Sharing a jdbc "Connection" across threads

I wouldn't recommend you to share connection between threads, as operations with connection is quite slow and overall performance of you application may harm.

I would rather suggest you to use Apache Connections Pool and provide separate connection to each thread.

You could create a proxy class that holds the JDBC connection and gives synchronized accessto it. The threads should never directly access the connection.

Depending on the use and the operations you provide you could use synchronized methods, or lock on objects if the proxy needs to be locked till he leaves a certain state.

For those not familiar with the proxy design pattern. Here the wiki article. The basic idea is that the proxy instance hides another object, but offers the same functionality.

In this case, consider creating a separate connection for each worker. If any one worker fails, roll back all the connections. If all pass, commit all connections.

If you're going to have hundreds of workers, then you'll need to provide synchronized access to the Connection objects, or use a connection pool as @mike and @NKukhar suggested.