MemoryCacheImageOutputStream (Java 2 Platform SE 5.0) (original) (raw)

javax.imageio.stream

Class MemoryCacheImageOutputStream

java.lang.Object extended by javax.imageio.stream.ImageInputStreamImpl javax.imageio.stream.ImageOutputStreamImpl javax.imageio.stream.MemoryCacheImageOutputStream

All Implemented Interfaces:

DataInput, DataOutput, ImageInputStream, ImageOutputStream

public class MemoryCacheImageOutputStream

extends ImageOutputStreamImpl

An implementation of ImageOutputStream that writes its output to a regular OutputStream. A memory buffer is used to cache at least the data between the discard position and the current write position. The only constructor takes an OutputStream, so this class may not be used for read/modify/write operations. Reading can occur only on parts of the stream that have already been written to the cache and not yet flushed.

Field Summary

Fields inherited from class javax.imageio.stream.ImageInputStreamImpl
bitOffset, byteOrder, flushedPos, streamPos

Constructor Summary
MemoryCacheImageOutputStream(OutputStream stream) Constructs a MemoryCacheImageOutputStream that will write to a given OutputStream.

Method Summary
void	close() Closes this MemoryCacheImageOutputStream.
void	flushBefore(long pos) Discards the initial portion of the stream prior to the indicated postion.
boolean	isCached() Returns true since thisImageOutputStream caches data in order to allow seeking backwards.
boolean	isCachedFile() Returns false since thisImageOutputStream does not maintain a file cache.
boolean	isCachedMemory() Returns true since thisImageOutputStream maintains a main memory cache.
long	length() Returns -1L to indicate that the stream has unknown length.
int	read() Reads a single byte from the stream and returns it as an integer between 0 and 255.
int	[read](../../../javax/imageio/stream/MemoryCacheImageOutputStream.html#read%28byte[], int, int%29)(byte[] b, int off, int len) Reads up to len bytes from the stream, and stores them into b starting at index off.
void	[write](../../../javax/imageio/stream/MemoryCacheImageOutputStream.html#write%28byte[], int, int%29)(byte[] b, int off, int len) Writes len bytes from arrayb, in order, to the output stream.
void	write(int b) Writes to the output stream the eight low-order bits of the argument b.

Methods inherited from class javax.imageio.stream.ImageOutputStreamImpl
flushBits, write, writeBit, [writeBits](../../../javax/imageio/stream/ImageOutputStreamImpl.html#writeBits%28long, int%29), writeBoolean, writeByte, writeBytes, writeChar, [writeChars](../../../javax/imageio/stream/ImageOutputStreamImpl.html#writeChars%28char[], int, int%29), writeChars, writeDouble, [writeDoubles](../../../javax/imageio/stream/ImageOutputStreamImpl.html#writeDoubles%28double[], int, int%29), writeFloat, [writeFloats](../../../javax/imageio/stream/ImageOutputStreamImpl.html#writeFloats%28float[], int, int%29), writeInt, [writeInts](../../../javax/imageio/stream/ImageOutputStreamImpl.html#writeInts%28int[], int, int%29), writeLong, [writeLongs](../../../javax/imageio/stream/ImageOutputStreamImpl.html#writeLongs%28long[], int, int%29), writeShort, [writeShorts](../../../javax/imageio/stream/ImageOutputStreamImpl.html#writeShorts%28short[], int, int%29), writeUTF

Methods inherited from class javax.imageio.stream.ImageOutputStreamImpl

flushBits, write, writeBit, [writeBits](../../../javax/imageio/stream/ImageOutputStreamImpl.html#writeBits%28long, int%29), writeBoolean, writeByte, writeBytes, writeChar, [writeChars](../../../javax/imageio/stream/ImageOutputStreamImpl.html#writeChars%28char[], int, int%29), writeChars, writeDouble, [writeDoubles](../../../javax/imageio/stream/ImageOutputStreamImpl.html#writeDoubles%28double[], int, int%29), writeFloat, [writeFloats](../../../javax/imageio/stream/ImageOutputStreamImpl.html#writeFloats%28float[], int, int%29), writeInt, [writeInts](../../../javax/imageio/stream/ImageOutputStreamImpl.html#writeInts%28int[], int, int%29), writeLong, [writeLongs](../../../javax/imageio/stream/ImageOutputStreamImpl.html#writeLongs%28long[], int, int%29), writeShort, [writeShorts](../../../javax/imageio/stream/ImageOutputStreamImpl.html#writeShorts%28short[], int, int%29), writeUTF

Methods inherited from class javax.imageio.stream.ImageInputStreamImpl
checkClosed, finalize, flush, getBitOffset, getByteOrder, getFlushedPosition, getStreamPosition, mark, read, readBit, readBits, readBoolean, readByte, [readBytes](../../../javax/imageio/stream/ImageInputStreamImpl.html#readBytes%28javax.imageio.stream.IIOByteBuffer, int%29), readChar, readDouble, readFloat, readFully, [readFully](../../../javax/imageio/stream/ImageInputStreamImpl.html#readFully%28byte[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStreamImpl.html#readFully%28char[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStreamImpl.html#readFully%28double[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStreamImpl.html#readFully%28float[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStreamImpl.html#readFully%28int[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStreamImpl.html#readFully%28long[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStreamImpl.html#readFully%28short[], int, int%29), readInt, readLine, readLong, readShort, readUnsignedByte, readUnsignedInt, readUnsignedShort, readUTF, reset, seek, setBitOffset, setByteOrder, skipBytes, skipBytes

Methods inherited from class javax.imageio.stream.ImageInputStreamImpl

checkClosed, finalize, flush, getBitOffset, getByteOrder, getFlushedPosition, getStreamPosition, mark, read, readBit, readBits, readBoolean, readByte, [readBytes](../../../javax/imageio/stream/ImageInputStreamImpl.html#readBytes%28javax.imageio.stream.IIOByteBuffer, int%29), readChar, readDouble, readFloat, readFully, [readFully](../../../javax/imageio/stream/ImageInputStreamImpl.html#readFully%28byte[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStreamImpl.html#readFully%28char[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStreamImpl.html#readFully%28double[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStreamImpl.html#readFully%28float[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStreamImpl.html#readFully%28int[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStreamImpl.html#readFully%28long[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStreamImpl.html#readFully%28short[], int, int%29), readInt, readLine, readLong, readShort, readUnsignedByte, readUnsignedInt, readUnsignedShort, readUTF, reset, seek, setBitOffset, setByteOrder, skipBytes, skipBytes

Methods inherited from class java.lang.Object
clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, [wait](../../../java/lang/Object.html#wait%28long, int%29)

Methods inherited from interface javax.imageio.stream.ImageInputStream
flush, getBitOffset, getByteOrder, getFlushedPosition, getStreamPosition, mark, read, readBit, readBits, readBoolean, readByte, [readBytes](../../../javax/imageio/stream/ImageInputStream.html#readBytes%28javax.imageio.stream.IIOByteBuffer, int%29), readChar, readDouble, readFloat, readFully, [readFully](../../../javax/imageio/stream/ImageInputStream.html#readFully%28byte[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStream.html#readFully%28char[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStream.html#readFully%28double[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStream.html#readFully%28float[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStream.html#readFully%28int[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStream.html#readFully%28long[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStream.html#readFully%28short[], int, int%29), readInt, readLine, readLong, readShort, readUnsignedByte, readUnsignedInt, readUnsignedShort, readUTF, reset, seek, setBitOffset, setByteOrder, skipBytes, skipBytes

Methods inherited from interface javax.imageio.stream.ImageInputStream

flush, getBitOffset, getByteOrder, getFlushedPosition, getStreamPosition, mark, read, readBit, readBits, readBoolean, readByte, [readBytes](../../../javax/imageio/stream/ImageInputStream.html#readBytes%28javax.imageio.stream.IIOByteBuffer, int%29), readChar, readDouble, readFloat, readFully, [readFully](../../../javax/imageio/stream/ImageInputStream.html#readFully%28byte[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStream.html#readFully%28char[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStream.html#readFully%28double[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStream.html#readFully%28float[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStream.html#readFully%28int[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStream.html#readFully%28long[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStream.html#readFully%28short[], int, int%29), readInt, readLine, readLong, readShort, readUnsignedByte, readUnsignedInt, readUnsignedShort, readUTF, reset, seek, setBitOffset, setByteOrder, skipBytes, skipBytes

Constructor Detail

MemoryCacheImageOutputStream

public MemoryCacheImageOutputStream(OutputStream stream)

Constructs a MemoryCacheImageOutputStream that will write to a given OutputStream.

Parameters:

stream - an OutputStream to write to.

Throws:

[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang") - if stream isnull.

Method Detail

read

public int read() throws IOException

Description copied from interface: [ImageInputStream](../../../javax/imageio/stream/ImageInputStream.html#read%28%29)

Reads a single byte from the stream and returns it as an integer between 0 and 255. If the end of the stream is reached, -1 is returned.

The bit offset within the stream is reset to zero before the read occurs.

Specified by:

[read](../../../javax/imageio/stream/ImageInputStream.html#read%28%29) in interface [ImageInputStream](../../../javax/imageio/stream/ImageInputStream.html "interface in javax.imageio.stream")

Specified by:

[read](../../../javax/imageio/stream/ImageInputStreamImpl.html#read%28%29) in class [ImageInputStreamImpl](../../../javax/imageio/stream/ImageInputStreamImpl.html "class in javax.imageio.stream")

Returns:

a byte value from the stream, as an int, or -1 to indicate EOF.

Throws:

[IOException](../../../java/io/IOException.html "class in java.io") - if an I/O error occurs.

read

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

Description copied from class: [ImageInputStreamImpl](../../../javax/imageio/stream/ImageInputStreamImpl.html#read%28byte[], int, int%29)

Reads up to len bytes from the stream, and stores them into b starting at index off. If no bytes can be read because the end of the stream has been reached, -1 is returned.

The bit offset within the stream must be reset to zero before the read occurs.

Subclasses must provide an implementation for this method. The subclass implementation should update the stream position before exiting.

Specified by:

[read](../../../javax/imageio/stream/ImageInputStream.html#read%28byte[], int, int%29) in interface [ImageInputStream](../../../javax/imageio/stream/ImageInputStream.html "interface in javax.imageio.stream")

Specified by:

[read](../../../javax/imageio/stream/ImageInputStreamImpl.html#read%28byte[], int, int%29) in class [ImageInputStreamImpl](../../../javax/imageio/stream/ImageInputStreamImpl.html "class in javax.imageio.stream")

Parameters:

b - an array of bytes to be written to.

off - the starting position within b to write to.

len - the maximum number of bytes to read.

Returns:

the number of bytes actually read, or -1 to indicate EOF.

Throws:

[IOException](../../../java/io/IOException.html "class in java.io") - if an I/O error occurs.

write

public void write(int b) throws IOException

Description copied from interface: [DataOutput](../../../java/io/DataOutput.html#write%28int%29)

Writes to the output stream the eight low-order bits of the argument b. The 24 high-order bits of b are ignored.

Specified by:

[write](../../../java/io/DataOutput.html#write%28int%29) in interface [DataOutput](../../../java/io/DataOutput.html "interface in java.io")

Specified by:

[write](../../../javax/imageio/stream/ImageOutputStream.html#write%28int%29) in interface [ImageOutputStream](../../../javax/imageio/stream/ImageOutputStream.html "interface in javax.imageio.stream")

Specified by:

[write](../../../javax/imageio/stream/ImageOutputStreamImpl.html#write%28int%29) in class [ImageOutputStreamImpl](../../../javax/imageio/stream/ImageOutputStreamImpl.html "class in javax.imageio.stream")

Parameters:

b - the byte to be written.

Throws:

[IOException](../../../java/io/IOException.html "class in java.io") - if an I/O error occurs.

write

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

Description copied from interface: [DataOutput](../../../java/io/DataOutput.html#write%28byte[], int, int%29)

Writes len bytes from arrayb, in order, to the output stream. If b is null, a NullPointerException is thrown. If off is negative, or len is negative, or off+len is greater than the length of the arrayb, then an IndexOutOfBoundsException is thrown. If len is zero, then no bytes are written. Otherwise, the byte b[off] is written first, then b[off+1], and so on; the last byte written is b[off+len-1].

Specified by:

[write](../../../java/io/DataOutput.html#write%28byte[], int, int%29) in interface [DataOutput](../../../java/io/DataOutput.html "interface in java.io")

Specified by:

[write](../../../javax/imageio/stream/ImageOutputStream.html#write%28byte[], int, int%29) in interface [ImageOutputStream](../../../javax/imageio/stream/ImageOutputStream.html "interface in javax.imageio.stream")

Specified by:

[write](../../../javax/imageio/stream/ImageOutputStreamImpl.html#write%28byte[], int, int%29) in class [ImageOutputStreamImpl](../../../javax/imageio/stream/ImageOutputStreamImpl.html "class in javax.imageio.stream")

Parameters:

b - the data.

off - the start offset in the data.

len - the number of bytes to write.

Throws:

[IOException](../../../java/io/IOException.html "class in java.io") - if an I/O error occurs.

length

public long length()

Description copied from class: [ImageInputStreamImpl](../../../javax/imageio/stream/ImageInputStreamImpl.html#length%28%29)

Returns -1L to indicate that the stream has unknown length. Subclasses must override this method to provide actual length information.

Specified by:

[length](../../../javax/imageio/stream/ImageInputStream.html#length%28%29) in interface [ImageInputStream](../../../javax/imageio/stream/ImageInputStream.html "interface in javax.imageio.stream")

Overrides:

[length](../../../javax/imageio/stream/ImageInputStreamImpl.html#length%28%29) in class [ImageInputStreamImpl](../../../javax/imageio/stream/ImageInputStreamImpl.html "class in javax.imageio.stream")

Returns:

-1L to indicate unknown length.

isCached

public boolean isCached()

Returns true since thisImageOutputStream caches data in order to allow seeking backwards.

Specified by:

[isCached](../../../javax/imageio/stream/ImageInputStream.html#isCached%28%29) in interface [ImageInputStream](../../../javax/imageio/stream/ImageInputStream.html "interface in javax.imageio.stream")

Overrides:

[isCached](../../../javax/imageio/stream/ImageInputStreamImpl.html#isCached%28%29) in class [ImageInputStreamImpl](../../../javax/imageio/stream/ImageInputStreamImpl.html "class in javax.imageio.stream")

Returns:

true.

See Also:

isCachedMemory(), isCachedFile()

isCachedFile

public boolean isCachedFile()

Returns false since thisImageOutputStream does not maintain a file cache.

Specified by:

[isCachedFile](../../../javax/imageio/stream/ImageInputStream.html#isCachedFile%28%29) in interface [ImageInputStream](../../../javax/imageio/stream/ImageInputStream.html "interface in javax.imageio.stream")

Overrides:

[isCachedFile](../../../javax/imageio/stream/ImageInputStreamImpl.html#isCachedFile%28%29) in class [ImageInputStreamImpl](../../../javax/imageio/stream/ImageInputStreamImpl.html "class in javax.imageio.stream")

Returns:

false.

See Also:

isCached(), isCachedMemory()

isCachedMemory

public boolean isCachedMemory()

Returns true since thisImageOutputStream maintains a main memory cache.

Specified by:

[isCachedMemory](../../../javax/imageio/stream/ImageInputStream.html#isCachedMemory%28%29) in interface [ImageInputStream](../../../javax/imageio/stream/ImageInputStream.html "interface in javax.imageio.stream")

Overrides:

[isCachedMemory](../../../javax/imageio/stream/ImageInputStreamImpl.html#isCachedMemory%28%29) in class [ImageInputStreamImpl](../../../javax/imageio/stream/ImageInputStreamImpl.html "class in javax.imageio.stream")

Returns:

true.

See Also:

isCached(), isCachedFile()

close

public void close() throws IOException

Closes this MemoryCacheImageOutputStream. All pending data is flushed to the output, and the cache is released. The destination OutputStream is not closed.

Specified by:

[close](../../../javax/imageio/stream/ImageInputStream.html#close%28%29) in interface [ImageInputStream](../../../javax/imageio/stream/ImageInputStream.html "interface in javax.imageio.stream")

Overrides:

[close](../../../javax/imageio/stream/ImageInputStreamImpl.html#close%28%29) in class [ImageInputStreamImpl](../../../javax/imageio/stream/ImageInputStreamImpl.html "class in javax.imageio.stream")

Throws:

[IOException](../../../java/io/IOException.html "class in java.io") - if an I/O error occurs.

flushBefore

public void flushBefore(long pos) throws IOException

Description copied from interface: [ImageInputStream](../../../javax/imageio/stream/ImageInputStream.html#flushBefore%28long%29)

Discards the initial portion of the stream prior to the indicated postion. Attempting to seek to an offset within the flushed portion of the stream will result in anIndexOutOfBoundsException.

Calling flushBefore may allow classes implementing this interface to free up resources such as memory or disk space that are being used to store data from the stream.

Specified by:

[flushBefore](../../../javax/imageio/stream/ImageInputStream.html#flushBefore%28long%29) in interface [ImageInputStream](../../../javax/imageio/stream/ImageInputStream.html "interface in javax.imageio.stream")

Specified by:

[flushBefore](../../../javax/imageio/stream/ImageOutputStream.html#flushBefore%28long%29) in interface [ImageOutputStream](../../../javax/imageio/stream/ImageOutputStream.html "interface in javax.imageio.stream")

Overrides:

[flushBefore](../../../javax/imageio/stream/ImageInputStreamImpl.html#flushBefore%28long%29) in class [ImageInputStreamImpl](../../../javax/imageio/stream/ImageInputStreamImpl.html "class in javax.imageio.stream")

Parameters:

pos - a long containing the length of the file prefix that may be flushed.

Throws:

[IOException](../../../java/io/IOException.html "class in java.io") - if an I/O error occurs.

Submit a bug or feature
For further API reference and developer documentation, see Java 2 SDK SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.