Controller that uses the UserCredentialsDataSourceAdapter

MyController.groovy

class MyController {
  
  def dataSource //instance of UserCredentialsDataSourceAdapter
  
  def index() {
    dataSource.setCredentialsForCurrentThread("user", "password")
    //this will call getConnection("user","password")
    //If we have a service, it will use the same username and password also
    Connection conn = dataSource.getConnection() 
  }
}

I cannot get this to work. What's the import for Connection type??