java.lang.Object
javax.imageio.stream.ImageInputStreamImpl
javax.imageio.stream.MemoryCacheImageInputStream
- All Implemented Interfaces:
Closeable,DataInput,AutoCloseable,ImageInputStream
An implementation of
ImageInputStream that gets its
input from a regular InputStream. A memory buffer is
used to cache at least the data between the discard position and
the current read position.
In general, it is preferable to use a
FileCacheImageInputStream when reading from a regular
InputStream. This class is provided for cases where
it is not possible to create a writable temporary file.
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Field Summary
Fields declared in class javax.imageio.stream.ImageInputStreamImpl
bitOffset, byteOrder, flushedPos, streamPos -
Constructor Summary
ConstructorsConstructorDescriptionConstructs aMemoryCacheImageInputStreamthat will read from a givenInputStream. -
Method Summary
Modifier and TypeMethodDescriptionvoidclose()Closes thisMemoryCacheImageInputStream, freeing the cache.protected voidfinalize()Deprecated, for removal: This API element is subject to removal in a future version.Finalization has been deprecated for removal.booleanisCached()Returnstruesince thisImageInputStreamcaches data in order to allow seeking backwards.booleanReturnsfalsesince thisImageInputStreamdoes not maintain a file cache.booleanReturnstruesince thisImageInputStreammaintains a main memory cache.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.Methods declared in class javax.imageio.stream.ImageInputStreamImpl
checkClosed, 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, skipBytes
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Constructor Details
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MemoryCacheImageInputStream
Constructs aMemoryCacheImageInputStreamthat will read from a givenInputStream.- Parameters:
stream- anInputStreamto read from.- 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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isCached
public boolean isCached()Returnstruesince thisImageInputStreamcaches 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 thisImageInputStreamdoes 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 thisImageInputStreammaintains a main memory cache.- Specified by:
isCachedMemoryin interfaceImageInputStream- Overrides:
isCachedMemoryin classImageInputStreamImpl- Returns:
true.- See Also:
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close
Closes thisMemoryCacheImageInputStream, freeing the cache. The sourceInputStreamis not closed.- Throws:
IOException- if an I/O error occurs.
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finalize
Deprecated, for removal: This API element is subject to removal in a future version.Finalization has been deprecated for removal. SeeObject.finalize()for background information and details about migration options.Finalizes this object prior to garbage collection. Theclosemethod is called to close any open input source. This method should not be called from application code.- Overrides:
finalizein classImageInputStreamImpl- Throws:
Throwable- if an error occurs during superclass finalization.- See Also:
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