channelservicebean.java

来自「EJB3 Annotation Sample」· Java 代码 · 共 66 行

/*
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 * and open the template in the editor.
 */

package com.s7turn.content.session;

import com.s7turn.content.entities.Channel;
import java.util.List;
import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.NoResultException;
import javax.persistence.PersistenceContext;
import javax.persistence.Query;

/**
 *
 * @author Long
 */
@Stateless
public class ChannelServiceBean implements ChannelServiceLocal {

    @PersistenceContext(unitName="s7turn-pu")
    private EntityManager em;
    
    public void saveChannel(Channel chn) {
        if( chn.getId() == null || new Long(0).equals( chn.getId() ) ){
            em.persist(chn);
        }
        else
        {
            em.merge(chn);
        }
    }

    public void deleteChannel(Channel chn) {
        em.remove( em.merge(chn));
    }

    public List getAllChannel() {
        Query q = em.createNamedQuery("Channel.findAllChannel");
        return q.getResultList();
    }

    public Channel findChannel(String chn) {
        Query q = em.createNamedQuery("Channel.findChannelByName");
        q.setParameter("name", chn);
        return (Channel)q.getSingleResult();
    }

    public Channel findChannelById(long id) {
        Query q = em.createNamedQuery("Channel.findChannelById");
        q.setParameter("id", id);
        try{
            return (Channel)q.getSingleResult();
        }catch(NoResultException re)
        {
            return null;
        }
    }
    
    // Add business logic below. (Right-click in editor and choose
    // "EJB Methods > Add Business Method" or "Web Service > Add Operation")
 
}