CODEWITHSUNDEEP
javaspringtransactionsspring-mybatis
user6023611
user6023611

Reputation:

Transactional annotation in spring - how does it work?

Let's consider: 

    delete()
    update()
    insert()
    @Transactional
    void doDBstuff(){
      delete()
      update()
      insert
    }

As you can see only doDBstuff. It calls other method (delete, update, insert). All of them using mybatis to work on database.

Tell me please, if this @Transactional annotation should be working. I tested it manually and it seems be ok, however I want to be sure and understand better how does it work.

So I ask for answers:
1. Is it transactional-safe ?
2. How does it work underhood ? I know that it is complex. I mean only some intuion, rougly view on subject.

Upvotes: 1

Views: 3285

Answers (1)

Stefan Nuxoll
Stefan Nuxoll

Reputation: 867

@Transactional works like most other magic in Spring, proxies (or not, if you are using AspectJ). If you inject a bean that has any @Transactional annotations Spring Framework automatically wires up a proxy to ensure any calls to @Transactional methods are wrapped in a transaction as requested by the annotation (and rolled back if an exception is thrown).

As to whether your code will actually run in a transaction or not depends. If you are using AspectJ then yes, it will run in a transaction as expected, end of story. If you are not using AspectJ and Spring has to create a proxy then it will work anywhere it is called on an autowired bean for your class - but if you try to call it on an instance you constructed manually or from within the class itself it will silently fail to run inside a transaction.

Upvotes: 4

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