/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.mahout.cf.taste.ejb;
import org.apache.mahout.cf.taste.common.Refreshable;
import org.apache.mahout.cf.taste.common.TasteException;
import org.apache.mahout.cf.taste.model.Item;
import org.apache.mahout.cf.taste.recommender.RecommendedItem;
import org.apache.mahout.cf.taste.recommender.Recommender;
import org.apache.mahout.cf.taste.recommender.Rescorer;
import javax.ejb.CreateException;
import javax.ejb.SessionBean;
import javax.ejb.SessionContext;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import java.util.Collection;
import java.util.List;
/**
* <p>Recommender EJB bean implementation.</p>
*
* <p>This class exposes a subset of the {@link Recommender} API. In particular it
* does not support {@link Recommender#getDataModel()}
* since it doesn't make sense to access this via an EJB component.</p>
*/
public class RecommenderEJBBean implements SessionBean {
private Recommender recommender;
public List<RecommendedItem> recommend(Object userID, int howMany) throws TasteException {
return recommender.recommend(userID, howMany);
}
public List<RecommendedItem> recommend(Object userID, int howMany, Rescorer<Item> rescorer)
throws TasteException {
return recommender.recommend(userID, howMany, rescorer);
}
public double estimatePreference(Object userID, Object itemID) throws TasteException {
return recommender.estimatePreference(userID, itemID);
}
public void setPreference(Object userID, Object itemID, double value) throws TasteException {
recommender.setPreference(userID, itemID, value);
}
public void removePreference(Object userID, Object itemID) throws TasteException {
recommender.removePreference(userID, itemID);
}
public void refresh(Collection<Refreshable> alreadyRefreshed) {
recommender.refresh(alreadyRefreshed);
}
@Override
public void setSessionContext(SessionContext sessionContext) {
// Do nothing
}
public void ejbCreate() throws CreateException {
Context ctx = null;
try {
ctx = new InitialContext();
String recommenderClassName = (String) ctx.lookup("java:comp/env/recommender-class");
if (recommenderClassName == null) {
String recommenderJNDIName = (String) ctx.lookup("java:comp/env/recommender-jndi-name");
if (recommenderJNDIName == null) {
throw new CreateException("recommender-class and recommender-jndi-name env-entry not defined");
}
recommender = (Recommender) ctx.lookup("java:comp/env/" + recommenderJNDIName);
} else {
recommender = Class.forName(recommenderClassName).asSubclass(Recommender.class).newInstance();
}
} catch (NamingException ne) {
throw new CreateException(ne.toString());
} catch (ClassNotFoundException cnfe) {
throw new CreateException(cnfe.toString());
} catch (InstantiationException ie) {
throw new CreateException(ie.toString());
} catch (IllegalAccessException iae) {
throw new CreateException(iae.toString());
} finally {
if (ctx != null) {
try {
ctx.close();
} catch (NamingException ne) {
throw new CreateException(ne.toString());
}
}
}
}
@Override
public void ejbRemove() {
// Do nothing
}
@Override
public void ejbActivate() {
// Do nothing: stateless session beans are not passivated/activated
}
@Override
public void ejbPassivate() {
// Do nothing: stateless session beans are not passivated/activated
}
@Override
public String toString() {
return "RecommenderEJBBean[recommender:" + recommender + ']';
}
}