Class FrameProcessor

java.lang.Object

org.simpleframework.http.socket.service.FrameProcessor

class FrameProcessor
extends Object

The FrameProcessor object is used to process incoming data and dispatch that data as WebSocket frames. Dispatching of the frames is done by making a callback to FrameListener objects registered. In addition to frames this will also notify of any errors that occur or on connection closure.

See Also:

• FrameConsumer

Field Summary

Fields

Modifier and Type	Field	Description
private final Channel	channel	This is the underlying TCP channel this reads frames from.
private final AtomicBoolean	closed	This is used to determine if a close notification was sent.
private final FrameConsumer	consumer	This is used to consume the frames from the underling channel.
private final ByteCursor	cursor	This is the cursor used to maintain a read seek position.
private final FrameEncoder	encoder	This is the encoder that is used to send control messages.
private final ReasonExtractor	extractor	This is used to extract the reason description from a frame.
private final Set<FrameListener>	listeners	This is the set of listeners to dispatch frames to.
private final Reason	normal	This is the reason message used for a normal closure.
private final Session	session	This is the session associated with the WebSocket connection.
private final Trace	trace	This is used to trace the events that occur on the channel.

Constructor Summary

Constructors

Constructor	Description
FrameProcessor(FrameEncoder encoder, Session session, Request request)	Constructor for the FrameProcessor object.

Method Summary

Modifier and Type	Method	Description
void	close()	This is used to close the connection when it has not responded to any activity for a configured period of time.
void	close(Reason reason)	This is used to close the connection without a specific reason.
void	failure(Exception reason)	This is used to report failures back to the client.
void	process()	This is used to process frames consumed from the underlying TCP connection.
void	register(FrameListener listener)	This is used to register a FrameListener to this instance.
void	remove(FrameListener listener)	This is used to remove a FrameListener from this instance.

Methods inherited from class Object

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

Field Details

listeners

private final Set<FrameListener> listeners

This is the set of listeners to dispatch frames to.

extractor

private final ReasonExtractor extractor

This is used to extract the reason description from a frame.

consumer

private final FrameConsumer consumer

This is used to consume the frames from the underling channel.

encoder

private final FrameEncoder encoder

This is the encoder that is used to send control messages.

closed

private final AtomicBoolean closed

This is used to determine if a close notification was sent.

cursor

private final ByteCursor cursor

This is the cursor used to maintain a read seek position.

session

private final Session session

This is the session associated with the WebSocket connection.

channel

private final Channel channel

This is the underlying TCP channel this reads frames from.

normal

private final Reason normal

This is the reason message used for a normal closure.

trace

private final Trace trace

This is used to trace the events that occur on the channel.

Constructor Details

FrameProcessor

public FrameProcessor(FrameEncoder encoder,
 Session session,
 Request request)

Constructor for the FrameProcessor object. This is used to create a processor that can consume and dispatch frames as defined by RFC 6455 to a set of registered listeners.

Parameters:

encoder - this is the encoder used to send control frames

session - this is the session associated with the channel

channel - this is the channel to read frames from

Method Details

register

public void register(FrameListener listener)

This is used to register a FrameListener to this instance. The registered listener will receive all user frames and control frames sent from the client. Also, when the frame is closed or when an unexpected error occurs the listener is notified. Any number of listeners can be registered at any time.

Parameters:

listener - this is the listener that is to be registered

remove

public void remove(FrameListener listener)

This is used to remove a FrameListener from this instance. After removal the listener will no longer receive any user frames or control messages from this specific instance.

Parameters:

listener - this is the listener to be removed

process

public void process()
             throws IOException

This is used to process frames consumed from the underlying TCP connection. It will respond to control frames such as pings and will also handle close frames. Each frame, regardless of its type will be dispatched to any FrameListener objects that are registered with the processor. If an a close frame is received it will echo that close frame, with the same close code and back to the sender as suggested by RFC 6455 section 5.5.1.

Throws:

IOException

failure

public void failure(Exception reason)
             throws IOException

This is used to report failures back to the client. Any I/O or frame processing exception is reported back to all of the registered listeners so that they can take action. The underlying TCP connection is closed after any failure.

Parameters:

reason - this is the cause of the failure

Throws:

IOException

close

public void close(Reason reason)
           throws IOException

This is used to close the connection without a specific reason. The close reason will be sent as a control frame before the TCP connection is terminated. All registered listeners will be notified of the close event.

Parameters:

reason - this is the reason for the connection closure

Throws:

IOException

close

public void close()
           throws IOException

This is used to close the connection when it has not responded to any activity for a configured period of time. It may be possible to send up a control frame, however if the TCP channel is closed this will just notify the listeners.

Throws:

IOException