OpenJDK 27 · java.nio.file.FileStore · APIdia, the JavaDoc alternative

Access	Constructor and Description
protected	FileStore() Initializes a new instance of this class.

Method Summary

Modifier and Type	Method and Description
public abstract Object	Returns: the attribute value; `null` may be valid for some attributes getAttribute(String the attribute to read attribute) Reads the value of a file store attribute.
public long	Returns: a positive value representing the block size of this file store, in bytes getBlockSize() Returns the number of bytes per block in this file store.
public abstract < The `FileStoreAttributeView` type V extends FileStoreAttributeView> V	Returns: a file store attribute view of the specified type or `null` if the attribute view is not available getFileStoreAttributeView(Class<V> the `Class` object corresponding to the attribute view type) Returns a `FileStoreAttributeView` of the given type.
public abstract long	Returns: the size of the file store, in bytes getTotalSpace() Returns the size, in bytes, of the file store.
public abstract long	Returns: the current number of unallocated bytes getUnallocatedSpace() Returns the number of unallocated bytes in the file store.
public abstract long	Returns: the current number of usable bytes getUsableSpace() Returns the number of bytes available to this Java virtual machine on the file store.
public abstract boolean	Returns: `true` if, and only if, this file store is read-only isReadOnly() Tells whether this file store is read-only.
public abstract String	Returns: the name of this file store name() Returns the name of this file store.
public abstract boolean	Returns: `true` if, and only if, the file attribute view is supported supportsFileAttributeView(Class<? extends FileAttributeView> the file attribute view type type) Tells whether or not this file store supports the file attributes identified by the given file attribute view.
public abstract boolean	Returns: `true` if, and only if, the file attribute view is supported supportsFileAttributeView(String the `name` of file attribute view name) Tells whether or not this file store supports the file attributes identified by the given file attribute view.
public abstract String	Returns: a string representing the type of this file store type() Returns the type of this file store.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

FileStore	back to summary
protected FileStore() Initializes a new instance of this class.

Method Detail

getAttribute back to summary

getAttribute	back to summary
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");` boolean compression = (Boolean)fs.getAttribute("zfs:compression"); Parameters attribute:String the attribute to read Returns:Object the attribute value; `null` may be valid for some attributes Exceptions IOException: if an I/O error occurs UnsupportedOperationException: if the attribute view is not available or it does not support reading the attribute

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:String: the attribute to read

Returns:Object

the attribute value; null may be valid for some attributes

Exceptions

IOException:: if an I/O error occurs
UnsupportedOperationException:: if the attribute view is not available or it does not support reading the attribute

getBlockSize back to summary

getBlockSize	back to summary
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 Specification The implementation in this class throws `UnsupportedOperationException`. Returns:long a positive value representing the block size of this file store, in bytes Exceptions IOException: if an I/O error occurs UnsupportedOperationException: if the operation is not supported Since 10

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 Specification

The implementation in this class throws UnsupportedOperationException.

Returns:long

a positive value representing the block size of this file store, in bytes

Exceptions

IOException:: if an I/O error occurs
UnsupportedOperationException:: if the operation is not supported

Since

getFileStoreAttributeView back to summary

getFileStoreAttributeView	back to summary
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. Parameters <V> The `FileStoreAttributeView` type type:Class<V> the `Class` object corresponding to the attribute view Returns:V a file store attribute view of the specified type or `null` if the attribute view is not available

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.

Parameters

<V>: The FileStoreAttributeView type
type:Class<V>: the Class object corresponding to the attribute view

Returns:V

a file store attribute view of the specified type or null if the attribute view is not available

getTotalSpace back to summary

getTotalSpace	back to summary
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:long the size of the file store, in bytes Exceptions IOException: if an I/O error occurs

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:long

the size of the file store, in bytes

Exceptions

IOException:: if an I/O error occurs

getUnallocatedSpace back to summary

getUnallocatedSpace	back to summary
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:long the current number of unallocated bytes Exceptions IOException: if an I/O error occurs

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:long

the current number of unallocated bytes

Exceptions

IOException:: if an I/O error occurs

getUsableSpace back to summary

getUsableSpace	back to summary
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:long the current number of usable bytes Exceptions IOException: if an I/O error occurs

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:long

the current number of usable bytes

Exceptions

IOException:: if an I/O error occurs

isReadOnly back to summary

isReadOnly	back to summary
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:boolean `true` if, and only if, this file store is read-only

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:boolean: true if, and only if, this file store is read-only

name back to summary

name	back to summary
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:String the name of this file store

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:String: the name of this file store

supportsFileAttributeView back to summary

supportsFileAttributeView	back to summary
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:Class<? extends FileAttributeView> the file attribute view type Returns:boolean `true` if, and only if, the file attribute view is supported

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:Class<? extends FileAttributeView>: the file attribute view type

Returns:boolean

true if, and only if, the file attribute view is supported

supportsFileAttributeView back to summary

supportsFileAttributeView	back to summary
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:String the `name` of file attribute view Returns:boolean `true` if, and only if, the file attribute view is supported

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:String: the name of file attribute view

Returns:boolean

true if, and only if, the file attribute view is supported

type	back to summary
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:String a string representing the type of this file store

type

back to summary

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:String: a string representing the type of this file store

public abstract Class FileStore

Constructor Summary

Method Summary

Constructor Detail

Method Detail