MemberListProducer.java

/*
 * JBoss, Home of Professional Open Source
 * Copyright 2013, Red Hat, Inc. and/or its affiliates, and individual
 * contributors by the @authors tag. See the copyright.txt in the
 * distribution for a full listing of individual contributors.
 *
 * Licensed 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.jboss.as.quickstarts.kitchensinkjsp.data;

import org.jboss.as.quickstarts.kitchensinkjsp.model.Member;
import java.util.List;
import javax.annotation.PostConstruct;
import javax.enterprise.context.RequestScoped;
import javax.enterprise.event.Observes;
import javax.enterprise.event.Reception;

import javax.enterprise.inject.Produces;
import javax.inject.Inject;
import javax.inject.Named;
import javax.persistence.EntityManager;
import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Root;

@RequestScoped
public class MemberListProducer {
    @Inject
    private EntityManager em;

    private List<Member> members;

    // @Named provides access the return value via the EL variable name "members" in the UI (e.g.,
    // Facelets or JSP view)
    @Produces
    @Named
    public List<Member> getMembers() {
        return members;
    }

    public void onMemberListChanged(@Observes(notifyObserver = Reception.IF_EXISTS) final Member member) {
        retrieveAllMembersOrderedByName();
    }

    @PostConstruct
    public void retrieveAllMembersOrderedByName() {
        CriteriaBuilder cb = em.getCriteriaBuilder();
        CriteriaQuery<Member> criteria = cb.createQuery(Member.class);
        Root<Member> member = criteria.from(Member.class);
        // Swap criteria statements if you would like to try out type-safe criteria queries, a new
        // feature in JPA 2.0
        // criteria.select(member).orderBy(cb.asc(member.get(Member_.name)));
        criteria.select(member).orderBy(cb.asc(member.get("name")));
        members = em.createQuery(criteria).getResultList();
    }
}