Hi all,
I just got subscribed to ejb mailing lists and totally
new to ejb and to this group.
So, pardon me if the doubts which I got are stupid/
very basic level.
I request you to also show me pointers, where I can
get more information.
1. How do you map a entity container managed
bean-field, which is not of java primitive type, but
an instance of a composite class to database. The
bean-field may require mapping to a table than a
column. How can you do it ? Can I assume this is the
limitation of CMP ?
eg., for primitive data type mapping, which is fine.
<object-link>
<bean-field>beanyear</bean-field>
<dbms-column>dbyear</dbms-column>
</object-link>
2. Why does the multiple-result finder methods in the
home interface of entity bean always return either a
enumeration (JDK 1.1) and collection (JDK 1.2)
interfaces ? Can't it return a Vector, HashMap classes
? Is there any restriction for the home interface ?
3. Data synchronization : Does the container-provided
data synchronization for entity beans through
ejbLoad() and ejbStore() is efficient ? When will
these methods be called ? Does every vendor will have
their own way of doing it or is there any standards
again ? My question is, whether these methods will be
called after every update of a field or only after
complete update of all the fields in the bean ? I
couldn't understand this concept. How do the container
know the data in the bean is dirty ?
<vendor> I heard that there is a flag in weblogic
isModified(), which will determine if the data is
dirty or not ? I am not clear about this one too
<vendor>
4. What is the necessity of ejbPostCreate() ? Is there
any thing to be coded here for BMP ? What is the
significance of this method ?
5. Can't you map an entity bean with CMP to more than
one table ? Again is that the limitation ? Whether I
need to go for BMP in this case ? Can someone show the
possible ways to do this with CMP ? Whether all ejb
containers support O-R mapping tools with CMP ?
6. Dependent objects : I am sure that everyone of you
is very familiar with dependent objects. Now when to
instantiate this dependent objects. Assume that I am
going for BMP. Now in which method should I
instantiate the dependent objects ? In ejbLoad() ? In
bean business methods ? How to do lazy initialization
in this case ?
7. Association : How to add associations between two
entity beans ? I am totally unclear about this.
Please treat all the above questions at the very entry
level and request you to give answers.
Thank you for your patience and help,
Manisha
__________________________________________________
Do You Yahoo!?
Yahoo! Mail - Free email you can access from anywhere!
http://mail.yahoo.com/
===========================================================================
To unsubscribe, send email to [EMAIL PROTECTED] and include in the body
of the message "signoff EJB-INTEREST". For general help, send email to
[EMAIL PROTECTED] and include in the body of the message "help".
