entitylifecycledaobean.java

jboss4 + Mysql +ejb3.0 EJB3 简单例子

/**
 * Copyright (c)上海烟草(集团)公司与上海康时信息系统有限公司。
 */
package com.myejb.imp;

import java.util.List;

import javax.ejb.Remote;
import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.persistence.Query;

import com.myejb.EntityLifecycleDAO;
import com.myejb.entity.EntityLifecycle;

/**
 * 
 * @author xywang
 * @since 2009-2-18
 * @version 1.0
 * 
 */
@Stateless
@Remote(EntityLifecycleDAO.class)
public class EntityLifecycleDAOBean implements EntityLifecycleDAO{
    @PersistenceContext protected EntityManager em;
    /* （非 Javadoc）
     * @see com.myejb.EntityLifecycleDAO#load()
     */
    public EntityLifecycle load(){
        return em.find(EntityLifecycle.class,1);
    }

    /* （非 Javadoc）
     * @see com.myejb.EntityLifecycleDAO#persist()
     */
    public void persist(){
        EntityLifecycle cycle = new EntityLifecycle("孙丽");
        em.persist(cycle);
    }

    /* （非 Javadoc）
     * @see com.myejb.EntityLifecycleDAO#remove()
     */
    @SuppressWarnings("unchecked")
    public void remove(){
        Query query = em.createQuery("select e from EntityLifecycle e");
        List<EntityLifecycle> result = (List<EntityLifecycle>)query.getResultList();
        if(result.size()>0){
            EntityLifecycle entity = result.get(0);
            em.remove(entity);
        }
    }

    /* （非 Javadoc）
     * @see com.myejb.EntityLifecycleDAO#update()
     */
    @SuppressWarnings("unchecked")
    public void update(){
        Query query = em.createQuery("select e from EntityLifecycle e");
        List<EntityLifecycle> result = (List<EntityLifecycle>)query.getResultList();
        if(result.size()>0){
            EntityLifecycle entity = result.get(0);
            entity.setName("张权");
        }
    }

}