public abstract class FileStore extends Object
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.Modifier | Constructor and Description |
---|---|
protected |
FileStore()
Initializes a new instance of this class.
|
Modifier and Type | Method and Description |
---|---|
abstract Object |
getAttribute(String attribute)
Reads the value of a file store attribute.
|
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(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.
|
public abstract Object getAttribute(String attribute) throws IOException
The attribute
parameter identifies the attribute to be read
and takes the form:
view-name:attribute-namewhere 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");
attribute
- the attribute to readnull
may be a valid valid for some
attributesUnsupportedOperationException
- if the attribute view is not available or it does not support
reading the attributeIOException
- if an I/O error occurspublic abstract long getTotalSpace() throws IOException
IOException
- if an I/O error occurspublic abstract long getUnallocatedSpace() throws IOException
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 the space attributes are obtained. It is likely to be made inaccurate by any external I/O operations including those made on the system outside of this virtual machine.
IOException
- if an I/O error occurspublic abstract long getUsableSpace() throws IOException
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 the space attributes are obtained. 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.
IOException
- if an I/O error occurspublic abstract boolean isReadOnly()
IOException
to be thrown.true
if, and only if, this file store is read-onlypublic abstract String name()
The string returned by this method may differ from the string
returned by the toString
method.
public abstract boolean supportsFileAttributeView(String name)
Invoking this method to test if the file store supports
the basic attribute view,
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.
name
- the name of file attribute viewtrue
if, and only if, the file attribute view is
supportedpublic abstract String type()
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