org.jboss.netty.handler.stream
Class ChunkedFile

java.lang.Object
  extended by org.jboss.netty.handler.stream.ChunkedFile
All Implemented Interfaces:
ChunkedInput

public class ChunkedFile
extends Object
implements ChunkedInput

A ChunkedInput that fetches data from a file chunk by chunk.

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

Version:
$Rev: 2243 $, $Date: 2010-04-16 14:01:55 +0900 (Fri, 16 Apr 2010) $
Author:
The Netty Project, Trustin Lee

Constructor Summary
ChunkedFile(File file)
          Creates a new instance that fetches data from the specified file.
ChunkedFile(File file, int chunkSize)
          Creates a new instance that fetches data from the specified file.
ChunkedFile(RandomAccessFile file)
          Creates a new instance that fetches data from the specified file.
ChunkedFile(RandomAccessFile file, int chunkSize)
          Creates a new instance that fetches data from the specified file.
ChunkedFile(RandomAccessFile file, long offset, long length, int chunkSize)
          Creates a new instance that fetches data from the specified file.
 
Method Summary
 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.
 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
 

Constructor Detail

ChunkedFile

public ChunkedFile(File file)
            throws IOException
Creates a new instance that fetches data from the specified file.

Throws:
IOException

ChunkedFile

public ChunkedFile(File file,
                   int chunkSize)
            throws 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:
IOException

ChunkedFile

public ChunkedFile(RandomAccessFile file)
            throws IOException
Creates a new instance that fetches data from the specified file.

Throws:
IOException

ChunkedFile

public ChunkedFile(RandomAccessFile file,
                   int chunkSize)
            throws 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:
IOException

ChunkedFile

public ChunkedFile(RandomAccessFile file,
                   long offset,
                   long length,
                   int chunkSize)
            throws 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:
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 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:
Exception

isEndOfInput

public boolean isEndOfInput()
                     throws 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:
Exception

close

public void close()
           throws Exception
Description copied from interface: ChunkedInput
Releases the resources associated with the stream.

Specified by:
close in interface ChunkedInput
Throws:
Exception

nextChunk

public Object nextChunk()
                 throws 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:
Exception


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