Class FileImageInputStream

java.lang.Object

javax.imageio.stream.ImageInputStreamImpl

javax.imageio.stream.FileImageInputStream

All Implemented Interfaces:

Closeable, DataInput, AutoCloseable, 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.

Field Summary

Fields declared in class javax.imageio.stream.ImageInputStreamImpl

bitOffset, byteOrder, flushedPos, streamPos

Constructor Summary

Constructors

Constructor	Description
FileImageInputStream(File f)	Constructs a FileImageInputStream that will read from a given File.
FileImageInputStream(RandomAccessFile raf)	Constructs a FileImageInputStream that will read from a given RandomAccessFile.

Method Summary

Modifier and Type	Method	Description
protected void	finalize()	Deprecated, for removal: This API element is subject to removal in a future version. Finalization has been deprecated for removal.
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.

Methods declared in class javax.imageio.stream.ImageInputStreamImpl

checkClosed, close, 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, seek, setBitOffset, setByteOrder, skipBytes, skipBytes

Methods declared in class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

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.

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.

Method Details

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.

finalize

@Deprecated(since="9",
            forRemoval=true)
protected void finalize()
                 throws Throwable

Deprecated, for removal: This API element is subject to removal in a future version.

Finalization has been deprecated for removal. See Object.finalize() for background information and details about migration options.

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.

See Also:

• WeakReference
• PhantomReference