JRebelServerRuntimeReloader.java

package strimillinn.jrebel;

import org.apache.cayenne.DataObject;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.zeroturnaround.javarebel.ClassEventListener;
import org.zeroturnaround.javarebel.ReloaderFactory;

import strimillinn.core.StrimillinnCore;

/**
 * Watches changes to classes, reloads the Cayenne Server Runtime if a DataObject class is changed
 */

public class JRebelServerRuntimeReloader implements ClassEventListener {

	private static final Logger logger = LoggerFactory.getLogger( JRebelServerRuntimeReloader.class );

	/**
	 * Start watching changes to classes. Invoke once, at application startup time.
	 */
	public static void register() {
		ReloaderFactory.getInstance().addClassReloadListener( new JRebelServerRuntimeReloader() );
	}

	/**
	 * Triggered when changes to classes are detected.
	 * 
	 * Reloads the Cayenne Server Runtime if the changed class is a subclass of DataObject (by nullifying a lazily initialized variable)
	 */
	@Override
	public void onClassEvent( int eventType, Class klass ) {
		if( eventType == ClassEventListener.EVENT_RELOADED ) {
			if( DataObject.class.isAssignableFrom( klass ) ) {
				logger.info( "Detected change to DataObject class. Reloading Server Runtime" );
				StrimillinnCore._serverRuntime = null;
			}
		}
	}

	@Override
	public int priority() {
		return 0;
	}
}