you are using Maven without the BOM, add this to your dependencies:
<dependency>
<groupId>com.google.cloud</groupId>
<artifactId>google-cloud-storage-control</artifactId>
<version>2.41.0</version>
</dependency>
If you are using Gradle 5.x or later, add this to your dependencies:
implementation platform('com.google.cloud:libraries-bom:26.44.0')
implementation 'com.google.cloud:google-cloud-storage-control'
If you are using Gradle without BOM, add this to your dependencies:
implementation 'com.google.cloud:google-cloud-storage-control:2.41.0'
Creating an authorized service object
To make authenticated requests to Google Cloud Storage, you must create a service object with credentials. You can then make API calls by calling methods on the Storage service object. The simplest way to authenticate is to use Application Default Credentials. These credentials are automatically inferred from your environment, so you only need the following code to create your service object:
import com.google.cloud.storage.Storage;
import com.google.cloud.storage.StorageOptions;
Storage storage = StorageOptions.getDefaultInstance().getService();
For other authentication options, see the Authentication page in Google Cloud Java.
Storing data
Stored objects are called "blobs" in google-cloud
and are organized into containers called "buckets". Blob
, a
subclass of BlobInfo
, adds a layer of service-related functionality over BlobInfo
. Similarly, Bucket
adds a
layer of service-related functionality over BucketInfo
. In this code snippet, we will create a new bucket and
upload a blob to that bucket.
Add the following imports at the top of your file:
import static java.nio.charset.StandardCharsets.UTF_8;
import com.google.cloud.storage.Blob;
import com.google.cloud.storage.Bucket;
import com.google.cloud.storage.BucketInfo;
Then add the following code to create a bucket and upload a simple blob.
Important: Bucket names have to be globally unique (among all users of Cloud Storage). If you choose a bucket name that already exists, you'll get a helpful error message telling you to choose another name. In the code below, replace "my_unique_bucket" with a unique bucket name. See more about naming rules here.
// Create a bucket
String bucketName = "my_unique_bucket"; // Change this to something unique
Bucket bucket = storage.create(BucketInfo.of(bucketName));
// Upload a blob to the newly created bucket
BlobId blobId = BlobId.of(bucketName, "my_blob_name");
BlobInfo blobInfo = BlobInfo.newBuilder(blobId).setContentType("text/plain").build();
Blob blob = storage.create(blobInfo, "a simple blob".getBytes(UTF_8));
A complete example for creating a blob can be found at UploadObject.java.
At this point, you will be able to see your newly created bucket and blob on the Google Developers Console.
Retrieving data
Now that we have content uploaded to the server, we can see how to read data from the server. Add the following line to your program to get back the blob we uploaded.
BlobId blobId = BlobId.of(bucketName, "my_blob_name");
byte[] content = storage.readAllBytes(blobId);
String contentString = new String(content, UTF_8);
A complete example for accessing blobs can be found at DownloadObject.java.
Updating data
Another thing we may want to do is update a blob. The following snippet shows how to update a Storage blob if it exists.
BlobId blobId = BlobId.of(bucketName, "my_blob_name");
Blob blob = storage.get(blobId);
if (blob != null) {
byte[] prevContent = blob.getContent();
System.out.println(new String(prevContent, UTF_8));
WritableByteChannel channel = blob.writer();
channel.write(ByteBuffer.wrap("Updated content".getBytes(UTF_8)));
channel.close();
}
Listing buckets and contents of buckets
Suppose that you've added more buckets and blobs, and now you want to see the names of your buckets and the contents of each one. Add the following code to list all your buckets and all the blobs inside each bucket.
// List all your buckets
System.out.println("My buckets:");
for (Bucket bucket : storage.list().iterateAll()) {
System.out.println(bucket);
// List all blobs in the bucket
System.out.println("Blobs in the bucket:");
for (Blob blob : bucket.list().iterateAll()) {
System.out.println(blob);
}
}
Complete source code
See ListObjects.java for a complete example.
Example Applications
Bookshelf
- An App Engine application that manages a virtual bookshelf.- This app uses
google-cloud
to interface with Cloud Datastore and Cloud Storage. It also uses Cloud SQL, another Google Cloud Platform service.
- This app uses
Flexible Environment/Storage example
- An app that uploads files to a public Cloud Storage bucket on the App Engine Flexible Environment runtime.
Samples
Samples are in the samples/
directory.
Sample | Source Code | Try it |
---|---|---|
Configure Retries | source code | |
Generate Signed Post Policy V4 | source code | |
Get Service Account | source code | |
Quickstart Grpc Dp Sample | source code | |
Quickstart Grpc Sample | source code | |
Quickstart Sample | source code | |
Quickstart Storage Control Sample | source code | |
Add Bucket Default Owner | source code | |
Add Bucket Iam Conditional Binding | source code | |
Add Bucket Iam Member | source code | |
Add Bucket Label | source code | |
Add Bucket Owner | source code | |
Change Default Storage Class | source code | |
Configure Bucket Cors | source code | |
Create Bucket | source code | |
Create Bucket Dual Region | source code | |
Create Bucket Pub Sub Notification | source code | |
Create Bucket With Object Retention | source code | |
Create Bucket With Storage Class And Location | source code | |
Create Bucket With Turbo Replication | source code | |
Delete Bucket | source code | |
Delete Bucket Pub Sub Notification | source code | |
Disable Bucket Versioning | source code | |
Disable Default Event Based Hold | source code | |
Disable Lifecycle Management | source code | |
Disable Requester Pays | source code | |
Disable Uniform Bucket Level Access | source code | |
Enable Bucket Versioning | source code | |
Enable Default Event Based Hold | source code | |
Enable Lifecycle Management | source code | |
Enable Requester Pays | source code | |
Enable Uniform Bucket Level Access | source code | |
Get Bucket Autoclass | source code | |
Get Bucket Metadata | source code | |
Get Bucket Rpo | source code | |
Get Default Event Based Hold | source code | |
Get Public Access Prevention | source code | |
Get Requester Pays Status | source code | |
Get Retention Policy | source code | |
Get Uniform Bucket Level Access | source code | |
List Bucket Iam Members | source code | |
List Buckets | source code | |
List Pub Sub Notifications | source code | |
Lock Retention Policy | source code | |
Make Bucket Public | source code | |
Print Bucket Acl | source code | |
Print Bucket Acl Filter By User | source code | |
Print Pub Sub Notification | source code | |
Remove Bucket Cors | source code | |
Remove Bucket Default Kms Key | source code | |
Remove Bucket Default Owner | source code | |
Remove Bucket Iam Conditional Binding | source code | |
Remove Bucket Iam Member | source code | |
Remove Bucket Label | source code | |
Remove Bucket Owner | source code | |
Remove Retention Policy | source code | |
Set Async Turbo Rpo | source code | |
Set Bucket Autoclass | source code | |
Set Bucket Default Kms Key | source code | |
Set Bucket Website Info | source code | |
Set Client Endpoint | source code | |
Set Default Rpo | source code | |
Set Public Access Prevention Enforced | source code | |
Set Public Access Prevention Inherited | source code | |
Set Retention Policy | source code | |
Create Folder | source code | |
Create Hierarchical Namespace Bucket | source code | |
Delete Folder | source code | |
Get Folder | source code | |
List Folders | source code | |
Rename Folder | source code | |
Activate Hmac Key | source code | |
Create Hmac Key | source code | |
Deactivate Hmac Key | source code | |
Delete Hmac Key | source code | |
Get Hmac Key | source code | |
List Hmac Keys | source code | |
Create Managed Folder | source code | |
Delete Managed Folder | source code | |
Get Managed Folder | source code | |
List Managed Folders | source code | |
Add File Owner | source code | |
Batch Set Object Metadata | source code | |
Change Object Csek To Kms | source code | |
Change Object Storage Class | source code | |
Compose Object | source code | |
Copy Object | source code | |
Copy Old Version Of Object | source code | |
Delete Object | source code | |
Delete Old Version Of Object | source code | |
Download Byte Range | source code | |
Download Encrypted Object | source code | |
Download Object | source code | |
Download Object Into Memory | source code | |
Download Public Object | source code | |
Download Requester Pays Object | source code | |
Generate Encryption Key | source code | |
Generate V4 Get Object Signed Url | source code | |
Generate V4 Put Object Signed Url | source code | |
Get Object Metadata | source code | |
List Objects | source code | |
List Objects With Old Versions | source code | |
List Objects With Prefix | source code | |
Make Object Public | source code | |
Move Object | source code | |
Print File Acl | source code | |
Print File Acl For User | source code | |
Release Event Based Hold | source code | |
Release Temporary Hold | source code | |
Remove File Owner | source code | |
Rotate Object Encryption Key | source code | |
Set Event Based Hold | source code | |
Set Object Metadata | source code | |
Set Object Retention Policy | source code | |
Set Temporary Hold | source code | |
Stream Object Download | source code | |
Stream Object Upload | source code | |
Upload Encrypted Object | source code | |
Upload Kms Encrypted Object | source code | |
Upload Object | source code | |
Upload Object From Memory | source code | |
Allow Divide And Conquer Download | source code | |
Allow Parallel Composite Upload | source code | |
Download Bucket | source code | |
Download Many | source code | |
Upload Directory | source code | |
Upload Many | source code |
Troubleshooting
To get help, follow the instructions in the shared Troubleshooting document.
Transport
Cloud Storage uses HTTP/JSON for the transport layer.
Supported Java Versions
Java 8 or above is required for using this client.
Google's Java client libraries, Google Cloud Client Libraries and Google Cloud API Libraries, follow the Oracle Java SE support roadmap (see the Oracle Java SE Product Releases section).
For new development
In general, new feature development occurs with support for the lowest Java LTS version covered by Oracle's Premier Support (which typically lasts 5 years from initial General Availability). If the minimum required JVM for a given library is changed, it is accompanied by a semver major release.
Java 11 and (in September 2021) Java 17 are the best choices for new development.
Keeping production systems current
Google tests its client libraries with all current LTS versions covered by Oracle's Extended Support (which typically lasts 8 years from initial General Availability).
Legacy support
Google's client libraries support legacy versions of Java runtimes with long term stable libraries that don't receive feature updates on a best efforts basis as it may not be possible to backport all patches.
Google provides updates on a best efforts basis to apps that continue to use Java 7, though apps might need to upgrade to current versions of the library that supports their JVM.
Where to find specific information
The latest versions and the supported Java versions are identified on
the individual GitHub repository github.com/GoogleAPIs/java-SERVICENAME
and on google-cloud-java.
Versioning
This library follows Semantic Versioning, but does update Storage interface to introduce new methods which can break your implementations if you implement this interface for testing purposes.
Contributing
Contributions to this library are always welcome and highly encouraged.
See CONTRIBUTING for more information 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.
CI Status
Java Version | Status |
---|---|
Java 8 | |
Java 8 OSX | |
Java 8 Windows | |
Java 11 |
Java is a registered trademark of Oracle and/or its affiliates.