org.apache.commons.vfs2.provider.ram
Class RamFileObject

java.lang.Object
  org.apache.commons.vfs2.provider.AbstractFileObject
      org.apache.commons.vfs2.provider.ram.RamFileObject

All Implemented Interfaces:

FileObject

public class RamFileObject
extends AbstractFileObject
implements FileObject

A RAM File contains a single RAM FileData instance, it provides methods to access the data by implementing FileObject interface.

Author:

Commons VFS team

Constructor Summary

protected

RamFileObject(AbstractFileName name, RamFileSystem fs)

Method Summary

protected void	doAttach() Attaches this file object to its file resource.
protected void	doCreateFolder() Creates this file as a folder.
protected void	doDelete() Deletes the file.
protected long	doGetContentSize() Returns the size of the file content (in bytes).
protected InputStream	doGetInputStream() Creates an input stream to read the file content from.
protected long	doGetLastModifiedTime() Returns the last modified time of this file.
protected OutputStream	doGetOutputStream(boolean bAppend) Creates an output stream to write the file content to.
protected RandomAccessContent	doGetRandomAccessContent(RandomAccessMode mode) Creates access to the file for random i/o.
protected FileType	doGetType() Determines the type of this file.
protected String[]	doListChildren() Lists the children of this file.
protected void	doRename(FileObject newfile) Renames the file.
protected boolean	doSetLastModifiedTime(long modtime) Sets the last modified time of this file.
protected void	endOutput() Called when the ouput stream for this file is closed.
protected void	injectType(FileType fileType)

Methods inherited from class org.apache.commons.vfs2.provider.AbstractFileObject

canRenameTo, childrenChanged, close, copyFrom, createFile, createFolder, delete, delete, doCreateFileContent, doDetach, doGetAttributes, doGetCertificates, doIsHidden, doIsReadable, doIsSameFile, doIsWriteable, doListChildrenResolved, doRemoveAttribute, doSetAttribute, exists, finalize, findFiles, findFiles, getChild, getChildren, getContent, getFileContentInfoFactory, getFileOperations, getFileSystem, getInputStream, getName, getOutputStream, getOutputStream, getParent, getRandomAccessContent, getType, getURL, handleChanged, handleCreate, handleDelete, holdObject, isAttached, isContentOpen, isHidden, isReadable, isSameFile, isWriteable, moveTo, notifyAllStreamsClosed, onChange, onChildrenChanged, refresh, resolveFile, resolveFile, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.commons.vfs2.FileObject

canRenameTo, close, copyFrom, createFile, createFolder, delete, delete, exists, findFiles, findFiles, getChild, getChildren, getContent, getFileOperations, getFileSystem, getName, getParent, getType, getURL, isAttached, isContentOpen, isHidden, isReadable, isWriteable, moveTo, refresh, resolveFile, resolveFile

Constructor Detail

RamFileObject

protected RamFileObject(AbstractFileName name,
                        RamFileSystem fs)

Parameters:

name - The name of the file.

fs - The FileSystem.

Method Detail

doGetType

protected FileType doGetType()
                      throws Exception

Description copied from class: AbstractFileObject

Determines the type of this file. Must not return null. The return value of this method is cached, so the implementation can be expensive.

Specified by:

doGetType in class AbstractFileObject

Returns:

the type of the file.

Throws:

Exception - if an error occurs.

doListChildren

protected String[] doListChildren()
                           throws Exception

Description copied from class: AbstractFileObject

Lists the children of this file. Is only called if AbstractFileObject.doGetType() returns FileType.FOLDER. The return value of this method is cached, so the implementation can be expensive.

Specified by:

doListChildren in class AbstractFileObject

Returns:

a possible empty String array if the file is a directory or null or an exception if the file is not a directory or can't be read.

Throws:

Exception - if an error occurs.

doGetContentSize

protected long doGetContentSize()
                         throws Exception

Description copied from class: AbstractFileObject

Returns the size of the file content (in bytes). Is only called if AbstractFileObject.doGetType() returns FileType.FILE.

Specified by:

doGetContentSize in class AbstractFileObject

Returns:

The size of the file in bytes.

Throws:

Exception - if an error occurs.

doGetInputStream

protected InputStream doGetInputStream()
                                throws Exception

Description copied from class: AbstractFileObject

Creates an input stream to read the file content from. Is only called if AbstractFileObject.doGetType() returns FileType.FILE.

It is guaranteed that there are no open output streams for this file when this method is called.

The returned stream does not have to be buffered.

Specified by:

doGetInputStream in class AbstractFileObject

Returns:

An InputStream to read the file content.

Throws:

Exception - if an error occurs.

doGetOutputStream

protected OutputStream doGetOutputStream(boolean bAppend)
                                  throws Exception

Description copied from class: AbstractFileObject

Creates an output stream to write the file content to. Is only called if:

• AbstractFileObject.doIsWriteable() returns true.
• AbstractFileObject.doGetType() returns FileType.FILE, or AbstractFileObject.doGetType() returns FileType.IMAGINARY, and the file's parent exists and is a folder.

It is guaranteed that there are no open stream (input or output) for this file when this method is called.

The returned stream does not have to be buffered.

This implementation throws an exception.

Overrides:

doGetOutputStream in class AbstractFileObject

Parameters:

bAppend - true if the file should be appended to, false if it should be overwritten.

Returns:

An OutputStream to write to the file.

Throws:

Exception - if an error occurs.

doDelete

protected void doDelete()
                 throws Exception

Description copied from class: AbstractFileObject

Deletes the file. Is only called when:

• AbstractFileObject.doGetType() does not return FileType.IMAGINARY.
• AbstractFileObject.doIsWriteable() returns true.
• This file has no children, if a folder.

This implementation throws an exception.

Overrides:

doDelete in class AbstractFileObject

Throws:

Exception - if an error occurs.

doGetLastModifiedTime

protected long doGetLastModifiedTime()
                              throws Exception

Description copied from class: AbstractFileObject

Returns the last modified time of this file. Is only called if AbstractFileObject.doGetType() does not return FileType.IMAGINARY.

This implementation throws an exception.

Overrides:

doGetLastModifiedTime in class AbstractFileObject

Returns:

The last modification time.

Throws:

Exception - if an error occurs.

doSetLastModifiedTime

protected boolean doSetLastModifiedTime(long modtime)
                                 throws Exception

Description copied from class: AbstractFileObject

Sets the last modified time of this file. Is only called if AbstractFileObject.doGetType() does not return FileType.IMAGINARY.

This implementation throws an exception.

Overrides:

doSetLastModifiedTime in class AbstractFileObject

Parameters:

modtime - The last modification time.

Returns:

true if the time was set.

Throws:

Exception - if an error occurs.

Since:

2.0

doCreateFolder

protected void doCreateFolder()
                       throws Exception

Description copied from class: AbstractFileObject

Creates this file as a folder. Is only called when:

• AbstractFileObject.doGetType() returns FileType.IMAGINARY.
• The parent folder exists and is writeable, or this file is the root of the file system.

This implementation throws an exception.

Overrides:

doCreateFolder in class AbstractFileObject

Throws:

Exception - if an error occurs.

doRename

protected void doRename(FileObject newfile)
                 throws Exception

Description copied from class: AbstractFileObject

Renames the file. Is only called when:

• AbstractFileObject.doIsWriteable() returns true.

This implementation throws an exception.

Overrides:

doRename in class AbstractFileObject

Parameters:

newfile - A FileObject with the new file name.

Throws:

Exception - if an error occurs.

doGetRandomAccessContent

protected RandomAccessContent doGetRandomAccessContent(RandomAccessMode mode)
                                                throws Exception

Description copied from class: AbstractFileObject

Creates access to the file for random i/o. Is only called if AbstractFileObject.doGetType() returns FileType.FILE.

It is guaranteed that there are no open output streams for this file when this method is called.

Overrides:

doGetRandomAccessContent in class AbstractFileObject

Parameters:

mode - The mode to access the file.

Returns:

The RandomAccessContext.

Throws:

Exception - if an error occurs.

doAttach

protected void doAttach()
                 throws Exception

Description copied from class: AbstractFileObject

Attaches this file object to its file resource. This method is called before any of the doBlah() or onBlah() methods. Sub-classes can use this method to perform lazy initialisation.

This implementation does nothing.

Overrides:

doAttach in class AbstractFileObject

Throws:

Exception - if an error occurs.

injectType

protected void injectType(FileType fileType)

Overrides:

injectType in class AbstractFileObject

endOutput

protected void endOutput()
                  throws Exception

Description copied from class: AbstractFileObject

Called when the ouput stream for this file is closed.

Overrides:

endOutput in class AbstractFileObject

Throws:

Exception - if an error occurs.