com.suse.salt.netapi.event

Class EventStream

java.lang.Object

com.suse.salt.netapi.event.EventStream

All Implemented Interfaces:

AutoCloseable

public class EventStream
extends Object
implements AutoCloseable

Event stream implementation based on a ClientEndpoint WebSocket. It is used to connect the WebSocket to a ServerEndpoint and receive messages from it; for each message a bunch of EventListener will be recalled and notified with it.

Constructor Summary

Constructors

Constructor and Description
EventStream(ClientConfig config, EventListener... listeners) Constructor used to create an event stream: open a websocket connection and start event processing.

Method Summary

Modifier and Type	Method and Description
void	addEventListener(EventListener listener) Implementation of addEventListener(EventListener)
void	close() Close the WebSocket Session.
void	close(javax.websocket.CloseReason closeReason) Close the WebSocket Session with a given close reason.
int	getListenerCount() Helper method that returns the current number of subscribed listeners.
boolean	isEventStreamClosed() Helper method to check if the WebSocket Session exists and is open.
void	onClose(javax.websocket.Session session, javax.websocket.CloseReason closeReason) On closing the websocket, refresh the session and notify all subscribed listeners.
void	onError(Throwable throwable) On error, convert Throwable into CloseReason and close the session.
void	onMessage(String partialMessage, boolean last) Notify listeners on each event received on the websocket and buffer partial messages.
void	onOpen(javax.websocket.Session session, javax.websocket.EndpointConfig config) On handshake completed, get the WebSocket Session and send a message to ServerEndpoint that WebSocket is ready.
void	removeEventListener(EventListener listener) Implementation of removeEventListener(EventListener).

Methods inherited from class java.lang.Object

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

Constructor Detail

EventStream

public EventStream(ClientConfig config,
                   EventListener... listeners)
            throws SaltException

Constructor used to create an event stream: open a websocket connection and start event processing.

Parameters:

config - client configuration containing the URL, token, timeouts, etc.

listeners - event listeners to be added before stream initialization

Throws:

SaltException - in case of an error during stream initialization

Method Detail

addEventListener

public void addEventListener(EventListener listener)

Implementation of addEventListener(EventListener)

Parameters:

listener - Reference to the class that implements EventListener.

removeEventListener

public void removeEventListener(EventListener listener)

Implementation of removeEventListener(EventListener).

Parameters:

listener - Reference to the class that implements EventListener.

getListenerCount

public int getListenerCount()

Helper method that returns the current number of subscribed listeners.

Returns:

The current number listeners.

isEventStreamClosed

public boolean isEventStreamClosed()

Helper method to check if the WebSocket Session exists and is open.

Returns:

A flag indicating the EventStream WebSocket Session state.

close

public void close()
           throws IOException

Close the WebSocket Session.

Specified by:

close in interface AutoCloseable

Throws:

IOException - in case of an error when closing the session

close

public void close(javax.websocket.CloseReason closeReason)
           throws IOException

Close the WebSocket Session with a given close reason.

Parameters:

closeReason - the reason for the websocket closure

Throws:

IOException - in case of an error when closing the session

onOpen

public void onOpen(javax.websocket.Session session,
                   javax.websocket.EndpointConfig config)
            throws IOException

On handshake completed, get the WebSocket Session and send a message to ServerEndpoint that WebSocket is ready. http://docs.saltstack.com/en/latest/ref/netapi/all/salt.netapi.rest_cherrypy.html#ws

Parameters:

session - The just started WebSocket Session.

config - The EndpointConfig containing the handshake informations.

Throws:

IOException - if something goes wrong sending message to the remote peer

onMessage

public void onMessage(String partialMessage,
                      boolean last)
               throws MessageTooBigException

Notify listeners on each event received on the websocket and buffer partial messages.

Parameters:

partialMessage - partial message received on this websocket

last - indicate the last part of a message

Throws:

MessageTooBigException - in case the message is longer than maxMessageLength

onError

public void onError(Throwable throwable)
             throws IOException

On error, convert Throwable into CloseReason and close the session.

Parameters:

throwable - The Throwable object received on the current error.

Throws:

IOException - in case of an error when closing the session

onClose

public void onClose(javax.websocket.Session session,
                    javax.websocket.CloseReason closeReason)

On closing the websocket, refresh the session and notify all subscribed listeners. Upon exit from this method, all subscribed listeners will be removed.

Parameters:

session - the websocket Session

closeReason - the CloseReason for the websocket closure