FileCacheImageOutputStream (Java 2 Platform SE 5.0) (original) (raw)
javax.imageio.stream
Class FileCacheImageOutputStream
java.lang.Object
javax.imageio.stream.ImageInputStreamImpl
javax.imageio.stream.ImageOutputStreamImpl
javax.imageio.stream.FileCacheImageOutputStream
All Implemented Interfaces:
DataInput, DataOutput, ImageInputStream, ImageOutputStream
public class FileCacheImageOutputStream
extends ImageOutputStreamImpl
An implementation of ImageOutputStream
that writes its output to a regular OutputStream
. A file is used to cache data until it is flushed to the output stream.
Field Summary |
---|
Fields inherited from class javax.imageio.stream.ImageInputStreamImpl |
---|
bitOffset, byteOrder, flushedPos, streamPos |
Constructor Summary |
---|
[FileCacheImageOutputStream](../../../javax/imageio/stream/FileCacheImageOutputStream.html#FileCacheImageOutputStream%28java.io.OutputStream, java.io.File%29)(OutputStream stream,File cacheDir) Constructs a FileCacheImageOutputStream that will write to a given outputStream. |
Method Summary | |
---|---|
void | close() Closes this FileCacheImageOututStream. |
void | flushBefore(long pos) Discards the initial portion of the stream prior to the indicated postion. |
boolean | isCached() Returns true since thisImageOutputStream caches data in order to allow seeking backwards. |
boolean | isCachedFile() Returns true since thisImageOutputStream maintains a file cache. |
boolean | isCachedMemory() Returns false since thisImageOutputStream does not maintain a main memory cache. |
long | length() Returns -1L to indicate that the stream has unknown length. |
int | read() Reads a single byte from the stream and returns it as an integer between 0 and 255. |
int | [read](../../../javax/imageio/stream/FileCacheImageOutputStream.html#read%28byte[], int, int%29)(byte[] b, int off, int len) Reads up to len bytes from the stream, and stores them into b starting at index off. |
void | seek(long pos) Sets the current stream position and resets the bit offset to 0. |
void | [write](../../../javax/imageio/stream/FileCacheImageOutputStream.html#write%28byte[], int, int%29)(byte[] b, int off, int len) Writes len bytes from arrayb, in order, to the output stream. |
void | write(int b) Writes to the output stream the eight low-order bits of the argument b. |
Methods inherited from class javax.imageio.stream.ImageOutputStreamImpl |
---|
flushBits, write, writeBit, [writeBits](../../../javax/imageio/stream/ImageOutputStreamImpl.html#writeBits%28long, int%29), writeBoolean, writeByte, writeBytes, writeChar, [writeChars](../../../javax/imageio/stream/ImageOutputStreamImpl.html#writeChars%28char[], int, int%29), writeChars, writeDouble, [writeDoubles](../../../javax/imageio/stream/ImageOutputStreamImpl.html#writeDoubles%28double[], int, int%29), writeFloat, [writeFloats](../../../javax/imageio/stream/ImageOutputStreamImpl.html#writeFloats%28float[], int, int%29), writeInt, [writeInts](../../../javax/imageio/stream/ImageOutputStreamImpl.html#writeInts%28int[], int, int%29), writeLong, [writeLongs](../../../javax/imageio/stream/ImageOutputStreamImpl.html#writeLongs%28long[], int, int%29), writeShort, [writeShorts](../../../javax/imageio/stream/ImageOutputStreamImpl.html#writeShorts%28short[], int, int%29), writeUTF |
Methods inherited from class javax.imageio.stream.ImageInputStreamImpl |
---|
checkClosed, finalize, flush, getBitOffset, getByteOrder, getFlushedPosition, getStreamPosition, mark, read, readBit, readBits, readBoolean, readByte, [readBytes](../../../javax/imageio/stream/ImageInputStreamImpl.html#readBytes%28javax.imageio.stream.IIOByteBuffer, int%29), readChar, readDouble, readFloat, readFully, [readFully](../../../javax/imageio/stream/ImageInputStreamImpl.html#readFully%28byte[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStreamImpl.html#readFully%28char[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStreamImpl.html#readFully%28double[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStreamImpl.html#readFully%28float[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStreamImpl.html#readFully%28int[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStreamImpl.html#readFully%28long[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStreamImpl.html#readFully%28short[], int, int%29), readInt, readLine, readLong, readShort, readUnsignedByte, readUnsignedInt, readUnsignedShort, readUTF, reset, setBitOffset, setByteOrder, skipBytes, skipBytes |
Methods inherited from class java.lang.Object |
---|
clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, [wait](../../../java/lang/Object.html#wait%28long, int%29) |
Methods inherited from interface javax.imageio.stream.ImageInputStream |
---|
flush, getBitOffset, getByteOrder, getFlushedPosition, getStreamPosition, mark, read, readBit, readBits, readBoolean, readByte, [readBytes](../../../javax/imageio/stream/ImageInputStream.html#readBytes%28javax.imageio.stream.IIOByteBuffer, int%29), readChar, readDouble, readFloat, readFully, [readFully](../../../javax/imageio/stream/ImageInputStream.html#readFully%28byte[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStream.html#readFully%28char[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStream.html#readFully%28double[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStream.html#readFully%28float[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStream.html#readFully%28int[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStream.html#readFully%28long[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStream.html#readFully%28short[], int, int%29), readInt, readLine, readLong, readShort, readUnsignedByte, readUnsignedInt, readUnsignedShort, readUTF, reset, setBitOffset, setByteOrder, skipBytes, skipBytes |
Constructor Detail |
---|
FileCacheImageOutputStream
public FileCacheImageOutputStream(OutputStream stream, File cacheDir) throws IOException
Constructs a FileCacheImageOutputStream
that will write to a given outputStream
.
A temporary file is used as a cache. IfcacheDir
is non-null
and 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.createTempFile
for details).
Parameters:
stream
- an OutputStream
to write to.
cacheDir
- a File
indicating where the cache file should be created, or null
to use the system directory.
Throws:
[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang")
- if stream
is null
.
[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang")
- if cacheDir
is non-null
but is not a directory.
[IOException](../../../java/io/IOException.html "class in java.io")
- if a cache file cannot be created.
Method Detail |
---|
read
public int read() throws IOException
Description copied from interface: [ImageInputStream](../../../javax/imageio/stream/ImageInputStream.html#read%28%29)
Reads a single byte from the stream and returns it as an integer between 0 and 255. If the end of the stream is reached, -1 is returned.
The bit offset within the stream is reset to zero before the read occurs.
Specified by:
[read](../../../javax/imageio/stream/ImageInputStream.html#read%28%29)
in interface [ImageInputStream](../../../javax/imageio/stream/ImageInputStream.html "interface in javax.imageio.stream")
Specified by:
[read](../../../javax/imageio/stream/ImageInputStreamImpl.html#read%28%29)
in class [ImageInputStreamImpl](../../../javax/imageio/stream/ImageInputStreamImpl.html "class in javax.imageio.stream")
Returns:
a byte value from the stream, as an int, or -1 to indicate EOF.
Throws:
[IOException](../../../java/io/IOException.html "class in java.io")
- if an I/O error occurs.
read
public int read(byte[] b, int off, int len) throws IOException
Description copied from class: [ImageInputStreamImpl](../../../javax/imageio/stream/ImageInputStreamImpl.html#read%28byte[], int, int%29)
Reads up to 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.
Specified by:
[read](../../../javax/imageio/stream/ImageInputStream.html#read%28byte[], int, int%29)
in interface [ImageInputStream](../../../javax/imageio/stream/ImageInputStream.html "interface in javax.imageio.stream")
Specified by:
[read](../../../javax/imageio/stream/ImageInputStreamImpl.html#read%28byte[], int, int%29)
in class [ImageInputStreamImpl](../../../javax/imageio/stream/ImageInputStreamImpl.html "class in javax.imageio.stream")
Parameters:
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.
Returns:
the number of bytes actually read, or -1
to indicate EOF.
Throws:
[IOException](../../../java/io/IOException.html "class in java.io")
- if an I/O error occurs.
write
public void write(int b) throws IOException
Description copied from interface: [DataOutput](../../../java/io/DataOutput.html#write%28int%29)
Writes to the output stream the eight low-order bits of the argument b
. The 24 high-order bits of b
are ignored.
Specified by:
[write](../../../java/io/DataOutput.html#write%28int%29)
in interface [DataOutput](../../../java/io/DataOutput.html "interface in java.io")
Specified by:
[write](../../../javax/imageio/stream/ImageOutputStream.html#write%28int%29)
in interface [ImageOutputStream](../../../javax/imageio/stream/ImageOutputStream.html "interface in javax.imageio.stream")
Specified by:
[write](../../../javax/imageio/stream/ImageOutputStreamImpl.html#write%28int%29)
in class [ImageOutputStreamImpl](../../../javax/imageio/stream/ImageOutputStreamImpl.html "class in javax.imageio.stream")
Parameters:
b
- the byte to be written.
Throws:
[IOException](../../../java/io/IOException.html "class in java.io")
- if an I/O error occurs.
write
public void write(byte[] b, int off, int len) throws IOException
Description copied from interface: [DataOutput](../../../java/io/DataOutput.html#write%28byte[], int, int%29)
Writes len
bytes from arrayb
, in order, to the output stream. If b
is null
, a NullPointerException
is thrown. If off
is negative, or len
is negative, or off+len
is greater than the length of the arrayb
, then an IndexOutOfBoundsException
is thrown. If len
is zero, then no bytes are written. Otherwise, the byte b[off]
is written first, then b[off+1]
, and so on; the last byte written is b[off+len-1]
.
Specified by:
[write](../../../java/io/DataOutput.html#write%28byte[], int, int%29)
in interface [DataOutput](../../../java/io/DataOutput.html "interface in java.io")
Specified by:
[write](../../../javax/imageio/stream/ImageOutputStream.html#write%28byte[], int, int%29)
in interface [ImageOutputStream](../../../javax/imageio/stream/ImageOutputStream.html "interface in javax.imageio.stream")
Specified by:
[write](../../../javax/imageio/stream/ImageOutputStreamImpl.html#write%28byte[], int, int%29)
in class [ImageOutputStreamImpl](../../../javax/imageio/stream/ImageOutputStreamImpl.html "class in javax.imageio.stream")
Parameters:
b
- the data.
off
- the start offset in the data.
len
- the number of bytes to write.
Throws:
[IOException](../../../java/io/IOException.html "class in java.io")
- if an I/O error occurs.
length
public long length()
Description copied from class: [ImageInputStreamImpl](../../../javax/imageio/stream/ImageInputStreamImpl.html#length%28%29)
Returns -1L
to indicate that the stream has unknown length. Subclasses must override this method to provide actual length information.
Specified by:
[length](../../../javax/imageio/stream/ImageInputStream.html#length%28%29)
in interface [ImageInputStream](../../../javax/imageio/stream/ImageInputStream.html "interface in javax.imageio.stream")
Overrides:
[length](../../../javax/imageio/stream/ImageInputStreamImpl.html#length%28%29)
in class [ImageInputStreamImpl](../../../javax/imageio/stream/ImageInputStreamImpl.html "class in javax.imageio.stream")
Returns:
-1L to indicate unknown length.
seek
public void seek(long pos) throws IOException
Sets the current stream position and resets the bit offset to 0. It is legal to seek past the end of the file; anEOFException
will be thrown only if a read is performed. The file length will not be increased until a write is performed.
Specified by:
[seek](../../../javax/imageio/stream/ImageInputStream.html#seek%28long%29)
in interface [ImageInputStream](../../../javax/imageio/stream/ImageInputStream.html "interface in javax.imageio.stream")
Overrides:
[seek](../../../javax/imageio/stream/ImageInputStreamImpl.html#seek%28long%29)
in class [ImageInputStreamImpl](../../../javax/imageio/stream/ImageInputStreamImpl.html "class in javax.imageio.stream")
Parameters:
pos
- a long
containing the desired file pointer position.
Throws:
[IndexOutOfBoundsException](../../../java/lang/IndexOutOfBoundsException.html "class in java.lang")
- if pos
is smaller than the flushed position.
[IOException](../../../java/io/IOException.html "class in java.io")
- if any other I/O error occurs.
isCached
public boolean isCached()
Returns true
since thisImageOutputStream
caches data in order to allow seeking backwards.
Specified by:
[isCached](../../../javax/imageio/stream/ImageInputStream.html#isCached%28%29)
in interface [ImageInputStream](../../../javax/imageio/stream/ImageInputStream.html "interface in javax.imageio.stream")
Overrides:
[isCached](../../../javax/imageio/stream/ImageInputStreamImpl.html#isCached%28%29)
in class [ImageInputStreamImpl](../../../javax/imageio/stream/ImageInputStreamImpl.html "class in javax.imageio.stream")
Returns:
true
.
See Also:
isCachedMemory(), isCachedFile()
isCachedFile
public boolean isCachedFile()
Returns true
since thisImageOutputStream
maintains a file cache.
Specified by:
[isCachedFile](../../../javax/imageio/stream/ImageInputStream.html#isCachedFile%28%29)
in interface [ImageInputStream](../../../javax/imageio/stream/ImageInputStream.html "interface in javax.imageio.stream")
Overrides:
[isCachedFile](../../../javax/imageio/stream/ImageInputStreamImpl.html#isCachedFile%28%29)
in class [ImageInputStreamImpl](../../../javax/imageio/stream/ImageInputStreamImpl.html "class in javax.imageio.stream")
Returns:
true
.
See Also:
isCachedMemory
public boolean isCachedMemory()
Returns false
since thisImageOutputStream
does not maintain a main memory cache.
Specified by:
[isCachedMemory](../../../javax/imageio/stream/ImageInputStream.html#isCachedMemory%28%29)
in interface [ImageInputStream](../../../javax/imageio/stream/ImageInputStream.html "interface in javax.imageio.stream")
Overrides:
[isCachedMemory](../../../javax/imageio/stream/ImageInputStreamImpl.html#isCachedMemory%28%29)
in class [ImageInputStreamImpl](../../../javax/imageio/stream/ImageInputStreamImpl.html "class in javax.imageio.stream")
Returns:
false
.
See Also:
close
public void close() throws IOException
Closes this FileCacheImageOututStream
. All pending data is flushed to the output, and the cache file is closed and removed. The destination OutputStream
is not closed.
Specified by:
[close](../../../javax/imageio/stream/ImageInputStream.html#close%28%29)
in interface [ImageInputStream](../../../javax/imageio/stream/ImageInputStream.html "interface in javax.imageio.stream")
Overrides:
[close](../../../javax/imageio/stream/ImageInputStreamImpl.html#close%28%29)
in class [ImageInputStreamImpl](../../../javax/imageio/stream/ImageInputStreamImpl.html "class in javax.imageio.stream")
Throws:
[IOException](../../../java/io/IOException.html "class in java.io")
- if an error occurs.
flushBefore
public void flushBefore(long pos) throws IOException
Description copied from interface: [ImageInputStream](../../../javax/imageio/stream/ImageInputStream.html#flushBefore%28long%29)
Discards the initial portion of the stream prior to the indicated postion. Attempting to seek to an offset within the flushed portion of the stream will result in anIndexOutOfBoundsException
.
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.
Specified by:
[flushBefore](../../../javax/imageio/stream/ImageInputStream.html#flushBefore%28long%29)
in interface [ImageInputStream](../../../javax/imageio/stream/ImageInputStream.html "interface in javax.imageio.stream")
Specified by:
[flushBefore](../../../javax/imageio/stream/ImageOutputStream.html#flushBefore%28long%29)
in interface [ImageOutputStream](../../../javax/imageio/stream/ImageOutputStream.html "interface in javax.imageio.stream")
Overrides:
[flushBefore](../../../javax/imageio/stream/ImageInputStreamImpl.html#flushBefore%28long%29)
in class [ImageInputStreamImpl](../../../javax/imageio/stream/ImageInputStreamImpl.html "class in javax.imageio.stream")
Parameters:
pos
- a long
containing the length of the file prefix that may be flushed.
Throws:
[IOException](../../../java/io/IOException.html "class in java.io")
- if an I/O error occurs.
Submit a bug or feature
For further API reference and developer documentation, see Java 2 SDK SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
Copyright © 2004, 2010 Oracle and/or its affiliates. All rights reserved. Use is subject to license terms. Also see the documentation redistribution policy.