public class FileCacheImageInputStream extends ImageInputStreamImpl
ImageInputStream that gets its
input from a regular InputStream. A file is used to
cache previously read data.bitOffset, byteOrder, flushedPos, streamPos| Constructor and Description |
|---|
FileCacheImageInputStream(InputStream stream,
File cacheDir)
Constructs a
FileCacheImageInputStream that will read
from a given InputStream. |
| Modifier and Type | Method and Description |
|---|---|
void |
close()
Closes this
FileCacheImageInputStream, closing
and removing the cache file. |
protected void |
finalize()
Finalizes this object prior to garbage collection.
|
boolean |
isCached()
Returns
true since this
ImageInputStream caches data in order to allow
seeking backwards. |
boolean |
isCachedFile()
Returns
true since this
ImageInputStream maintains a file cache. |
boolean |
isCachedMemory()
Returns
false since this
ImageInputStream does not maintain a main memory
cache. |
int |
read()
Reads a single byte from the stream and returns it as an
int between 0 and 255. |
int |
read(byte[] b,
int off,
int len)
Reads up to
len bytes from the stream, and stores
them into b starting at index off. |
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, skipBytespublic FileCacheImageInputStream(InputStream stream, File cacheDir) throws IOException
FileCacheImageInputStream that will read
from a given InputStream.
A temporary file is used as a cache. If
cacheDiris non-null and is a
directory, the file will be created there. If it is
null, the system-dependent default temporary-file
directory will be used (see the documentation for
File.createTempFile for details).
stream - an InputStream to read from.cacheDir - a File indicating where the
cache file should be created, or null to use the
system directory.IllegalArgumentException - if stream is
null.IllegalArgumentException - if cacheDir is
non-null but is not a directory.IOException - if a cache file cannot be created.public int read()
throws IOException
ImageInputStreamImplint between 0 and 255. If EOF is reached,
-1 is 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.
read in interface ImageInputStreamread in class ImageInputStreamImpl-1
if EOF is reached.IOException - if the stream has been closed.public int read(byte[] b,
int off,
int len)
throws IOException
ImageInputStreamImpllen 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.
read in interface ImageInputStreamread in class ImageInputStreamImplb - 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.-1
to indicate EOF.IOException - if an I/O error occurs.public boolean isCached()
true since this
ImageInputStream caches data in order to allow
seeking backwards.isCached in interface ImageInputStreamisCached in class ImageInputStreamImpltrue.isCachedMemory(),
isCachedFile()public boolean isCachedFile()
true since this
ImageInputStream maintains a file cache.isCachedFile in interface ImageInputStreamisCachedFile in class ImageInputStreamImpltrue.isCached(),
isCachedMemory()public boolean isCachedMemory()
false since this
ImageInputStream does not maintain a main memory
cache.isCachedMemory in interface ImageInputStreamisCachedMemory in class ImageInputStreamImplfalse.isCached(),
isCachedFile()public void close()
throws IOException
FileCacheImageInputStream, closing
and removing the cache file. The source InputStream
is not closed.close in interface Closeableclose in interface AutoCloseableclose in interface ImageInputStreamclose in class ImageInputStreamImplIOException - if an error occurs.protected void finalize()
throws Throwable
close method is called to close any open input
source. This method should not be called from application
code.finalize in class ImageInputStreamImplThrowable - if an error occurs during superclass
finalization.WeakReference,
PhantomReference Submit a bug or feature
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
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