public class

FileImageInputStream

extends ImageInputStreamImpl
java.lang.Object
   ↳ javax.imageio.stream.ImageInputStreamImpl
     ↳ javax.imageio.stream.FileImageInputStream

Class Overview

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.

Summary

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Inherited Fields
From class javax.imageio.stream.ImageInputStreamImpl
Public Constructors
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.
Public Methods
void close()
Closes the stream.
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.
Protected Methods
void finalize()
Finalizes this object prior to garbage collection.
[Expand]
Inherited Methods
From class javax.imageio.stream.ImageInputStreamImpl
From class java.lang.Object
From interface java.io.DataInput
From interface javax.imageio.stream.ImageInputStream

Public Constructors

public FileImageInputStream (File f)

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.

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.

Public Methods

public void close ()

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.

Throws
IOException

public long length ()

Returns the length of the underlying file, or -1 if it is unknown.

Returns
  • the file length as a long, or -1.

public int read ()

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.

Returns
  • the value of the next byte in the stream, or -1 if EOF is reached.
Throws
IOException

public 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. 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.

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

public void seek (long pos)

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.

Parameters
pos a long containing the desired file pointer position.
Throws
IOException

Protected Methods

protected void finalize ()

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.

Throws
Throwable