Styjun

I have my version column defined like this

@org.springframework.data.annotation.Version
protected long version;

With Spring Data JDBC it's always trying to INSERT. Updates are not happening. When I debug I see that, PersistentEntityIsNewStrategy is being used which is the default strategy. It has isNew() method to determine the state of the entity being persisted. I do see that version and id are used for this determination.

But my question is who is responsible to increment the version column after every save, so that when the second time .save() is called, the isNew() method can return false.

Should we do fire a BeforeSaveEvent and handle the incrementation of Version column? Would that be good enough to handle the OptimisticLock ?

Edit
I added an ApplicationListener to listen to BeforeSaveEvent like this.

public ApplicationListener<BeforeSaveEvent> incrementingVersion() 
 return event -> 
 Object entity = event.getEntity();
 if (BaseDataModel.class.isAssignableFrom(entity.getClass())) 
 BaseDataModel baseDataModel = (BaseDataModel) entity;
 Long version = baseDataModel.getVersion();
 if (version == null) 
 baseDataModel.setVersion(0L);
 else 
 baseDataModel.setVersion(version + 1L);
 
 
 ;

So now the version column works, but rest of Auditable fields @CreatedAt, @CreatedBy,@LastModifiedDate and @LastModifiedBy are not set!!

Edit2

Created a new ApplicationListener like below. In this case both my custom listener and Spring's RelationalAuditingListener are getting called. But still it doesn't solve the problem. Because the order of listeners[custom one followed by spring's] making the markAudited to invoke markUpdated instead of markCreated, since the version column is already incremented. I tried to make my Listener be the LOWEST_PRECEDENCE still no luck.

My custom listener here

public class CustomRelationalAuditingEventListener
 implements ApplicationListener<BeforeSaveEvent>, Ordered 

@Override
public void onApplicationEvent(BeforeSaveEvent event) 

 Object entity = event.getEntity();
 // handler.markAudited(entity);

 if (BaseDataModel.class.isAssignableFrom(entity.getClass())) 
 BaseDataModel baseDataModel = (BaseDataModel) entity;

 if (baseDataModel.getVersion() == null) 
 baseDataModel.setVersion(0L);
 else 
 baseDataModel.setVersion(baseDataModel.getVersion() + 1L);
 
 


@Override
public int getOrder() 
 return LOWEST_PRECEDENCE;

Currently, you have to increment the version manually and there is no optimistic locking, i.e. the version is only used for checking if an entity is new.

There is an open issue for support of optimistic locking and there is even a PR open for it.
Therefore it is likely that this feature will be available with an upcoming 1.1 milestone.