FileSystemProvider (Java Platform SE 7 )

java.lang.Object
- java.nio.file.spi.FileSystemProvider

```
public abstract class FileSystemProvider
extends Object
```
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.

Since:

1.7

Constructor Summary

Constructors
Modifier Constructor and Description

protected FileSystemProvider()
Initializes a new instance of this class.

Constructors
Modifier	Constructor and Description
`protected`	`FileSystemProvider()` Initializes a new instance of this class.

Method Summary

Methods
Modifier and Type	Method and Description
`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 `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.
`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, DirectoryStream.Filter<? super Path> filter)` Opens a directory, returning a `DirectoryStream` to iterate over the entries in the directory.
`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.
`FileSystem`	`newFileSystem(Path path, Map<String,?> env)` Constructs a new `FileSystem` to access the contents of a file as a file system.
`abstract FileSystem`	`newFileSystem(URI uri, Map<String,?> env)` Constructs a new `FileSystem` object identified by a URI.
`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 <A extends BasicFileAttributes> A`	`readAttributes(Path path, Class<A> type, LinkOption... options)` Reads a file's attributes as a bulk operation.
`abstract Map<String,Object>`	`readAttributes(Path path, String attributes, LinkOption... options)` Reads a set of file 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.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - 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")
- Method Detail
  - 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:
    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
  - getScheme
```
public abstract String getScheme()
```
    Returns the URI scheme that identifies this provider.
    
    Returns:
    The URI scheme
  - newFileSystem
```
public abstract FileSystem newFileSystem(URI uri,
                       Map<String,?> env)
                                  throws IOException
```
    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 reference
    env - A map of provider specific properties to configure the file system; may be empty
    
    Returns:
    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
  - 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 reference
    
    Returns:
    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 - 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
    
    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.
  - newFileSystem
```
public FileSystem newFileSystem(Path path,
                       Map<String,?> env)
                         throws IOException
```
    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 - The path to the file
    env - A map of provider specific properties to configure the file system; may be empty
    
    Returns:
    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

Class FileSystemProvider

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

FileSystemProvider

Method Detail

installedProviders

getScheme

newFileSystem

getFileSystem

getPath

newFileSystem