Closeable
, DataInput
, AutoCloseable
, ImageInputStream
public class MemoryCacheImageInputStream extends ImageInputStreamImpl
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.
bitOffset, byteOrder, flushedPos, streamPos
Constructor | Description |
---|---|
MemoryCacheImageInputStream(InputStream stream) |
Constructs a
MemoryCacheImageInputStream that will read
from a given InputStream . |
Modifier and Type | Method | Description |
---|---|---|
void |
close() |
Closes this
MemoryCacheImageInputStream , freeing
the cache. |
protected void |
finalize() |
Finalizes this object prior to garbage collection.
|
void |
flushBefore(long pos) |
Discards the initial portion of the stream prior to the
indicated position.
|
boolean |
isCached() |
Returns
true since this
ImageInputStream caches data in order to allow
seeking backwards. |
boolean |
isCachedFile() |
Returns
false since this
ImageInputStream does not maintain a file cache. |
boolean |
isCachedMemory() |
Returns
true since this
ImageInputStream maintains 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, 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
public MemoryCacheImageInputStream(InputStream stream)
MemoryCacheImageInputStream
that will read
from a given InputStream
.stream
- an InputStream
to read from.IllegalArgumentException
- if stream
is
null
.public int read() throws IOException
ImageInputStreamImpl
int
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 ImageInputStream
read
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
ImageInputStreamImpl
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.
read
in interface ImageInputStream
read
in class ImageInputStreamImpl
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.-1
to indicate EOF.IOException
- if an I/O error occurs.public void flushBefore(long pos) throws IOException
ImageInputStream
IndexOutOfBoundsException
.
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.
flushBefore
in interface ImageInputStream
flushBefore
in class ImageInputStreamImpl
pos
- a long
containing the length of the
stream prefix that may be flushed.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 ImageInputStream
isCached
in class ImageInputStreamImpl
true
.isCachedMemory()
,
isCachedFile()
public boolean isCachedFile()
false
since this
ImageInputStream
does not maintain a file cache.isCachedFile
in interface ImageInputStream
isCachedFile
in class ImageInputStreamImpl
false
.isCached()
,
isCachedMemory()
public boolean isCachedMemory()
true
since this
ImageInputStream
maintains a main memory cache.isCachedMemory
in interface ImageInputStream
isCachedMemory
in class ImageInputStreamImpl
true
.isCached()
,
isCachedFile()
public void close() throws IOException
MemoryCacheImageInputStream
, freeing
the cache. The source InputStream
is not closed.close
in interface AutoCloseable
close
in interface Closeable
close
in interface ImageInputStream
close
in class ImageInputStreamImpl
IOException
- if an I/O 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 ImageInputStreamImpl
Throwable
- 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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DRAFT 9-internal+0-adhoc.mlchung.jdk9-jdeps