org.zkoss.zkmax.au.websocket

Class WebSocketServerPush

java.lang.Object

org.zkoss.zkmax.au.websocket.WebSocketServerPush

All Implemented Interfaces:

ServerPush

public class WebSocketServerPush
extends java.lang.Object
implements ServerPush

A server-push implementation that is based on WebSocket. This is the default server-push class when WebSocket connection is enabled. To enable WebSocket connection, please refer to WebSocketWebAppInit for more information.

Since:

8.5.0

Author:

wenninghsu

Constructor Summary

Constructors

Constructor and Description
WebSocketServerPush()

Method Summary

Modifier and Type	Method and Description
boolean	activate(long timeout) Activate the current thread (which must be a server-push thread).
boolean	deactivate(boolean stop) Deactivates the current thread (which must be a server-push thread).
boolean	isActive() Returns if the working thread of the server push is active.
void	onPiggyback() Called when Events.ON_PIGGYBACK is received.
void	resume() Resumes server-push - this is required after desktop recycling.
<T extends Event> void	schedule(EventListener<T> listener, T event, Scheduler<T> scheduler) Called by the associated desktop to schedule a task to execute asynchronously.
void	setReady(boolean ready)
protected void	setWebSocketConnectionInfos(WebSocketEndPoint webSocketEndpoint, javax.servlet.http.HttpServletRequest request)
void	start(Desktop desktop) Starts and initializes the server-push controller.
void	stop() Stops and cleans up the server-push controller.
protected void	wakePending()

Methods inherited from class java.lang.Object

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

Constructor Detail

WebSocketServerPush

public WebSocketServerPush()

Method Detail

setReady

public void setReady(boolean ready)

setWebSocketConnectionInfos

protected void setWebSocketConnectionInfos(WebSocketEndPoint webSocketEndpoint,
                                           javax.servlet.http.HttpServletRequest request)

isActive

public boolean isActive()

Description copied from interface: ServerPush

Returns if the working thread of the server push is active. In other words, it is true if it is between Executions.activate(org.zkoss.zk.ui.Desktop) and Executions.deactivate(org.zkoss.zk.ui.Desktop).

Specified by:

isActive in interface ServerPush

start

public void start(Desktop desktop)

Description copied from interface: ServerPush

Starts and initializes the server-push controller. One server-push controller is associated with exactly one desktop.

ServerPush.start(org.zkoss.zk.ui.Desktop) is called when Desktop.enableServerPush(boolean) is called to enable the server-push feature for the specified desktop.

Specified by:

start in interface ServerPush

stop

public void stop()

Description copied from interface: ServerPush

Stops and cleans up the server-push controller.

ServerPush.stop() is called when Desktop.enableServerPush(boolean) is called to disable the server-push feature, or when the desktop is being removed.

Specified by:

stop in interface ServerPush

resume

public void resume()

Description copied from interface: ServerPush

Resumes server-push - this is required after desktop recycling. (added ServerPush interface to fix ZK-1777)

ServerPush.resume() is called when UiEngine.recycleDesktop(org.zkoss.zk.ui.Execution, org.zkoss.zk.ui.Page, java.io.Writer) is called to resume a previously enabled server-push on the recycled desktop.

Specified by:

resume in interface ServerPush

schedule

public <T extends Event> void schedule(EventListener<T> listener,
                                       T event,
                                       Scheduler<T> scheduler)

Description copied from interface: ServerPush

Called by the associated desktop to schedule a task to execute asynchronously.

The implementation usually delegates the scheduling to the scheduler passed as the third argument, which is controlled by the desktop. Of course, it could schedule it by itself.

Specified by:

schedule in interface ServerPush

Parameters:

listener - the task to execute

event - the event to be passed to the task (i.e., the event listener). It could null or any instance as long as the task recognizes it.

scheduler - the default scheduler to schedule the task. The implementation usually delegates the scheduling back to it. If you prefer to handle it by yourself, you could ignore it.

activate

public boolean activate(long timeout)
                 throws java.lang.InterruptedException,
                        DesktopUnavailableException

Description copied from interface: ServerPush

Activate the current thread (which must be a server-push thread). It causes the current thread to wait until the desktop is available to access, the desktop no longer exists, some other thread interrupts this thread, or a certain amount of real time has elapsed.

The invoker of this method must invoke ServerPush.deactivate(boolean) in this finally clause.

Note: the activation is applied to the desktop that was assigned by ServerPush.start(org.zkoss.zk.ui.Desktop).

Unlike ServerPush.onPiggyback(), this method is NOT called in the context of an event listener. Rather, it is called in the thread of a server-push thread.

Specified by:

activate in interface ServerPush

Parameters:

timeout - the maximum time to wait in milliseconds. Ignored (i.e., never timeout) if non-positive.

Returns:

whether it is activated or it is timeout. The only reason it returns false is timeout.

Throws:

java.lang.InterruptedException - if it is interrupted by other thread

DesktopUnavailableException - if the desktop is removed (when activating).

deactivate

public boolean deactivate(boolean stop)

Description copied from interface: ServerPush

Deactivates the current thread (which must be a server-push thread).

Specified by:

deactivate in interface ServerPush

Parameters:

stop - whether to stop after deactivate

Returns:

true if it is stopped

See Also:

ServerPush.activate(long)

wakePending

protected void wakePending()

onPiggyback

public void onPiggyback()

Description copied from interface: ServerPush

Called when Events.ON_PIGGYBACK is received. The invocation is passive (i.e., triggered by other events, rather than spontaneous).

This method is called in the context of an event listener. In other words, the execution is activated and you can retrieve it by Executions.getCurrent().

Specified by:

onPiggyback in interface ServerPush