org.simpleframework.http.message
Class UpdateConsumer

java.lang.Object
  org.simpleframework.http.message.UpdateConsumer

All Implemented Interfaces:

BodyConsumer, ByteConsumer

Direct Known Subclasses:

ChunkedConsumer, FixedLengthConsumer

public abstract class UpdateConsumer
extends Object
implements BodyConsumer

The UpdateConsumer object is used to create a consumer that is used to consume and process large bodies. Typically a large body will be one that is delivered as part of a multipart upload or as a large form POST. The task of the large consumer is to consume all the bytes for the body, and reset the cursor after the last byte that has been send with the body. This ensures that the next character read from the cursor is the first character of a HTTP header within the pipeline.

Author:

Niall Gallagher

Field Summary

protected byte[]	array This is an external array used to copy data between buffers.
protected boolean	finished This is used to determine whether the consumer has finished.

Constructor Summary

protected	UpdateConsumer() Constructor for the UpdateConsumer object.
protected	UpdateConsumer(int chunk) Constructor for the UpdateConsumer object.

Method Summary

protected void	commit(ByteCursor cursor) This method can be used to commit the consumer when all data has been consumed.
void	consume(ByteCursor cursor) This method is used to consume bytes from the provided cursor.
boolean	isFinished() This is used to determine whether the consumer has finished reading.
protected abstract int	update(byte[] array, int off, int count) This is used to process the bytes that have been read from the cursor.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.simpleframework.http.message.BodyConsumer

getBody

Field Detail

array

protected byte[] array

This is an external array used to copy data between buffers.

finished

protected boolean finished

This is used to determine whether the consumer has finished.

Constructor Detail

UpdateConsumer

protected UpdateConsumer()

Constructor for the UpdateConsumer object. This is used to create a consumer with a one kilobyte buffer used to read the contents from the cursor and transfer it to the buffer.

UpdateConsumer

protected UpdateConsumer(int chunk)

Constructor for the UpdateConsumer object. This is used to create a consumer with a variable size buffer used to read the contents from the cursor and transfer it to the buffer.

Parameters:

chunk - this is the size of the buffer used to read bytes

Method Detail

isFinished

public boolean isFinished()

This is used to determine whether the consumer has finished reading. The consumer is considered finished if it has read a terminal token or if it has exhausted the stream and can not read any more. Once finished the consumed bytes can be parsed.

Specified by:

isFinished in interface ByteConsumer

Returns:

true if the consumer has finished reading its content

consume

public void consume(ByteCursor cursor)
             throws IOException

This method is used to consume bytes from the provided cursor. Consuming of bytes from the cursor should be done in such a way that it does not block. So typically only the number of ready bytes in the ByteCursor object should be read. If there are no ready bytes then this will return.

Specified by:

consume in interface ByteConsumer

Parameters:

cursor - used to consume the bytes from the HTTP pipeline

Throws:

IOException

commit

protected void commit(ByteCursor cursor)
               throws IOException

This method can be used to commit the consumer when all data has been consumed. It is often used to push back some data on to the cursor so that the next consumer can read valid tokens from the stream of bytes. If no commit is required then the default implementation of this will simply return quietly.

Parameters:

cursor - this is the cursor used by this consumer

Throws:

IOException

update

protected abstract int update(byte[] array,
                              int off,
                              int count)
                       throws IOException

This is used to process the bytes that have been read from the cursor. Depending on the delimiter used this knows when the end of the body has been encountered. If the end is encountered this method must return the number of bytes overflow, and set the state of the consumer to finished.

Parameters:

array - this is a chunk read from the cursor

off - this is the offset within the array the chunk starts

count - this is the number of bytes within the array

Returns:

this returns the number of bytes overflow that is read

Throws:

IOException