Module java.desktop
Package javax.imageio.stream

# 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.
The `finalize` method has been deprecated.
`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`.
  `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 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") protected void finalize() throws Throwable
Deprecated.
The `finalize` method has been deprecated. Subclasses that override `finalize` in order to perform cleanup should be modified to use alternative cleanup mechanisms and to remove the overriding `finalize` method. When overriding the `finalize` method, its implementation must explicitly ensure that `super.finalize()` is invoked as described in `Object.finalize()`. See the specification for `Object.finalize()` for further information 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`