org.tinygroup.weblayer.webcontext.parser.fileupload

Class DeferredByteOutputStream

java.lang.Object

java.io.OutputStream

org.apache.commons.io.output.ThresholdingOutputStream

org.tinygroup.weblayer.webcontext.parser.fileupload.DeferredByteOutputStream

All Implemented Interfaces:

Closeable, Flushable, AutoCloseable

public class DeferredByteOutputStream
extends org.apache.commons.io.output.ThresholdingOutputStream

功能说明:对普通字段与表单字段延迟输出

开发人员: renhui
开发时间: 2014-1-2

Constructor Summary

Constructors

Constructor and Description
DeferredByteOutputStream(int threshold) 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

Modifier and Type	Method and Description
void	clearData()
void	close() Closes underlying output stream, and mark this as closed
byte[]	getFileData() 返回文件字节流
byte[]	getMemoryData() Returns the data for this output stream as an array of bytes, assuming that the data has been retained in memory.
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.
void	writeTo(OutputStream out) Writes the data from this output stream to the specified output stream, after it has been closed.

Methods inherited from class org.apache.commons.io.output.ThresholdingOutputStream

checkThreshold, flush, getByteCount, getThreshold, isThresholdExceeded, resetByteCount, write, write, write

Methods inherited from class java.lang.Object

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

Constructor Detail

DeferredByteOutputStream

public DeferredByteOutputStream(int threshold)

Constructs an instance of this class which will trigger an event at the specified threshold, and save data to a file beyond that point.

Parameters:

threshold - The number of bytes at which to trigger an event.

outputFile - The file to which data is saved beyond the threshold.

Method Detail

getStream

protected OutputStream getStream()
                          throws IOException

Returns the current output stream. This may be memory based or disk based, depending on the current state with respect to the threshold.

Specified by:

getStream in class org.apache.commons.io.output.ThresholdingOutputStream

Returns:

The underlying output stream.

Throws:

IOException - if an error occurs.

thresholdReached

protected void thresholdReached()
                         throws IOException

Switches the underlying output stream from a memory based stream to one that is backed by disk. This is the point at which we realise that too much data is being written to keep in memory, so we elect to switch to disk-based storage.

Specified by:

thresholdReached in class org.apache.commons.io.output.ThresholdingOutputStream

Throws:

IOException - if an error occurs.

isInMemory

public boolean isInMemory()

Determines whether or not the data for this output stream has been retained in memory.

Returns:

true if the data is available in memory; false otherwise.

getMemoryData

public byte[] getMemoryData()

Returns the data for this output stream as an array of bytes, assuming that the data has been retained in memory. If the data was written to mongo, this method returns null.

Returns:

The data for this output stream, or null if no such data is available.

getFileData

public byte[] getFileData()

返回文件字节流

Returns:

close

public void close()
           throws IOException

Closes underlying output stream, and mark this as closed

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Overrides:

close in class org.apache.commons.io.output.ThresholdingOutputStream

Throws:

IOException - if an error occurs.

writeTo

public void writeTo(OutputStream out)
             throws IOException

Writes the data from this output stream to the specified output stream, after it has been closed.

Parameters:

out - output stream to write to.

Throws:

IOException - if this stream is not yet closed or an error occurs.

clearData

public void clearData()