FileImageInputStream (Java 2 Platform SE v1.4.1_"07")

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JavaTM 2 Platform
Std. Ed. v1.4.1_"07"

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## 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.

Field Summary

Fields inherited from class javax.imageio.stream.ImageInputStreamImpl
`bitOffset, byteOrder, flushedPos, streamPos`

Constructor Summary
`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
`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 integer 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, finalize, 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`

Methods inherited from class java.lang.Object
`clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Constructor Detail

### 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`.

Method Detail

### read

    public int read()
             throws IOException

  Description copied from interface: `ImageInputStream`
  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` in interface `ImageInputStream`
  Specified by:
    `read` in class `ImageInputStreamImpl`
  Returns:
    a byte value from the stream, as an int, or -1 to indicate EOF.
  Throws:
    `IOException` - if an I/O error occurs.

### 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 `IOException`s 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.

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JavaTM 2 Platform
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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 2002 Sun Microsystems, Inc. All rights reserved. Use is subject to license terms.