April 2003
Beginner to intermediate
380 pages
12h 25m
English
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Transient-Transactional Instances
You can cause transient instances to observe transaction
boundaries, such that their state is preserved at commit and restored on
rollback. A transient instance that observes transaction boundaries is
called a transient-transactional instance
. Support for transient-transactional instances is
optional; their use requires support of the optional TransientTransactional feature. If your implementation does not support TransientTransactional, it will not include
the functionality that causes the state transitions associated with
transient-transactional instances.
You can use the following PersistenceManager methods to make transient
instances transactional:
void makeTransactional(Object obj); void makeTransactionalAll(Object[] objs); void makeTransactionalAll(Collection objs);
After these methods complete, the instances observe transaction
boundaries. If the transaction commits, the transient-transactional
instances retain their values. The makeTransactional( ) method throws a JDOUnsupportedOptionException if you pass a transient instance as a parameter and the
implementation does not support the optional TransientTransactional feature.
If the call to makeTransactional(
) is made within the current transaction and the transaction
is rolled back, the fields of the transient-transactional instances are
restored to the values they had when makeTransactional( )
was called, using their captured before image (discussed in Chapter 14). If the call to makeTransactional( ...
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I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
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I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.