CODEWITHSUNDEEP
javahibernate
pfh
pfh

Reputation: 530

Hibernate multiple users, dynamically changing

There are technically two questions here, but are tightly coupled :)

I'm using Hibernate in a new project. It's a POS project. It uses Oracle database.

We have decided to use Hibernate because the project is large, and because it provides (the most popular) ORM capabilities.

Spring is, for now, out of the question - the reason being: the project is a Swing client-server application, and it adds needless complexity. And, also, Spring is supposed to be very hungry on the hardware resources.

There is a possibility to throw away Hibernate, and to use JDBC. Why? The project requirement is precise database interaction. Meaning, we should have complete control over the connections, sessions and transactions(and, yes, going as low as unoptimized queries).

The first question is - what are your opinions on using the mentioned requrement?

The second question revolves around Hibernate.

We developed a simple Hibernate pilot project. Another project requirement is - one database user / one connection per user / one session per user / transactions are flexibile(we can end them when we want, as sessions). Multiple user can log in the application at the same time.

We achived something like that. To be precise, we achived the full described functionality without the multiple users requirement.

Now, looking at the available resources, I came to a conclusion that if we are to have multiple users on the database(on the same schema), we will end up using multiple SessionFactory, implementing a dynamic ConnectionProvider for new user connections. Why?

The users hashed passwords are in the database, so we need to dynamically add a user to the list of current users.

The second question is - can this be done a little easier, it seems weird that Hibernate doesn't support such configurations.

Thank you.

Upvotes: 3

Views: 4189

Answers (2)

pfh
pfh

Reputation: 530

So, as far as Hibernate goes, I still dont know if the only way to dynamicaly change database users(change database connections) was to create multiple session factories, but I presume it is.

We have lowered our requriements, and decided to use Hibernate, use only one user on the database(one connection), one session per user(multiple sessions/multiple "logical" users). We created a couple of Java classes to wrap that functionality. The resources how this can be done can be found here.

Why did we use Hibernate eventually? Using JDBC is more precise, and more flexibile, but the effort to once again map the ResultSet values into objects is, again, the same manual ORM approach.

For example, if I have a GUI that needs to save a Page, first I have to fetch all the Page Articles and then, after I save the Page, update all the Articles FK to that Page. Notice that Im speaking in nouns(objects), and I dont see any other way to wrap the Page/Articles, except using global state. This is the one thing I wouldnt like to see in my application, and we are, after all, using Java, a OO language.

When we already have an ORM mapper that can be configured(forced would be the more precise word to use in this particular example) to process these thing itself, why to go programming it?

Also, we decided to user google Guice - its much faster, typesafe, and could significantly simplify our development/maintence/testing.

Upvotes: 0

Shivan Dragon
Shivan Dragon

Reputation: 15219

If you're pondering about weather to use Hibernate or JDBC, honestlly go for JDBC. If your domain model is not too complex, you don't really get a lot of advantages from using hibernate. On the other hand using JDBC will greatly improve performance, as you have better control on your queries, and you get A LOT less memory usage from not habing all the Hibernate overhead. Balance this my making an as detailed as possible first scetch of your model. If you're able to schetch it all from the start (no parts that are possible to change wildly in throughout the project), and if said model doesn't look to involved, JDBC will be your friend.

About your users and sessions there, I think you might be mistaking (tho it could just be me), but I don't think you need multiple SessionFactories to have multiple sessions. SessionFactory is a heavy object to initialize, but once you have one you can get multiple hibernate session objects from it which are lightweight.

As a final remark, if you truly stick with an ORM solution (for whatever reason), if possible chose EclipseLink JPA2 implementation. JPA2 has more features over hibernate and the Eclipselink implementation is less buggy then hibernate.

Upvotes: 1

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