Java – transaction handling in dao or service layer in pure jdbc without frameworks – software engineering stack exchange

Your problem is, as I understand it, that from the perspective from the service layer, you want small grained DAO functionality (CRUD) that should be combined to more complex database operations on the service layer. Data recovery utah You want to ensure the integrity of the complex operations using db transactions. Data recovery deleted files The issue arising is the visibility of transaction handling and database access outside the dao classes.


Database health check Your business code gets dirty with transaction and connection handling code, distracting away from the BL to happen.

This is a common problem also on ORM based approaches. R studio data recovery software For example on plain Hibernate applications, you need to decide, if you are already in a running session or if you need to start a new session. Data recovery iphone If you encapsulate the hibernate code into seperate classes, you need to handle the opening and closing of the session in a smart way to avoid code duplication.

Another arising issue is the stacking of methods: If each methods handles the connection/transaction, you cannot easily have one method call another.

• The connections are given out using a connection/transaction provider. Ease use data recovery commit and rollback are methods of the provider. Free database software If you open a transaction twice, you need to commit it twice to do the actual commit. Raid 0 data recovery software On rollback, you may want to reconsider the strategy and rollback immediately ignoring the references.

This allows to start transactions and connections on any level of your code, calling beginTransaction is idempotent regarding the database, but will raise a counter. Mail database You need to take care a lot, not to skip a commit on your code, otherwise your transaction boundaries are not going to be executed.

Using this method will clutter your code at every level with obtainConnection/startTransaction/commit/rollback/returnConnection calls. Hdata recovery master There is a lot of boilerplate here.

Yet, keep this method in mind, I solved the stacking issue with this for my frameworks. In database Now, we need to find ways to remove all this connection clutter from our code. Drupal 7 database query Find the following approaches useful, with an emphasis on the third one.

Dependency injection of connection: Your DAOs are not singletons but throw-away objects, receiving the connection on creation time. Data recovery usa The calling code will control the connection creation for you.

Bind the connection/transaction to the running thread: Your DAOs can be singletons. Data recovery business You bind runtime information in a thread local context object. Database visualization The business layer will initialize the context for the DAO. Data recovery qatar For web applications, this can happen on request start.

• The DAO and Service objects are singletons, the services are wrapped with a proxy. Data recovery no root The invocation handler of the proxy will prepare the connection object outside the service class.

• PRO: Stacking is solved by approach given above, doing reference counting. Database keywords Since the invocation handler is the place to obtain the connection, you will not suffer from lost commit/close as the invocation handler will take care of it on return from the proxied object.

• CON: Complex, yet straight forward implementation (you need annotations, proxy, interfaces, context, a factory for your proxied service implementations, possibly major refactorings of your code)

I have implemented all three approaches (without Spring etal). Normalization in database The last one is especially very powerful and cleans up your service infrastructure a lot. Database 3nf You will demystify the frameworks – it is fun to do 🙂

banner