Hello,

I'm trying to use Lazy Loading on one-to-one mappings.

I followed the delegate pattern.

Here are my mappings:

<class name="com.ditech.loanexceptions.db.LoanDbBean"
table="pub.loans" >
<id name="loanNumber" type="string" column="loan_no" >
<generator class="assigned" />
</id>

...

<one-to-one name="loanException"
class="com.ditech.loanexceptions.db.LoanExceptionsDbBean"
cascade="none"
constrained="true"
outer-join="true" />

</class>

<class name="com.ditech.loanexceptions.db.LoanExceptionsDbBean"
table="loan_except"
proxy="com.ditech.loanexceptions.db.LoanExceptionsDbBean" >
<id name="loanNumber" type="string" column="loan_no" >
<generator class="assigned" />
</id>

...

<one-to-one name="loan"
class="com.ditech.loanexceptions.db.LoanDbBean"
cascade="none" />
</class>

It works except when the LoanException has not been created. I get an ObjectNotFoundException


This, of course, makes sense, but I would like to be able to do logic as follows:

LoanExceptionDbBean exception = loan.getException();

if (exception != null) {
// do logic where exception has been created
} else {
// create the exception
}

I thought I could do this if I simple set the "outer-join" attribute to true.

How can I do this without having to catch the "ObjectNotFoundException"?

Thanks,
-Ben

constrainted="true" means mandatory association. Mandatory means every LoanDbBean MUST have associated LoanExceptionsDbBean.

Btw, in the case you decide to drop constrainted="true", remember you will lose lazy loading immediately. Lazy loading for 1-to-1 associations is possible for mandatory associations only:

http://www.hibernate.org/117.html#A14

http://www.hibernate.org/162.html