public class OWFile
extends java.lang.Object
User interfaces and operating systems use system-dependent pathname strings to name files and directories. This class presents an abstract, system-independent view of hierarchical pathnames. An abstract pathname has two components:
"/"
for the UNIX root
directory, or "\\"
for a Win32 UNC pathname, and
The conversion of a pathname string to or from an abstract pathname is
inherently system-dependent. When an abstract pathname is converted into a
pathname string, each name is separated from the next by a single copy of
the default separator character. The default name-separator
character is defined by the system property OWFile.separator
, and
is made available in the public static fields
and separator
of this class.
When a pathname string is converted into an abstract pathname, the names
within it may be separated by the default name-separator character or by any
other name-separator character that is supported by the underlying system.
separatorChar
A pathname, whether abstract or in string form, may be either
absolute or relative. An absolute pathname is complete in
that no other information is required in order to locate the file that it
denotes. A relative pathname, in contrast, must be interpreted in terms of
information taken from some other pathname. By default the classes in the
java.io
package always resolve relative pathnames against the
current user directory. This directory is named by the system property
user.dir
, and is typically the directory in which the Java
virtual machine was invoked. The pathname provided to this OWFile
however is always absolute.
The prefix concept is used to handle root directories on UNIX platforms, and drive specifiers, root directories and UNC pathnames on Win32 platforms, as follows:
"/"
. The abstract pathname denoting the root directory
has the prefix "/"
and an empty name sequence.
Instances of the OWFile
class are immutable; that is, once
created, the abstract pathname represented by a OWFile
object
will never change.
The methods in the class are the same as in the java.io.File version 1.2 with the following exceptions
Methods provided but of limited functionallity
Methods not provided or supported:
Extra Methods (not usually in 1.2 java.io.File)
File and directory name limitations
OWFile
instance is closed with the
close()
method or the sync()
method
from the OWFileDescriptor
sync()
method for flushing the changes to the
Filesystem is preferred since it can be called multiple times if
there is a connection problem
format()
method in order for files or directories to
be added or changed.
format()
method
is used to link these devices then only the 'root' need be used
in future constuctors of this class or the 1-Wire file stream classes.
getFreeMemory()
method to get an estimate of free memory
available.
close()
method to release system resources
allocated when done with the OWFile
instance
// create a 1-Wire file at root
OWFile owfile = new OWFile(owd, "");
// format Filesystem
owfile.format();
// get 1-Wire File descriptor to flush to device
OWFileDescriptor owfd = owfile.getFD();
// loop until sync is successful
do
{
try
{
owfd.sync();
done = true;
}
catch (SyncFailedException e)
{
// do something
...
done = false;
}
}
while (!done)
// close the 1-Wire file to release system resources
owfile.close();
OWFile owfile = new OWFile(owd, "/doc/text/temp");
// make the directories
if (owfile.mkdirs())
System.out.println("Success!");
else
System.out.println("Out of memory or invalid file/directory");
// get 1-Wire File descriptor to flush to device
...
OWFileDescriptor
,
OWFileInputStream
,
OWFileOutputStream
Modifier and Type | Field and Description |
---|---|
static java.lang.String |
pathSeparator
Field pathSeparator
|
static char |
pathSeparatorChar
Field pathSeparatorChar
|
static java.lang.String |
separator
Field separator
|
static char |
separatorChar
Field separatorChar
|
Constructor and Description |
---|
OWFile(OneWireContainer[] owd,
java.lang.String pathname)
Creates a new
OWFile instance by converting the given
pathname string into an abstract pathname. |
OWFile(OneWireContainer owd,
java.lang.String pathname)
Creates a new
OWFile instance by converting the given
pathname string into an abstract pathname. |
OWFile(OneWireContainer owd,
java.lang.String parent,
java.lang.String child)
Creates a new
OWFile instance from a parent pathname string
and a child pathname string. |
OWFile(OWFile parent,
java.lang.String child)
Creates a new
OWFile instance from a parent abstract
pathname and a child pathname string. |
Modifier and Type | Method and Description |
---|---|
boolean |
canRead()
Tests whether the application can read the file denoted by this
abstract pathname.
|
boolean |
canWrite()
Tests whether the application can modify to the file denoted by this
abstract pathname.
|
void |
close()
Closes this file and releases any system resources
associated with this stream.
|
int |
compareTo(java.lang.Object o)
Compares this abstract pathname to another object.
|
int |
compareTo(OWFile pathname)
Compares two abstract pathnames lexicographically.
|
boolean |
createNewFile()
Atomically creates a new, empty file named by this abstract pathname if
and only if a file with this name does not yet exist.
|
boolean |
delete()
Deletes the file or directory denoted by this abstract pathname.
|
boolean |
equals(java.lang.Object obj)
Tests this abstract pathname for equality with the given object.
|
boolean |
exists()
Tests whether the file denoted by this abstract pathname exists.
|
void |
format()
Format the Filesystem on the 1-Wire device provided in
the constructor.
|
OWFile |
getAbsoluteFile()
Returns the absolute form of this abstract pathname.
|
java.lang.String |
getAbsolutePath()
Returns the absolute pathname string of this abstract pathname.
|
OWFile |
getCanonicalFile()
Returns the canonical form of this abstract pathname.
|
java.lang.String |
getCanonicalPath()
Returns the canonical pathname string of this abstract pathname.
|
OWFileDescriptor |
getFD()
Returns the
OWFileDescriptor
object that represents the connection to
the actual file in the Filesystem being
used by this OWFileInputStream . |
int |
getFreeMemory()
Gets the number of bytes available on this device for
file and directory information.
|
int |
getLocalPage(int page)
Get's the local page number on the memory bank object for
the specified page.
|
PagedMemoryBank |
getMemoryBankForPage(int page)
Get's the memory bank object for the specified page.
|
java.lang.String |
getName()
Returns the name of the file or directory denoted by this abstract
pathname.
|
OneWireContainer |
getOneWireContainer()
Gets the OneWireContainer that this File resides on.
|
OneWireContainer[] |
getOneWireContainers()
Gets the OneWireContainer(s) that this File resides on.
|
int[] |
getPageList()
Get's an array of integers that represents the page
list of the file or directory represented by this
OWFile.
|
java.lang.String |
getParent()
Returns the pathname string of this abstract pathname's parent, or
null if this pathname does not name a parent directory. |
OWFile |
getParentFile()
Returns the abstract pathname of this abstract pathname's parent,
or
null if this pathname does not name a parent
directory. |
java.lang.String |
getPath()
Converts this abstract pathname into a pathname string.
|
int |
getStartPage()
Returns an integer which represents the starting memory page
of the file or directory represented by this OWFile.
|
int |
hashCode()
Computes a hash code for this abstract pathname.
|
boolean |
isAbsolute()
Tests whether this abstract pathname is absolute.
|
boolean |
isDirectory()
Tests whether the file denoted by this abstract pathname is a
directory.
|
boolean |
isFile()
Tests whether the file denoted by this abstract pathname is a normal
file.
|
boolean |
isHidden()
Tests whether the file named by this abstract pathname is a hidden
file.
|
long |
lastModified()
Returns the time that the file denoted by this abstract pathname was
last modified.
|
long |
length()
Returns the length of the file denoted by this abstract pathname.
|
java.lang.String[] |
list()
Returns an array of strings naming the files and directories in the
directory denoted by this abstract pathname.
|
OWFile[] |
listFiles()
Returns an array of abstract pathnames denoting the files in the
directory denoted by this abstract pathname.
|
static OWFile[] |
listRoots(OneWireContainer owc)
List the available filesystem roots.
|
boolean |
mkdir()
Creates the directory named by this abstract pathname.
|
boolean |
mkdirs()
Creates the directory named by this abstract pathname, including any
necessary but nonexistent parent directories.
|
boolean |
renameTo(OWFile dest)
Renames the file denoted by this abstract pathname.
|
boolean |
setLastModified(long time)
Sets the last-modified time of the file or directory named by this
abstract pathname.
|
boolean |
setReadOnly()
Marks the file or directory named by this abstract pathname so that
only read operations are allowed.
|
java.lang.String |
toString()
Returns the pathname string of this abstract pathname.
|
public static final java.lang.String separator
public static final char separatorChar
public static final java.lang.String pathSeparator
public static final char pathSeparatorChar
public OWFile(OneWireContainer owd, java.lang.String pathname)
OWFile
instance by converting the given
pathname string into an abstract pathname. If the given string is
the empty string, then the result is the empty abstract pathname.owd
- OneWireContainer that this Filesystem resides onpathname
- A pathname stringjava.lang.NullPointerException
- If the pathname
argument is null
public OWFile(OneWireContainer[] owd, java.lang.String pathname)
OWFile
instance by converting the given
pathname string into an abstract pathname. If the given string is
the empty string, then the result is the empty abstract pathname.owd
- ordered array of OneWireContainers that this Filesystem
resides onpathname
- A pathname stringjava.lang.NullPointerException
- If the pathname
argument is null
Change the OWFileDescriptor to accept only an array of containers
Change the local ref to be an array
Create a single array in constructors with single passed owcpublic OWFile(OneWireContainer owd, java.lang.String parent, java.lang.String child)
OWFile
instance from a parent pathname string
and a child pathname string.
If parent
is null
then the new
OWFile
instance is created as if by invoking the
single-argument OWFile
constructor on the given
child
pathname string.
Otherwise the parent
pathname string is taken to denote
a directory, and the child
pathname string is taken to
denote either a directory or a file. If the child
pathname
string is absolute then it is converted into a relative pathname in a
system-dependent way. If parent
is the empty string then
the new OWFile
instance is created by converting
child
into an abstract pathname and resolving the result
against a system-dependent default directory. Otherwise each pathname
string is converted into an abstract pathname and the child abstract
pathname is resolved against the parent.
owd
- OneWireContainer that this Filesystem resides onparent
- The parent pathname stringchild
- The child pathname stringjava.lang.NullPointerException
- If child
is null
public OWFile(OWFile parent, java.lang.String child)
OWFile
instance from a parent abstract
pathname and a child pathname string.
If parent
is null
then the new
OWFile
instance is created as if by invoking the
single-argument OWFile
constructor on the given
child
pathname string.
Otherwise the parent
abstract pathname is taken to
denote a directory, and the child
pathname string is taken
to denote either a directory or a file. If the child
pathname string is absolute then it is converted into a relative
pathname in a system-dependent way. If parent
is the empty
abstract pathname then the new OWFile
instance is created by
converting child
into an abstract pathname and resolving
the result against a system-dependent default directory. Otherwise each
pathname string is converted into an abstract pathname and the child
abstract pathname is resolved against the parent.
owd
- OneWireContainer that this Filesystem resides onparent
- The parent abstract pathnamechild
- The child pathname stringjava.lang.NullPointerException
- If child
is null
public java.lang.String getName()
public java.lang.String getParent()
null
if this pathname does not name a parent directory.
The parent of an abstract pathname consists of the pathname's prefix, if any, and each name in the pathname's name sequence except for the last. If the name sequence is empty then the pathname does not name a parent directory.
null
if this pathname
does not name a parentpublic OWFile getParentFile()
null
if this pathname does not name a parent
directory.
The parent of an abstract pathname consists of the pathname's prefix, if any, and each name in the pathname's name sequence except for the last. If the name sequence is empty then the pathname does not name a parent directory.
null
if this pathname
does not name a parentpublic java.lang.String getPath()
default name-separator character
to
separate the names in the name sequence.public boolean isAbsolute()
"/"
. On Win32 systems, a
pathname is absolute if its prefix is a drive specifier followed by
"\\"
, or if its prefix is "\\"
.true
if this abstract pathname is absolute,
false
otherwisepublic java.lang.String getAbsolutePath()
If this abstract pathname is already absolute, then the pathname
string is simply returned as if by the
method. If this abstract pathname is the empty abstract pathname then
the pathname string of the current user directory, which is named by the
system property getPath()
user.dir
, is returned. Otherwise this
pathname is resolved in a system-dependent way. On UNIX systems, a
relative pathname is made absolute by resolving it against the current
user directory. On Win32 systems, a relative pathname is made absolute
by resolving it against the current directory of the drive named by the
pathname, if any; if not, it is resolved against the current user
directory.
File.isAbsolute()
public OWFile getAbsoluteFile()
new File(this.getAbsolutePath()
())
.public java.lang.String getCanonicalPath() throws java.io.IOException
The precise definition of canonical form is system-dependent, but
canonical forms are always absolute. Thus if this abstract pathname is
relative it will be converted to absolute form as if by the
method.
getAbsoluteFile()
Every pathname that denotes an existing file or directory has a unique canonical form. Every pathname that denotes a nonexistent file or directory also has a unique canonical form. The canonical form of the pathname of a nonexistent file or directory may be different from the canonical form of the same pathname after the file or directory is created. Similarly, the canonical form of the pathname of an existing file or directory may be different from the canonical form of the same pathname after the file or directory is deleted.
java.io.IOException
- If an I/O error occurs, which is possible because the
construction of the canonical pathname may require
filesystem queriespublic OWFile getCanonicalFile() throws java.io.IOException
new File(this.getCanonicalPath()
())
.java.io.IOException
- If an I/O error occurs, which is possible because the
construction of the canonical pathname may require
filesystem queriespublic boolean canRead()
true
if and only if the file specified by this
abstract pathname exists and can be read by the
application; false
otherwisepublic boolean canWrite()
true
if and only if the Filesystem actually
contains a file denoted by this abstract pathname and
the application is allowed to write to the file;
false
otherwise.public boolean exists()
true
if and only if the file denoted by this
abstract pathname exists; false
otherwisepublic boolean isDirectory()
true
if and only if the file denoted by this
abstract pathname exists and is a directory;
false
otherwisepublic boolean isFile()
true
if and only if the file denoted by this
abstract pathname exists and is a normal file;
false
otherwisepublic boolean isHidden()
'.'
). On Win32 systems, a file is
considered to be hidden if it has been marked as such in the filesystem.true
if and only if the file denoted by this
abstract pathname is hidden according to the conventions of the
underlying platformpublic long lastModified()
long
value representing the time the file was
last modified, measured in milliseconds since the epoch
(00:00:00 GMT, January 1, 1970), or 0L
if the
file does not exist or if an I/O error occurspublic long length()
0L
if the file does not existpublic boolean createNewFile() throws java.io.IOException
true
if the named file does not exist and was
successfully created; false
if the named file
already existsjava.io.IOException
- If an I/O error occurredpublic boolean delete()
true
if and only if the file or directory is
successfully deleted; false
otherwisepublic java.lang.String[] list()
If this abstract pathname does not denote a directory, then this
method returns null
. Otherwise an array of strings is
returned, one for each file or directory in the directory. Names
denoting the directory itself and the directory's parent directory are
not included in the result. Each string is a file name rather than a
complete path.
There is no guarantee that the name strings in the resulting array will appear in any specific order; they are not, in particular, guaranteed to appear in alphabetical order.
null
if
this abstract pathname does not denote a directory, or if an
I/O error occurs.public OWFile[] listFiles()
If this abstract pathname does not denote a directory, then this
method returns null
. Otherwise an array of
OWFile
objects is returned, one for each file or directory in
the directory. Pathnames denoting the directory itself and the
directory's parent directory are not included in the result. Each
resulting abstract pathname is constructed from this abstract pathname
using the
constructor. Therefore if this pathname
is absolute then each resulting pathname is absolute; if this pathname
is relative then each resulting pathname will be relative to the same
directory.
OWFile(OWFile, String)
There is no guarantee that the name strings in the resulting array will appear in any specific order; they are not, in particular, guaranteed to appear in alphabetical order.
null
if this abstract pathname
does not denote a directory, or if an I/O error occurs.public boolean mkdir()
true
if and only if the directory was
created; false
otherwisepublic boolean mkdirs()
true
if and only if the directory was created,
along with all necessary parent directories; false
otherwisepublic boolean renameTo(OWFile dest)
dest
- The new abstract pathname for the named filetrue
if and only if the renaming succeeded;
false
otherwisejava.lang.NullPointerException
- If parameter dest
is null
public boolean setLastModified(long time)
All platforms support file-modification times to the nearest second,
but some provide more precision. The argument will be truncated to fit
the supported precision. If the operation succeeds and no intervening
operations on the file take place, then the next invocation of the
method will return the (possibly
truncated) lastModified()
time
argument that was passed to this method.
time
- The new last-modified time, measured in milliseconds since
the epoch (00:00:00 GMT, January 1, 1970)true
if and only if the operation succeeded;
false
otherwisejava.lang.IllegalArgumentException
- If the argument is negativepublic boolean setReadOnly()
true
if and only if the operation succeeded;
false
otherwisepublic static OWFile[] listRoots(OneWireContainer owc)
A particular Java platform may support zero or more
hierarchically-organized Filesystems. Each Filesystem has a
root
directory from which all other files in that file
system can be reached. Windows platforms, for example, have a root
directory for each active drive; UNIX platforms have a single root
directory, namely "/"
. The set of available filesystem
roots is affected by various system-level operations such the insertion
or ejection of removable media and the disconnecting or unmounting of
physical or virtual disk drives.
This method returns an array of OWFile
objects that
denote the root directories of the available filesystem roots. It is
guaranteed that the canonical pathname of any file physically present on
the local machine will begin with one of the roots returned by this
method.
The canonical pathname of a file that resides on some other machine
and is accessed via a remote-filesystem protocol such as SMB or NFS may
or may not begin with one of the roots returned by this method. If the
pathname of a remote file is syntactically indistinguishable from the
pathname of a local file then it will begin with one of the roots
returned by this method. Thus, for example, OWFile
objects
denoting the root directories of the mapped network drives of a Windows
platform will be returned by this method, while OWFile
objects containing UNC pathnames will not be returned by this method.
owc
- OneWireContainer that this Filesystem resides onOWFile
objects denoting the available
filesystem roots, or null
if the set of roots
could not be determined. The array will be empty if there are
no filesystem roots.public int compareTo(OWFile pathname)
pathname
- The abstract pathname to be compared to this abstract
pathnamepublic int compareTo(java.lang.Object o)
compareTo(OWFile)
. Otherwise, it throws a
ClassCastException
, since abstract pathnames can only be
compared to abstract pathnames.o
- The Object
to be compared to this abstract
pathnameClassCastException
- if the argument is not an
abstract pathnameComparable
public boolean equals(java.lang.Object obj)
true
if and only if the argument is not
null
and is an abstract pathname that denotes the same file
or directory as this abstract pathname. Whether or not two abstract
pathnames are equal depends upon the underlying system. On UNIX
systems, alphabetic case is significant in comparing pathnames; on Win32
systems it is not.equals
in class java.lang.Object
obj
- The object to be compared with this abstract pathnametrue
if and only if the objects are the same;
false
otherwisepublic int hashCode()
1234321
. On Win32 systems, the hash
code is equal to the exclusive or of its pathname string,
convered to lower case, and the decimal value 1234321
.hashCode
in class java.lang.Object
public java.lang.String toString()
getPath()
method.toString
in class java.lang.Object
public OWFileDescriptor getFD() throws java.io.IOException
OWFileDescriptor
object that represents the connection to
the actual file in the Filesystem being
used by this OWFileInputStream
.java.io.IOException
- if an I/O error occurs.OWFileDescriptor
public OneWireContainer getOneWireContainer()
public OneWireContainer[] getOneWireContainers()
public void format() throws java.io.IOException
WARNING this will remove any files/directories.
java.io.IOException
- if an I/O error occurs.public int getFreeMemory() throws java.io.IOException
java.io.IOException
- if an I/O error occurspublic void close() throws java.io.IOException
java.io.IOException
- if an I/O error occurs.public int[] getPageList() throws java.io.IOException
java.io.IOException
- if an I/O error occurs.public int getStartPage() throws java.io.IOException
java.io.IOException
- if the file doesn't existpublic PagedMemoryBank getMemoryBankForPage(int page)
public int getLocalPage(int page)
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