Birt is a rich open source platform for reporting task performing. I’am just working on it with usefull Eclipse IDE birt reporting tools. Easy to produce reports with chart or multiples data sources.
Good ressources to start available here: http://www.eclipse.org/birt/phoenix/
Exadel has developped an extension for Java Server Faces integration. more details on http://exadel.org/forum/jsf4birt