com.tangosol.io.nio
Class ByteBufferInputStream

java.lang.Object
  java.io.InputStream
      com.tangosol.io.nio.ByteBufferInputStream

All Implemented Interfaces:

InputStreaming, Closeable

public class ByteBufferInputStream
extends InputStream
implements InputStreaming

An InputStream implementation on top of a Java NIO ByteBuffer.

Since:

Coherence 2.2

Author:

cp 2002.09.06

Field Summary

protected ByteBuffer

m_buf The ByteBuffer object from which data is read.

Constructor Summary

ByteBufferInputStream(ByteBuffer buffer)
Construct a ByteBufferInputStream on a ByteBuffer object.

Method Summary

int	available() Returns 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() Close the stream, flushing any accumulated bytes.
ByteBuffer	getByteBuffer() Obtain the ByteBuffer that this InputStream is based on.
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.
protected NullPointerException	potentialStreamClosedException(NullPointerException e) Check if an NPE is caused by the stream being closed.
int	read() Reads the next byte of data from the input stream.
int	read(byte[] abDest, int ofDest, int cbDest) Reads up to len bytes of data from the 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 lcb) Skips over and discards n bytes of data from this input stream.

Methods inherited from class java.io.InputStream

read

Methods inherited from interface com.tangosol.io.InputStreaming

read

Field Detail

m_buf

protected ByteBuffer m_buf

The ByteBuffer object from which data is read.

Constructor Detail

ByteBufferInputStream

public ByteBufferInputStream(ByteBuffer buffer)

Construct a ByteBufferInputStream on a ByteBuffer object.

Parameters:

buffer - the ByteBuffer to read the data from

Method Detail

getByteBuffer

public ByteBuffer getByteBuffer()

Obtain the ByteBuffer that this InputStream is based on.

Returns:

the underlying ByteBuffer

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 interface InputStreaming

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

read

public int read(byte[] abDest,
                int ofDest,
                int cbDest)
         throws IOException

Reads up to len bytes of data from the input stream into an array of bytes. An attempt is made to read as many as len bytes, but a smaller number may be read, possibly zero. The number of bytes actually read is returned as an integer.

Specified by:

read in interface InputStreaming

Overrides:

read in class InputStream

Parameters:

abDest - the buffer into which the data is read

ofDest - the start offset in array b at which the data is written

cbDest - the maximum number of bytes to 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:

IOException - if an I/O error occurs

skip

public long skip(long lcb)
          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.

Specified by:

skip in interface InputStreaming

Overrides:

skip in class InputStream

Parameters:

lcb - 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 (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 or another thread.

Specified by:

available in interface InputStreaming

Overrides:

available in class InputStream

Returns:

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

Throws:

IOException - if an I/O error occurs

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.

Specified by:

mark in interface InputStreaming

Overrides:

mark in class InputStream

Parameters:

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

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.

Specified by:

reset in interface InputStreaming

Overrides:

reset in class InputStream

Throws:

IOException - if an I/O error occurs.

markSupported

public boolean markSupported()

Tests if this input stream supports the mark and reset methods. The markSupported method of InputStream returns false.

Specified by:

markSupported in interface InputStreaming

Overrides:

markSupported in class InputStream

Returns:

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

close

public void close()
           throws IOException

Close the stream, flushing any accumulated bytes. The underlying buffer is not closed.

Specified by:

close in interface InputStreaming

Specified by:

close in interface Closeable

Overrides:

close in class InputStream

Throws:

IOException - if an I/O error occurs.

potentialStreamClosedException

protected NullPointerException potentialStreamClosedException(NullPointerException e)
                                                       throws IOException

Check if an NPE is caused by the stream being closed. Either throws an IO exception if the stream is closed or throws the original NPE.

Parameters:

e - an NPE

Returns:

this method never returns normally but is designed so that the developer can write "throw potentialStreamClosedException(e)" so that the compiler knows that an exception is thrown at that point in the code

Throws:

IOException - if the stream is closed