Velocity

See http://velocity.apache.org/

How to configure Velocity?

Manage null value

Create class NullValueInsertionEventHandler which implements ReferenceInsertionEventHandler from Velocity that implements the bahaviour of Velocity:

public class NullValueInsertionEventHandler implements ReferenceInsertionEventHandler {

	@Override
	public Object referenceInsert(String string, Object object) {
		if (object == null) {
			return "";
		}
		return object;
	}
}

Use NullValueInsertionEventHandler like this :

IContext context = report.createContext();

EventCartridge eventCartridge = new EventCartridge();
eventCartridge.addEventHandler(new NullValueInsertionEventHandler());
eventCartridge.attachToContext((VelocityContext) context);