| This interceptor binds a new TopLink Session to the thread before a method
call, closing and removing it afterwards in case of any method outcome.
If there already is a pre-bound Session (e.g. from TopLinkTransactionManager,
or from a surrounding TopLink-intercepted method), the interceptor simply
takes part in it.
Application code must retrieve a TopLink Session via the
SessionFactoryUtils.getSession method or - preferably -
TopLink's own Session.getActiveSession() method, to be able to
detect a thread-bound Session. Typically, the code will look like as follows:
public void doSomeDataAccessAction() {
Session session = this.serverSession.getActiveSession();
...
}
Note that this interceptor automatically translates TopLinkExceptions,
via delegating to the SessionFactoryUtils.convertTopLikAccessException
method that converts them to exceptions that are compatible with the
org.springframework.dao exception hierarchy (like TopLinkTemplate does).
This can be turned off if the raw exceptions are preferred.
This class can be considered a declarative alternative to TopLinkTemplate's
callback approach. The advantages are:
- no anonymous classes necessary for callback implementations;
- the possibility to throw any application exceptions from within data access code.
The drawback is the dependency on interceptor configuration. However, note
that this interceptor is usually not necessary in scenarios where the
data access code always executes within transactions. A transaction will always
have a thread-bound Session in the first place, so adding this interceptor to the
configuration just adds value when potentially executing outside of transactions
and/or when relying on exception translation.
author:
Juergen Hoeller
since:
1.2 |
