javax.mail.util
Class SharedFileInputStream

java.lang.Object
  java.io.InputStream
      java.io.FilterInputStream
          java.io.BufferedInputStream
              javax.mail.util.SharedFileInputStream

All Implemented Interfaces:

Closeable, SharedInputStream

public class SharedFileInputStream
extends BufferedInputStream
implements SharedInputStream

Field Summary

protected long	bufpos The file offset that is the first byte in the read buffer.
protected int	bufsize The normal size of the read buffer.
protected long	datalen The size of the file subset represented by this stream instance.
protected RandomAccessFile	in The source of the file data.
protected long	start The starting position of data represented by this stream relative to the start of the file data.

Fields inherited from class java.io.BufferedInputStream

buf, count, marklimit, markpos, pos

Constructor Summary

SharedFileInputStream(File file)
Construct a SharedFileInputStream from a File object, using the default buffer size.

SharedFileInputStream(File file, int bufferSize)
Construct a SharedFileInputStream from a File object, with a given initial buffer size.

SharedFileInputStream(String file)
Construct a SharedFileInputStream from a file name, using the default buffer size.

SharedFileInputStream(String file, int bufferSize)
Construct a SharedFileInputStream from a file name, with a given initial buffer size.

Method Summary

int	available() Return the number of bytes available for reading without blocking for a long period.
void	close() Close the stream.
long	getPosition() Return the current read position of the stream.
void	mark(int readlimit) Mark the current position for retracing.
boolean	markSupported() Indicates the mark() operation is supported.
InputStream	newStream(long offset, long end) Create a new stream from this stream, using the given start offset and length.
int	read() Read a single byte of data from the input stream.
int	read(byte[] buffer, int offset, int length) Read multiple bytes of data and place them directly into a byte-array buffer.
void	reset() Reset the mark position.
long	skip(long n) Skip the read pointer ahead a given number of bytes.

Methods inherited from class java.io.FilterInputStream

read

Methods inherited from class java.lang.Object

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

Field Detail

bufpos

protected long bufpos

The file offset that is the first byte in the read buffer.

bufsize

protected int bufsize

The normal size of the read buffer.

datalen

protected long datalen

The size of the file subset represented by this stream instance.

in

protected RandomAccessFile in

The source of the file data. This is shared across multiple instances.

start

protected long start

The starting position of data represented by this stream relative to the start of the file data. This stream instance represents data in the range start to (start + datalen - 1).

Constructor Detail

SharedFileInputStream

public SharedFileInputStream(String file)
                      throws IOException

Construct a SharedFileInputStream from a file name, using the default buffer size.

Parameters:

file - The name of the file.

Throws:

IOException

SharedFileInputStream

public SharedFileInputStream(File file)
                      throws IOException

Construct a SharedFileInputStream from a File object, using the default buffer size.

Parameters:

file - The name of the file.

Throws:

IOException

SharedFileInputStream

public SharedFileInputStream(String file,
                             int bufferSize)
                      throws IOException

Construct a SharedFileInputStream from a file name, with a given initial buffer size.

Parameters:

file - The name of the file.

bufferSize - The initial buffer size.

Throws:

IOException

SharedFileInputStream

public SharedFileInputStream(File file,
                             int bufferSize)
                      throws IOException

Construct a SharedFileInputStream from a File object, with a given initial buffer size.

Parameters:

file - The name of the file.

bufferSize - The initial buffer size.

Throws:

IOException

Method Detail

available

public int available()
              throws IOException

Return the number of bytes available for reading without blocking for a long period.

Overrides:

available in class BufferedInputStream

Returns:

For this stream, this is the number of bytes between the current read position and the indicated end of the file.

Throws:

IOException

getPosition

public long getPosition()

Return the current read position of the stream.

Specified by:

getPosition in interface SharedInputStream

Returns:

The current position relative to the beginning of the stream. This is not the position relative to the start of the file, since the stream starting position may be other than the beginning.

mark

public void mark(int readlimit)

Mark the current position for retracing.

Overrides:

mark in class BufferedInputStream

Parameters:

readlimit - The limit for the distance the read position can move from the mark position before the mark is reset.

read

public int read()
         throws IOException

Read a single byte of data from the input stream.

Overrides:

read in class BufferedInputStream

Returns:

The read byte. Returns -1 if an eof condition has been hit.

Throws:

IOException

read

public int read(byte[] buffer,
                int offset,
                int length)
         throws IOException

Read multiple bytes of data and place them directly into a byte-array buffer.

Overrides:

read in class BufferedInputStream

Parameters:

buffer - The target buffer.

offset - The offset within the buffer to place the data.

length - The length to attempt to read.

Returns:

The number of bytes actually read. Returns -1 for an EOF condition.

Throws:

IOException

skip

public long skip(long n)
          throws IOException

Skip the read pointer ahead a given number of bytes.

Overrides:

skip in class BufferedInputStream

Parameters:

n - The number of bytes to skip.

Returns:

The number of bytes actually skipped.

Throws:

IOException

reset

public void reset()
           throws IOException

Reset the mark position.

Overrides:

reset in class BufferedInputStream

Throws:

IOException

markSupported

public boolean markSupported()

Indicates the mark() operation is supported.

Overrides:

markSupported in class BufferedInputStream

Returns:

Always returns true.

close

public void close()
           throws IOException

Close the stream. This does not close the source file until the last shared instance is closed.

Specified by:

close in interface Closeable

Overrides:

close in class BufferedInputStream

Throws:

IOException

newStream

public InputStream newStream(long offset,
                             long end)

Create a new stream from this stream, using the given start offset and length.

Specified by:

newStream in interface SharedInputStream

Parameters:

offset - The offset relative to the start of this stream instance.

end - The end offset of the substream. If -1, the end of the parent stream is used.

Returns:

A new SharedFileInputStream object sharing the same source input file.