jcontrol.io
Class FileInputStream

java.lang.Object
  jcontrol.io.FileInputStream

All Implemented Interfaces:

BasicInputStream

public class FileInputStream
extends Object
implements BasicInputStream

A FileInputStream obtains input bytes from a file in a file system. What files are available depends on the host environment.

FileInputStream is meant for reading streams of raw bytes such as image data.

Since:

JCVM32 (Gimlin3+Gimlin4)

Constructor Summary

FileInputStream(File file)
Creates a FileInputStream by opening a connection to an actual file, the file named by the File object file in the file system.

FileInputStream(String name)
Creates a FileInputStream by opening a connection to an actual file, the file named by the path name name in the file system.

Method Summary

int	available() Returns the number of bytes that can be read from this file input stream without blocking.
void	close() Closes this file input stream and releases any system resources associated with the stream.
protected void	finalize() Free internal data structures used by this file object.
void	mark(int readlimit) NOTE: not supported!
boolean	markSupported() NOTE: not supported!
int	read() Reads a byte of data from this input stream.
int	read(byte[] b) Reads up to b.length bytes of data from this input stream into an array of bytes.
int	read(byte[] b, int off, int len) Reads up to len bytes of data from this input stream into an array of bytes.
void	reset() NOTE: not supported!
int	skip(int n) Skips over and discards n bytes of data from the input stream.

Methods inherited from class java.lang.Object

clone, equals, getClass, notifyAll, toString, wait

Constructor Detail

FileInputStream

public FileInputStream(String name)
                throws FileNotFoundException,
                       IOException

Creates a FileInputStream by opening a connection to an actual file, the file named by the path name name in the file system. A new FileDescriptor object is created to represent this file connection.

If the named file does not exist, is a directory rather than a regular file, or for some other reason cannot be opened for reading then a FileNotFoundException is thrown.

Parameters:

name - the system-dependent file name.

Throws:

FileNotFoundException - if the file does not exist, is a directory rather than a regular file, or for some other reason cannot be opened for reading.

IOException

FileInputStream

public FileInputStream(File file)
                throws FileNotFoundException,
                       IOException

Creates a FileInputStream by opening a connection to an actual file, the file named by the File object file in the file system. A new FileDescriptor object is created to represent this file connection.

If the named file does not exist, is a directory rather than a regular file, or for some other reason cannot be opened for reading then a FileNotFoundException is thrown.

Parameters:

file - the file to be opened for reading.

Throws:

FileNotFoundException - if the file does not exist, is a directory rather than a regular file, or for some other reason cannot be opened for reading.

IOException

See Also:

File.getPath()

Method Detail

read

public int read()
         throws IOException

Reads a byte of data from this input stream. This method blocks if no input is yet available.

Specified by:

read in interface BasicInputStream

Returns:

the next byte of data or -1 if end of file reached.

Throws:

IOException - if an I/O error occurs.

read

public int read(byte[] b)
         throws IOException

Reads up to b.length bytes of data from this input stream into an array of bytes. This method blocks until some input is available.

Specified by:

read in interface BasicInputStream

Parameters:

b - the buffer into which the data is read.

Returns:

the total number of bytes read into the buffer, or -1 if there is no more data because the end of the file has been reached.

Throws:

IOException - if an I/O error occurs.

See Also:

InputStream.read(byte[], int, int)

read

public int read(byte[] b,
                int off,
                int len)
         throws IOException

Reads up to len bytes of data from this input stream into an array of bytes. This method blocks until some input is available.

Specified by:

read in interface BasicInputStream

Parameters:

b - the buffer into which the data is read.

off - the start offset of the data.

len - the maximum number of bytes read.

Returns:

the total number of bytes read into the buffer, or -1 if there is no more data because the end of the file has been reached.

Throws:

IOException - if an I/O error occurs.

See Also:

InputStream.read()

skip

public int skip(int n)
         throws IOException

Skips over and discards n bytes of data from the input stream. The skip method may, for a variety of reasons, end up skipping over some smaller number of bytes, possibly 0. The actual number of bytes skipped is returned.

Specified by:

skip in interface BasicInputStream

Parameters:

n - the number of bytes to be skipped.

Returns:

the actual number of bytes skipped.

Throws:

IOException - if an I/O error occurs.

available

public int available()
              throws IOException

Returns the number of bytes that can be read from this file input stream without blocking.

Specified by:

available in interface BasicInputStream

Returns:

the number of bytes that can be read from this file input stream without blocking.

Throws:

IOException - if an I/O error occurs.

close

public void close()
           throws IOException

Closes this file input stream and releases any system resources associated with the stream.

If this stream has an associated channel then the channel is closed as well.

Specified by:

close in interface BasicInputStream

Throws:

IOException - if an I/O error occurs.

finalize

protected void finalize()

Free internal data structures used by this file object.

mark

public void mark(int readlimit)

NOTE: not supported!

Specified by:

mark in interface BasicInputStream

Parameters:

readlimit - the maximum limit of bytes that can be read before the mark position becomes invalid.

markSupported

public boolean markSupported()

NOTE: not supported!

Specified by:

markSupported in interface BasicInputStream

Returns:

true if this stream instance supports the mark and reset methods; false otherwise.

reset

public void reset()
           throws IOException

NOTE: not supported!

Specified by:

reset in interface BasicInputStream

Throws:

IOException - if this stream has not been makred or if the mark has been invalidated.