Class FileChannelImageOutputStream

java.lang.Object

javax.imageio.stream.ImageInputStreamImpl

javax.imageio.stream.ImageOutputStreamImpl

com.github.jaiimageio.stream.FileChannelImageOutputStream

All Implemented Interfaces:

Closeable, DataInput, DataOutput, AutoCloseable, ImageInputStream, ImageOutputStream

public class FileChannelImageOutputStream
extends ImageOutputStreamImpl

A class which implements ImageOutputStream using a FileChannel as the eventual data destination.

Memory mapping is used for reading and direct buffers for writing. Only methods which provide significant performance improvement with respect to the superclass implementation are overridden. Overridden methods are not commented individually unless some noteworthy aspect of the implementation must be described.

The methods of this class are not synchronized.

See Also:

• ImageOutputStream
• java.nio
• FileChannel

Field Summary

Fields

Modifier and Type	Field	Description
private ByteBuffer	byteBuffer	A ByteBuffer used for writing to the channel.
private FileChannel	channel	The FileChannel data destination.
private static final int	DEFAULT_WRITE_BUFFER_SIZE	The size of the write buffer.
private ImageInputStream	readStream	An ImageInputStream used for reading.

Fields inherited from class ImageInputStreamImpl

bitOffset, byteOrder, flushedPos, streamPos

Constructor Summary

Constructors

Constructor	Description
FileChannelImageOutputStream(FileChannel channel)	Constructs a FileChannelImageOutputStream from a FileChannel.

Method Summary

Modifier and Type	Method	Description
void	close()	Invokes the superclass method, writes any unwritten data, and sets the internal reference to the source FileChannel to null.
private void	flushBuffer()	Write to the FileChannel any remaining bytes in the byte output buffer.
private ImageInputStream	getImageInputStream()	Returns an ImageInputStream for reading.
long	length()	Returns the number of bytes currently in the FileChannel.
int	read()
int	read(byte[] b, int off, int len)
void	readFully(char[] c, int off, int len)
void	readFully(double[] d, int off, int len)
void	readFully(float[] f, int off, int len)
void	readFully(int[] i, int off, int len)
void	readFully(long[] l, int off, int len)
void	readFully(short[] s, int off, int len)
void	seek(long pos)	Invokes the superclass method, writes any unwritten data, and sets the channel position to the supplied parameter.
void	setByteOrder(ByteOrder networkByteOrder)
void	write(byte[] b, int off, int len)
void	write(int b)
void	writeChars(char[] c, int off, int len)
void	writeDoubles(double[] d, int off, int len)
void	writeFloats(float[] f, int off, int len)
void	writeInts(int[] i, int off, int len)
void	writeLongs(long[] l, int off, int len)
void	writeShorts(short[] s, int off, int len)

Methods inherited from class ImageOutputStreamImpl

flushBits, write, writeBit, writeBits, writeBoolean, writeByte, writeBytes, writeChar, writeChars, writeDouble, writeFloat, writeInt, writeLong, writeShort, writeUTF

Methods inherited from class ImageInputStreamImpl

checkClosed, finalize, flush, flushBefore, getBitOffset, getByteOrder, getFlushedPosition, getStreamPosition, isCached, isCachedFile, isCachedMemory, mark, read, readBit, readBits, readBoolean, readByte, readBytes, readChar, readDouble, readFloat, readFully, readFully, readInt, readLine, readLong, readShort, readUnsignedByte, readUnsignedInt, readUnsignedShort, readUTF, reset, setBitOffset, skipBytes, skipBytes

Methods inherited from class Object

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

Methods inherited from interface ImageInputStream

flush, getBitOffset, getByteOrder, getFlushedPosition, getStreamPosition, isCached, isCachedFile, isCachedMemory, mark, read, readBit, readBits, readBoolean, readByte, readBytes, readChar, readDouble, readFloat, readFully, readFully, readInt, readLine, readLong, readShort, readUnsignedByte, readUnsignedInt, readUnsignedShort, readUTF, reset, setBitOffset, skipBytes, skipBytes

Methods inherited from interface ImageOutputStream

flushBefore

Field Details

DEFAULT_WRITE_BUFFER_SIZE

private static final int DEFAULT_WRITE_BUFFER_SIZE

The size of the write buffer.

See Also:

• Constant Field Values

channel

private FileChannel channel

The FileChannel data destination.

byteBuffer

private ByteBuffer byteBuffer

A ByteBuffer used for writing to the channel.

readStream

private ImageInputStream readStream

An ImageInputStream used for reading.

Constructor Details

FileChannelImageOutputStream

public FileChannelImageOutputStream(FileChannel channel)
                             throws IOException

Constructs a FileChannelImageOutputStream from a FileChannel. The initial position of the stream stream is taken to be the position of the FileChannel parameter when this constructor is invoked. The stream and flushed positions are therefore both initialized to channel.position().

Parameters:

channel - the destination FileChannel.

Throws:

IllegalArgumentException - if channel is null or is not open.

IOException - if a method invoked on channel throws an IOException.

Method Details

getImageInputStream

private ImageInputStream getImageInputStream()
                                      throws IOException

Returns an ImageInputStream for reading. The returned stream has byte order, stream and flushed positions, and bit offset set to the current values for this stream.

Throws:

IOException

flushBuffer

private void flushBuffer()
                  throws IOException

Write to the FileChannel any remaining bytes in the byte output buffer.

Throws:

IOException

read

public int read()
         throws IOException

Specified by:

read in interface ImageInputStream

Specified by:

read in class ImageInputStreamImpl

Throws:

IOException

read

public int read(byte[] b,
 int off,
 int len)
         throws IOException

Specified by:

read in interface ImageInputStream

Specified by:

read in class ImageInputStreamImpl

Throws:

IOException

write

public void write(int b)
           throws IOException

Specified by:

write in interface DataOutput

Specified by:

write in interface ImageOutputStream

Specified by:

write in class ImageOutputStreamImpl

Throws:

IOException

write

public void write(byte[] b,
 int off,
 int len)
           throws IOException

Specified by:

write in interface DataOutput

Specified by:

write in interface ImageOutputStream

Specified by:

write in class ImageOutputStreamImpl

Throws:

IOException

readFully

public void readFully(char[] c,
 int off,
 int len)
               throws IOException

Specified by:

readFully in interface ImageInputStream

Overrides:

readFully in class ImageInputStreamImpl

Throws:

IOException

readFully

public void readFully(short[] s,
 int off,
 int len)
               throws IOException

Specified by:

readFully in interface ImageInputStream

Overrides:

readFully in class ImageInputStreamImpl

Throws:

IOException

readFully

public void readFully(int[] i,
 int off,
 int len)
               throws IOException

Specified by:

readFully in interface ImageInputStream

Overrides:

readFully in class ImageInputStreamImpl

Throws:

IOException

readFully

public void readFully(long[] l,
 int off,
 int len)
               throws IOException

Specified by:

readFully in interface ImageInputStream

Overrides:

readFully in class ImageInputStreamImpl

Throws:

IOException

readFully

public void readFully(float[] f,
 int off,
 int len)
               throws IOException

Specified by:

readFully in interface ImageInputStream

Overrides:

readFully in class ImageInputStreamImpl

Throws:

IOException

readFully

public void readFully(double[] d,
 int off,
 int len)
               throws IOException

Specified by:

readFully in interface ImageInputStream

Overrides:

readFully in class ImageInputStreamImpl

Throws:

IOException

writeChars

public void writeChars(char[] c,
 int off,
 int len)
                throws IOException

Specified by:

writeChars in interface ImageOutputStream

Overrides:

writeChars in class ImageOutputStreamImpl

Throws:

IOException

writeShorts

public void writeShorts(short[] s,
 int off,
 int len)
                 throws IOException

Specified by:

writeShorts in interface ImageOutputStream

Overrides:

writeShorts in class ImageOutputStreamImpl

Throws:

IOException

writeInts

public void writeInts(int[] i,
 int off,
 int len)
               throws IOException

Specified by:

writeInts in interface ImageOutputStream

Overrides:

writeInts in class ImageOutputStreamImpl

Throws:

IOException

writeLongs

public void writeLongs(long[] l,
 int off,
 int len)
                throws IOException

Specified by:

writeLongs in interface ImageOutputStream

Overrides:

writeLongs in class ImageOutputStreamImpl

Throws:

IOException

writeFloats

public void writeFloats(float[] f,
 int off,
 int len)
                 throws IOException

Specified by:

writeFloats in interface ImageOutputStream

Overrides:

writeFloats in class ImageOutputStreamImpl

Throws:

IOException

writeDoubles

public void writeDoubles(double[] d,
 int off,
 int len)
                  throws IOException

Specified by:

writeDoubles in interface ImageOutputStream

Overrides:

writeDoubles in class ImageOutputStreamImpl

Throws:

IOException

close

public void close()
           throws IOException

Invokes the superclass method, writes any unwritten data, and sets the internal reference to the source FileChannel to null. The source FileChannel is not closed.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Specified by:

close in interface ImageInputStream

Overrides:

close in class ImageInputStreamImpl

Throws:

IOException - if an error occurs.

length

public long length()

Returns the number of bytes currently in the FileChannel. If an IOException is encountered when querying the channel's size, -1L will be returned.

Specified by:

length in interface ImageInputStream

Overrides:

length in class ImageInputStreamImpl

Returns:

The number of bytes in the channel -1L to indicate unknown length.

seek

public void seek(long pos)
          throws IOException

Invokes the superclass method, writes any unwritten data, and sets the channel position to the supplied parameter.

Specified by:

seek in interface ImageInputStream

Overrides:

seek in class ImageInputStreamImpl

Throws:

IOException

setByteOrder

public void setByteOrder(ByteOrder networkByteOrder)

Specified by:

setByteOrder in interface ImageInputStream

Overrides:

setByteOrder in class ImageInputStreamImpl