Added in API level 26

FileSystemProvider

abstract class FileSystemProvider

kotlin.Any
↳	java.nio.file.spi.FileSystemProvider

Service-provider class for file systems. The methods defined by the class will typically delegate to an instance of this class.

A file system provider is a concrete implementation of this class that implements the abstract methods defined by this class. A provider is identified by a URI scheme. The default provider is identified by the URI scheme "file". It creates the FileSystem that provides access to the file systems accessible to the Java virtual machine. The FileSystems class defines how file system providers are located and loaded. The default provider is typically a system-default provider but may be overridden if the system property java.nio.file.spi.DefaultFileSystemProvider is set. In that case, the provider has a one argument constructor whose formal parameter type is FileSystemProvider. All other providers have a zero argument constructor that initializes the provider.

A provider is a factory for one or more FileSystem instances. Each file system is identified by a URI where the URI's scheme matches the provider's scheme. The default file system, for example, is identified by the URI "file:///". A memory-based file system, for example, may be identified by a URI such as "memory:///?name=logfs". The #newFileSystem method may be used to create a file system, and the getFileSystem method may be used to obtain a reference to an existing file system created by the provider. Where a provider is the factory for a single file system then it is provider dependent if the file system is created when the provider is initialized, or later when the newFileSystem method is invoked. In the case of the default provider, the FileSystem is created when the provider is initialized.

All of the methods in this class are safe for use by multiple concurrent threads.

Summary

Protected constructors
`FileSystemProvider()` Initializes a new instance of this class.

Public methods
abstract Unit	`checkAccess(path: Path!, vararg modes: AccessMode!)` Checks the existence, and optionally the accessibility, of a file.
abstract Unit	`copy(source: Path!, target: Path!, vararg options: CopyOption!)` Copy a file to a target file.
abstract Unit	`createDirectory(dir: Path!, vararg attrs: FileAttribute<*>!)` Creates a new directory.
open Unit	`createLink(link: Path!, existing: Path!)` Creates a new link (directory entry) for an existing file.
open Unit	`createSymbolicLink(link: Path!, target: Path!, vararg attrs: FileAttribute<*>!)` Creates a symbolic link to a target.
abstract Unit	`delete(path: Path!)` Deletes a file.
open Boolean	`deleteIfExists(path: Path!)` Deletes a file if it exists.
abstract V	`getFileAttributeView(path: Path!, type: Class<V>!, vararg options: LinkOption!)` Returns a file attribute view of a given type.
abstract FileStore!	`getFileStore(path: Path!)` Returns the `FileStore` representing the file store where a file is located.
abstract FileSystem!	`getFileSystem(uri: URI!)` Returns an existing `FileSystem` created by this provider.
abstract Path!	`getPath(uri: URI!)` Return a `Path` object by converting the given `URI`.
abstract String!	`getScheme()` Returns the URI scheme that identifies this provider.
open static MutableList<FileSystemProvider!>!	`installedProviders()` Returns a list of the installed file system providers.
abstract Boolean	`isHidden(path: Path!)` Tells whether or not a file is considered hidden.
abstract Boolean	`isSameFile(path: Path!, path2: Path!)` Tests if two paths locate the same file.
abstract Unit	`move(source: Path!, target: Path!, vararg options: CopyOption!)` Move or rename a file to a target file.
open AsynchronousFileChannel!	`newAsynchronousFileChannel(path: Path!, options: MutableSet<out OpenOption!>!, executor: ExecutorService!, vararg attrs: FileAttribute<*>!)` Opens or creates a file for reading and/or writing, returning an asynchronous file channel to access the file.
abstract SeekableByteChannel!	`newByteChannel(path: Path!, options: MutableSet<out OpenOption!>!, vararg attrs: FileAttribute<*>!)` Opens or creates a file, returning a seekable byte channel to access the file.
abstract DirectoryStream<Path!>!	`newDirectoryStream(dir: Path!, filter: DirectoryStream.Filter<in Path!>!)` Opens a directory, returning a `DirectoryStream` to iterate over the entries in the directory.
open FileChannel!	`newFileChannel(path: Path!, options: MutableSet<out OpenOption!>!, vararg attrs: FileAttribute<*>!)` Opens or creates a file for reading and/or writing, returning a file channel to access the file.
abstract FileSystem!	`newFileSystem(uri: URI!, env: MutableMap<String!, *>!)` Constructs a new `FileSystem` object identified by a URI.
open FileSystem!	`newFileSystem(path: Path!, env: MutableMap<String!, *>!)` Constructs a new `FileSystem` to access the contents of a file as a file system.
open InputStream!	`newInputStream(path: Path!, vararg options: OpenOption!)` Opens a file, returning an input stream to read from the file.
open OutputStream!	`newOutputStream(path: Path!, vararg options: OpenOption!)` Opens or creates a file, returning an output stream that may be used to write bytes to the file.
abstract A	`readAttributes(path: Path!, type: Class<A>!, vararg options: LinkOption!)` Reads a file's attributes as a bulk operation.
abstract MutableMap<String!, Any!>!	`readAttributes(path: Path!, attributes: String!, vararg options: LinkOption!)` Reads a set of file attributes as a bulk operation.
open Path!	`readSymbolicLink(link: Path!)` Reads the target of a symbolic link.
abstract Unit	`setAttribute(path: Path!, attribute: String!, value: Any!, vararg options: LinkOption!)` Sets the value of a file attribute.

Protected constructors

FileSystemProvider

Added in API level 26

protected FileSystemProvider()

Initializes a new instance of this class.

During construction a provider may safely access files associated with the default provider but care needs to be taken to avoid circular loading of other installed providers. If circular loading of installed providers is detected then an unspecified error is thrown.

Exceptions
`java.lang.SecurityException`	If a security manager has been installed and it denies `RuntimePermission`("fileSystemProvider")

Public methods

checkAccess

Added in API level 26

abstract fun checkAccess(
    path: Path!, 
    vararg modes: AccessMode!
): Unit

Checks the existence, and optionally the accessibility, of a file.

This method may be used by the isReadable, isWritable and isExecutable methods to check the accessibility of a file.

This method checks the existence of a file and that this Java virtual machine has appropriate privileges that would allow it access the file according to all of access modes specified in the modes parameter as follows:

Value	Description
`READ`	Checks that the file exists and that the Java virtual machine has permission to read the file.
`WRITE`	Checks that the file exists and that the Java virtual machine has permission to write to the file,
`EXECUTE`	Checks that the file exists and that the Java virtual machine has permission to java.lang.Runtime#exec the file. The semantics may differ when checking access to a directory. For example, on UNIX systems, checking for `EXECUTE` access checks that the Java virtual machine has permission to search the directory in order to access file or subdirectories.

If the modes parameter is of length zero, then the existence of the file is checked.

This method follows symbolic links if the file referenced by this object is a symbolic link. Depending on the implementation, this method may require to read file permissions, access control lists, or other file attributes in order to check the effective access to the file. To determine the effective access to a file may require access to several attributes and so in some implementations this method may not be atomic with respect to other file system operations.

Parameters
`path`	Path!: the path to the file to check
`modes`	AccessMode!: The access modes to check; may have zero elements

Exceptions
`java.lang.UnsupportedOperationException`	an implementation is required to support checking for `READ`, `WRITE`, and `EXECUTE` access. This exception is specified to allow for the `Access` enum to be extended in future releases.
`java.nio.file.NoSuchFileException`	if a file does not exist (optional specific exception)
`java.nio.file.AccessDeniedException`	the requested access would be denied or the access cannot be determined because the Java virtual machine has insufficient privileges or other reasons. (optional specific exception)
`java.io.IOException`	if an I/O error occurs
`java.lang.SecurityException`	In the case of the default provider, and a security manager is installed, the `checkRead` is invoked when checking read access to the file or only the existence of the file, the `checkWrite` is invoked when checking write access to the file, and `checkExec` is invoked when checking execute access.

copy

Added in API level 26

abstract fun copy(
    source: Path!, 
    target: Path!, 
    vararg options: CopyOption!
): Unit

Copy a file to a target file. This method works in exactly the manner specified by the Files#copy(Path,Path,CopyOption[]) method except that both the source and target paths must be associated with this provider.

Parameters
`source`	Path!: the path to the file to copy
`target`	Path!: the path to the target file
`options`	CopyOption!: options specifying how the copy should be done

Exceptions
`java.lang.UnsupportedOperationException`	if the array contains a copy option that is not supported
`java.nio.file.FileAlreadyExistsException`	if the target file exists but cannot be replaced because the `REPLACE_EXISTING` option is not specified (optional specific exception)
`java.nio.file.DirectoryNotEmptyException`	the `REPLACE_EXISTING` option is specified but the file cannot be replaced because it is a non-empty directory (optional specific exception)
`java.io.IOException`	if an I/O error occurs
`java.lang.SecurityException`	In the case of the default provider, and a security manager is installed, the `checkRead` method is invoked to check read access to the source file, the `checkWrite` is invoked to check write access to the target file. If a symbolic link is copied the security manager is invoked to check `LinkPermission("symbolic")`.

createDirectory

Added in API level 26

abstract fun createDirectory(
    dir: Path!, 
    vararg attrs: FileAttribute<*>!
): Unit

Creates a new directory. This method works in exactly the manner specified by the Files#createDirectory method.

Parameters
`dir`	Path!: the directory to create
`attrs`	FileAttribute<*>!: an optional list of file attributes to set atomically when creating the directory

Exceptions
`java.lang.UnsupportedOperationException`	if the array contains an attribute that cannot be set atomically when creating the directory
`java.nio.file.FileAlreadyExistsException`	if a directory could not otherwise be created because a file of that name already exists (optional specific exception)
`java.io.IOException`	if an I/O error occurs or the parent directory does not exist
`java.lang.SecurityException`	In the case of the default provider, and a security manager is installed, the `checkWrite` method is invoked to check write access to the new directory.

createLink

Added in API level 26

open fun createLink(
    link: Path!, 
    existing: Path!
): Unit

Creates a new link (directory entry) for an existing file. This method works in exactly the manner specified by the Files#createLink method.

The default implementation of this method throws UnsupportedOperationException.

Parameters
`link`	Path!: the link (directory entry) to create
`existing`	Path!: a path to an existing file

Exceptions
`java.lang.UnsupportedOperationException`	if the implementation does not support adding an existing file to a directory
`java.nio.file.FileAlreadyExistsException`	if the entry could not otherwise be created because a file of that name already exists (optional specific exception)
`java.io.IOException`	if an I/O error occurs
`java.lang.SecurityException`	In the case of the default provider, and a security manager is installed, it denies `LinkPermission`("hard") or its `checkWrite` method denies write access to either the link or the existing file.

createSymbolicLink

Added in API level 26

open fun createSymbolicLink(
    link: Path!, 
    target: Path!, 
    vararg attrs: FileAttribute<*>!
): Unit

Creates a symbolic link to a target. This method works in exactly the manner specified by the Files#createSymbolicLink method.

The default implementation of this method throws UnsupportedOperationException.

Parameters
`link`	Path!: the path of the symbolic link to create
`target`	Path!: the target of the symbolic link
`attrs`	FileAttribute<*>!: the array of attributes to set atomically when creating the symbolic link

Exceptions
`java.lang.UnsupportedOperationException`	if the implementation does not support symbolic links or the array contains an attribute that cannot be set atomically when creating the symbolic link
`java.nio.file.FileAlreadyExistsException`	if a file with the name already exists (optional specific exception)
`java.io.IOException`	if an I/O error occurs
`java.lang.SecurityException`	In the case of the default provider, and a security manager is installed, it denies `LinkPermission`("symbolic") or its `checkWrite` method denies write access to the path of the symbolic link.

delete

Added in API level 26

abstract fun delete(path: Path!): Unit

Deletes a file. This method works in exactly the manner specified by the Files#delete method.

Parameters
`path`	Path!: the path to the file to delete

Exceptions
`java.nio.file.NoSuchFileException`	if the file does not exist (optional specific exception)
`java.nio.file.DirectoryNotEmptyException`	if the file is a directory and could not otherwise be deleted because the directory is not empty (optional specific exception)
`java.io.IOException`	if an I/O error occurs
`java.lang.SecurityException`	In the case of the default provider, and a security manager is installed, the `SecurityManager#checkDelete(String)` method is invoked to check delete access to the file

deleteIfExists

Added in API level 26

open fun deleteIfExists(path: Path!): Boolean

Deletes a file if it exists. This method works in exactly the manner specified by the Files#deleteIfExists method.

The default implementation of this method simply invokes delete ignoring the NoSuchFileException when the file does not exist. It may be overridden where appropriate.

Parameters
`path`	Path!: the path to the file to delete

Return
`Boolean`	`true` if the file was deleted by this method; `false` if the file could not be deleted because it did not exist

Exceptions
`java.nio.file.DirectoryNotEmptyException`	if the file is a directory and could not otherwise be deleted because the directory is not empty (optional specific exception)
`java.io.IOException`	if an I/O error occurs
`java.lang.SecurityException`	In the case of the default provider, and a security manager is installed, the `SecurityManager#checkDelete(String)` method is invoked to check delete access to the file

getFileAttributeView

Added in API level 26

abstract fun <V : FileAttributeView!> getFileAttributeView(
    path: Path!, 
    type: Class<V>!, 
    vararg options: LinkOption!
): V

Returns a file attribute view of a given type. This method works in exactly the manner specified by the Files#getFileAttributeView method.

Parameters
`<V>`	The `FileAttributeView` type
`path`	Path!: the path to the file
`type`	Class<V>!: the `Class` object corresponding to the file attribute view
`options`	LinkOption!: options indicating how symbolic links are handled

Return
`V`	a file attribute view of the specified type, or `null` if the attribute view type is not available

getFileStore

Added in API level 26

abstract fun getFileStore(path: Path!): FileStore!

Returns the FileStore representing the file store where a file is located. This method works in exactly the manner specified by the Files#getFileStore method.

Parameters
`path`	Path!: the path to the file

Return
`FileStore!`	the file store where the file is stored

Exceptions
`java.io.IOException`	if an I/O error occurs
`java.lang.SecurityException`	In the case of the default provider, and a security manager is installed, the `checkRead` method is invoked to check read access to the file, and in addition it checks `RuntimePermission` ("getFileStoreAttributes")

getFileSystem

Added in API level 26

abstract fun getFileSystem(uri: URI!): FileSystem!

Returns an existing FileSystem created by this provider.

This method returns a reference to a FileSystem that was created by invoking the newFileSystem(URI,Map) method. File systems created the newFileSystem(Path,Map) method are not returned by this method. The file system is identified by its URI. Its exact form is highly provider dependent. In the case of the default provider the URI's path component is "/" and the authority, query and fragment components are undefined (Undefined components are represented by null).

Once a file system created by this provider is java.nio.file.FileSystem#close it is provider-dependent if this method returns a reference to the closed file system or throws FileSystemNotFoundException. If the provider allows a new file system to be created with the same URI as a file system it previously created then this method throws the exception if invoked after the file system is closed (and before a new instance is created by the #newFileSystem method).

If a security manager is installed then a provider implementation may require to check a permission before returning a reference to an existing file system. In the case of the default file system, no permission check is required.

Parameters
`uri`	URI!: URI reference

Return
`FileSystem!`	The file system

Exceptions
`java.lang.IllegalArgumentException`	If the pre-conditions for the `uri` parameter aren't met
`java.nio.file.FileSystemNotFoundException`	If the file system does not exist
`java.lang.SecurityException`	If a security manager is installed and it denies an unspecified permission.

getPath

Added in API level 26

abstract fun getPath(uri: URI!): Path!

Return a Path object by converting the given URI. The resulting Path is associated with a FileSystem that already exists or is constructed automatically.

The exact form of the URI is file system provider dependent. In the case of the default provider, the URI scheme is "file" and the given URI has a non-empty path component, and undefined query, and fragment components. The resulting Path is associated with the default default FileSystem.

If a security manager is installed then a provider implementation may require to check a permission. In the case of the default file system, no permission check is required.

Parameters
`uri`	URI!: The URI to convert

Return
`Path!`	The resulting `Path`

Exceptions
`java.lang.IllegalArgumentException`	If the URI scheme does not identify this provider or other preconditions on the uri parameter do not hold
`java.nio.file.FileSystemNotFoundException`	The file system, identified by the URI, does not exist and cannot be created automatically
`java.lang.SecurityException`	If a security manager is installed and it denies an unspecified permission.

getScheme

Added in API level 26

abstract fun getScheme(): String!

Returns the URI scheme that identifies this provider.

Return
`String!`	The URI scheme

installedProviders

Added in API level 26

open static fun installedProviders(): MutableList<FileSystemProvider!>!

Returns a list of the installed file system providers.

The first invocation of this method causes the default provider to be initialized (if not already initialized) and loads any other installed providers as described by the FileSystems class.

Return
`MutableList<FileSystemProvider!>!`	An unmodifiable list of the installed file system providers. The list contains at least one element, that is the default file system provider

Exceptions
`java.util.ServiceConfigurationError`	When an error occurs while loading a service provider

isHidden

Added in API level 26

abstract fun isHidden(path: Path!): Boolean

Tells whether or not a file is considered hidden. This method works in exactly the manner specified by the Files#isHidden method.

This method is invoked by the isHidden method.

Parameters
`path`	Path!: the path to the file to test

Return
`Boolean`	`true` if the file is considered hidden

Exceptions
`java.io.IOException`	if an I/O error occurs
`java.lang.SecurityException`	In the case of the default provider, and a security manager is installed, the `checkRead` method is invoked to check read access to the file.

isSameFile

Added in API level 26

abstract fun isSameFile(
    path: Path!, 
    path2: Path!
): Boolean

Tests if two paths locate the same file. This method works in exactly the manner specified by the Files#isSameFile method.

Parameters
`path`	Path!: one path to the file
`path2`	Path!: the other path

Return
`Boolean`	`true` if, and only if, the two paths locate the same file

Exceptions
`java.io.IOException`	if an I/O error occurs
`java.lang.SecurityException`	In the case of the default provider, and a security manager is installed, the `checkRead` method is invoked to check read access to both files.

move

Added in API level 26

abstract fun move(
    source: Path!, 
    target: Path!, 
    vararg options: CopyOption!
): Unit

Move or rename a file to a target file. This method works in exactly the manner specified by the Files#move method except that both the source and target paths must be associated with this provider.

Parameters
`source`	Path!: the path to the file to move
`target`	Path!: the path to the target file
`options`	CopyOption!: options specifying how the move should be done

Exceptions
`java.lang.UnsupportedOperationException`	if the array contains a copy option that is not supported
`java.nio.file.FileAlreadyExistsException`	if the target file exists but cannot be replaced because the `REPLACE_EXISTING` option is not specified (optional specific exception)
`java.nio.file.DirectoryNotEmptyException`	the `REPLACE_EXISTING` option is specified but the file cannot be replaced because it is a non-empty directory (optional specific exception)
`java.nio.file.AtomicMoveNotSupportedException`	if the options array contains the `ATOMIC_MOVE` option but the file cannot be moved as an atomic file system operation.
`java.io.IOException`	if an I/O error occurs
`java.lang.SecurityException`	In the case of the default provider, and a security manager is installed, the `checkWrite` method is invoked to check write access to both the source and target file.

newAsynchronousFileChannel

Added in API level 26

open fun newAsynchronousFileChannel(
    path: Path!, 
    options: MutableSet<out OpenOption!>!, 
    executor: ExecutorService!, 
    vararg attrs: FileAttribute<*>!
): AsynchronousFileChannel!

Opens or creates a file for reading and/or writing, returning an asynchronous file channel to access the file. This method works in exactly the manner specified by the AsynchronousFileChannel.open method. A provider that does not support all the features required to construct an asynchronous file channel throws UnsupportedOperationException. The default provider is required to support the creation of asynchronous file channels. When not overridden, the default implementation of this method throws UnsupportedOperationException.

Parameters
`path`	Path!: the path of the file to open or create
`options`	MutableSet<out OpenOption!>!: options specifying how the file is opened
`executor`	ExecutorService!: the thread pool or `null` to associate the channel with the default thread pool
`attrs`	FileAttribute<*>!: an optional list of file attributes to set atomically when creating the file

Return
`AsynchronousFileChannel!`	a new asynchronous file channel

Exceptions
`java.lang.IllegalArgumentException`	If the set contains an invalid combination of options
`java.lang.UnsupportedOperationException`	If this provider that does not support creating asynchronous file channels, or an unsupported open option or file attribute is specified
`java.io.IOException`	If an I/O error occurs
`java.lang.SecurityException`	In the case of the default file system, the `java.lang.SecurityManager#checkRead(java.lang.String)` method is invoked to check read access if the file is opened for reading. The `java.lang.SecurityManager#checkWrite(java.lang.String)` method is invoked to check write access if the file is opened for writing

newByteChannel

Added in API level 26

abstract fun newByteChannel(
    path: Path!, 
    options: MutableSet<out OpenOption!>!, 
    vararg attrs: FileAttribute<*>!
): SeekableByteChannel!

Opens or creates a file, returning a seekable byte channel to access the file. This method works in exactly the manner specified by the java.nio.file.Files#newByteChannel(java.nio.file.Path,java.util.Set,java.nio.file.attribute.FileAttribute[]) method.

Parameters
`path`	Path!: the path to the file to open or create
`options`	MutableSet<out OpenOption!>!: options specifying how the file is opened
`attrs`	FileAttribute<*>!: an optional list of file attributes to set atomically when creating the file

Return
`SeekableByteChannel!`	a new seekable byte channel

Exceptions
`java.lang.IllegalArgumentException`	if the set contains an invalid combination of options
`java.lang.UnsupportedOperationException`	if an unsupported open option is specified or the array contains attributes that cannot be set atomically when creating the file
`java.nio.file.FileAlreadyExistsException`	if a file of that name already exists and the `CREATE_NEW` option is specified (optional specific exception)
`java.io.IOException`	if an I/O error occurs
`java.lang.SecurityException`	In the case of the default provider, and a security manager is installed, the `checkRead` method is invoked to check read access to the path if the file is opened for reading. The `checkWrite` method is invoked to check write access to the path if the file is opened for writing. The `checkDelete` method is invoked to check delete access if the file is opened with the `DELETE_ON_CLOSE` option.

newDirectoryStream

Added in API level 26

abstract fun newDirectoryStream(
    dir: Path!, 
    filter: DirectoryStream.Filter<in Path!>!
): DirectoryStream<Path!>!

Opens a directory, returning a DirectoryStream to iterate over the entries in the directory. This method works in exactly the manner specified by the java.nio.file.Files#newDirectoryStream(java.nio.file.Path,java.nio.file.DirectoryStream.Filter) method.

Parameters
`dir`	Path!: the path to the directory
`filter`	DirectoryStream.Filter<in Path!>!: the directory stream filter

Return
`DirectoryStream<Path!>!`	a new and open `DirectoryStream` object

Exceptions
`java.nio.file.NotDirectoryException`	if the file could not otherwise be opened because it is not a directory (optional specific exception)
`java.io.IOException`	if an I/O error occurs
`java.lang.SecurityException`	In the case of the default provider, and a security manager is installed, the `checkRead` method is invoked to check read access to the directory.

newFileChannel

Added in API level 26

open fun newFileChannel(
    path: Path!, 
    options: MutableSet<out OpenOption!>!, 
    vararg attrs: FileAttribute<*>!
): FileChannel!

Opens or creates a file for reading and/or writing, returning a file channel to access the file. This method works in exactly the manner specified by the FileChannel.open method. A provider that does not support all the features required to construct a file channel throws UnsupportedOperationException. The default provider is required to support the creation of file channels. When not overridden, the default implementation throws UnsupportedOperationException.

Parameters
`path`	Path!: the path of the file to open or create
`options`	MutableSet<out OpenOption!>!: options specifying how the file is opened
`attrs`	FileAttribute<*>!: an optional list of file attributes to set atomically when creating the file

Return
`FileChannel!`	a new file channel

Exceptions
`java.lang.IllegalArgumentException`	If the set contains an invalid combination of options
`java.lang.UnsupportedOperationException`	If this provider that does not support creating file channels, or an unsupported open option or file attribute is specified
`java.io.IOException`	If an I/O error occurs
`java.lang.SecurityException`	In the case of the default file system, the `java.lang.SecurityManager#checkRead(java.lang.String)` method is invoked to check read access if the file is opened for reading. The `java.lang.SecurityManager#checkWrite(java.lang.String)` method is invoked to check write access if the file is opened for writing

newFileSystem

Added in API level 26

abstract fun newFileSystem(
    uri: URI!, 
    env: MutableMap<String!, *>!
): FileSystem!

Constructs a new FileSystem object identified by a URI. This method is invoked by the FileSystems#newFileSystem(URI,Map) method to open a new file system identified by a URI.

The uri parameter is an absolute, hierarchical URI, with a scheme equal (without regard to case) to the scheme supported by this provider. The exact form of the URI is highly provider dependent. The env parameter is a map of provider specific properties to configure the file system.

This method throws FileSystemAlreadyExistsException if the file system already exists because it was previously created by an invocation of this method. Once a file system is java.nio.file.FileSystem#close it is provider-dependent if the provider allows a new file system to be created with the same URI as a file system it previously created.

Parameters
`uri`	URI!: URI reference
`env`	MutableMap<String!, *>!: A map of provider specific properties to configure the file system; may be empty

Return
`FileSystem!`	A new file system

Exceptions
`java.lang.IllegalArgumentException`	If the pre-conditions for the `uri` parameter aren't met, or the `env` parameter does not contain properties required by the provider, or a property value is invalid
`java.io.IOException`	An I/O error occurs creating the file system
`java.lang.SecurityException`	If a security manager is installed and it denies an unspecified permission required by the file system provider implementation
`java.nio.file.FileSystemAlreadyExistsException`	If the file system has already been created

newFileSystem

Added in API level 26

open fun newFileSystem(
    path: Path!, 
    env: MutableMap<String!, *>!
): FileSystem!

Constructs a new FileSystem to access the contents of a file as a file system.

This method is intended for specialized providers of pseudo file systems where the contents of one or more files is treated as a file system. The env parameter is a map of provider specific properties to configure the file system.

If this provider does not support the creation of such file systems or if the provider does not recognize the file type of the given file then it throws UnsupportedOperationException. The default implementation of this method throws UnsupportedOperationException.

Parameters
`path`	Path!: The path to the file
`env`	MutableMap<String!, *>!: A map of provider specific properties to configure the file system; may be empty

Return
`FileSystem!`	A new file system

Exceptions
`java.lang.UnsupportedOperationException`	If this provider does not support access to the contents as a file system or it does not recognize the file type of the given file
`java.lang.IllegalArgumentException`	If the `env` parameter does not contain properties required by the provider, or a property value is invalid
`java.io.IOException`	If an I/O error occurs
`java.lang.SecurityException`	If a security manager is installed and it denies an unspecified permission.

newInputStream

Added in API level 26

open fun newInputStream(
    path: Path!, 
    vararg options: OpenOption!
): InputStream!

Opens a file, returning an input stream to read from the file. This method works in exactly the manner specified by the java.nio.file.Files#newInputStream method.

The default implementation of this method opens a channel to the file as if by invoking the newByteChannel method and constructs a stream that reads bytes from the channel. This method should be overridden where appropriate.

Parameters
`path`	Path!: the path to the file to open
`options`	OpenOption!: options specifying how the file is opened

Return
`InputStream!`	a new input stream

Exceptions
`java.lang.IllegalArgumentException`	if an invalid combination of options is specified
`java.lang.UnsupportedOperationException`	if an unsupported option is specified
`java.io.IOException`	if an I/O error occurs
`java.lang.SecurityException`	In the case of the default provider, and a security manager is installed, the `checkRead` method is invoked to check read access to the file.

newOutputStream

Added in API level 26

open fun newOutputStream(
    path: Path!, 
    vararg options: OpenOption!
): OutputStream!

Opens or creates a file, returning an output stream that may be used to write bytes to the file. This method works in exactly the manner specified by the Files#newOutputStream method.

The default implementation of this method opens a channel to the file as if by invoking the newByteChannel method and constructs a stream that writes bytes to the channel. This method should be overridden where appropriate.

Parameters
`path`	Path!: the path to the file to open or create
`options`	OpenOption!: options specifying how the file is opened

Return
`OutputStream!`	a new output stream

Exceptions
`java.lang.IllegalArgumentException`	if `options` contains an invalid combination of options
`java.lang.UnsupportedOperationException`	if an unsupported option is specified
`java.io.IOException`	if an I/O error occurs
`java.lang.SecurityException`	In the case of the default provider, and a security manager is installed, the `checkWrite` method is invoked to check write access to the file. The `checkDelete` method is invoked to check delete access if the file is opened with the `DELETE_ON_CLOSE` option.

readAttributes

Added in API level 26

abstract fun <A : BasicFileAttributes!> readAttributes(
    path: Path!, 
    type: Class<A>!, 
    vararg options: LinkOption!
): A

Reads a file's attributes as a bulk operation. This method works in exactly the manner specified by the java.nio.file.Files#readAttributes(java.nio.file.Path,java.lang.Class,java.nio.file.LinkOption[]) method.

Parameters
`<A>`	The `BasicFileAttributes` type
`path`	Path!: the path to the file
`type`	Class<A>!: the `Class` of the file attributes required to read
`options`	LinkOption!: options indicating how symbolic links are handled

Return
`A`	the file attributes

Exceptions
`java.lang.UnsupportedOperationException`	if an attributes of the given type are not supported
`java.io.IOException`	if an I/O error occurs
`java.lang.SecurityException`	In the case of the default provider, a security manager is installed, its `checkRead` method is invoked to check read access to the file

readAttributes

Added in API level 26

abstract fun readAttributes(
    path: Path!, 
    attributes: String!, 
    vararg options: LinkOption!
): MutableMap<String!, Any!>!

Reads a set of file attributes as a bulk operation. This method works in exactly the manner specified by the java.nio.file.Files#readAttributes(java.nio.file.Path,java.lang.String,java.nio.file.LinkOption[]) method.

Parameters
`path`	Path!: the path to the file
`attributes`	String!: the attributes to read
`options`	LinkOption!: options indicating how symbolic links are handled

Return
`MutableMap<String!, Any!>!`	a map of the attributes returned; may be empty. The map's keys are the attribute names, its values are the attribute values

Exceptions
`java.lang.UnsupportedOperationException`	if the attribute view is not available
`java.lang.IllegalArgumentException`	if no attributes are specified or an unrecognized attributes is specified
`java.io.IOException`	If an I/O error occurs
`java.lang.SecurityException`	In the case of the default provider, and a security manager is installed, its `checkRead` method denies read access to the file. If this method is invoked to read security sensitive attributes then the security manager may be invoke to check for additional permissions.

readSymbolicLink

Added in API level 26

open fun readSymbolicLink(link: Path!): Path!

Reads the target of a symbolic link. This method works in exactly the manner specified by the Files#readSymbolicLink method.

The default implementation of this method throws UnsupportedOperationException.

Parameters
`link`	Path!: the path to the symbolic link

Return
`Path!`	The target of the symbolic link

Exceptions
`java.lang.UnsupportedOperationException`	if the implementation does not support symbolic links
`java.nio.file.NotLinkException`	if the target could otherwise not be read because the file is not a symbolic link (optional specific exception)
`java.io.IOException`	if an I/O error occurs
`java.lang.SecurityException`	In the case of the default provider, and a security manager is installed, it checks that `FilePermission` has been granted with the "`readlink`" action to read the link.

setAttribute

Added in API level 26

abstract fun setAttribute(
    path: Path!, 
    attribute: String!, 
    value: Any!, 
    vararg options: LinkOption!
): Unit

Sets the value of a file attribute. This method works in exactly the manner specified by the Files#setAttribute method.

Parameters
`path`	Path!: the path to the file
`attribute`	String!: the attribute to set
`value`	Any!: the attribute value
`options`	LinkOption!: options indicating how symbolic links are handled

Exceptions
`java.lang.UnsupportedOperationException`	if the attribute view is not available
`java.lang.IllegalArgumentException`	if the attribute name is not specified, or is not recognized, or the attribute value is of the correct type but has an inappropriate value
`java.lang.ClassCastException`	If the attribute value is not of the expected type or is a collection containing elements that are not of the expected type
`java.io.IOException`	If an I/O error occurs
`java.lang.SecurityException`	In the case of the default provider, and a security manager is installed, its `checkWrite` method denies write access to the file. If this method is invoked to set security sensitive attributes then the security manager may be invoked to check for additional permissions.