Class FileCacheImageInputStream
java.lang.Object
javax.imageio.stream.ImageInputStreamImpl
javax.imageio.stream.FileCacheImageInputStream
- All Implemented Interfaces:
- Closeable,- DataInput,- AutoCloseable,- ImageInputStream
An implementation of 
ImageInputStream that gets its
 input from a regular InputStream.  A file is used to
 cache previously read data.- 
Field SummaryFields declared in class javax.imageio.stream.ImageInputStreamImplbitOffset, byteOrder, flushedPos, streamPos
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Constructor SummaryConstructorsConstructorDescriptionFileCacheImageInputStream(InputStream stream, File cacheDir) Constructs aFileCacheImageInputStreamthat will read from a givenInputStream.
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Method SummaryModifier and TypeMethodDescriptionvoidclose()Closes thisFileCacheImageInputStream, closing and removing the cache file.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.booleanReturnstruesince thisImageInputStreammaintains a file cache.booleanReturnsfalsesince thisImageInputStreamdoes not maintain 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.ImageInputStreamImplcheckClosed, 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- 
FileCacheImageInputStreamConstructs aFileCacheImageInputStreamthat will read from a givenInputStream.A temporary file is used as a cache. If cacheDiris non-nulland is a directory, the file will be created there. If it isnull, the system-dependent default temporary-file directory will be used (see the documentation forFile.createTempFilefor details).- Parameters:
- stream- an- InputStreamto read from.
- cacheDir- a- Fileindicating where the cache file should be created, or- nullto use the system directory.
- Throws:
- IllegalArgumentException- if- streamis- null.
- IllegalArgumentException- if- cacheDiris non-- nullbut is not a directory.
- IOException- if a cache file cannot be created.
 
 
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Method Details- 
readDescription 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 interface- ImageInputStream
- Specified by:
- readin class- ImageInputStreamImpl
- 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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readDescription 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 interface- ImageInputStream
- Specified by:
- readin class- ImageInputStreamImpl
- Parameters:
- b- an array of bytes to be written to.
- off- the starting position within- bto 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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isCachedpublic boolean isCached()Returnstruesince thisImageInputStreamcaches data in order to allow seeking backwards.- Specified by:
- isCachedin interface- ImageInputStream
- Overrides:
- isCachedin class- ImageInputStreamImpl
- Returns:
- true.
- See Also:
 
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isCachedFilepublic boolean isCachedFile()Returnstruesince thisImageInputStreammaintains a file cache.- Specified by:
- isCachedFilein interface- ImageInputStream
- Overrides:
- isCachedFilein class- ImageInputStreamImpl
- Returns:
- true.
- See Also:
 
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isCachedMemorypublic boolean isCachedMemory()Returnsfalsesince thisImageInputStreamdoes not maintain a main memory cache.- Specified by:
- isCachedMemoryin interface- ImageInputStream
- Overrides:
- isCachedMemoryin class- ImageInputStreamImpl
- Returns:
- false.
- See Also:
 
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closeCloses thisFileCacheImageInputStream, closing and removing the cache file. The sourceInputStreamis not closed.- Throws:
- IOException- if an error occurs.
 
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finalizeDeprecated, 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 class- ImageInputStreamImpl
- Throws:
- Throwable- if an error occurs during superclass finalization.
- See Also:
 
 
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