DataSourceUtils.getConnection vs DataSource.getConnection

Question

I have datasource bean initialized in the spring context. I wonder what way should be used? Why I just can not write dataSource.getConnection()?

Answer 1

DataSourceUtils#getConnection() pretty clearly documents why you may want to use it: in particular, it uses the Spring JDBC exception hierarchy as opposed to raw SQL exceptions and it will participate in Spring's transaction management facility. If you don't need either of those two features, you can just use DataSource#getConnection() and get on with your code.

Answer 2

There is one important difference: dataSource.getConnection() always returns a new connection obtained from the dataSource or connection pool. DataSourceUtils.getConnection() checks if there is an active transaction for the current thread. If there is one, it will return connection with this transaction. If there is none it will behave exactly the same way as dataSource.getConnection().

You need to be careful when using DataSourceUtils.getConnection(). If it returns connection for the active transaction it means someone else will be closing it since it's the responsibility of whoever opened the transaction. On the other hand, if it returns a brand new connection from the dataSource it's you who should commit/rollback/close it.