org.jmrtd.io

Class SplittableInputStream

java.lang.Object

java.io.InputStream

org.jmrtd.io.SplittableInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

public class SplittableInputStream
extends InputStream

An input stream which will wrap another input stream (and yield the same bytes) and which can spawn new fresh input stream copies (using getInputStream(int)) (that also yield the same bytes).

Version:

$Revision: 1601 $

Author:

Martijn Oostdijk ([email protected])

Field Summary

Fields

Modifier and Type	Field and Description
InputStreamBuffer	inputStreamBuffer

Constructor Summary

Constructors

Constructor and Description
SplittableInputStream(InputStream inputStream, int length) Wraps an input stream so that copy streams can be split off.

Method Summary

Modifier and Type	Method and Description
int	available() Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking by the next invocation of a method for this input stream.
void	close() Closes this input stream and releases any system resources associated with the stream.
int	getBytesBuffered()
InputStream	getInputStream(int position) Gets a copy of the inputstream positioned at position.
int	getLength()
int	getPosition() The position of the input stream (the number of bytes read since this input stream was constructed)
void	mark(int readlimit) Marks the current position in this input stream.
boolean	markSupported() Tests if this input stream supports the mark and reset methods.
int	read() Reads the next byte of data from the input stream.
void	reset() Repositions this stream to the position at the time the mark method was last called on this input stream.
long	skip(long n) Skips over and discards n bytes of data from this input stream.
void	updateFrom(SplittableInputStream other)

Methods inherited from class java.io.InputStream

read, read

Methods inherited from class java.lang.Object

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

Field Detail

inputStreamBuffer

public InputStreamBuffer inputStreamBuffer

Constructor Detail

SplittableInputStream

public SplittableInputStream(InputStream inputStream,
                             int length)

Wraps an input stream so that copy streams can be split off.

Parameters:

inputStream - the original input stream

length - the precise length of bytes that the original input stream provides

Method Detail

updateFrom

public void updateFrom(SplittableInputStream other)

getInputStream

public InputStream getInputStream(int position)

Gets a copy of the inputstream positioned at position.

Parameters:

position - a position between 0 and getPosition()

Returns:

a fresh input stream

getPosition

public int getPosition()

The position of the input stream (the number of bytes read since this input stream was constructed)

Returns:

the position of this input stream

read

public int read()
         throws IOException

Reads the next byte of data from the input stream. The value byte is returned as an int in the range 0 to 255. If no byte is available because the end of the stream has been reached, the value -1 is returned. This method blocks until input data is available, the end of the stream is detected, or an exception is thrown.

Specified by:

read in class InputStream

Returns:

the next byte of data, or -1 if the end of the stream is reached.

Throws:

IOException - if an I/O error occurs.

skip

public long skip(long n)
          throws IOException

Skips over and discards n bytes of data from this input stream. The skip method may, for a variety of reasons, end up skipping over some smaller number of bytes, possibly 0. This may result from any of a number of conditions; reaching end of file before n bytes have been skipped is only one possibility. The actual number of bytes skipped is returned. If n is negative, no bytes are skipped.

Overrides:

skip in class InputStream

Parameters:

n - the number of bytes to be skipped.

Returns:

the actual number of bytes skipped.

Throws:

IOException - if the stream does not support seek, or if some other I/O error occurs.

available

public int available()
              throws IOException

Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking by the next invocation of a method for this input stream. The next invocation might be the same thread or another thread. A single read or skip of this many bytes will not block, but may read or skip fewer bytes.

Overrides:

available in class InputStream

Returns:

an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking or 0 when it reaches the end of the input stream.

Throws:

IOException - on error

close

public void close()
           throws IOException

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

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Overrides:

close in class InputStream

Throws:

IOException - on error

mark

public void mark(int readlimit)

Marks the current position in this input stream. A subsequent call to the reset method repositions this stream at the last marked position so that subsequent reads re-read the same bytes.

The readlimit arguments tells this input stream to allow that many bytes to be read before the mark position gets invalidated.

The general contract of mark is that, if the method markSupported returns true, the stream somehow remembers all the bytes read after the call to mark and stands ready to supply those same bytes again if and whenever the method reset is called. However, the stream is not required to remember any data at all if more than readlimit bytes are read from the stream before reset is called.

Overrides:

mark in class InputStream

Parameters:

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

See Also:

InputStream.reset()

reset

public void reset()
           throws IOException

Repositions this stream to the position at the time the mark method was last called on this input stream. The general contract of reset is:

• If the method markSupported returns true, then:
  • If the method mark has not been called since the stream was created, or the number of bytes read from the stream since mark was last called is larger than the argument to mark at that last call, then an IOException might be thrown.
  • If such an IOException is not thrown, then the stream is reset to a state such that all the bytes read since the most recent call to mark (or since the start of the file, if mark has not been called) will be resupplied to subsequent callers of the read method, followed by any bytes that otherwise would have been the next input data as of the time of the call to reset.
• If the method markSupported returns false, then:
  • The call to reset may throw an IOException.
  • If an IOException is not thrown, then the stream is reset to a fixed state that depends on the particular type of the input stream and how it was created. The bytes that will be supplied to subsequent callers of the read method depend on the particular type of the input stream.

Overrides:

reset in class InputStream

Throws:

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

IOException - on error

See Also:

InputStream.mark(int), IOException

markSupported

public boolean markSupported()

Tests if this input stream supports the mark and reset methods. Whether or not mark and reset are supported is an invariant property of a particular input stream instance. The markSupported method of InputStream returns false.

Overrides:

markSupported in class InputStream

Returns:

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

See Also:

InputStream.mark(int), InputStream.reset()

getLength

public int getLength()

getBytesBuffered

public int getBytesBuffered()