| JavaTM 2 Platform Std. Ed. v1.6.0
javax.imageio.stream
Class FileImageInputStream
java.lang.Object
 javax.imageio.stream.ImageInputStreamImpl
javax.imageio.stream.FileImageInputStream
- All Implemented Interfaces:
- DataInput, ImageInputStream
public class FileImageInputStream - extends ImageInputStreamImpl
An implementation of ImageInputStream that gets its
input from a File or RandomAccessFile.
The file contents are assumed to be stable during the lifetime of
the object.
|
Method Summary |
void |
close()
Closes the stream. |
protected void |
finalize()
Finalizes this object prior to garbage collection. |
long |
length()
Returns the length of the underlying file, or -1
if it is unknown. |
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. |
void |
seek(long pos)
Sets the current stream position to the desired location. |
| Methods inherited from class javax.imageio.stream.ImageInputStreamImpl |
checkClosed, flush, flushBefore, getBitOffset, getByteOrder, getFlushedPosition, getStreamPosition, isCached, isCachedFile, isCachedMemory, 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, setBitOffset, setByteOrder, skipBytes, skipBytes |
FileImageInputStream
public FileImageInputStream(File f)
throws FileNotFoundException,
IOException
- Constructs a
FileImageInputStream that will read
from a given File.
The file contents must not change between the time this
object is constructed and the time of the last call to a read
method.
- Parameters:
f - a File to read from.
- Throws:
IllegalArgumentException - if f is
null.
SecurityException - if a security manager exists
and does not allow read access to the file.
FileNotFoundException - if f is a
directory or cannot be opened for reading for any other reason.
IOException - if an I/O error occurs.
FileImageInputStream
public FileImageInputStream(RandomAccessFile raf)
- Constructs a
FileImageInputStream that will read
from a given RandomAccessFile.
The file contents must not change between the time this
object is constructed and the time of the last call to a read
method.
- Parameters:
raf - a RandomAccessFile to read from.
- Throws:
IllegalArgumentException - if raf is
null.
read
public int read()
throws IOException
- Description copied from class:
ImageInputStreamImpl
- Reads a single byte from the stream and returns it as an
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.
- Specified by:
read in interface ImageInputStream- Specified by:
read in class ImageInputStreamImpl
- Returns:
- the value of the next byte in the stream, or
-1
if EOF is reached.
- Throws:
IOException - if the stream has been closed.
read
public int read(byte[] b,
int off,
int len)
throws IOException
- Description copied from class:
ImageInputStreamImpl
- 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 in interface ImageInputStream- Specified by:
read in class ImageInputStreamImpl
- 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 - if an I/O error occurs.
length
public long length()
- Returns the length of the underlying file, or
-1
if it is unknown.
- Specified by:
length in interface ImageInputStream- Overrides:
length in class ImageInputStreamImpl
- Returns:
- the file length as a
long, or
-1.
seek
public void seek(long pos)
throws IOException
- Description copied from interface:
ImageInputStream
- Sets the current stream position to the desired location. The
next read will occur at this location. The bit offset is set
to 0.
An IndexOutOfBoundsException will be thrown if
pos is smaller than the flushed position (as
returned by getflushedPosition).
It is legal to seek past the end of the file; an
EOFException will be thrown only if a read is
performed.
- Specified by:
seek in interface ImageInputStream- Overrides:
seek in class ImageInputStreamImpl
- Parameters:
pos - a long containing the desired file
pointer position.
- Throws:
IOException - if any other I/O error occurs.
close
public void close()
throws IOException
- Description copied from interface:
ImageInputStream
- Closes the stream. Attempts to access a stream that has been
closed may result in
IOExceptions or incorrect
behavior. Calling this method may allow classes implementing
this interface to release resources associated with the stream
such as memory, disk space, or file descriptors.
- Specified by:
close in interface ImageInputStream- Overrides:
close in class ImageInputStreamImpl
- Throws:
IOException - if an I/O error occurs.
finalize
protected void finalize()
throws Throwable
- Finalizes this object prior to garbage collection. The
close method is called to close any open input
source. This method should not be called from application
code.
- Overrides:
finalize in class ImageInputStreamImpl
- Throws:
Throwable - if an error occurs during superclass
finalization.
Copyright 2003 Sun Microsystems, Inc. All rights reserved
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