/*
* Copyright (c) 2007, 2011, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
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*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package java.nio.file.spi;
import java.nio.file.*;
import java.nio.file.attribute.*;
import java.nio.channels.*;
import java.net.URI;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.IOException;
import java.util.*;
import java.util.concurrent.ExecutorService;
import java.security.AccessController;
import java.security.PrivilegedAction;
/**
* Service-provider class for file systems. The methods defined by the {@link
* java.nio.file.Files} class will typically delegate to an instance of this
* class.
*
* <p> 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 {@code URI} {@link #getScheme() scheme}. The default provider
* is identified by the URI scheme "file". It creates the {@link FileSystem} that
* provides access to the file systems accessible to the Java virtual machine.
* The {@link 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 {@code
* java.nio.file.spi.DefaultFileSystemProvider} is set. In that case, the
* provider has a one argument constructor whose formal parameter type is {@code
* FileSystemProvider}. All other providers have a zero argument constructor
* that initializes the provider.
*
* <p> A provider is a factory for one or more {@link FileSystem} instances. Each
* file system is identified by a {@code URI} where the URI's scheme matches
* the provider's {@link #getScheme scheme}. The default file system, for example,
* is identified by the URI {@code "file:///"}. A memory-based file system,
* for example, may be identified by a URI such as {@code "memory:///?name=logfs"}.
* The {@link #newFileSystem newFileSystem} method may be used to create a file
* system, and the {@link #getFileSystem 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 {@code newFileSystem} method is invoked. In the case of the default
* provider, the {@code FileSystem} is created when the provider is initialized.
*
* <p> All of the methods in this class are safe for use by multiple concurrent
* threads.
*
* @since 1.7
*/
public abstract class FileSystemProvider {
// lock using when loading providers
private static final Object lock = new Object();
// installed providers
private static volatile List<FileSystemProvider> installedProviders;
// used to avoid recursive loading of instaled providers
private static boolean loadingProviders = false;
private static Void checkPermission() {
SecurityManager sm = System.getSecurityManager();
if (sm != null)
sm.checkPermission(new RuntimePermission("fileSystemProvider"));
return null;
}
private FileSystemProvider(Void ignore) { }
/**
* Initializes a new instance of this class.
*
* <p> 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
* {@link RuntimePermission}<tt>("fileSystemProvider")</tt>
*/
protected FileSystemProvider() {
this(checkPermission());
}
// loads all installed providers
private static List<FileSystemProvider> loadInstalledProviders() {
List<FileSystemProvider> list = new ArrayList<FileSystemProvider>();
ServiceLoader<FileSystemProvider> sl = ServiceLoader
.load(FileSystemProvider.class, ClassLoader.getSystemClassLoader());
// ServiceConfigurationError may be throw here
for (FileSystemProvider provider: sl) {
String scheme = provider.getScheme();
// add to list if the provider is not "file" and isn't a duplicate
if (!scheme.equalsIgnoreCase("file")) {
boolean found = false;
for (FileSystemProvider p: list) {
if (p.getScheme().equalsIgnoreCase(scheme)) {
found = true;
break;
}
}
if (!found) {
list.add(provider);
}
}
}
return list;
}
/**
* Returns a list of the installed file system providers.
*
* <p> 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 {@link FileSystems} class.
*
* @return 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
*/
public static List<FileSystemProvider> installedProviders() {
if (installedProviders == null) {
// ensure default provider is initialized
FileSystemProvider defaultProvider = FileSystems.getDefault().provider();
synchronized (lock) {
if (installedProviders == null) {
if (loadingProviders) {
throw new Error("Circular loading of installed providers detected");
}
loadingProviders = true;
List<FileSystemProvider> list = AccessController
.doPrivileged(new PrivilegedAction<List<FileSystemProvider>>() {
@Override
public List<FileSystemProvider> run() {
return loadInstalledProviders();
}});
// insert the default provider at the start of the list
list.add(0, defaultProvider);
installedProviders = Collections.unmodifiableList(list);
}
}
}
return installedProviders;
}
/**
* Returns the URI scheme that identifies this provider.
*
* @return The URI scheme
*/
public abstract String getScheme();
/**
* Constructs a new {@code FileSystem} object identified by a URI. This
* method is invoked by the {@link FileSystems#newFileSystem(URI,Map)}
* method to open a new file system identified by a URI.
*
* <p> The {@code 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
* {@code env} parameter is a map of provider specific properties to configure
* the file system.
*
* <p> This method throws {@link FileSystemAlreadyExistsException} if the
* file system already exists because it was previously created by an
* invocation of this method. Once a file system is {@link
* java.nio.file.FileSystem#close 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.
*
* @param uri
* URI reference
* @param env
* A map of provider specific properties to configure the file system;
* may be empty
*
* @return A new file system
*
* @throws IllegalArgumentException
* If the pre-conditions for the {@code uri} parameter aren't met,
* or the {@code env} parameter does not contain properties required
* by the provider, or a property value is invalid
* @throws IOException
* An I/O error occurs creating the file system
* @throws SecurityException
* If a security manager is installed and it denies an unspecified
* permission required by the file system provider implementation
* @throws FileSystemAlreadyExistsException
* If the file system has already been created
*/
public abstract FileSystem newFileSystem(URI uri, Map<String,?> env)
throws IOException;
/**
* Returns an existing {@code FileSystem} created by this provider.
*
* <p> This method returns a reference to a {@code FileSystem} that was
* created by invoking the {@link #newFileSystem(URI,Map) newFileSystem(URI,Map)}
* method. File systems created the {@link #newFileSystem(Path,Map)
* newFileSystem(Path,Map)} method are not returned by this method.
* The file system is identified by its {@code URI}. Its exact form
* is highly provider dependent. In the case of the default provider the URI's
* path component is {@code "/"} and the authority, query and fragment components
* are undefined (Undefined components are represented by {@code null}).
*
* <p> Once a file system created by this provider is {@link
* java.nio.file.FileSystem#close closed} it is provider-dependent if this
* method returns a reference to the closed file system or throws {@link
* 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 {@link #newFileSystem
* newFileSystem} method).
*
* <p> 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 {@link FileSystems#getDefault
* default} file system, no permission check is required.
*
* @param uri
* URI reference
*
* @return The file system
*
* @throws IllegalArgumentException
* If the pre-conditions for the {@code uri} parameter aren't met
* @throws FileSystemNotFoundException
* If the file system does not exist
* @throws SecurityException
* If a security manager is installed and it denies an unspecified
* permission.
*/
public abstract FileSystem getFileSystem(URI uri);
/**
* Return a {@code Path} object by converting the given {@link URI}. The
* resulting {@code Path} is associated with a {@link FileSystem} that
* already exists or is constructed automatically.
*
* <p> The exact form of the URI is file system provider dependent. In the
* case of the default provider, the URI scheme is {@code "file"} and the
* given URI has a non-empty path component, and undefined query, and
* fragment components. The resulting {@code Path} is associated with the
* default {@link FileSystems#getDefault default} {@code FileSystem}.
*
* <p> If a security manager is installed then a provider implementation
* may require to check a permission. In the case of the {@link
* FileSystems#getDefault default} file system, no permission check is
* required.
*
* @param uri
* The URI to convert
*
* @throws IllegalArgumentException
* If the URI scheme does not identify this provider or other
* preconditions on the uri parameter do not hold
* @throws FileSystemNotFoundException
* The file system, identified by the URI, does not exist and
* cannot be created automatically
* @throws SecurityException
* If a security manager is installed and it denies an unspecified
* permission.
*/
public abstract Path getPath(URI uri);
/**
* Constructs a new {@code FileSystem} to access the contents of a file as a
* file system.
*
* <p> 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 {@code env} parameter is a map of provider specific properties
* to configure the file system.
*
* <p> 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 {@code UnsupportedOperationException}. The default implementation
* of this method throws {@code UnsupportedOperationException}.
*
* @param path
* The path to the file
* @param env
* A map of provider specific properties to configure the file system;
* may be empty
*
* @return 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
* @throws IllegalArgumentException
* If the {@code env} parameter does not contain properties required
* by the provider, or a property value is invalid
* @throws IOException
* If an I/O error occurs
* @throws SecurityException
* If a security manager is installed and it denies an unspecified
* permission.
*/
public FileSystem newFileSystem(Path path, Map<String,?> env)
throws IOException
{
throw new UnsupportedOperationException();
}
/**
* Opens a file, returning an input stream to read from the file. This
* method works in exactly the manner specified by the {@link
* Files#newInputStream} method.
*
* <p> The default implementation of this method opens a channel to the file
* as if by invoking the {@link #newByteChannel} method and constructs a
* stream that reads bytes from the channel. This method should be overridden
* where appropriate.
*
* @param path
* the path to the file to open
* @param options
* options specifying how the file is opened
*
* @return a new input stream
*
* @throws IllegalArgumentException
* if an invalid combination of options is specified
* @throws UnsupportedOperationException
* if an unsupported option is specified
* @throws IOException
* if an I/O error occurs
* @throws SecurityException
* In the case of the default provider, and a security manager is
* installed, the {@link SecurityManager#checkRead(String) checkRead}
* method is invoked to check read access to the file.
*/
public InputStream newInputStream(Path path, OpenOption... options)
throws IOException
{
if (options.length > 0) {
for (OpenOption opt: options) {
if (opt != StandardOpenOption.READ)
throw new UnsupportedOperationException("'" + opt + "' not allowed");
}
}
return Channels.newInputStream(Files.newByteChannel(path));
}
/**
* 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 {@link Files#newOutputStream} method.
*
* <p> The default implementation of this method opens a channel to the file
* as if by invoking the {@link #newByteChannel} method and constructs a
* stream that writes bytes to the channel. This method should be overridden
* where appropriate.
*
* @param path
* the path to the file to open or create
* @param options
* options specifying how the file is opened
*
* @return a new output stream
*
* @throws IllegalArgumentException
* if {@code options} contains an invalid combination of options
* @throws UnsupportedOperationException
* if an unsupported option is specified
* @throws IOException
* if an I/O error occurs
* @throws SecurityException
* In the case of the default provider, and a security manager is
* installed, the {@link SecurityManager#checkWrite(String) checkWrite}
* method is invoked to check write access to the file. The {@link
* SecurityManager#checkDelete(String) checkDelete} method is
* invoked to check delete access if the file is opened with the
* {@code DELETE_ON_CLOSE} option.
*/
public OutputStream newOutputStream(Path path, OpenOption... options)
throws IOException
{
int len = options.length;
Set<OpenOption> opts = new HashSet<OpenOption>(len + 3);
if (len == 0) {
opts.add(StandardOpenOption.CREATE);
opts.add(StandardOpenOption.TRUNCATE_EXISTING);
} else {
for (OpenOption opt: options) {
if (opt == StandardOpenOption.READ)
throw new IllegalArgumentException("READ not allowed");
opts.add(opt);
}
}
opts.add(StandardOpenOption.WRITE);
return Channels.newOutputStream(newByteChannel(path, opts));
}
/**
* 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 {@link FileChannel#open(Path,Set,FileAttribute[])
* FileChannel.open} method. A provider that does not support all the
* features required to construct a file channel throws {@code
* UnsupportedOperationException}. The default provider is required to
* support the creation of file channels. When not overridden, the default
* implementation throws {@code UnsupportedOperationException}.
*
* @param path
* the path of the file to open or create
* @param options
* options specifying how the file is opened
* @param attrs
* an optional list of file attributes to set atomically when
* creating the file
*
* @return a new file channel
*
* @throws IllegalArgumentException
* If the set contains an invalid combination of options
* @throws UnsupportedOperationException
* If this provider that does not support creating file channels,
* or an unsupported open option or file attribute is specified
* @throws IOException
* If an I/O error occurs
* @throws SecurityException
* In the case of the default file system, the {@link
* SecurityManager#checkRead(String)} method is invoked to check
* read access if the file is opened for reading. The {@link
* SecurityManager#checkWrite(String)} method is invoked to check
* write access if the file is opened for writing
*/
public FileChannel newFileChannel(Path path,
Set<? extends OpenOption> options,
FileAttribute<?>... attrs)
throws IOException
{
throw new UnsupportedOperationException();
}
/**
* 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 {@link
* AsynchronousFileChannel#open(Path,Set,ExecutorService,FileAttribute[])
* AsynchronousFileChannel.open} method.
* A provider that does not support all the features required to construct
* an asynchronous file channel throws {@code UnsupportedOperationException}.
* The default provider is required to support the creation of asynchronous
* file channels. When not overridden, the default implementation of this
* method throws {@code UnsupportedOperationException}.
*
* @param path
* the path of the file to open or create
* @param options
* options specifying how the file is opened
* @param executor
* the thread pool or {@code null} to associate the channel with
* the default thread pool
* @param attrs
* an optional list of file attributes to set atomically when
* creating the file
*
* @return a new asynchronous file channel
*
* @throws IllegalArgumentException
* If the set contains an invalid combination of options
* @throws UnsupportedOperationException
* If this provider that does not support creating asynchronous file
* channels, or an unsupported open option or file attribute is
* specified
* @throws IOException
* If an I/O error occurs
* @throws SecurityException
* In the case of the default file system, the {@link
* SecurityManager#checkRead(String)} method is invoked to check
* read access if the file is opened for reading. The {@link
* SecurityManager#checkWrite(String)} method is invoked to check
* write access if the file is opened for writing
*/
public AsynchronousFileChannel newAsynchronousFileChannel(Path path,
Set<? extends OpenOption> options,
ExecutorService executor,
FileAttribute<?>... attrs)
throws IOException
{
throw new UnsupportedOperationException();
}
/**
* Opens or creates a file, returning a seekable byte channel to access the
* file. This method works in exactly the manner specified by the {@link
* Files#newByteChannel(Path,Set,FileAttribute[])} method.
*
* @param path
* the path to the file to open or create
* @param options
* options specifying how the file is opened
* @param attrs
* an optional list of file attributes to set atomically when
* creating the file
*
* @return a new seekable byte channel
*
* @throws IllegalArgumentException
* if the set contains an invalid combination of options
* @throws UnsupportedOperationException
* if an unsupported open option is specified or the array contains
* attributes that cannot be set atomically when creating the file
* @throws FileAlreadyExistsException
* if a file of that name already exists and the {@link
* StandardOpenOption#CREATE_NEW CREATE_NEW} option is specified
* <i>(optional specific exception)</i>
* @throws IOException
* if an I/O error occurs
* @throws SecurityException
* In the case of the default provider, and a security manager is
* installed, the {@link SecurityManager#checkRead(String) checkRead}
* method is invoked to check read access to the path if the file is
* opened for reading. The {@link SecurityManager#checkWrite(String)
* checkWrite} method is invoked to check write access to the path
* if the file is opened for writing. The {@link
* SecurityManager#checkDelete(String) checkDelete} method is
* invoked to check delete access if the file is opened with the
* {@code DELETE_ON_CLOSE} option.
*/
public abstract SeekableByteChannel newByteChannel(Path path,
Set<? extends OpenOption> options, FileAttribute<?>... attrs) throws IOException;
/**
* Opens a directory, returning a {@code DirectoryStream} to iterate over
* the entries in the directory. This method works in exactly the manner
* specified by the {@link
* Files#newDirectoryStream(java.nio.file.Path, java.nio.file.DirectoryStream.Filter)}
* method.
*
* @param dir
* the path to the directory
* @param filter
* the directory stream filter
*
* @return a new and open {@code DirectoryStream} object
*
* @throws NotDirectoryException
* if the file could not otherwise be opened because it is not
* a directory <i>(optional specific exception)</i>
* @throws IOException
* if an I/O error occurs
* @throws SecurityException
* In the case of the default provider, and a security manager is
* installed, the {@link SecurityManager#checkRead(String) checkRead}
* method is invoked to check read access to the directory.
*/
public abstract DirectoryStream<Path> newDirectoryStream(Path dir,
DirectoryStream.Filter<? super Path> filter) throws IOException;
/**
* Creates a new directory. This method works in exactly the manner
* specified by the {@link Files#createDirectory} method.
*
* @param dir
* the directory to create
* @param attrs
* 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
* @throws FileAlreadyExistsException
* if a directory could not otherwise be created because a file of
* that name already exists <i>(optional specific exception)</i>
* @throws IOException
* if an I/O error occurs or the parent directory does not exist
* @throws SecurityException
* In the case of the default provider, and a security manager is
* installed, the {@link SecurityManager#checkWrite(String) checkWrite}
* method is invoked to check write access to the new directory.
*/
public abstract void createDirectory(Path dir, FileAttribute<?>... attrs)
throws IOException;
/**
* Creates a symbolic link to a target. This method works in exactly the
* manner specified by the {@link Files#createSymbolicLink} method.
*
* <p> The default implementation of this method throws {@code
* UnsupportedOperationException}.
*
* @param link
* the path of the symbolic link to create
* @param target
* the target of the symbolic link
* @param attrs
* 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
* @throws FileAlreadyExistsException
* if a file with the name already exists <i>(optional specific
* exception)</i>
* @throws IOException
* if an I/O error occurs
* @throws SecurityException
* In the case of the default provider, and a security manager
* is installed, it denies {@link LinkPermission}<tt>("symbolic")</tt>
* or its {@link SecurityManager#checkWrite(String) checkWrite}
* method denies write access to the path of the symbolic link.
*/
public void createSymbolicLink(Path link, Path target, FileAttribute<?>... attrs)
throws IOException
{
throw new UnsupportedOperationException();
}
/**
* Creates a new link (directory entry) for an existing file. This method
* works in exactly the manner specified by the {@link Files#createLink}
* method.
*
* <p> The default implementation of this method throws {@code
* UnsupportedOperationException}.
*
* @param link
* the link (directory entry) to create
* @param existing
* a path to an existing file
*
* @throws UnsupportedOperationException
* if the implementation does not support adding an existing file
* to a directory
* @throws FileAlreadyExistsException
* if the entry could not otherwise be created because a file of
* that name already exists <i>(optional specific exception)</i>
* @throws IOException
* if an I/O error occurs
* @throws SecurityException
* In the case of the default provider, and a security manager
* is installed, it denies {@link LinkPermission}<tt>("hard")</tt>
* or its {@link SecurityManager#checkWrite(String) checkWrite}
* method denies write access to either the link or the
* existing file.
*/
public void createLink(Path link, Path existing) throws IOException {
throw new UnsupportedOperationException();
}
/**
* Deletes a file. This method works in exactly the manner specified by the
* {@link Files#delete} method.
*
* @param path
* the path to the file to delete
*
* @throws NoSuchFileException
* if the file does not exist <i>(optional specific exception)</i>
* @throws DirectoryNotEmptyException
* if the file is a directory and could not otherwise be deleted
* because the directory is not empty <i>(optional specific
* exception)</i>
* @throws IOException
* if an I/O error occurs
* @throws SecurityException
* In the case of the default provider, and a security manager is
* installed, the {@link SecurityManager#checkDelete(String)} method
* is invoked to check delete access to the file
*/
public abstract void delete(Path path) throws IOException;
/**
* Deletes a file if it exists. This method works in exactly the manner
* specified by the {@link Files#deleteIfExists} method.
*
* <p> The default implementation of this method simply invokes {@link
* #delete} ignoring the {@code NoSuchFileException} when the file does not
* exist. It may be overridden where appropriate.
*
* @param path
* the path to the file to delete
*
* @return {@code true} if the file was deleted by this method; {@code
* 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 <i>(optional specific
* exception)</i>
* @throws IOException
* if an I/O error occurs
* @throws SecurityException
* In the case of the default provider, and a security manager is
* installed, the {@link SecurityManager#checkDelete(String)} method
* is invoked to check delete access to the file
*/
public boolean deleteIfExists(Path path) throws IOException {
try {
delete(path);
return true;
} catch (NoSuchFileException ignore) {
return false;
}
}
/**
* Reads the target of a symbolic link. This method works in exactly the
* manner specified by the {@link Files#readSymbolicLink} method.
*
* <p> The default implementation of this method throws {@code
* UnsupportedOperationException}.
*
* @param link
* the path to the symbolic link
*
* @throws UnsupportedOperationException
* if the implementation does not support symbolic links
* @throws NotLinkException
* if the target could otherwise not be read because the file
* is not a symbolic link <i>(optional specific exception)</i>
* @throws IOException
* if an I/O error occurs
* @throws SecurityException
* In the case of the default provider, and a security manager
* is installed, it checks that {@code FilePermission} has been
* granted with the "{@code readlink}" action to read the link.
*/
public Path readSymbolicLink(Path link) throws IOException {
throw new UnsupportedOperationException();
}
/**
* Copy a file to a target file. This method works in exactly the manner
* specified by the {@link Files#copy(Path,Path,CopyOption[])} method
* except that both the source and target paths must be associated with
* this provider.
*
* @param source
* the path to the file to copy
* @param target
* the path to the target file
* @param options
* options specifying how the copy should be done
*
* @throws UnsupportedOperationException
* if the array contains a copy option that is not supported
* @throws FileAlreadyExistsException
* if the target file exists but cannot be replaced because the
* {@code REPLACE_EXISTING} option is not specified <i>(optional
* specific exception)</i>
* @throws DirectoryNotEmptyException
* the {@code REPLACE_EXISTING} option is specified but the file
* cannot be replaced because it is a non-empty directory
* <i>(optional specific exception)</i>
* @throws IOException
* if an I/O error occurs
* @throws SecurityException
* In the case of the default provider, and a security manager is
* installed, the {@link SecurityManager#checkRead(String) checkRead}
* method is invoked to check read access to the source file, the
* {@link SecurityManager#checkWrite(String) checkWrite} is invoked
* to check write access to the target file. If a symbolic link is
* copied the security manager is invoked to check {@link
* LinkPermission}{@code ("symbolic")}.
*/
public abstract void copy(Path source, Path target, CopyOption... options)
throws IOException;
/**
* Move or rename a file to a target file. This method works in exactly the
* manner specified by the {@link Files#move} method except that both the
* source and target paths must be associated with this provider.
*
* @param source
* the path to the file to move
* @param target
* the path to the target file
* @param options
* options specifying how the move should be done
*
* @throws UnsupportedOperationException
* if the array contains a copy option that is not supported
* @throws FileAlreadyExistsException
* if the target file exists but cannot be replaced because the
* {@code REPLACE_EXISTING} option is not specified <i>(optional
* specific exception)</i>
* @throws DirectoryNotEmptyException
* the {@code REPLACE_EXISTING} option is specified but the file
* cannot be replaced because it is a non-empty directory
* <i>(optional specific exception)</i>
* @throws AtomicMoveNotSupportedException
* if the options array contains the {@code ATOMIC_MOVE} option but
* the file cannot be moved as an atomic file system operation.
* @throws IOException
* if an I/O error occurs
* @throws SecurityException
* In the case of the default provider, and a security manager is
* installed, the {@link SecurityManager#checkWrite(String) checkWrite}
* method is invoked to check write access to both the source and
* target file.
*/
public abstract void move(Path source, Path target, CopyOption... options)
throws IOException;
/**
* Tests if two paths locate the same file. This method works in exactly the
* manner specified by the {@link Files#isSameFile} method.
*
* @param path
* one path to the file
* @param path2
* the other path
*
* @return {@code true} if, and only if, the two paths locate the same file
*
* @throws IOException
* if an I/O error occurs
* @throws SecurityException
* In the case of the default provider, and a security manager is
* installed, the {@link SecurityManager#checkRead(String) checkRead}
* method is invoked to check read access to both files.
*/
public abstract boolean isSameFile(Path path, Path path2)
throws IOException;
/**
* Tells whether or not a file is considered <em>hidden</em>. This method
* works in exactly the manner specified by the {@link Files#isHidden}
* method.
*
* <p> This method is invoked by the {@link Files#isHidden isHidden} method.
*
* @param path
* the path to the file to test
*
* @return {@code true} if the file is considered hidden
*
* @throws IOException
* if an I/O error occurs
* @throws SecurityException
* In the case of the default provider, and a security manager is
* installed, the {@link SecurityManager#checkRead(String) checkRead}
* method is invoked to check read access to the file.
*/
public abstract boolean isHidden(Path path) throws IOException;
/**
* Returns the {@link FileStore} representing the file store where a file
* is located. This method works in exactly the manner specified by the
* {@link Files#getFileStore} method.
*
* @param path
* the path to the file
*
* @return the file store where the file is stored
*
* @throws IOException
* if an I/O error occurs
* @throws SecurityException
* In the case of the default provider, and a security manager is
* installed, the {@link SecurityManager#checkRead(String) checkRead}
* method is invoked to check read access to the file, and in
* addition it checks {@link RuntimePermission}<tt>
* ("getFileStoreAttributes")</tt>
*/
public abstract FileStore getFileStore(Path path) throws IOException;
/**
* Checks the existence, and optionally the accessibility, of a file.
*
* <p> This method may be used by the {@link Files#isReadable isReadable},
* {@link Files#isWritable isWritable} and {@link Files#isExecutable
* isExecutable} methods to check the accessibility of a file.
*
* <p> 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 {@code modes} parameter
* as follows:
*
* <table border=1 cellpadding=5 summary="">
* <tr> <th>Value</th> <th>Description</th> </tr>
* <tr>
* <td> {@link AccessMode#READ READ} </td>
* <td> Checks that the file exists and that the Java virtual machine has
* permission to read the file. </td>
* </tr>
* <tr>
* <td> {@link AccessMode#WRITE WRITE} </td>
* <td> Checks that the file exists and that the Java virtual machine has
* permission to write to the file, </td>
* </tr>
* <tr>
* <td> {@link AccessMode#EXECUTE EXECUTE} </td>
* <td> Checks that the file exists and that the Java virtual machine has
* permission to {@link Runtime#exec execute} the file. The semantics
* may differ when checking access to a directory. For example, on UNIX
* systems, checking for {@code EXECUTE} access checks that the Java
* virtual machine has permission to search the directory in order to
* access file or subdirectories. </td>
* </tr>
* </table>
*
* <p> If the {@code modes} parameter is of length zero, then the existence
* of the file is checked.
*
* <p> 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.
*
* @param path
* the path to the file to check
* @param modes
* The access modes to check; may have zero elements
*
* @throws UnsupportedOperationException
* an implementation is required to support checking for
* {@code READ}, {@code WRITE}, and {@code EXECUTE} access. This
* exception is specified to allow for the {@code Access} enum to
* be extended in future releases.
* @throws NoSuchFileException
* if a file does not exist <i>(optional specific exception)</i>
* @throws AccessDeniedException
* the requested access would be denied or the access cannot be
* determined because the Java virtual machine has insufficient
* privileges or other reasons. <i>(optional specific exception)</i>
* @throws IOException
* if an I/O error occurs
* @throws SecurityException
* In the case of the default provider, and a security manager is
* installed, the {@link SecurityManager#checkRead(String) checkRead}
* is invoked when checking read access to the file or only the
* existence of the file, the {@link SecurityManager#checkWrite(String)
* checkWrite} is invoked when checking write access to the file,
* and {@link SecurityManager#checkExec(String) checkExec} is invoked
* when checking execute access.
*/
public abstract void checkAccess(Path path, AccessMode... modes)
throws IOException;
/**
* Returns a file attribute view of a given type. This method works in
* exactly the manner specified by the {@link Files#getFileAttributeView}
* method.
*
* @param path
* the path to the file
* @param type
* the {@code Class} object corresponding to the file attribute view
* @param options
* options indicating how symbolic links are handled
*
* @return a file attribute view of the specified type, or {@code null} if
* the attribute view type is not available
*/
public abstract <V extends FileAttributeView> V
getFileAttributeView(Path path, Class<V> type, LinkOption... options);
/**
* Reads a file's attributes as a bulk operation. This method works in
* exactly the manner specified by the {@link
* Files#readAttributes(Path,Class,LinkOption[])} method.
*
* @param path
* the path to the file
* @param type
* the {@code Class} of the file attributes required
* to read
* @param options
* options indicating how symbolic links are handled
*
* @return the file attributes
*
* @throws UnsupportedOperationException
* if an attributes of the given type are not supported
* @throws IOException
* if an I/O error occurs
* @throws SecurityException
* In the case of the default provider, a security manager is
* installed, its {@link SecurityManager#checkRead(String) checkRead}
* method is invoked to check read access to the file
*/
public abstract <A extends BasicFileAttributes> A
readAttributes(Path path, Class<A> type, LinkOption... options) throws IOException;
/**
* Reads a set of file attributes as a bulk operation. This method works in
* exactly the manner specified by the {@link
* Files#readAttributes(Path,String,LinkOption[])} method.
*
* @param path
* the path to the file
* @param attributes
* the attributes to read
* @param options
* options indicating how symbolic links are handled
*
* @return 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
* @throws IllegalArgumentException
* if no attributes are specified or an unrecognized attributes is
* specified
* @throws IOException
* If an I/O error occurs
* @throws SecurityException
* In the case of the default provider, and a security manager is
* installed, its {@link SecurityManager#checkRead(String) 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.
*/
public abstract Map<String,Object> readAttributes(Path path, String attributes,
LinkOption... options)
throws IOException;
/**
* Sets the value of a file attribute. This method works in exactly the
* manner specified by the {@link Files#setAttribute} method.
*
* @param path
* the path to the file
* @param attribute
* the attribute to set
* @param value
* the attribute value
* @param options
* options indicating how symbolic links are handled
*
* @throws UnsupportedOperationException
* if the attribute view is not available
* @throws 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
* @throws ClassCastException
* If the attribute value is not of the expected type or is a
* collection containing elements that are not of the expected
* type
* @throws IOException
* If an I/O error occurs
* @throws SecurityException
* In the case of the default provider, and a security manager is
* installed, its {@link SecurityManager#checkWrite(String) 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.
*/
public abstract void setAttribute(Path path, String attribute,
Object value, LinkOption... options)
throws IOException;
}