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package com.sun.enterprise.v3.server;
import com.sun.enterprise.config.serverbeans.Applications;
import com.sun.enterprise.config.serverbeans.DasConfig;
import java.beans.PropertyChangeEvent;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Timer;
import java.util.TimerTask;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.glassfish.hk2.runlevel.RunLevel;
import org.glassfish.internal.api.PostStartupRunLevel;
import javax.inject.Inject;
import org.jvnet.hk2.annotations.Service;
import org.glassfish.hk2.api.PostConstruct;
import org.glassfish.hk2.api.PreDestroy;
import org.glassfish.hk2.api.ServiceLocator;
import org.jvnet.hk2.config.ConfigListener;
import org.jvnet.hk2.config.UnprocessedChangeEvent;
import org.jvnet.hk2.config.UnprocessedChangeEvents;
/**
* A service wrapper around the dynamic reload processor.
* <p>
* The module system will start this service during GlassFish start-up. In turn
* it will start the actual reload logic to run periodically.
* <p>
*
* @author tjquinn
*/
@Service
@RunLevel(PostStartupRunLevel.VAL)
public class DynamicReloadService implements ConfigListener, PostConstruct, PreDestroy {
@Inject
DasConfig activeDasConfig;
@Inject
Applications applications;
@Inject
ServiceLocator habitat;
private Logger logger;
private Timer timer;
private TimerTask timerTask;
private DynamicReloader reloader;
private static final String DEFAULT_POLL_INTERVAL_IN_SECONDS = "2";
private static final List<String> configPropertyNames = Arrays.asList(
"dynamic-reload-enabled", "dynamic-reload-poll-interval-in-seconds"
);
public DynamicReloadService() {
}
public void postConstruct() {
logger = Logger.getLogger(DynamicReloadService.class.getName());
/*
* Create the dynamic reloader right away, even if its use is disabled
* currently. This way any initialization errors will appear early
* in the log rather than later if and when the reloader is
* enabled.
*/
try {
logger.fine("[Reloader] ReloaderService starting");
reloader = new DynamicReloader(
applications,
habitat
);
if (isEnabled(activeDasConfig)) {
start(getPollIntervalInSeconds(activeDasConfig));
} else {
logger.fine("[Reloader] Reloader is configured as disabled, so NOT starting the periodic task");
}
logger.fine("[Reloader] Service start-up complete");
} catch (Exception e) {
logger.log(Level.SEVERE, e.getLocalizedMessage(), e);
}
}
public void preDestroy() {
stop();
}
static String getValue(String value, String defaultValue) {
return (value == null || value.equals("")) ? defaultValue : value;
}
private boolean isEnabled(DasConfig config) {
return Boolean.parseBoolean(config.getDynamicReloadEnabled());
}
private int getPollIntervalInSeconds(DasConfig config) {
int result;
try {
result = Integer.parseInt(config.getDynamicReloadPollIntervalInSeconds());
} catch (NumberFormatException e) {
result = Integer.parseInt(DEFAULT_POLL_INTERVAL_IN_SECONDS);
}
return result;
}
private void start(int pollIntervalInSeconds) {
long pollIntervalInMS = pollIntervalInSeconds * 1000L;
reloader.init();
timer = new Timer("DynamicReloader", true);
timer.schedule(
timerTask = new TimerTask() {
@Override
public void run() {
try {
reloader.run();
} catch (Exception ex) {
ex.printStackTrace();
}
}
},
pollIntervalInMS,
pollIntervalInMS);
logger.fine("[Reloader] Started, monitoring every " +
pollIntervalInSeconds + " seconds"
);
}
private void stop() {
/*
* Tell the running autodeployer to stop, then cancel the timer task
* and the timer.
*/
logger.fine("[Reloader] Stopping");
reloader.cancel();
if(timerTask != null) {
timerTask.cancel();
}
if (timer != null) {
timer.cancel();
}
}
/**
* Reschedules the autodeployer because a configuration change has altered
* the frequency.
*/
private void reschedule(int pollIntervalInSeconds) {
logger.fine("[Reloader] Restarting...");
stop();
try {
reloader.waitUntilIdle();
} catch (InterruptedException e) {
// XXX OK to glide through here?
}
start(pollIntervalInSeconds);
}
public synchronized UnprocessedChangeEvents changed(PropertyChangeEvent[] events) {
/*
* Deal with any changes to the DasConfig that might affect whether
* the reloader should be stopped or started or rescheduled with a
* different frequency. Those change are handled here, by this
* class.
*/
/* Record any events we tried to process but could not. */
List<UnprocessedChangeEvent> unprocessedEvents = new ArrayList<UnprocessedChangeEvent>();
Boolean newEnabled = null;
Integer newPollIntervalInSeconds = null;
for (PropertyChangeEvent event : events) {
String propName = event.getPropertyName();
if (event.getSource() instanceof DasConfig) {
if (configPropertyNames.contains(propName) && (event.getOldValue().equals(event.getNewValue()))) {
logger.fine("[DynamicReload] Ignoring reconfig of " + propName +
" from " + event.getOldValue() + " to " + event.getNewValue());
continue;
}
if (propName.equals("dynamic-reload-enabled")) {
/*
* Either start the currently stopped reloader or stop the
* currently running one.
*/
newEnabled = Boolean.valueOf((String) event.getNewValue());
} else if (propName.equals("dynamic-reload-poll-interval-in-seconds")) {
try {
newPollIntervalInSeconds = new Integer((String) event.getNewValue());
} catch (NumberFormatException ex) {
String reason = ex.getClass().getName() + " " + ex.getLocalizedMessage();
logger.log(Level.WARNING, reason);
}
}
}
}
if (newEnabled != null) {
if (newEnabled) {
start(newPollIntervalInSeconds == null ? getPollIntervalInSeconds(activeDasConfig) : newPollIntervalInSeconds);
} else {
stop();
}
} else {
if (newPollIntervalInSeconds != null && isEnabled(activeDasConfig)) {
/*
* There is no change in whether the reloader should be running, only
* in how often it should run. If it is not running now don't
* start it. If it is running now, restart it to use the new
* polling interval.
*/
reschedule(newPollIntervalInSeconds);
}
}
return (unprocessedEvents.size() > 0) ? new UnprocessedChangeEvents(unprocessedEvents) : null;
}
}