Package com.google.cloud.storage.contrib.nio

Class CloudStorageFileSystemProvider

java.lang.Object

java.nio.file.spi.FileSystemProvider

com.google.cloud.storage.contrib.nio.CloudStorageFileSystemProvider

@Singleton
@ThreadSafe
public final class CloudStorageFileSystemProvider
extends FileSystemProvider

Google Cloud Storage FileSystemProvider implementation.

Note: This class should never be used directly. This class is instantiated by the service loader and called through a standardized API, e.g. Files. However the javadocs in this class serve as useful documentation for the behavior of the Google Cloud Storage NIO library.

Constructor Summary

Constructors

Constructor	Description
CloudStorageFileSystemProvider()	Default constructor which should only be called by Java SPI.

Method Summary

Modifier and Type	Method	Description
void	checkAccess(Path path, AccessMode... modes)
void	copy(Path source, Path target, CopyOption... options)
void	createDirectory(Path dir, FileAttribute<?>... attrs)	Does nothing since Google Cloud Storage uses fake directories.
void	delete(Path path)
boolean	deleteIfExists(Path path)
boolean	equals(Object other)
<V extends FileAttributeView> V	getFileAttributeView(Path path, Class<V> type, LinkOption... options)
FileStore	getFileStore(Path path)	Throws UnsupportedOperationException because this feature hasn't been implemented yet.
CloudStorageFileSystem	getFileSystem(URI uri)	Returns Cloud Storage file system, provided a URI with no path, e.g.
CloudStoragePath	getPath(String uriInStringForm)	Convenience method: replaces spaces with "%20", builds a URI, and calls getPath(uri).
CloudStoragePath	getPath(URI uri)
String	getProject()	Returns the project that is assigned to this provider.
String	getScheme()
int	hashCode()
boolean	isHidden(Path path)	Always returns false, because Google Cloud Storage doesn't support hidden files.
boolean	isSameFile(Path path, Path path2)
void	move(Path source, Path target, CopyOption... options)
SeekableByteChannel	newByteChannel(Path path, Set<? extends OpenOption> options, FileAttribute<?>... attrs)	Open a file for reading or writing.
DirectoryStream<Path>	newDirectoryStream(Path dir, DirectoryStream.Filter<? super Path> filter)
FileChannel	newFileChannel(Path path, Set<? extends OpenOption> options, FileAttribute<?>... attrs)	Open a file for reading OR writing.
CloudStorageFileSystem	newFileSystem(URI uri, Map<String,?> env)	Returns Cloud Storage file system, provided a URI, e.g.
InputStream	newInputStream(Path path, OpenOption... options)
<A extends BasicFileAttributes> A	readAttributes(Path path, Class<A> type, LinkOption... options)
Map<String,Object>	readAttributes(Path path, String attributes, LinkOption... options)
boolean	requesterPays(String bucketName)
void	setAttribute(Path path, String attribute, Object value, LinkOption... options)	Throws UnsupportedOperationException because Cloud Storage objects are immutable.
static void	setDefaultCloudStorageConfiguration(CloudStorageConfiguration newDefault)	Changes the default configuration for every filesystem object created from here on, including via SPI.
static void	setStorageOptions(com.google.cloud.storage.StorageOptions newStorageOptions)	Sets options that are only used by the constructor.
String	toString()
CloudStorageFileSystemProvider	withNoUserProject()	Returns a NEW CloudStorageFileSystemProvider identical to this one, but with userProject removed.

Methods inherited from class java.nio.file.spi.FileSystemProvider

createLink, createSymbolicLink, installedProviders, newAsynchronousFileChannel, newFileSystem, newOutputStream, readSymbolicLink

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Details

CloudStorageFileSystemProvider

public CloudStorageFileSystemProvider()

Default constructor which should only be called by Java SPI.

See Also:

• FileSystems.getFileSystem(URI)
• CloudStorageFileSystem.forBucket(String)

Method Details

setStorageOptions

public static void setStorageOptions(@Nullable
 com.google.cloud.storage.StorageOptions newStorageOptions)

Sets options that are only used by the constructor.

Instead of calling this, when possible use CloudStorageFileSystem.forBucket and pass StorageOptions as an argument.

setDefaultCloudStorageConfiguration

public static void setDefaultCloudStorageConfiguration(@Nullable
 CloudStorageConfiguration newDefault)

Changes the default configuration for every filesystem object created from here on, including via SPI. If null then future filesystem objects will have the factory default configuration.

If options are specified later then they override the defaults. Methods that take a whole CloudStorageConfiguration (eg. CloudStorageFileSystem.forBucket) will completely override the defaults. Methods that take individual options (eg. CloudStorageFileSystemProvier.newFileSystem) will override only these options; the rest will be taken from the defaults specified here.

This is meant to be done only once, at the beginning of some main program, in order to force all libraries to use some settings we like.

Libraries should never call this. If you're a library then, instead, create your own filesystem object with the right configuration and pass it along.

Parameters:

newDefault - new default CloudStorageConfiguration

getScheme

public String getScheme()

Specified by:

getScheme in class FileSystemProvider

getFileSystem

public CloudStorageFileSystem getFileSystem(URI uri)

Returns Cloud Storage file system, provided a URI with no path, e.g. gs://bucket.

Specified by:

getFileSystem in class FileSystemProvider

newFileSystem

public CloudStorageFileSystem newFileSystem(URI uri,
 Map<String,?> env)

Returns Cloud Storage file system, provided a URI, e.g. gs://bucket. The URI can include a path component (that will be ignored).

Specified by:

newFileSystem in class FileSystemProvider

Parameters:

uri - bucket and current working directory, e.g. gs://bucket

env - map of configuration options, whose keys correspond to the method names of CloudStorageConfiguration.Builder. However you are not allowed to set the working directory, as that should be provided in the uri

Throws:

IllegalArgumentException - if uri specifies a port, user, query, or fragment, or if scheme is not "gs"

getPath

public CloudStoragePath getPath(URI uri)

Specified by:

getPath in class FileSystemProvider

getPath

public CloudStoragePath getPath(String uriInStringForm)

Convenience method: replaces spaces with "%20", builds a URI, and calls getPath(uri).

newByteChannel

public SeekableByteChannel newByteChannel(Path path,
 Set<? extends OpenOption> options,
 FileAttribute<?>... attrs)
                                   throws IOException

Open a file for reading or writing. To read receiver-pays buckets, specify the BlobSourceOption.userProject option.

Specified by:

newByteChannel in class FileSystemProvider

Parameters:

path - : the path to the file to open or create

options - : options specifying how the file is opened, e.g. StandardOpenOption.WRITE or BlobSourceOption.userProject

attrs - : (not supported, values will be ignored)

Returns:

Throws:

IOException

newFileChannel

public FileChannel newFileChannel(Path path,
 Set<? extends OpenOption> options,
 FileAttribute<?>... attrs)
                           throws IOException

Open a file for reading OR writing. The FileChannel that is returned will only allow reads or writes depending on the OpenOptions that are specified. If any of the following have been specified, the FileChannel will be write-only: StandardOpenOption.CREATE

• StandardOpenOption.CREATE
• StandardOpenOption.CREATE_NEW
• StandardOpenOption.WRITE
• StandardOpenOption.TRUNCATE_EXISTING

In all other cases the FileChannel will be read-only.

Overrides:

newFileChannel in class FileSystemProvider

Parameters:

path - The path to the file to open or create

options - The options specifying how the file should be opened, and whether the FileChannel should be read-only or write-only.

attrs - (not supported, the values will be ignored)

Throws:

IOException

newInputStream

public InputStream newInputStream(Path path,
 OpenOption... options)
                           throws IOException

Overrides:

newInputStream in class FileSystemProvider

Throws:

IOException

deleteIfExists

public boolean deleteIfExists(Path path)
                       throws IOException

Overrides:

deleteIfExists in class FileSystemProvider

Throws:

IOException

delete

public void delete(Path path)
            throws IOException

Specified by:

delete in class FileSystemProvider

Throws:

IOException

move

public void move(Path source,
 Path target,
 CopyOption... options)
          throws IOException

Specified by:

move in class FileSystemProvider

Throws:

IOException

copy

public void copy(Path source,
 Path target,
 CopyOption... options)
          throws IOException

Specified by:

copy in class FileSystemProvider

Throws:

IOException

isSameFile

public boolean isSameFile(Path path,
 Path path2)

Specified by:

isSameFile in class FileSystemProvider

isHidden

public boolean isHidden(Path path)

Always returns false, because Google Cloud Storage doesn't support hidden files.

Specified by:

isHidden in class FileSystemProvider

checkAccess

public void checkAccess(Path path,
 AccessMode... modes)
                 throws IOException

Specified by:

checkAccess in class FileSystemProvider

Throws:

IOException

readAttributes

public <A extends BasicFileAttributes> A readAttributes(Path path,
 Class<A> type,
 LinkOption... options)
                                                 throws IOException

Specified by:

readAttributes in class FileSystemProvider

Throws:

IOException

readAttributes

public Map<String,Object> readAttributes(Path path,
 String attributes,
 LinkOption... options)
                                  throws IOException

Specified by:

readAttributes in class FileSystemProvider

Throws:

IOException

getFileAttributeView

public <V extends FileAttributeView> V getFileAttributeView(Path path,
 Class<V> type,
 LinkOption... options)

Specified by:

getFileAttributeView in class FileSystemProvider

createDirectory

public void createDirectory(Path dir,
 FileAttribute<?>... attrs)

Does nothing since Google Cloud Storage uses fake directories.

Specified by:

createDirectory in class FileSystemProvider

newDirectoryStream

public DirectoryStream<Path> newDirectoryStream(Path dir,
 DirectoryStream.Filter<? super Path> filter)

Specified by:

newDirectoryStream in class FileSystemProvider

setAttribute

public void setAttribute(Path path,
 String attribute,
 Object value,
 LinkOption... options)

Throws UnsupportedOperationException because Cloud Storage objects are immutable.

Specified by:

setAttribute in class FileSystemProvider

getFileStore

public FileStore getFileStore(Path path)

Throws UnsupportedOperationException because this feature hasn't been implemented yet.

Specified by:

getFileStore in class FileSystemProvider

equals

public boolean equals(Object other)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object

requesterPays

public boolean requesterPays(String bucketName)

Parameters:

bucketName - the name of the bucket to check

Returns:

whether requester pays is enabled for that bucket

withNoUserProject

public CloudStorageFileSystemProvider withNoUserProject()

Returns a NEW CloudStorageFileSystemProvider identical to this one, but with userProject removed.

Perhaps you want to call this is you realize you'll be working on a bucket that is not requester-pays.

getProject

public String getProject()

Returns the project that is assigned to this provider.