grails transactional controller, handling exceptions

Question

I have the following method within my controller:

@Transactional
    def update(Filter filterInstance) {
        bindData(filterInstance, params, [include: ['name, 'code', 'value']])

        filterService.update(filterInstance)
        mappingService.update(filterInstance)

        respond  filterInstance
    }

I need to use @Transactional here because I call multiple services. How to handle case when transaction fails for some reason? Should I use try catch or may be there is some other way?

Thanks!

Answer 1

If you have the code inside a controller action, you have to keep an eye on 2 things:

• transactionality (with try/catch/finally etc)
• what should the action return/render in case of TX-success/-failure.

It's complicated enough, so you should put the service calls into another service method, where you have to deal with the transactions only.

A controller action is a place, where you may fire really simple 1-step transactions. If you need to implement a more complex TX-logic, do it on the service layer

see ref-doc on how to control multi-step transactions.

you can make your update() methods return false or throw an exception, and if such thing occurs, call status.setRollbackOnly() . Don't forget also to mark the update() methods with @Transactional(propagation = Propagation.SUPPORTS)