org.das2.util.filesystem

Class WebFileObject

java.lang.Object

org.das2.util.filesystem.FileObject

org.das2.util.filesystem.WebFileObject

Direct Known Subclasses:

FtpFileObject, GitHubFileObject

public class WebFileObject
extends FileObject

Field Summary

Fields

Modifier and Type	Field and Description
protected static java.util.logging.Logger	logger
int	METADATA_FRESH_TIMEOUT_MS

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	WebFileObject(WebFileSystem wfs, java.lang.String pathname, java.util.Date modifiedDate)

Method Summary

Modifier and Type	Method and Description
boolean	canRead() returns true if the file can be read by the client.
boolean	exists() returns true if the file exists.
java.nio.channels.ReadableByteChannel	getChannel(ProgressMonitor monitor) return a Channel for the resource.
FileObject[]	getChildren() returns objects within a folder.
java.io.File	getFile(ProgressMonitor monitor) return the file for the WebFileObject.
java.io.InputStream	getInputStream(ProgressMonitor monitor) opens an inputStream, perhaps transferring the file to a cache first.
protected java.io.File	getLocalFile() returns the File that corresponds to the remote file.
java.lang.String	getNameExt() returns the canonical name of the file within the filesystem.
FileObject	getParent() returns the parent FileObject (a folder).
long	getSize() return the fileObject size in bytes.
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 is 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.
protected void	maybeLoadMetadata() load the metadata for the file object, presently only for HTTP doing a HEAD request.
boolean	removeLocalFile() remove the local file in the cache, if any.
protected void	setLastModified(java.util.Date d) allow subclasses, such as FtpBeanFileSystem, to delay loading of the date.
protected void	setSize(long size) allow classes to delay loading of the size.
java.lang.String	toString()

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

getCapability, getChannel, getFile, getInputStream

Methods inherited from class java.lang.Object

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

Field Detail

logger

protected static final java.util.logging.Logger logger

METADATA_FRESH_TIMEOUT_MS

public int METADATA_FRESH_TIMEOUT_MS

Constructor Detail

WebFileObject

protected WebFileObject(WebFileSystem wfs,
                        java.lang.String pathname,
                        java.util.Date modifiedDate)

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)

maybeLoadMetadata

protected void maybeLoadMetadata()
                          throws java.io.IOException

load the metadata for the file object, presently only for HTTP doing a HEAD request. This is nasty and needs to be rewritten... For thread safety, metadata should only be read by other threads, and only if it exists.

Throws:

java.io.IOException

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

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:

a WebFileObject referencing the parent directory.

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.

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.

getSize

public long getSize()

return the fileObject size in bytes. This may contact the server to get the size, and this caches the size.

Specified by:

getSize in class FileObject

Returns:

setLastModified

protected void setLastModified(java.util.Date d)

allow subclasses, such as FtpBeanFileSystem, to delay loading of the date.

Parameters:

d -

setSize

protected void setSize(long size)

allow classes to delay loading of the size.

Parameters:

size - the size in bytes of the file.

Throws:

java.lang.IllegalArgumentException - if the size is reset to a different value from a valid value.

getLocalFile

protected java.io.File getLocalFile()

returns the File that corresponds to the remote file. This may or may not exist, depending on whether it's been downloaded yet.

Returns:

the file reference within the cache.

removeLocalFile

public boolean removeLocalFile()

Description copied from class: FileObject

remove the local file in the cache, if any. This can/will be overriden by other filesystems.

Overrides:

removeLocalFile in class FileObject

Returns:

true if the action was handled. (Local files are not deleted.)

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

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

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.

getChannel

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

return a Channel for the resource. If the resource can be made locally available, a FileChannel is returned.

Specified by:

getChannel in class FileObject

Parameters:

monitor -

Returns:

Throws:

java.io.FileNotFoundException

java.io.IOException

getFile

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

return the file for the WebFileObject.

Specified by:

getFile in class FileObject

Parameters:

monitor -

Returns:

Throws:

java.io.FileNotFoundException

java.io.IOException

isLocal

public boolean isLocal()

returns true is the file is locally available, meaning clients can call getFile() and the readable File reference will be available in interactive time. For FileObjects from HttpFileSystem, a HEAD request is made to ensure that the local file is as new as the website one (when offline=false).

Specified by:

isLocal in class FileObject

Returns:

true if the file is local and can be used without web access.