一、描述：

它是一个新颖的、轻量级的、独立的、易于使用的Java DAO Framework 

二、目的：

• 定义简单
  1. 写DAO层不必像Hibernate或ibatis那样为每个数据实体都创建一个新的配置文件。:)
  2. 只需定义一个接口，集中了对数据库的操作、程序的调用、数据源的使用等。:)

• 使用简单
  1. 使用时只需为数据实体创建一个接口，不需对其实现 :)
  2. 使用主或从主库，指定数据源都在此接口中。 :)

• 不用拼写复杂的sql
  1. 不用程序拼写sql将参数加入进来，框架对参数自动填充处理。:)
  2. 除支持标准sql外，另外增加了动态操作语法：if/else、for 循环等。:)

• 主从分离
  1. 根据查找或更新操作自动的判断使用主或从库。 :)
  2. 执行sql时动态的切换主从数据库，不必为分库烦恼。 :)
  3. 也可在执行强制的使用主或从（暂未实现）。 :(

 @DAO(catalog = "c1")   public interface MailDAO {          // 查询          @SQL(value = "select * from mail")          public List<Mail> queryAll() throws Throwable;             @SQL(value = "select * from mail where id=:1")          public List<Mail> queryById(long id) throws Throwable;             @SQL(value = "select * from mail where id in (:1)")          public List<Mail> queryInIds(List<Long> ids) throws Throwable;             @SQL(value = "select * from mail where mail_user = :1.mailUser and mail_smtp=:1.mailSmtp")          public List<Mail> queryByUser(Mail mail) throws Throwable;             // 更新          @SQL(value = "update mail set mail_user=:1, mail_password=:2")          public UpdateResult upAll(String mailUser, String mailPassword) throws Throwable;             @SQL(value = "update mail set mail_user='sunnymoon', mail_password='passwordhe' where id=:1")          public UpdateResult upById(long id) throws Throwable;             @SQL(value = "update mail set mail_password='passwordhe' where mail_name=:1")          public UpdateResult upByName(String name) throws Throwable;             // 插入          @SQL(value = "insert into mail (mail_user,mail_password,mail_smtp,mail_ssl) values ('ad','ff','dd','1')")          public UpdateResult addMail() throws Throwable;             @SQL(value = "insert into mail (mail_user,mail_password,mail_smtp) values (:1.mailUser, :1.mailPassword, :1.mailSmtp)")          public UpdateResult addMail(Mail mail) throws Throwable;             @SQL(value = "insert into mail (mail_user,mail_password,mail_smtp) values #for(mail in :1) { #if(:current){,} (:mail.mailUser, :mail.mailPassword, :mail.mailSmtp)}")          public UpdateResult addMails(Collection<Mail> mails) throws Throwable;             // 删除          @SQL(value = "delete from mail where id=:1")          public UpdateResult delById(long id) throws Throwable;             @SQL(value = "delete from mail where id in (:1)")          public UpdateResult delInIds(List<Long> ids) throws Throwable;       }

项目主页：http://www.open-open.com/lib/view/home/1331298834968