org.apache.commons.fileupload
public class DeferredFileOutputStream extends ThresholdingOutputStream
An output stream which will retain data in memory until a specified threshold is reached, and only then commit it to disk. If the stream is closed before the threshold is reached, the data will not be written to disk at all.
Version: $Id: DeferredFileOutputStream.java,v 1.2 2003/05/31 22:31:08 martinc Exp $
Field Summary | |
---|---|
OutputStream | currentOutputStream
The output stream to which data will be written at any given time. |
FileOutputStream | diskOutputStream
The output stream to which data will be written after the theshold is
reached. |
ByteArrayOutputStream | memoryOutputStream
The output stream to which data will be written prior to the theshold
being reached. |
File | outputFile
The file to which output will be directed if the threshold is exceeded. |
Constructor Summary | |
---|---|
DeferredFileOutputStream(int threshold, File outputFile)
Constructs an instance of this class which will trigger an event at the
specified threshold, and save data to a file beyond that point.
|
Method Summary | |
---|---|
byte[] | getData()
Returns the data for this output stream as an array of bytes, assuming
that the data has been retained in memory. |
File | getFile()
Returns the data for this output stream as a File , assuming
that the data was written to disk. |
protected OutputStream | getStream()
Returns the current output stream. |
boolean | isInMemory()
Determines whether or not the data for this output stream has been
retained in memory.
|
protected void | thresholdReached()
Switches the underlying output stream from a memory based stream to one
that is backed by disk. |
memoryOutputStream
or
diskOutputStream
.Parameters: threshold The number of bytes at which to trigger an event. outputFile The file to which data is saved beyond the threshold.
null
.
Returns: The data for this output stream, or null
if no such
data is available.
File
, assuming
that the data was written to disk. If the data was retained in memory,
this method returns null
.
Returns: The file for this output stream, or null
if no such
file exists.
Returns: The underlying output stream.
Throws: IOException if an error occurs.
Returns: true
if the data is available in memory;
false
otherwise.
Throws: IOException if an error occurs.