org.jboss.netty.handler.stream

Class ChunkedNioFile

java.lang.Object

org.jboss.netty.handler.stream.ChunkedNioFile

All Implemented Interfaces:

ChunkedInput

public class ChunkedNioFile
extends java.lang.Object
implements ChunkedInput

A ChunkedInput that fetches data from a file chunk by chunk using NIO FileChannel.

If your operating system supports zero-copy file transfer such as sendfile(), you might want to use FileRegion instead.

Field Summary

Fields

Modifier and Type	Field and Description
private int	chunkSize
private long	endOffset
private java.nio.channels.FileChannel	in
private long	offset
private long	startOffset

Constructor Summary

Constructors

Constructor and Description
ChunkedNioFile(java.io.File in) Creates a new instance that fetches data from the specified file.
ChunkedNioFile(java.nio.channels.FileChannel in) Creates a new instance that fetches data from the specified file.
ChunkedNioFile(java.nio.channels.FileChannel in, int chunkSize) Creates a new instance that fetches data from the specified file.
ChunkedNioFile(java.nio.channels.FileChannel in, long offset, long length, int chunkSize) Creates a new instance that fetches data from the specified file.
ChunkedNioFile(java.io.File in, int chunkSize) Creates a new instance that fetches data from the specified file.

Method Summary

Modifier and Type	Method and Description
void	close() Releases the resources associated with the stream.
long	getCurrentOffset() Returns the offset in the file where the transfer is happening currently.
long	getEndOffset() Returns the offset in the file where the transfer will end.
long	getStartOffset() Returns the offset in the file where the transfer began.
boolean	hasNextChunk() Returns true if and only if there is any data left in the stream.
boolean	isEndOfInput() Return true if and only if there is no data left in the stream and the stream has reached at its end.
java.lang.Object	nextChunk() Fetches a chunked data from the stream.

Methods inherited from class java.lang.Object

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

Field Detail

in

private final java.nio.channels.FileChannel in

startOffset

private final long startOffset

endOffset

private final long endOffset

chunkSize

private final int chunkSize

offset

private long offset

Constructor Detail

ChunkedNioFile

public ChunkedNioFile(java.io.File in)
               throws java.io.IOException

Creates a new instance that fetches data from the specified file.

Throws:

java.io.IOException

ChunkedNioFile

public ChunkedNioFile(java.io.File in,
                      int chunkSize)
               throws java.io.IOException

Creates a new instance that fetches data from the specified file.

Parameters:

chunkSize - the number of bytes to fetch on each nextChunk() call

Throws:

java.io.IOException

ChunkedNioFile

public ChunkedNioFile(java.nio.channels.FileChannel in)
               throws java.io.IOException

Creates a new instance that fetches data from the specified file.

Throws:

java.io.IOException

ChunkedNioFile

public ChunkedNioFile(java.nio.channels.FileChannel in,
                      int chunkSize)
               throws java.io.IOException

Creates a new instance that fetches data from the specified file.

Parameters:

chunkSize - the number of bytes to fetch on each nextChunk() call

Throws:

java.io.IOException

ChunkedNioFile

public ChunkedNioFile(java.nio.channels.FileChannel in,
                      long offset,
                      long length,
                      int chunkSize)
               throws java.io.IOException

Creates a new instance that fetches data from the specified file.

Parameters:

offset - the offset of the file where the transfer begins

length - the number of bytes to transfer

chunkSize - the number of bytes to fetch on each nextChunk() call

Throws:

java.io.IOException

Method Detail

getStartOffset

public long getStartOffset()

Returns the offset in the file where the transfer began.

getEndOffset

public long getEndOffset()

Returns the offset in the file where the transfer will end.

getCurrentOffset

public long getCurrentOffset()

Returns the offset in the file where the transfer is happening currently.

hasNextChunk

public boolean hasNextChunk()
                     throws java.lang.Exception

Description copied from interface: ChunkedInput

Returns true if and only if there is any data left in the stream. Please note that false does not necessarily mean that the stream has reached at its end. In a slow stream, the next chunk might be unavailable just momentarily.

Specified by:

hasNextChunk in interface ChunkedInput

Throws:

java.lang.Exception

isEndOfInput

public boolean isEndOfInput()
                     throws java.lang.Exception

Description copied from interface: ChunkedInput

Return true if and only if there is no data left in the stream and the stream has reached at its end.

Specified by:

isEndOfInput in interface ChunkedInput

Throws:

java.lang.Exception

close

public void close()
           throws java.lang.Exception

Description copied from interface: ChunkedInput

Releases the resources associated with the stream.

Specified by:

close in interface ChunkedInput

Throws:

java.lang.Exception

nextChunk

public java.lang.Object nextChunk()
                           throws java.lang.Exception

Description copied from interface: ChunkedInput

Fetches a chunked data from the stream. The returned chunk is usually a ChannelBuffer, but you could extend an existing implementation to convert the ChannelBuffer into a different type that your handler or encoder understands. Once this method returns the last chunk and thus the stream has reached at its end, any subsequent ChunkedInput.isEndOfInput() call must return false.

Specified by:

nextChunk in interface ChunkedInput

Returns:

the fetched chunk, which is usually ChannelBuffer. null if there is no data left in the stream. Please note that null does not necessarily mean that the stream has reached at its end. In a slow stream, the next chunk might be unavailable just momentarily.

Throws:

java.lang.Exception