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An S3 File System Provider for Java 7
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An Amazon AWS S3 FileSystem Provider JSR-203 for Java 7 (NIO2)

Amazon Simple Storage Service provides a fully redundant data storage infrastructure for storing and retrieving any amount of data, at any time. NIO2 is the new file management API, introduced in Java version 7. This project provides a first API implementation, little optimized, but "complete" to manage files and folders directly on Amazon S3.

Build Status Coverage Status Maven Central

#### How to use

Download from Maven Central

And add to your META-INF/services/java.nio.file.spi.FileSystemProvider (create if not exists yet) a new line like this: com.upplication.s3fs.S3FileSystemProvider.

S3FileSystem and AmazonS3 settings

All settings for S3FileSystem and for the underlying AmazonS3 connector library can be set through System properties or environment variables. Possible settings can be found in com.upplication.s3fs.AmazonS3Factory.

#### Using service locator and system vars

Check that s3fs_access_key and s3fs_secret_key system vars are present with the correct values to have full access to your amazon s3 bucket.

Use this code to create the fileSystem and set to a concrete endpoint.

FileSystems.newFileSystem("s3:///", new HashMap<String,Object>(), Thread.currentThread().getContextClassLoader());
Using service locator and in the classpath

Add to your resources folder the file with the content: s3fs_access_key=access-key s3fs_secret_key=secret-key

Use this code to create the fileSystem and set to a concrete endpoint.

FileSystems.newFileSystem("s3:///", new HashMap<String,Object>(), Thread.currentThread().getContextClassLoader());
Using service locator and programatically authentication

Create a map with the authentication and use the fileSystem to create the fileSystem and set to a concrete endpoint.

Map<String, ?> env = ImmutableMap.<String, Object> builder()
				.put(com.upplication.s3fs.AmazonS3Factory.ACCESS_KEY, "access key")
				.put(com.upplication.s3fs.AmazonS3Factory.SECRET_KEY, "secret key").build()
FileSystems.newFileSystem("s3:///", env, Thread.currentThread().getContextClassLoader());

Complete settings lists:

  • s3fs_access_key
  • s3fs_secret_key
  • s3fs_request_metric_collector_class
  • s3fs_connection_timeout
  • s3fs_max_connections
  • s3fs_max_retry_error
  • s3fs_protocol
  • s3fs_proxy_domain
  • s3fs_proxy_host
  • s3fs_proxy_password
  • s3fs_proxy_port
  • s3fs_proxy_username
  • s3fs_proxy_workstation
  • s3fs_socket_send_buffer_size_hint
  • s3fs_socket_receive_buffer_size_hint
  • s3fs_socket_timeout
  • s3fs_user_agent
  • s3fs_amazon_s3_factory
  • s3fs_signer_override
  • s3fs_path_style_access
Set endpoint to reduce data latency in your applications
// Northern Virginia or Pacific Northwest
FileSystems.newFileSystem("s3://", env, Thread.currentThread().getContextClassLoader());
// Northern Virginia only
FileSystems.newFileSystem("s3://", env, Thread.currentThread().getContextClassLoader());
// US West (Oregon) Region
FileSystems.newFileSystem("s3://", env, Thread.currentThread().getContextClassLoader());
// US West (Northern California) Region
FileSystems.newFileSystem("s3://", env, Thread.currentThread().getContextClassLoader());
// EU (Ireland) Region
FileSystems.newFileSystem("s3://", env, Thread.currentThread().getContextClassLoader());

For a complete list of available regions look at:

How to use in Apache MINA
public FileSystemFactory createFileSystemFactory(String bucketName) throws IOException, URISyntaxException {
    FileSystem fileSystem = FileSystems.newFileSystem(new URI("s3:///"), env, Thread.currentThread().getContextClassLoader());
    String bucketPath = fileSystem.getPath("/" + bucketName);

    return new VirtualFileSystemFactory(bucketPath);
How to use in Spring

Add to classpath and configure:

public class AwsConfig {

    private String accessKey;

    private String secretKey;

    public FileSystem s3FileSystem() throws IOException {
        Map<String, String> env = new HashMap<>();
        env.put(com.upplication.s3fs.AmazonS3Factory.ACCESS_KEY, accessKey);
        env.put(com.upplication.s3fs.AmazonS3Factory.SECRET_KEY, secretKey);

        return FileSystems.newFileSystem(URI.create("s3:///"), env, Thread.currentThread().getContextClassLoader());

Now you can inject in any spring component:

private FileSystem s3FileSystem;
What is new 2.0.0
  • Preserve URI with end slash #76
  • Removed META-INF/services/java.nio.file.spi.FileTypeDetector #78
  • Bucket are filestores and root directories for a bucket is the bucket itself.
  • getFileName for a root Path is null
  • Added new method toURL to S3Path and can be customized with the property s3fs_path_style_access #83
  • Improved S3Path Tests

#### Features:

  • Copy and create folders and files
  • Delete folders and files
  • Copy paths between different providers
  • Walk file tree
  • Works with virtual s3 folders (not really exists and are element's subkeys)
  • List buckets for the client
  • Multi endpoint fileSystem


  • Performance issue (slow querys with virtual folders, add multipart submit...)
  • Disallow upload binary files with same name as folders and vice versa

#### Out of Roadmap:

  • Watchers

How to contribute

Clone the github repository:

git clone

To run the tests:

First, you must copy the file src/test/resources/ and paste in the same directory with the name In your copy you must edit all the keys:

bucket_name=/your-bucket-name for test
s3fs_secret_key= your secret key for test
s3fs_access_key=your access key for test

Thats all, now you can run the test with the command: mvn test or mvn integration-test -Pintegration-tests


Amazon S3 FileSystem NIO2 is released under the MIT License.

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