Mybatis创建SessionFactroy的完美方式

Mybatis创建SessionFactroy的完美方式

/**
     * SqlSessionFactory的生命周期应为全局单例
     */
    public class SqlSessionFactoryUtil{
        //SqlSessionFactory对象
        private static SqlSessionFactory sqlSessionFactory = null;
        //类线程锁
        private static final Class CLASS_LOCK = SqlSessionFactoryUtil.class;
        /*
        * 私有化构造参数
        */
        private SqlSessionFactoryUtil(){     }

        //构建SqlSessionFactory
        public static SqlSessionFactory initSqlSessionFactory(){
            String resouce = "MybatisConfig.xml";
            InputStream inputStream = null;
            try{
                inputStream = Resources.getResourceAsStream(resouce);
            }catch(IOException ex){
                Logger.getLogger(sqlSessionFactoryUtil.class.getName()).log(Level.SEVERE,null,ex);
                System.out.println(ex.getMessage());
            }

            synchronized(CLASS_LOCK){
                if(sqlSessionFactory == null){
                    sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream); 
                }
            }
            return sqlSessionFactory
        }

        //打开SqlSession
        public static SqlSession getSqlSession(){
            if(sqlSessionFactory == null){
                initSqlSessionFactory();
            }
            return sqlSessionFactory.openSqlSession();
        }
    }