- All Implemented Interfaces:
Closeable,DataInput,DataOutput,AutoCloseable,ImageInputStream,ImageOutputStream
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 declared in class javax.imageio.stream.ImageInputStreamImpl
bitOffset, byteOrder, flushedPos, streamPos -
Constructor Summary
ConstructorsConstructorDescriptionConstructs aMemoryCacheImageOutputStreamthat will write to a givenOutputStream. -
Method Summary
Modifier and TypeMethodDescriptionvoidclose()Closes thisMemoryCacheImageOutputStream.voidflushBefore(long pos) Flushes all data prior to the given position to the underlying destination, such as anOutputStreamorFile.booleanisCached()Returnstruesince thisImageOutputStreamcaches data in order to allow seeking backwards.booleanReturnsfalsesince thisImageOutputStreamdoes not maintain a file cache.booleanReturnstruesince thisImageOutputStreammaintains a main memory cache.longlength()Returns-1Lto indicate that the stream has unknown length.intread()Reads a single byte from the stream and returns it as anintbetween 0 and 255.intread(byte[] b, int off, int len) Reads up tolenbytes from the stream, and stores them intobstarting at indexoff.voidwrite(byte[] b, int off, int len) Writes a sequence of bytes to the stream at the current position.voidwrite(int b) Writes a single byte to the stream at the current position.Methods declared in class javax.imageio.stream.ImageOutputStreamImpl
flushBits, write, writeBit, writeBits, writeBoolean, writeByte, writeBytes, writeChar, writeChars, writeChars, writeDouble, writeDoubles, writeFloat, writeFloats, writeInt, writeInts, writeLong, writeLongs, writeShort, writeShorts, writeUTFMethods declared in class javax.imageio.stream.ImageInputStreamImpl
checkClosed, finalize, flush, flushBefore, getBitOffset, getByteOrder, getFlushedPosition, getStreamPosition, length, mark, read, readBit, readBits, readBoolean, readByte, readBytes, readChar, readDouble, readFloat, readFully, readFully, readFully, readFully, readFully, readFully, readFully, readFully, readInt, readLine, readLong, readShort, readUnsignedByte, readUnsignedInt, readUnsignedShort, readUTF, reset, seek, setBitOffset, setByteOrder, skipBytes, skipBytesMethods declared in class java.lang.Object
clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, waitMethods declared in interface javax.imageio.stream.ImageInputStream
flush, getBitOffset, getByteOrder, getFlushedPosition, getStreamPosition, mark, read, readBit, readBits, readBoolean, readByte, readBytes, readChar, readDouble, readFloat, readFully, readFully, readFully, readFully, readFully, readFully, readFully, readFully, readInt, readLine, readLong, readShort, readUnsignedByte, readUnsignedInt, readUnsignedShort, readUTF, reset, seek, setBitOffset, setByteOrder, skipBytes, skipBytes
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Constructor Details
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MemoryCacheImageOutputStream
Constructs aMemoryCacheImageOutputStreamthat will write to a givenOutputStream.- Parameters:
stream- anOutputStreamto write to.- Throws:
IllegalArgumentException- ifstreamisnull.
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Method Details
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read
Description copied from class:ImageInputStreamImplReads a single byte from the stream and returns it as anintbetween 0 and 255. If EOF is reached,-1is returned.Subclasses must provide an implementation for this method. The subclass implementation should update the stream position before exiting.
The bit offset within the stream must be reset to zero before the read occurs.
- Specified by:
readin interfaceImageInputStream- Specified by:
readin classImageInputStreamImpl- Returns:
- the value of the next byte in the stream, or
-1if EOF is reached. - Throws:
IOException- if the stream has been closed.
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read
Description copied from class:ImageInputStreamImplReads up tolenbytes from the stream, and stores them intobstarting at indexoff. If no bytes can be read because the end of the stream has been reached,-1is 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:
readin interfaceImageInputStream- Specified by:
readin classImageInputStreamImpl- Parameters:
b- an array of bytes to be written to.off- the starting position withinbto write to.len- the maximum number of bytes to read.- Returns:
- the number of bytes actually read, or
-1to indicate EOF. - Throws:
IOException- if an I/O error occurs.
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write
Description copied from interface:ImageOutputStreamWrites a single byte to the stream at the current position. The 24 high-order bits ofbare ignored.If the bit offset within the stream is non-zero, the remainder of the current byte is padded with 0s and written out first. The bit offset will be 0 after the write. Implementers can use the
flushBitsmethod ofImageOutputStreamImplto guarantee this.- Parameters:
b- anintwhose lower 8 bits are to be written.- Throws:
IOException- if an I/O error occurs.
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write
Description copied from interface:ImageOutputStreamWrites a sequence of bytes to the stream at the current position. Iflenis 0, nothing is written. The byteb[off]is written first, then the byteb[off + 1], and so on.If the bit offset within the stream is non-zero, the remainder of the current byte is padded with 0s and written out first. The bit offset will be 0 after the write. Implementers can use the
flushBitsmethod ofImageOutputStreamImplto guarantee this.- Parameters:
b- an array ofbytes to be written.off- the start offset in the data.len- the number ofbytes to write.- Throws:
IOException- if an I/O error occurs.
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length
public long length()Description copied from class:ImageInputStreamImplReturns-1Lto indicate that the stream has unknown length. Subclasses must override this method to provide actual length information.- Specified by:
lengthin interfaceImageInputStream- Overrides:
lengthin classImageInputStreamImpl- Returns:
- -1L to indicate unknown length.
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isCached
public boolean isCached()Returnstruesince thisImageOutputStreamcaches data in order to allow seeking backwards.- Specified by:
isCachedin interfaceImageInputStream- Overrides:
isCachedin classImageInputStreamImpl- Returns:
true.- See Also:
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isCachedFile
public boolean isCachedFile()Returnsfalsesince thisImageOutputStreamdoes not maintain a file cache.- Specified by:
isCachedFilein interfaceImageInputStream- Overrides:
isCachedFilein classImageInputStreamImpl- Returns:
false.- See Also:
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isCachedMemory
public boolean isCachedMemory()Returnstruesince thisImageOutputStreammaintains a main memory cache.- Specified by:
isCachedMemoryin interfaceImageInputStream- Overrides:
isCachedMemoryin classImageInputStreamImpl- Returns:
true.- See Also:
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close
Closes thisMemoryCacheImageOutputStream. All pending data is flushed to the output, and the cache is released. The destinationOutputStreamis not closed.- Throws:
IOException- if an I/O error occurs.
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flushBefore
Description copied from interface:ImageOutputStreamFlushes all data prior to the given position to the underlying destination, such as anOutputStreamorFile. Attempting to seek to the flushed portion of the stream will result in anIndexOutOfBoundsException.- Parameters:
pos- alongcontaining the length of the stream prefix that may be flushed to the destination.- Throws:
IOException- if an I/O error occurs.
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