org.ptolemy.ptango.lib.webSocket

Class WebSocketEndpoint

java.lang.Object

org.ptolemy.ptango.lib.webSocket.WebSocketEndpoint

All Implemented Interfaces:

org.eclipse.jetty.websocket.WebSocket, org.eclipse.jetty.websocket.WebSocket.OnTextMessage

public class WebSocketEndpoint
extends java.lang.Object
implements org.eclipse.jetty.websocket.WebSocket.OnTextMessage

A class that keeps a reference to the WebSocket connection, notifies services of incoming messages and allows services to write to the WebSocket. Uses Jetty 8 WebSocket classes. Note that Jetty 9 has substantial WebSocket revisions that are not backward compatible. Based on http://java.dzone.com/articles/creating-websocket-chat

Since:

Ptolemy II 11.0

Version:

$Id$

Author:

Elizabeth Latronico

Pt.AcceptedRating:

Red (ltrnc)

Pt.ProposedRating:

Red (ltrnc)

Nested Class Summary

Nested classes/interfaces inherited from interface org.eclipse.jetty.websocket.WebSocket

org.eclipse.jetty.websocket.WebSocket.Connection, org.eclipse.jetty.websocket.WebSocket.FrameConnection, org.eclipse.jetty.websocket.WebSocket.OnBinaryMessage, org.eclipse.jetty.websocket.WebSocket.OnControl, org.eclipse.jetty.websocket.WebSocket.OnFrame, org.eclipse.jetty.websocket.WebSocket.OnTextMessage

Field Summary

Fields

Modifier and Type	Field and Description
(package private) java.lang.Exception	_connectionException An exception that might be thrown when connecting.

Constructor Summary

Constructors

Constructor and Description
WebSocketEndpoint() Create a new WebSocketEndpoint.
WebSocketEndpoint(WebSocketService service) Create a new WebSocketEndpoint with the given parent service.

Method Summary

Modifier and Type	Method and Description
void	addSubscriber(WebSocketService service) Add a subscriber to this endpoint.
void	close() Close the connection.
int	getSubscriberCount() Return the number of subscribers this endpoint has.
boolean	isOpen() Return true if the connection is open; false otherwise.
void	onClose(int statusCode, java.lang.String statusMessage) Upon close, set the connection to null.
void	onMessage(java.lang.String message) Notify subscribers about a new message.
void	onOpen(org.eclipse.jetty.websocket.WebSocket.Connection connection) Upon opening, save a reference to the connection.
void	removeSubscriber(WebSocketService service) Remove the given subscriber for this endpoint.
boolean	sendMessage(java.lang.String message) Send the given message.

Methods inherited from class java.lang.Object

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

Field Detail

_connectionException

java.lang.Exception _connectionException

An exception that might be thrown when connecting.

Constructor Detail

WebSocketEndpoint

public WebSocketEndpoint()

Create a new WebSocketEndpoint.

WebSocketEndpoint

public WebSocketEndpoint(WebSocketService service)

Create a new WebSocketEndpoint with the given parent service.

Parameters:

service - The WebSocketService to be notified of messages.

Method Detail

addSubscriber

public void addSubscriber(WebSocketService service)

Add a subscriber to this endpoint.

Parameters:

service - A parent WebSocketService of this endpoint.

See Also:

removeSubscriber(WebSocketService)

close

public void close()

Close the connection. _connection will be assigned to null in onClose(), which is invoked automatically after a close().

getSubscriberCount

public int getSubscriberCount()

Return the number of subscribers this endpoint has.

Returns:

The number of subscribers this endpoint has.

isOpen

public boolean isOpen()

Return true if the connection is open; false otherwise.

Returns:

True if the connection is open; false otherwise.

onClose

public void onClose(int statusCode,
                    java.lang.String statusMessage)

Upon close, set the connection to null. Note that the connection might be closed unexpectedly and close() is not necessarily called. Synchronized so that onOpen() and onClose() can't be interleaved.

Specified by:

onClose in interface org.eclipse.jetty.websocket.WebSocket

Parameters:

statusCode - The status code of the closed connection.

statusMessage - The status message of the closed connection.

See Also:

onClose(int, String)

onMessage

public void onMessage(java.lang.String message)

Notify subscribers about a new message.

Specified by:

onMessage in interface org.eclipse.jetty.websocket.WebSocket.OnTextMessage

Parameters:

message - The message that was received.

onOpen

public void onOpen(org.eclipse.jetty.websocket.WebSocket.Connection connection)

Upon opening, save a reference to the connection. Synchronized so that onOpen() and onClose() can't be interleaved.

Specified by:

onOpen in interface org.eclipse.jetty.websocket.WebSocket

Parameters:

connection - The connection that was opened.

See Also:

WebSocket.onOpen(Connection)

removeSubscriber

public void removeSubscriber(WebSocketService service)

Remove the given subscriber for this endpoint.

Parameters:

service - A parent WebSocketService of this endpoint.

See Also:

addSubscriber(WebSocketService)

sendMessage

public boolean sendMessage(java.lang.String message)

Send the given message. If the connection is not open, return false. If the connection is not open, there are multiple potential options: the sender could block, messages could be buffered, messages could be discarded, or some combination. Currently, messages are discarded. Synchronized so that only one sender can write to the websocket at a time. Returns true if the message was successfully sent; false otherwise.

Parameters:

message - The message to send.

Returns:

True if the message was successfully sent; false otherwise.