Weird GWT and OpenJPA problem
I had the strangest problem the other day. I have a GWT app which uses Spring to load the backend beans – and this has always worked well. Recently I have added a servlet to this application, which provides an entrypoint into the system from another app (in a callback kinda way). Now this servlet needs to load my backend beans (DAO) using Spring, so as to effect changes to my database. I have full SHOW SQL logging on so that I can see every SQL statement that gets executed.
My problem – any kind of SELECT query works fine, retrieving the data as one would expect. However any UPDATE or INSERT just doesn’t happen – and here is the funny thing. No exceptions thrown whatsoever, nothing breaking, but also NO logging – it’s as if the framework just decided to skip the execution of these SQL statements (turns out this was exactly what was happening).
My thinking led me to transactions, and so I started investigating this – I had a @Transactional annotation on a method in my servlet, and it seems that this was the cause of my problems. As soon as I moved the method to a backend POJO bean with an annotated method – problem solved.
My understanding of it isn’t complete (I’m by no means a Spring expert), but I suspect it had something to do with the transaction boundaries being set in the backend layer and not the Service layer??? Please feel free to enlighten me 🙂
For the record, these are my project specs:
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Windows XP
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Tomcat 6.0.16
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GWT 1.5
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OpenJPA 1.1.0
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Spring 2
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Java 1.5
It had me baffled (for a while at least) – hope it can help someone else someday…
