ch.randelshofer.io
Class ImageInputStreamAdapter

java.lang.Object
  java.io.InputStream
      java.io.FilterInputStream
          ch.randelshofer.io.ImageInputStreamAdapter

All Implemented Interfaces:

java.io.Closeable

public class ImageInputStreamAdapter
extends java.io.FilterInputStream

ImageInputStreamAdapter.

Version:

1.0 2009-12-17 Created.

Author:

Werner Randelshofer

Field Summary

Fields inherited from class java.io.FilterInputStream

in

Constructor Summary

ImageInputStreamAdapter(javax.imageio.stream.ImageInputStream iis)

Method Summary

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 caller of a method for this input stream.
void	close() Closes this input stream and releases any system resources associated with the stream.
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 this input stream.
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() Repositions this stream to the position at the time the mark method was last called on this input stream.
long	skip(long n)

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

Constructor Detail

ImageInputStreamAdapter

public ImageInputStreamAdapter(javax.imageio.stream.ImageInputStream iis)

Method Detail

read

public int read()
         throws java.io.IOException

Reads the next byte of data from this 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.

This method simply performs in.read() and returns the result.

Overrides:

read in class java.io.FilterInputStream

Returns:

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

Throws:

java.io.IOException - if an I/O error occurs.

See Also:

FilterInputStream.in

read

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

Reads up to len bytes of data from this input stream into an array of bytes. If len is not zero, the method blocks until some input is available; otherwise, no bytes are read and 0 is returned.

This method simply performs in.read(b, off, len) and returns the result.

Overrides:

read in class java.io.FilterInputStream

Parameters:

b - the buffer into which the data is read.

off - the start offset in the destination array b

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 stream has been reached.

Throws:

java.lang.NullPointerException - If b is null.

java.lang.IndexOutOfBoundsException - If off is negative, len is negative, or len is greater than b.length - off

java.io.IOException - if an I/O error occurs.

See Also:

FilterInputStream.in

skip

public long skip(long n)
          throws java.io.IOException

This method simply performs in.skip(n).

Overrides:

skip in class java.io.FilterInputStream

Throws:

java.io.IOException

available

public int available()
              throws java.io.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 caller of a method for this input stream. The next caller 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.

This method returns the result of in.available().

Overrides:

available in class java.io.FilterInputStream

Returns:

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

Throws:

java.io.IOException - if an I/O error occurs.

close

public void close()
           throws java.io.IOException

Closes this input stream and releases any system resources associated with the stream. This method simply performs in.close().

Specified by:

close in interface java.io.Closeable

Overrides:

close in class java.io.FilterInputStream

Throws:

java.io.IOException - if an I/O error occurs.

See Also:

FilterInputStream.in

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

This method simply performs in.mark(readlimit).

Overrides:

mark in class java.io.FilterInputStream

Parameters:

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

See Also:

FilterInputStream.in, FilterInputStream.reset()

reset

public void reset()
           throws java.io.IOException

Repositions this stream to the position at the time the mark method was last called on this input stream.

This method simply performs in.reset().

Stream marks are intended to be used in situations where you need to read ahead a little to see what's in the stream. Often this is most easily done by invoking some general parser. If the stream is of the type handled by the parse, it just chugs along happily. If the stream is not of that type, the parser should toss an exception when it fails. If this happens within readlimit bytes, it allows the outer code to reset the stream and try another parser.

Overrides:

reset in class java.io.FilterInputStream

Throws:

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

See Also:

FilterInputStream.in, FilterInputStream.mark(int)

markSupported

public boolean markSupported()

Tests if this input stream supports the mark and reset methods. This method simply performs in.markSupported().

Overrides:

markSupported in class java.io.FilterInputStream

Returns:

true if this stream type supports the mark and reset method; false otherwise.

See Also:

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