FileSystemProvider
public
abstract
class
FileSystemProvider
extends Object
java.lang.Object | |
↳ | java.nio.file.spi.FileSystemProvider |
Service-provider class for file systems. The methods defined by the Files
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
void
|
checkAccess(Path path, AccessMode... modes)
Checks the existence, and optionally the accessibility, of a file. |
abstract
void
|
copy(Path source, Path target, CopyOption... options)
Copy a file to a target file. |
abstract
void
|
createDirectory(Path dir, FileAttribute...<?> attrs)
Creates a new directory. |
void
|
createLink(Path link, Path existing)
Creates a new link (directory entry) for an existing file. |
void
|
createSymbolicLink(Path link, Path target, FileAttribute...<?> attrs)
Creates a symbolic link to a target. |
abstract
void
|
delete(Path path)
Deletes a file. |
boolean
|
deleteIfExists(Path path)
Deletes a file if it exists. |
abstract
<V extends FileAttributeView>
V
|
getFileAttributeView(Path path, Class<V> type, LinkOption... options)
Returns a file attribute view of a given type. |
abstract
FileStore
|
getFileStore(Path path)
Returns the |
abstract
FileSystem
|
getFileSystem(URI uri)
Returns an existing |
abstract
Path
|
getPath(URI uri)
Return a |
abstract
String
|
getScheme()
Returns the URI scheme that identifies this provider. |
static
List<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, Path path2)
Tests if two paths locate the same file. |
abstract
void
|
move(Path source, Path target, CopyOption... options)
Move or rename a file to a target file. |
AsynchronousFileChannel
|
newAsynchronousFileChannel(Path path, Set<? extends OpenOption> options, ExecutorService executor, FileAttribute...<?> attrs)
Opens or creates a file for reading and/or writing, returning an asynchronous file channel to access the file. |
abstract
SeekableByteChannel
|
newByteChannel(Path path, Set<? extends OpenOption> options, FileAttribute...<?> attrs)
Opens or creates a file, returning a seekable byte channel to access the file. |
abstract
DirectoryStream<Path>
|
newDirectoryStream(Path dir, Filter<? super Path> filter)
Opens a directory, returning a |
FileChannel
|
newFileChannel(Path path, Set<? extends OpenOption> options, FileAttribute...<?> attrs)
Opens or creates a file for reading and/or writing, returning a file channel to access the file. |
abstract
FileSystem
|
newFileSystem(URI uri, Map<String, ?> env)
Constructs a new |
FileSystem
|
newFileSystem(Path path, Map<String, ?> env)
Constructs a new |
InputStream
|
newInputStream(Path path, OpenOption... options)
Opens a file, returning an input stream to read from the file. |
OutputStream
|
newOutputStream(Path path, OpenOption... options)
Opens or creates a file, returning an output stream that may be used to write bytes to the file. |
abstract
Map<String, Object>
|
readAttributes(Path path, String attributes, LinkOption... options)
Reads a set of file attributes as a bulk operation. |
abstract
<A extends BasicFileAttributes>
A
|
readAttributes(Path path, Class<A> type, LinkOption... options)
Reads a file's attributes as a bulk operation. |
Path
|
readSymbolicLink(Path link)
Reads the target of a symbolic link. |
abstract
void
|
setAttribute(Path path, String attribute, Object value, LinkOption... options)
Sets the value of a file attribute. |
Inherited methods | |
---|---|
Protected constructors
FileSystemProvider
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.
Throws | |
---|---|
SecurityException |
If a security manager has been installed and it denies
RuntimePermission ("fileSystemProvider") |
Public methods
checkAccess
public abstract void checkAccess (Path path, AccessMode... modes)
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 execute 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 |
Throws | |
---|---|
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. |
NoSuchFileException |
if a file does not exist (optional specific exception) |
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) |
IOException |
if an I/O error occurs |
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
public abstract void copy (Path source, Path target, CopyOption... options)
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 |
Throws | |
---|---|
UnsupportedOperationException |
if the array contains a copy option that is not supported |
FileAlreadyExistsException |
if the target file exists but cannot be replaced because the
REPLACE_EXISTING option is not specified (optional
specific exception) |
DirectoryNotEmptyException |
the REPLACE_EXISTING option is specified but the file
cannot be replaced because it is a non-empty directory
(optional specific exception) |
IOException |
if an I/O error occurs |
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
public abstract void createDirectory (Path dir, FileAttribute...<?> attrs)
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 |
Throws | |
---|---|
UnsupportedOperationException |
if the array contains an attribute that cannot be set atomically when creating the directory |
FileAlreadyExistsException |
if a directory could not otherwise be created because a file of that name already exists (optional specific exception) |
IOException |
if an I/O error occurs or the parent directory does not exist |
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
public void createLink (Path link, Path existing)
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 |
Throws | |
---|---|
UnsupportedOperationException |
if the implementation does not support adding an existing file to a directory |
FileAlreadyExistsException |
if the entry could not otherwise be created because a file of that name already exists (optional specific exception) |
IOException |
if an I/O error occurs |
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
public void createSymbolicLink (Path link, Path target, FileAttribute...<?> attrs)
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 |
Throws | |
---|---|
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 |
FileAlreadyExistsException |
if a file with the name already exists (optional specific exception) |
IOException |
if an I/O error occurs |
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
public abstract void delete (Path path)
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 |
Throws | |
---|---|
NoSuchFileException |
if the file does not exist (optional specific exception) |
DirectoryNotEmptyException |
if the file is a directory and could not otherwise be deleted because the directory is not empty (optional specific exception) |
IOException |
if an I/O error occurs |
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
public boolean deleteIfExists (Path path)
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(Path)
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 |
Returns | |
---|---|
boolean |
true if the file was deleted by this method; false if the file could not be deleted because it did not
exist |
Throws | |
---|---|
DirectoryNotEmptyException |
if the file is a directory and could not otherwise be deleted because the directory is not empty (optional specific exception) |
IOException |
if an I/O error occurs |
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
public abstract V getFileAttributeView (Path path, Class<V> type, LinkOption... options)
Returns a file attribute view of a given type. This method works in
exactly the manner specified by the Files#getFileAttributeView
method.
Parameters | |
---|---|
path |
Path : the path to the file |
type |
Class : the Class object corresponding to the file attribute view |
options |
LinkOption : options indicating how symbolic links are handled |
Returns | |
---|---|
V |
a file attribute view of the specified type, or null if
the attribute view type is not available |
getFileStore
public abstract FileStore getFileStore (Path path)
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 |
Returns | |
---|---|
FileStore |
the file store where the file is stored |
Throws | |
---|---|
IOException |
if an I/O error occurs |
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
public abstract FileSystem getFileSystem (URI uri)
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 closed
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 |
Returns | |
---|---|
FileSystem |
The file system |
Throws | |
---|---|
IllegalArgumentException |
If the pre-conditions for the uri parameter aren't met |
FileSystemNotFoundException |
If the file system does not exist |
SecurityException |
If a security manager is installed and it denies an unspecified permission. |
getPath
public abstract Path getPath (URI uri)
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 |
Returns | |
---|---|
Path |
The resulting Path |
Throws | |
---|---|
IllegalArgumentException |
If the URI scheme does not identify this provider or other preconditions on the uri parameter do not hold |
FileSystemNotFoundException |
The file system, identified by the URI, does not exist and cannot be created automatically |
SecurityException |
If a security manager is installed and it denies an unspecified permission. |
getScheme
public abstract String getScheme ()
Returns the URI scheme that identifies this provider.
Returns | |
---|---|
String |
The URI scheme |
installedProviders
public static List<FileSystemProvider> installedProviders ()
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.
Returns | |
---|---|
List<FileSystemProvider> |
An unmodifiable list of the installed file system providers. The list contains at least one element, that is the default file system provider |
Throws | |
---|---|
ServiceConfigurationError |
When an error occurs while loading a service provider |
isHidden
public abstract boolean isHidden (Path path)
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 |
Returns | |
---|---|
boolean |
true if the file is considered hidden |
Throws | |
---|---|
IOException |
if an I/O error occurs |
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
public abstract boolean isSameFile (Path path, Path path2)
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 |
Returns | |
---|---|
boolean |
true if, and only if, the two paths locate the same file |
Throws | |
---|---|
IOException |
if an I/O error occurs |
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
public abstract void move (Path source, Path target, CopyOption... options)
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 |
Throws | |
---|---|
UnsupportedOperationException |
if the array contains a copy option that is not supported |
FileAlreadyExistsException |
if the target file exists but cannot be replaced because the
REPLACE_EXISTING option is not specified (optional
specific exception) |
DirectoryNotEmptyException |
the REPLACE_EXISTING option is specified but the file
cannot be replaced because it is a non-empty directory
(optional specific exception) |
AtomicMoveNotSupportedException |
if the options array contains the ATOMIC_MOVE option but
the file cannot be moved as an atomic file system operation. |
IOException |
if an I/O error occurs |
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
public AsynchronousFileChannel newAsynchronousFileChannel (Path path, Set<? extends OpenOption> options, ExecutorService executor, FileAttribute...<?> attrs)
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 |
Set : 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 |
Returns | |
---|---|
AsynchronousFileChannel |
a new asynchronous file channel |
Throws | |
---|---|
IllegalArgumentException |
If the set contains an invalid combination of options |
UnsupportedOperationException |
If this provider that does not support creating asynchronous file channels, or an unsupported open option or file attribute is specified |
IOException |
If an I/O error occurs |
SecurityException |
In the case of the default file system, the SecurityManager.checkRead(java.lang.String) method is invoked to check
read access if the file is opened for reading. The SecurityManager.checkWrite(java.lang.String) method is invoked to check
write access if the file is opened for writing |
newByteChannel
public abstract SeekableByteChannel newByteChannel (Path path, Set<? extends OpenOption> options, FileAttribute...<?> attrs)
Opens or creates a file, returning a seekable byte channel to access the
file. This method works in exactly the manner specified by the 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 |
Set : options specifying how the file is opened |
attrs |
FileAttribute : an optional list of file attributes to set atomically when
creating the file |
Returns | |
---|---|
SeekableByteChannel |
a new seekable byte channel |
Throws | |
---|---|
IllegalArgumentException |
if the set contains an invalid combination of options |
UnsupportedOperationException |
if an unsupported open option is specified or the array contains attributes that cannot be set atomically when creating the file |
FileAlreadyExistsException |
if a file of that name already exists and the CREATE_NEW option is specified
(optional specific exception) |
IOException |
if an I/O error occurs |
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
public abstract DirectoryStream<Path> newDirectoryStream (Path dir, Filter<? super Path> filter)
Opens a directory, returning a DirectoryStream
to iterate over
the entries in the directory. This method works in exactly the manner
specified by the Files.newDirectoryStream(java.nio.file.Path, java.nio.file.DirectoryStream.Filter)
method.
Parameters | |
---|---|
dir |
Path : the path to the directory |
filter |
Filter : the directory stream filter |
Returns | |
---|---|
DirectoryStream<Path> |
a new and open DirectoryStream object |
Throws | |
---|---|
NotDirectoryException |
if the file could not otherwise be opened because it is not a directory (optional specific exception) |
IOException |
if an I/O error occurs |
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
public FileChannel newFileChannel (Path path, Set<? extends OpenOption> options, FileAttribute...<?> attrs)
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 |
Set : options specifying how the file is opened |
attrs |
FileAttribute : an optional list of file attributes to set atomically when
creating the file |
Returns | |
---|---|
FileChannel |
a new file channel |
Throws | |
---|---|
IllegalArgumentException |
If the set contains an invalid combination of options |
UnsupportedOperationException |
If this provider that does not support creating file channels, or an unsupported open option or file attribute is specified |
IOException |
If an I/O error occurs |
SecurityException |
In the case of the default file system, the SecurityManager.checkRead(java.lang.String) method is invoked to check
read access if the file is opened for reading. The SecurityManager.checkWrite(java.lang.String) method is invoked to check
write access if the file is opened for writing |
newFileSystem
public abstract FileSystem newFileSystem (URI uri, Map<String, ?> env)
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 closed
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 |
Map : A map of provider specific properties to configure the file system;
may be empty |
Returns | |
---|---|
FileSystem |
A new file system |
Throws | |
---|---|
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 |
IOException |
An I/O error occurs creating the file system |
SecurityException |
If a security manager is installed and it denies an unspecified permission required by the file system provider implementation |
FileSystemAlreadyExistsException |
If the file system has already been created |
newFileSystem
public FileSystem newFileSystem (Path path, Map<String, ?> env)
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 |
Map : A map of provider specific properties to configure the file system;
may be empty |
Returns | |
---|---|
FileSystem |
A new file system |
Throws | |
---|---|
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 |
IllegalArgumentException |
If the env parameter does not contain properties required
by the provider, or a property value is invalid |
IOException |
If an I/O error occurs |
SecurityException |
If a security manager is installed and it denies an unspecified permission. |
newInputStream
public InputStream newInputStream (Path path, OpenOption... options)
Opens a file, returning an input stream to read from the file. This
method works in exactly the manner specified by the Files.newInputStream(Path, OpenOption)
method.
The default implementation of this method opens a channel to the file
as if by invoking the newByteChannel(Path, Set, FileAttribute)
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 |
Returns | |
---|---|
InputStream |
a new input stream |
Throws | |
---|---|
IllegalArgumentException |
if an invalid combination of options is specified |
UnsupportedOperationException |
if an unsupported option is specified |
IOException |
if an I/O error occurs |
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
public OutputStream newOutputStream (Path path, OpenOption... options)
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(Path, Set, FileAttribute)
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 |
Returns | |
---|---|
OutputStream |
a new output stream |
Throws | |
---|---|
IllegalArgumentException |
if options contains an invalid combination of options |
UnsupportedOperationException |
if an unsupported option is specified |
IOException |
if an I/O error occurs |
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
public abstract Map<String, Object> readAttributes (Path path, String attributes, LinkOption... options)
Reads a set of file attributes as a bulk operation. This method works in
exactly the manner specified by the 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 |
Returns | |
---|---|
Map<String, Object> |
a map of the attributes returned; may be empty. The map's keys are the attribute names, its values are the attribute values |
Throws | |
---|---|
UnsupportedOperationException |
if the attribute view is not available |
IllegalArgumentException |
if no attributes are specified or an unrecognized attributes is specified |
IOException |
If an I/O error occurs |
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. |
readAttributes
public abstract A readAttributes (Path path, Class<A> type, LinkOption... options)
Reads a file's attributes as a bulk operation. This method works in
exactly the manner specified by the Files.readAttributes(java.nio.file.Path, java.lang.Class, java.nio.file.LinkOption[])
method.
Parameters | |
---|---|
path |
Path : the path to the file |
type |
Class : the Class of the file attributes required
to read |
options |
LinkOption : options indicating how symbolic links are handled |
Returns | |
---|---|
A |
the file attributes |
Throws | |
---|---|
UnsupportedOperationException |
if an attributes of the given type are not supported |
IOException |
if an I/O error occurs |
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 |
readSymbolicLink
public Path readSymbolicLink (Path link)
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 |
Returns | |
---|---|
Path |
The target of the symbolic link |
Throws | |
---|---|
UnsupportedOperationException |
if the implementation does not support symbolic links |
NotLinkException |
if the target could otherwise not be read because the file is not a symbolic link (optional specific exception) |
IOException |
if an I/O error occurs |
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
public abstract void setAttribute (Path path, String attribute, Object value, LinkOption... options)
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 |
Object : the attribute value |
options |
LinkOption : options indicating how symbolic links are handled |
Throws | |
---|---|
UnsupportedOperationException |
if the attribute view is not available |
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 |
ClassCastException |
If the attribute value is not of the expected type or is a collection containing elements that are not of the expected type |
IOException |
If an I/O error occurs |
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. |