org.tickcode.broadcast.BroadcastImpl.aj Maven / Gradle / Ivy

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package org.tickcode.broadcast;

import org.apache.log4j.Logger;

/**
 * This aspect will provide behavior to any class implementing interfaces that
 * extend {@link Broadcast}. Any interface that extends {@link Broadcast} must
 * have methods that are unique across all the subclass interfaces.
 * 
 * @author Eyon Land
 */
public aspect BroadcastImpl {

	private static Logger log;
	public static boolean loggingOn;
	public static boolean isUsingAspectJ;

	static {
		log = Logger.getLogger(org.tickcode.broadcast.Broadcast.class);
		loggingOn = (log.getEffectiveLevel() != org.apache.log4j.Level.OFF);
		AbstractMessageBroker.setUsingAspectJ(true);
	}
	

	pointcut shouldLog() : !within(Logging) && if(loggingOn);

	pointcut broadcastPointcutWithArguments(Broadcast _this): 
		execution(@BroadcastProducer public * org.tickcode.broadcast.Broadcast+.*(..))		  	
	    && this(_this) && if(AbstractMessageBroker.isUsingAspectJ());

	/**
	 * Use this advice for methods with @BroadcastProducer annotations
	 */
	after(Broadcast _this) returning: broadcastPointcutWithArguments(_this){
		MessageBroker broker = _this.messageBroker;
		if(broker == null)
			throw new NoMessageBrokerException("Did you forget to add " + _this.getClass().getName() + " to a message broker?");

		String methodName = thisJoinPointStaticPart.getSignature().getName();
		Object[] params = thisJoinPoint.getArgs();

		broker.broadcast(_this, methodName, params);

	}

	
	pointcut messageBrokerAddPointcut(MessageBroker _this, Broadcast consumer): 
		execution(public void org.tickcode.broadcast.MessageBroker+.add(Broadcast))		  	
	    && this(_this) && args(consumer) && if(AbstractMessageBroker.isUsingAspectJ());
	/**
	 * This advice will be ensure that the field messageBroker this aspect provides get's set
	 * when the implementation is added to a {@link MessageBroker} implementation.
	 * @param _this
	 * @param consumer
	 */
	before(MessageBroker _this, Broadcast consumer) : messageBrokerAddPointcut(_this, consumer){
		if(consumer.messageBroker != null && consumer.messageBroker != _this)
			throw new OnlyOneMessageBrokerSupportedException("You can only have one MessageBroker for each implementation.");
		consumer.messageBroker = _this;
	}
	
	pointcut messageBrokerRemovePointcut(MessageBroker _this, Broadcast consumer): 
		execution(public void org.tickcode.broadcast.MessageBroker+.remove(Broadcast))		  	
	    && this(_this) && args(consumer) && if(AbstractMessageBroker.isUsingAspectJ());
	/**
	 * When the {@link MessageBroker} removes this implementation of Broadcast, we make sure
	 * our internal messageBroker field gets set to null.
	 * @param _this
	 * @param consumer
	 */
	after(MessageBroker _this, Broadcast consumer) returning : messageBrokerRemovePointcut(_this, consumer){
		consumer.messageBroker = null;
	}

	/**
	 * An internal field to hold the {@link MessageBroker}.  This field is used only by this aspect.
	 * @return
	 */
	private MessageBroker Broadcast.messageBroker;

}