org.das2.util.filesystem

Class VFSFileObject

java.lang.Object

org.das2.util.filesystem.FileObject

org.das2.util.filesystem.VFSFileObject

public class VFSFileObject
extends FileObject

This class is part of a wrapper for the Apache Commons VFS. NOTE: At the moment, many situations where the Commons VFS throws a FileSystemException will result in a RuntimeException from this code. A better way of handling these exceptions should probably be found.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	VFSFileObject(VFSFileSystem fs, org.apache.commons.vfs.FileObject f) Create a das2 FileObject from the given VFS FileObject

Method Summary

Modifier and Type	Method and Description
boolean	canRead() returns true if the file can be read by the client.
boolean	canWrite()
void	close()
void	createFile() Create the file named by this VFSFileObject.
void	createFolder() Create a folder named by this VFSFileObject.
void	delete() Deletes the file.
boolean	exists() returns true if the file exists.
java.nio.channels.ReadableByteChannel	getChannel(ProgressMonitor monitor) opens a Channel, perhaps transferring the file to a local cache first.
FileObject[]	getChildren() returns objects within a folder.
java.io.File	getFile(ProgressMonitor monitor) gets a File object that can be opened by the client.
java.io.InputStream	getInputStream(ProgressMonitor monitor) opens an inputStream, perhaps transferring the file to a cache first.
java.lang.String	getNameExt() returns the canonical name of the file within the filesystem.
java.io.OutputStream	getOutputStream(boolean append)
FileObject	getParent() returns the parent FileObject (a folder).
long	getSize() returns the size of the file.
boolean	isData() returns true if the file is a data file that to be used reading or writing data.
boolean	isFolder() indicates the type of FileObject
boolean	isLocal() returns true if the file is locally available, meaning clients can call getFile() and the readable File reference will be available in interactive time.
boolean	isReadOnly() true is the file is read-only.
boolean	isRoot() returns true if this is the root of the filesystem it came from.
java.util.Date	lastModified() returns the Date when the file was last modified.

Methods inherited from class org.das2.util.filesystem.FileObject

getCapability, getChannel, getFile, getInputStream, removeLocalFile

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

VFSFileObject

protected VFSFileObject(VFSFileSystem fs,
                        org.apache.commons.vfs.FileObject f)

Create a das2 FileObject from the given VFS FileObject

Parameters:

fs -

f -

Method Detail

canRead

public boolean canRead()

Description copied from class: FileObject

returns true if the file can be read by the client.

Specified by:

canRead in class FileObject

Returns:

true if the file can be read (see getInputStream)

getChildren

public FileObject[] getChildren()
                         throws java.io.IOException

Description copied from class: FileObject

returns objects within a folder.

Specified by:

getChildren in class FileObject

Returns:

an array of all FileObjects with the folder.

Throws:

java.io.IOException

getInputStream

public java.io.InputStream getInputStream(ProgressMonitor monitor)
                                   throws java.io.FileNotFoundException,
                                          java.io.IOException

Description copied from class: FileObject

opens an inputStream, perhaps transferring the file to a cache first.

Specified by:

getInputStream in class FileObject

Parameters:

monitor - for monitoring the download. The monitor won't be used when the access is immediate, for example with local FileObjects.

Returns:

an InputStream

Throws:

java.io.FileNotFoundException - if the file doesn't exist.

java.io.IOException

getChannel

public java.nio.channels.ReadableByteChannel getChannel(ProgressMonitor monitor)
                                                 throws java.io.FileNotFoundException,
                                                        java.io.IOException

Description copied from class: FileObject

opens a Channel, perhaps transferring the file to a local cache first. monitor is used to monitor the download.

Specified by:

getChannel in class FileObject

Parameters:

monitor - for monitoring the download. The monitor won't be used when the access is immediate, for example with local FileObjects.

Returns:

a java.nio.channels.Channel for fast IO reads.

Throws:

java.io.FileNotFoundException - if the file doesn't exist.

java.io.IOException

getFile

public java.io.File getFile(ProgressMonitor monitor)
                     throws java.io.FileNotFoundException,
                            java.io.IOException

Description copied from class: FileObject

gets a File object that can be opened by the client. This may download a remote file, so a progress monitor can be used to monitor the download.

Specified by:

getFile in class FileObject

Parameters:

monitor - for monitoring the download. The monitor won't be used when the access is immediate, for example with local FileObjects.

Returns:

a reference to a File that can be opened.

Throws:

java.io.FileNotFoundException - if the file doesn't exist.

java.io.IOException - if the file cannot be made local

getParent

public FileObject getParent()

Description copied from class: FileObject

returns the parent FileObject (a folder). If the fileObject is root, then null should be returned.

Specified by:

getParent in class FileObject

Returns:

the parent folder of this object.

getSize

public long getSize()

Description copied from class: FileObject

returns the size of the file.

Specified by:

getSize in class FileObject

Returns:

the size in bytes of the file, and -1 if the size is unknown.

isData

public boolean isData()

Description copied from class: FileObject

returns true if the file is a data file that to be used reading or writing data. (And not a folder.)

Specified by:

isData in class FileObject

Returns:

true if the file is a data file

isFolder

public boolean isFolder()

Description copied from class: FileObject

indicates the type of FileObject

Specified by:

isFolder in class FileObject

Returns:

true if the object is a folder (directory).

isReadOnly

public boolean isReadOnly()

Description copied from class: FileObject

true is the file is read-only.

Specified by:

isReadOnly in class FileObject

Returns:

true if the file is read-only

isRoot

public boolean isRoot()

Description copied from class: FileObject

returns true if this is the root of the filesystem it came from.

Specified by:

isRoot in class FileObject

Returns:

true if this is the root of the filesystem it came from.

isLocal

public boolean isLocal()

Description copied from class: FileObject

returns true if the file is locally available, meaning clients can call getFile() and the readable File reference will be available in interactive time. Note that isLocal does not imply exists(). Also, This may result in side effects such as a website hit.

Specified by:

isLocal in class FileObject

Returns:

true if the file is locally available and fresh

exists

public boolean exists()

Description copied from class: FileObject

returns true if the file exists. This may have the side effect of downloading the file.

Specified by:

exists in class FileObject

Returns:

true if the file exists

getNameExt

public java.lang.String getNameExt()

Description copied from class: FileObject

returns the canonical name of the file within the filesystem. For example, in the local filesystem /mnt/data/steven/, /mnt/data/steven/jan/01.dat would be /jan/01.dat. For example, /a/b/c.dat.

Specified by:

getNameExt in class FileObject

Returns:

the name of the file within the FileSystem.

lastModified

public java.util.Date lastModified()

Description copied from class: FileObject

returns the Date when the file was last modified. or new Date(0L) if the date is not available.

Specified by:

lastModified in class FileObject

Returns:

the last modified Date, or new Date(0) if it is not available.

canWrite

public boolean canWrite()
                 throws java.io.IOException

Throws:

java.io.IOException

createFolder

public void createFolder()
                  throws java.io.IOException

Create a folder named by this VFSFileObject. This method will also create any necessary ancestor folders. Does nothing if the folder already exists.

Throws:

java.io.IOException - If parent folder is read-only, or other error creating this folder or ancestors, or if folder name exists as file.

createFile

public void createFile()
                throws java.io.IOException

Create the file named by this VFSFileObject. Also creates any necessary ancestor folders. Does nothing if file already exists and is a file (not a folder).

Throws:

java.io.IOException - If parent folder is read-only, or error creating ancestor folders, or if file exists and is a folder.

delete

public void delete()
            throws java.io.IOException

Deletes the file. Does nothing if the file doesn't exist or is a non-empty folder.

Throws:

java.io.IOException - If the file is a non-empty folder, or is read-only, or on other error during deletion.

getOutputStream

public java.io.OutputStream getOutputStream(boolean append)
                                     throws java.io.IOException

Throws:

java.io.IOException

close

public void close()
           throws java.io.IOException

Throws:

java.io.IOException