Question

Is it ok to open a connection in the init method and close it in the destroy method? Also what’s the best way to open a connection to a mysql database. Currently I’m using this:

Class.forName("com.mysql.jdbc.Driver");

Connection connect = DriverManager.getConnection("jdbc:mysql://" + ipaddress + "?user=" + user + "&password=" + pass);

But I read somewhere that this is inefficient and I should use connection pool. How to do that?

Answer 1

I would strongly suggest using a connection pool, either explicitly (such as c3p0) or one provided by your servlet container.

Open your database connection when you need it, then close it as soon as you can – the connection pool will take care of the real network connection.

Unless you do this, you’ll end up with one connection for your whole application – which means you can only process one query at a time, and all your code needs to synchronize around database queries. Surely you want multiple entirely-independent queries to be able to execute simultaneously? You can’t do this with a single connection.

As for the best way of opening a connection having configured an appropriate connection pool – you may well still end up using DriverManager.getConnection(), but specifying the connection pool instead of mysql directly.