J2EE questions

Hi, all,

first time to this form ,

following are questions from exam. can anybody give me a answer?

1. why are activation and passivation so important for EJB technology? What enterprise computing problems are addressed by these mechanism? how does the EJB container implement the process of activation and passivation in SessionBean and Entity Bean?

2. Describe the mechanism adopted by the EJB container to manage the persistence of an entity bean's state. How does this mechanism differ between entity beans using CMP & entity beans using BMP?

thanks in advance.

activation 和 passivation 其实对于EJB使用并不重要，一般使用无状态Session Bean无需关心 activation and passivation 。

activation 和 passivation是EJB容器实现的内部过程，对于一般EJB使用者无需关心，如果你想做J2EE 容器软件开发，如JBoss等，可以钻研一下。


第二个问题是，现在如果需要事务就用CMP，读取使用DAO＋JDBC，更新的方案是使用JDO，BMP已经被逐步抛弃，只能在旧代码中看到。

这个试题不回答也罢。

thanks.

banq

These two are sample questions from exam. they contribute 12 marks for total score. The real exam question may not be same but could be similar. I must answer them

thanks again for ur answer

你在哪读书呢，大几了:)？

从 i_love_this_game 我猜应该是在地球那一边吧，呵呵，你看英文多溜。不过我到现在对有些概念还不是很清楚，比如，DAO到底是什么东西？是一个概念还是一个解决方案

DAO是持久层设计模式，所以当然是一种解决方案！

该是一个NBA的球迷.

大家好，
哈哈，这么久的帖子都被翻出来了。
读大几了？毕业16年了（绝不是玩笑〕
曾是NBA球迷，乔丹退役后就不怎么看了

祝大家在坛子里玩得愉快

用英文不是为了卖弄，我中文打字速度很慢，请见谅