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Configuring TimestampLockingPolicy via JPA Persistence Unit Property [message #1220409]

Wed, 11 December 2013 14:54

J H

Messages: 2
Registered: December 2013

Junior Member

I recently came across the TimestampLockingPolicy class which allows setting of version timestamp source (data source or local) when using optimistic locking.

The wiki page http://wiki.eclipse.org/EclipseLink/Examples/JPA/Locking mentions that the behavior can be configured.
I have looked around, even checked the source code but have not found a way to configure the policy from within a JPA project (running inside Glassfish 3 server).

I just wonder if I can configure the behavior via a Persistence Unit property.
Or is there another way to do it within a JPA project?

Thanks a lot,
J

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Re: Configuring TimestampLockingPolicy via JPA Persistence Unit Property [message #1220540 is a reply to message #1220409]

Thu, 12 December 2013 13:00

Lukas Jungmann

Messages: 33
Registered: November 2013
Location: Prague, Czech Republic

Member

Hi,
this can be configured using DescriptorCustomizer (or eventually using SessionCustomizer), ie this way:

@Entity
@Customizer(Cust.class)
public class MyEntity {
...

or in persistence xml using:

      <property name="eclipselink.descriptor.customizer.NewEntity" value="<pkg>.Cust"/>

where Cust.java looks like:

public class Cust implements DescriptorCustomizer {

    @Override
    public void customize(ClassDescriptor cd) throws Exception {
        //TODO: error handling
        TimestampLockingPolicy tlp = (TimestampLockingPolicy) cd.getOptimisticLockingPolicy();
        tlp.useLocalTime();
    }   
}

HTH,
--lukas

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