Yes, this is possible. You can create a connection pool for each of your databases.
When you need a connection for a particular database, you ask one from the corresponding pool.
When you later close that connection, it will be automatically given back to the right pool.
1st you need to configure Tomcat 5.5 with admin console. After configuring that Create a helper class. Use JNDI to look up the connection. Create a static method to get connection(the return type for which is Connection)
I am providing you some part of the code
Whenever you want to create a connection( logical connection), just call Classname.getConnection. (in my case DbUtil.getConnection)