org.realityforge.gwt.webpoller.client

Class WebPoller

java.lang.Object

org.realityforge.gwt.webpoller.client.WebPoller

Direct Known Subclasses:

TimerBasedWebPoller, TimerBasedWebPoller

public abstract class WebPoller
extends java.lang.Object

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	WebPoller.Factory

Field Summary

Fields

Modifier and Type	Field and Description
static int	DEFAULT_ERROR_COUNT_THRESHOLD The number of error before the poller is marked as failed.
static int	DEFAULT_INTER_ERROR_DURATION The duration between attempts when in error.
static int	DEFAULT_INTER_REQUEST_DURATION The duration between polls when not using long polling.

Constructor Summary

Constructors

Constructor and Description
WebPoller()

Method Summary

Modifier and Type	Method and Description
static boolean	deregister(WebPoller.Factory factory)
protected void	doPoll() Perform actual polling.
protected void	doStart() Sub-classes should override this method to provide functionality.
protected void	doStop() Sub-classes should override this method to provide functionality.
int	getErrorCountThreshold()
int	getInterErrorDuration()
int	getInterRequestDuration()
java.util.logging.Level	getLogLevel()
protected RequestContext	getRequestContext()
RequestFactory	getRequestFactory()
protected void	incErrorCount()
boolean	inError()
boolean	isActive()
protected boolean	isInPoll()
boolean	isPaused()
protected abstract boolean	isTimerActive() Return true if the timer or the error timer is active.
static WebPoller	newWebPoller()
protected void	onEmptyPollResult() Invoked after a successful poll returning no data.
protected void	onError(java.lang.Throwable exception) Fire an Error event.
protected void	onMessage(java.util.Map<java.lang.String,java.lang.String> context, java.lang.String data) Fire a Message event.
protected void	onStart() Fire a Start event.
protected void	onStop() Fire a Stop event.
void	pause() Pause the active poller.
protected void	poll() Orchestrate the polling.
protected void	pollReturned() This should be invoked when the poll has completed.
static void	register(WebPoller.Factory factory)
protected void	resetErrorState() Invoked after a successful poll, regardless of whether data was received or not.
void	resume() Resume an already paused poller.
void	setErrorCountThreshold(int errorCountThreshold) Set the number of errors before poller is stopped.
void	setInterErrorDuration(int interErrorDuration)
void	setInterRequestDuration(int interRequestDuration)
void	setListener(WebPollerListener listener)
void	setLogLevel(java.util.logging.Level logLevel)
void	setRequestFactory(RequestFactory requestFactory)
void	start() Start polling.
protected abstract void	startErrorTimer()
protected abstract void	startTimer() Start the timer that triggers the polling.
void	stop() Stop polling.
protected abstract void	stopErrorTimer()
protected abstract void	stopTimer() Stop the timer that is triggering the polling if any exists.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_INTER_REQUEST_DURATION

public static final int DEFAULT_INTER_REQUEST_DURATION

The duration between polls when not using long polling.

See Also:

Constant Field Values

DEFAULT_INTER_ERROR_DURATION

public static final int DEFAULT_INTER_ERROR_DURATION

The duration between attempts when in error.

See Also:

Constant Field Values

DEFAULT_ERROR_COUNT_THRESHOLD

public static final int DEFAULT_ERROR_COUNT_THRESHOLD

The number of error before the poller is marked as failed.

See Also:

Constant Field Values

Constructor Detail

WebPoller

public WebPoller()

Method Detail

newWebPoller

public static WebPoller newWebPoller()

register

public static void register(@Nonnull
                            WebPoller.Factory factory)

deregister

public static boolean deregister(@Nonnull
                                 WebPoller.Factory factory)

getLogLevel

public java.util.logging.Level getLogLevel()

setLogLevel

public void setLogLevel(java.util.logging.Level logLevel)

isActive

public boolean isActive()

Returns:

true if the poller is active.

inError

public boolean inError()

Returns:

true if active and the last poll resulted in error, false otherwise.

start

public void start()
           throws java.lang.IllegalStateException

Start polling.

Throws:

java.lang.IllegalStateException - if the poller is already active.

stop

public void stop()
          throws java.lang.IllegalStateException

Stop polling.

Throws:

java.lang.IllegalStateException - if the poller is not active.

setRequestFactory

public void setRequestFactory(@Nullable
                              RequestFactory requestFactory)

getRequestFactory

public final RequestFactory getRequestFactory()

getErrorCountThreshold

public final int getErrorCountThreshold()

Returns:

the number of errors before poller is stopped.

setErrorCountThreshold

public void setErrorCountThreshold(int errorCountThreshold)

Set the number of errors before poller is stopped.

getInterRequestDuration

public final int getInterRequestDuration()

setInterRequestDuration

public final void setInterRequestDuration(int interRequestDuration)

getInterErrorDuration

public int getInterErrorDuration()

setInterErrorDuration

public void setInterErrorDuration(int interErrorDuration)

setListener

public void setListener(@Nullable
                        WebPollerListener listener)

pause

public void pause()

Pause the active poller. The poller will cease actually polling until resume is called.

Throws:

java.lang.IllegalStateException - if poller is not active or poller is already paused

resume

public void resume()

Resume an already paused poller. The poller will resume polling.

Throws:

java.lang.IllegalStateException - if poller is not active or poller is not paused.

isPaused

public boolean isPaused()

Returns:

true if poller is paused.

doStop

protected final void doStop()

Sub-classes should override this method to provide functionality.

stopTimer

protected abstract void stopTimer()

Stop the timer that is triggering the polling if any exists.

isTimerActive

protected abstract boolean isTimerActive()

Return true if the timer or the error timer is active.

doStart

protected final void doStart()

Sub-classes should override this method to provide functionality.

startErrorTimer

protected abstract void startErrorTimer()

stopErrorTimer

protected abstract void stopErrorTimer()

startTimer

protected abstract void startTimer()

Start the timer that triggers the polling.

onEmptyPollResult

protected final void onEmptyPollResult()

Invoked after a successful poll returning no data.

resetErrorState

protected void resetErrorState()

Invoked after a successful poll, regardless of whether data was received or not.

onStart

protected final void onStart()

Fire a Start event.

onStop

protected final void onStop()

Fire a Stop event.

onMessage

protected final void onMessage(@Nonnull
                               java.util.Map<java.lang.String,java.lang.String> context,
                               @Nonnull
                               java.lang.String data)

Fire a Message event.

onError

protected final void onError(@Nonnull
                             java.lang.Throwable exception)

Fire an Error event. If the number of successive errors reaches a threshold then shut-down the poller.

incErrorCount

protected void incErrorCount()

isInPoll

protected boolean isInPoll()

Returns:

true if a poll request is outstanding.

pollReturned

protected void pollReturned()

This should be invoked when the poll has completed. It may be overriden by sub-classes to perform other cleanup.

poll

protected void poll()

Orchestrate the polling.

getRequestContext

protected final RequestContext getRequestContext()

doPoll

protected void doPoll()

Perform actual polling.