java.nio.file.FileStore

public abstract class FileStore extends Object

Storage for files. A FileStore represents a storage pool, device, partition, volume, concrete file system or other implementation specific means of file storage. The FileStore for where a file is stored is obtained by invoking the getFileStore method, or all file stores can be enumerated by invoking the getFileStores method.

In addition to the methods defined by this class, a file store may support one or more FileStoreAttributeView classes that provide a read-only or updatable view of a set of file store attributes.

Since:: 1.7

Constructor Summary

Constructors

Modifier

Constructor

Description

protected

FileStore()

Initializes a new instance of this class.
Method Summary

Modifier and Type

Method

Description

abstract Object

getAttribute(String attribute)

Reads the value of a file store attribute.

long

getBlockSize()

Returns the number of bytes per block in this file store.

abstract <V extends FileStoreAttributeView> V

getFileStoreAttributeView(Class<V> type)

Returns a FileStoreAttributeView of the given type.

abstract long

getTotalSpace()

Returns the size, in bytes, of the file store.

abstract long

getUnallocatedSpace()

Returns the number of unallocated bytes in the file store.

abstract long

getUsableSpace()

Returns the number of bytes available to this Java virtual machine on the file store.

abstract boolean

isReadOnly()

Tells whether this file store is read-only.

abstract String

name()

Returns the name of this file store.

abstract boolean

supportsFileAttributeView(Class<? extends FileAttributeView> type)

Tells whether or not this file store supports the file attributes identified by the given file attribute view.

abstract boolean

supportsFileAttributeView(String name)

Tells whether or not this file store supports the file attributes identified by the given file attribute view.

abstract String

type()

Returns the type of this file store.

Methods declared in class Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Modifier and Type

Method

Description

protected Object

clone()

Answers a new instance of the same class as the receiver, whose slots have been filled in with the values in the slots of the receiver.

boolean

equals(Object o)

Compares the argument to the receiver, and answers true if they represent the same object using a class specific comparison.

protected void

finalize()

Deprecated, for removal: This API element is subject to removal in a future version.
May cause performance issues, deadlocks and hangs.

final Class<? extends Object>

getClass()

Answers the unique instance of java.lang.Class which represents the class of the receiver.

int

hashCode()

Answers an integer hash code for the receiver.

final void

notify()

Causes one thread which is waiting on the receiver to be made ready to run.

final void

notifyAll()

Causes all threads which are waiting on the receiver to be made ready to run.

String

toString()

Answers a string containing a concise, human-readable description of the receiver.

final void

wait()

Causes the thread which sent this message to be made not ready to run pending some change in the receiver (as indicated by notify or notifyAll).

final void

wait(long time)

Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.

final void

wait(long time, int frac)

Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.

Constructor Details
- FileStore
  
  protected FileStore()
  
  Initializes a new instance of this class.
Method Details
- name
  
  public abstract String name()
  
  Returns the name of this file store. The format of the name is highly implementation specific. It will typically be the name of the storage pool or volume.
  The string returned by this method may differ from the string returned by the toString method.
  
  Returns:
  
  the name of this file store
- type
  
  public abstract String type()
  
  Returns the type of this file store. The format of the string returned by this method is highly implementation specific. It may indicate, for example, the format used or if the file store is local or remote.
  
  Returns:
  
  a string representing the type of this file store
- isReadOnly
  
  public abstract boolean isReadOnly()
  
  Tells whether this file store is read-only. A file store is read-only if it does not support write operations or other changes to files. Any attempt to create a file, open an existing file for writing etc. causes an IOException to be thrown.
  
  Returns:
  
  true if, and only if, this file store is read-only
- getTotalSpace
  
  public abstract long getTotalSpace() throws IOException
  
  Returns the size, in bytes, of the file store. If the total number of bytes in the file store is greater than Long.MAX_VALUE, then Long.MAX_VALUE will be returned.
  
  Returns:
  
  the size of the file store, in bytes
  
  Throws:
  
  IOException - if an I/O error occurs
- getUsableSpace
  
  public abstract long getUsableSpace() throws IOException
  
  Returns the number of bytes available to this Java virtual machine on the file store. If the number of bytes available is greater than Long.MAX_VALUE, then Long.MAX_VALUE will be returned.
  The returned number of available bytes is a hint, but not a guarantee, that it is possible to use most or any of these bytes. The number of usable bytes is most likely to be accurate immediately after this method returns. It is likely to be made inaccurate by any external I/O operations including those made on the system outside of this Java virtual machine.
  
  Returns:
  
  the current number of usable bytes
  
  Throws:
  
  IOException - if an I/O error occurs
- getUnallocatedSpace
  
  public abstract long getUnallocatedSpace() throws IOException
  
  Returns the number of unallocated bytes in the file store. If the number of unallocated bytes is greater than Long.MAX_VALUE, then Long.MAX_VALUE will be returned.
  The returned number of unallocated bytes is a hint, but not a guarantee, that it is possible to use most or any of these bytes. The number of unallocated bytes is most likely to be accurate immediately after this method returns. It is likely to be made inaccurate by any external I/O operations including those made on the system outside of this virtual machine.
  
  Returns:
  
  the current number of unallocated bytes
  
  Throws:
  
  IOException - if an I/O error occurs
- getBlockSize
  
  public long getBlockSize() throws IOException
  
  Returns the number of bytes per block in this file store.
  File storage is typically organized into discrete sequences of bytes called blocks. A block is the smallest storage unit of a file store. Every read and write operation is performed on a multiple of blocks.
  
  Implementation Requirements:
  
  The implementation in this class throws UnsupportedOperationException.
  
  Returns:
  
  a positive value representing the block size of this file store, in bytes
  
  Throws:
  
  IOException - if an I/O error occurs
  
  UnsupportedOperationException - if the operation is not supported
  
  Since:
  
  10
- supportsFileAttributeView
  
  public abstract boolean supportsFileAttributeView(Class<? extends FileAttributeView> type)
  
  Tells whether or not this file store supports the file attributes identified by the given file attribute view.
  Invoking this method to test if the file store supports BasicFileAttributeView will always return true. In the case of the default provider, this method cannot guarantee to give the correct result when the file store is not a local storage device. The reasons for this are implementation specific and therefore unspecified.
  
  Parameters:
  
  type - the file attribute view type
  
  Returns:
  
  true if, and only if, the file attribute view is supported
- supportsFileAttributeView
  
  public abstract boolean supportsFileAttributeView(String name)
  
  Tells whether or not this file store supports the file attributes identified by the given file attribute view.
  Invoking this method to test if the file store supports BasicFileAttributeView, identified by the name "basic" will always return true. In the case of the default provider, this method cannot guarantee to give the correct result when the file store is not a local storage device. The reasons for this are implementation specific and therefore unspecified.
  
  Parameters:
  
  name - the name of file attribute view
  
  Returns:
  
  true if, and only if, the file attribute view is supported
- getFileStoreAttributeView
  
  public abstract <V extends FileStoreAttributeView> V getFileStoreAttributeView(Class<V> type)
  
  Returns a FileStoreAttributeView of the given type.
  This method is intended to be used where the file store attribute view defines type-safe methods to read or update the file store attributes. The type parameter is the type of the attribute view required and the method returns an instance of that type if supported.
  
  Type Parameters:
  
  V - The FileStoreAttributeView type
  
  Parameters:
  
  type - the Class object corresponding to the attribute view
  
  Returns:
  
  a file store attribute view of the specified type or null if the attribute view is not available
- getAttribute
  public abstract Object getAttribute(String attribute) throws IOException
  
  Reads the value of a file store attribute.
  The attribute parameter identifies the attribute to be read and takes the form:
  view-name:attribute-name
  where the character ':' stands for itself.
  view-name is the name of a AttributeView that identifies a set of file attributes. attribute-name is the name of the attribute.
  Usage Example: Suppose we want to know if ZFS compression is enabled (assuming the "zfs" view is supported):
  
  boolean compression = (Boolean)fs.getAttribute("zfs:compression");
  
  Parameters:
  
  attribute - the attribute to read
  
  Returns:
  
  the attribute value; null may be valid for some attributes
  
  Throws:
  
  UnsupportedOperationException - if the attribute view is not available or it does not support reading the attribute
  
  IOException - if an I/O error occurs

Class FileStore

Constructor Summary

Method Summary

Methods declared in class Object

Constructor Details

FileStore

Method Details

name

type

isReadOnly

getTotalSpace

getUsableSpace

getUnallocatedSpace

getBlockSize

supportsFileAttributeView

supportsFileAttributeView

getFileStoreAttributeView

getAttribute