hibernate之工具类HibernateUtil

1.最简单的工具类，实现SessionFactory的单例共享，session的管理

package com.cc.hibernate;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;

public class HibernateUtil {
    //创建工厂类，是静态的单例的，只能被赋值一次
    private static final SessionFactory sessionFactory=buildSessionFactory();
    /** init sessionFactory */
    private static SessionFactory buildSessionFactory(){
        SessionFactory sessionFactory=null;
        try{
            //configure函数里面可以写hibernate的配置文件，空则默认为hibernate.cfg.xml
            Configuration configuration=new Configuration().configure();
            ServiceRegistry serviceRegistry=new ServiceRegistryBuilder().applySettings(configuration.getProperties()).buildServiceRegistry();
            sessionFactory= configuration.buildSessionFactory(serviceRegistry);
        }
        catch(Throwable te){
            System.err.println("init sessionFactory Error:"+te);
            te.printStackTrace();
        }
        return sessionFactory;
    }
    /** get session */
    public static Session getSession(){
        //得到session
        Session session=sessionFactory.openSession();
        return session;
    }
}

2.将常见事务方法封装进工具类

添加如下方法：

//删除
public static boolean delete(Object obj){
    Session session=null;
    Transaction tran=null;
    boolean result=false;
    try{
        session=getSession();
        tran=session.beginTransaction();
        session.delete(obj);
        tran.commit();
        result=true;
    }
    catch (Exception e){
        if(tran!=null){
            //事物回滚
            tran.rollback();
        }
    }
    finally{
        if(session!=null){
            //关闭session
            session.close();
        }
    }
    return result;
}
//更新
public static boolean update(Object object)
{
    Session session=null;
    Transaction tran=null;
    boolean result=false;
    try{
        session=getSession();
        tran=session.beginTransaction();
        session.update(object);
        tran.commit();
        result=true;
    }
    catch (Exception e){
        if(tran!=null){
            //事物回滚
            tran.rollback();
        }
    }
    finally{
        if(session!=null){
            //关闭session
            session.close();
        }
    }
    return result;
}
//增加
public static boolean add(Object obj){
    Session session=null;
    Transaction tran=null;
    boolean result=false;
    try{
        session=getSession();
        tran=session.beginTransaction();
        session.save(obj);
        tran.commit();
        result=true;
    }
    catch (Exception e){
       if(tran!=null){
           //事物回滚
           tran.rollback();
       }
    }
    finally
    {
        if(session!=null){
            //关闭session
            session.close();
        }
    }
    return result;
}
//执行sql语句，返回单条记录
public static Object queryOne(String sql,String[] param){
    Object object=null;
    Session session=null;
    try{
        session=getSession();
        Query query=session.createQuery(sql);
        if(param!=null){
            for(int i=0;i<param.length;i++){
                query.setString(0,param[i]);
            }
            object=query.uniqueResult();
        }
    }
    catch (Exception e){
    }
    finally{
        if(session!=null){
            session.close();
        }
    }
    return object;
}   

参考：http://blog.csdn.net/hanhan313/article/details/8125924