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Spring/Hibernate: InvocationTargetException when deleting entity

Answer 1

+1 A:

The exception has to do with how hibernate stores objects in it's Session and where you've set your transaction boundaries. I'm assuming that the transaction boundary is around the code posted in "Update 2". When you ask hibernate to delete something, it doesn't execute the query right then. Rather, it queues up that query for execution the next time the Session is flushed to the database. Inserts are done the same way. This allows Hibernate to batch up similar queries for efficieny reasons.

Typically the session is flushed when the transaction is committed. The initial request for the object stores that object by id in the Hibernate session, and the delete marks that object for deletion when the 'delete' method is called. When you try to associate a new object with the same id, Hibernate doesn't know what to do at this point and throws an exception. It seems to me that there are two possibilities for how to handle your particular situation.

Explicitly flush the Session after the delete. You may also need to call 'evict' as well, I don't recall if flush() does this automatically or not.
Change the logic of your code to something like this:


    MyEntity instance = myEntityService.read(instance.getId());
    if (instance == null) {
      instance = new MyEntity();
    }
    fillEntityFromRequest(instance, request);
    myEntityService.save(instance); // calls saveOrUpdate() method

By updating the object returned from the 'read' method, you're updating the object that Hibernate already knows about. The 'saveOrUpdate' method knows how to perform either an UPDATE statement on the object or a new INSTANCE, based on whether the object in question is already in the Hibernate session.

David 2010-05-17 15:19:56

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Spring/Hibernate: InvocationTargetException when deleting entity

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