注:也可不抽取,但每次都需要创建EntityManagerFactory和EntityManager,比较麻烦
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;
/**
* @author:
* @create: 2019/8/12 13:34
* jpa的工具类,提供了加载factory方法,以及获取实体管理器
*/
public class JpaUtils {
private static EntityManagerFactory factory;
static {
factory = Persistence.createEntityManagerFactory("myJpa");
}
public static EntityManager getEntityManager(){
return factory.createEntityManager();
}
}
关于static的技术点
见:https://blog.youkuaiyun.com/ricky_monarch/article/category/9219932