org.apache.commons.vfs
Interface FileContent

All Known Implementing Classes:

DefaultFileContent

public interface FileContent

Represents the data content of a file.

To read from a file, use the InputStream returned by getInputStream().

To write to a file, use the OutputStream returned by getOutputStream() method. This will create the file, and the parent folder, if necessary.

A file may have multiple InputStreams open at the sametime.

Version:

$Revision: 480428 $ $Date: 2006-11-29 07:15:24 +0100 (Mi, 29 Nov 2006) $

Author:

Adam Murdoch

See Also:

FileObject.getContent()

Method Summary

void	close() Closes all resources used by the content, including any open stream.
Object	getAttribute(String attrName) Gets the value of an attribute of the file's content.
String[]	getAttributeNames() Lists the attributes of the file's content.
Map	getAttributes() Returns a read-only map of this file's attributes.
Certificate[]	getCertificates() Retrieves the certificates if any used to sign this file or folder.
FileContentInfo	getContentInfo() get the content info. e.g. type, encoding, ...
FileObject	getFile() Returns the file which this is the content of.
InputStream	getInputStream() Returns an input stream for reading the file's content.
long	getLastModifiedTime() Determines the last-modified timestamp of the file.
OutputStream	getOutputStream() Returns an output stream for writing the file's content.
OutputStream	getOutputStream(boolean bAppend) Returns an output stream for writing the file's content.
RandomAccessContent	getRandomAccessContent(RandomAccessMode mode) Returns an stream for reading/writing the file's content.
long	getSize() Determines the size of the file, in bytes.
boolean	isOpen() check if this file has open streams
void	setAttribute(String attrName, Object value) Sets the value of an attribute of the file's content.
void	setLastModifiedTime(long modTime) Sets the last-modified timestamp of the file.

Method Detail

getFile

public FileObject getFile()

Returns the file which this is the content of.

getSize

public long getSize()
             throws FileSystemException

Determines the size of the file, in bytes.

Returns:

The size of the file, in bytes.

Throws:

FileSystemException - If the file does not exist, or is being written to, or on error determining the size.

getLastModifiedTime

public long getLastModifiedTime()
                         throws FileSystemException

Determines the last-modified timestamp of the file.

Returns:

The last-modified timestamp.

Throws:

FileSystemException - If the file does not exist, or is being written to, or on error determining the last-modified timestamp.

setLastModifiedTime

public void setLastModifiedTime(long modTime)
                         throws FileSystemException

Sets the last-modified timestamp of the file. Creates the file if it does not exist.

Parameters:

modTime - The time to set the last-modified timestamp to.

Throws:

FileSystemException - If the file is read-only, or is being written to, or on error setting the last-modified timestamp.

getAttributes

public Map getAttributes()
                  throws FileSystemException

Returns a read-only map of this file's attributes.

Throws:

FileSystemException - If the file does not exist, or does not support attributes.

getAttributeNames

public String[] getAttributeNames()
                           throws FileSystemException

Lists the attributes of the file's content.

Returns:

The names of the attributes. Never returns null;

Throws:

FileSystemException - If the file does not exist, or does not support attributes.

getAttribute

public Object getAttribute(String attrName)
                    throws FileSystemException

Gets the value of an attribute of the file's content.

Parameters:

attrName - The name of the attribute. Attribute names are case insensitive.

Returns:

The value of the attribute, or null if the attribute value is unknown.

Throws:

FileSystemException - If the file does not exist, or does not support attributes.

setAttribute

public void setAttribute(String attrName,
                         Object value)
                  throws FileSystemException

Sets the value of an attribute of the file's content. Creates the file if it does not exist.

Parameters:

attrName - The name of the attribute.

value - The value of the attribute.

Throws:

FileSystemException - If the file does not exist, or is read-only, or does not support attributes, or on error setting the attribute.

getCertificates

public Certificate[] getCertificates()
                              throws FileSystemException

Retrieves the certificates if any used to sign this file or folder.

Returns:

The certificates, or an empty array if there are no certificates or the file does not support signing.

Throws:

FileSystemException - If the file does not exist, or is being written.

getInputStream

public InputStream getInputStream()
                           throws FileSystemException

Returns an input stream for reading the file's content.

There may only be a single input or output stream open for the file at any time.

Returns:

An input stream to read the file's content from. The input stream is buffered, so there is no need to wrap it in a BufferedInputStream.

Throws:

FileSystemException - If the file does not exist, or is being read, or is being written, or on error opening the stream.

getOutputStream

public OutputStream getOutputStream()
                             throws FileSystemException

Returns an output stream for writing the file's content.

If the file does not exist, this method creates it, and the parent folder, if necessary. If the file does exist, it is replaced with whatever is written to the output stream.

There may only be a single input or output stream open for the file at any time.

Returns:

An output stream to write the file's content to. The stream is buffered, so there is no need to wrap it in a BufferedOutputStream.

Throws:

FileSystemException - If the file is read-only, or is being read, or is being written, or on error opening the stream.

getRandomAccessContent

public RandomAccessContent getRandomAccessContent(RandomAccessMode mode)
                                           throws FileSystemException

Returns an stream for reading/writing the file's content.

If the file does not exist, and you use one of the write* methods, this method creates it, and the parent folder, if necessary. If the file does exist, parts of the file are replaced with whatever is written at a given position.

There may only be a single input or output stream open for the file at any time.

Throws:

FileSystemException - If the file is read-only, or is being read, or is being written, or on error opening the stream.

getOutputStream

public OutputStream getOutputStream(boolean bAppend)
                             throws FileSystemException

Returns an output stream for writing the file's content.

If the file does not exist, this method creates it, and the parent folder, if necessary. If the file does exist, it is replaced with whatever is written to the output stream.

There may only be a single input or output stream open for the file at any time.

Parameters:

bAppend - true if you would like to append to the file

Returns:

An output stream to write the file's content to. The stream is buffered, so there is no need to wrap it in a BufferedOutputStream.

Throws:

FileSystemException - If the file is read-only, or is being read, or is being written, or on error opening the stream.

close

public void close()
           throws FileSystemException

Closes all resources used by the content, including any open stream. Commits pending changes to the file.

This method is a hint to the implementation that it can release resources. This object can continue to be used after calling this method.

Throws:

FileSystemException

getContentInfo

public FileContentInfo getContentInfo()
                               throws FileSystemException

get the content info. e.g. type, encoding, ...

Throws:

FileSystemException

isOpen

public boolean isOpen()

check if this file has open streams