ChainedInterceptor.java

package fr.openwide.core.jpa.hibernate.interceptor;

import java.io.Serializable;
import java.util.List;

import org.hibernate.EmptyInterceptor;
import org.hibernate.type.Type;

import com.google.common.collect.Lists;

/**
 * Hibernate only allows one interceptor per session. While it might seem like a sensible choice to some people, it's
 * a common use to be able to apply different interceptors to different types of entities - or even, several interceptors
 * changing different properties.
 * 
 * Note that we don't implement all the methods of Interceptor as it's probably wise to think twice about it before
 * adding a method here. Not all interceptor methods might be good candidates for this chain mechanism.
 * 
 * This interceptor allows to chain several interceptors.
 *
 */
public class ChainedInterceptor extends EmptyInterceptor {
	
	private List<AbstractChainableInterceptor> interceptors = Lists.newArrayList();

	private static final long serialVersionUID = 3326023814493672159L;
	
	@Override
	public boolean onSave(Object entity, Serializable id, Object[] state, String[] propertyNames, Type[] types) {
		boolean result = false;
		
		for (AbstractChainableInterceptor interceptor : interceptors) {
			if (interceptor.applyTo(entity)) {
				boolean modified = interceptor.onSave(entity, id, state, propertyNames, types);
				result = result || modified;
			}
		}
		return result;
	}
	
	@Override
	public boolean onFlushDirty(Object entity, Serializable id, Object[] currentState, Object[] previousState,
			String[] propertyNames, Type[] types) {
		boolean result = false;
		
		for (AbstractChainableInterceptor interceptor : interceptors) {
			if (interceptor.applyTo(entity)) {
				boolean modified = interceptor.onFlushDirty(entity, id, currentState, previousState, propertyNames, types);
				result = result || modified;
			}
		}
		return result;
	}
	
	@Override
	public void onDelete(Object entity, Serializable id, Object[] state, String[] propertyNames, Type[] types) {
		for (AbstractChainableInterceptor interceptor : interceptors) {
			if (interceptor.applyTo(entity)) {
				interceptor.onDelete(entity, id, state, propertyNames, types);
			}
		}
	}
	
	public ChainedInterceptor add(AbstractChainableInterceptor interceptor) {
		interceptors.add(interceptor);
		return this;
	}

}