Check exception logic on calls to the EventHandler

In Java SE 6, the EventHandler constructor and create() methods throw a IllegalArgumentException or a NullPointerException if a null is passed for the listener, object, or action parameters. In previous releases, the NullPointerException was thrown later during processing.

This rule flags calls to the java.beans.EventHandler constructor and the create() method so that you can evaluate your exception handling. If your application contains logic to handle the NullPointerException caused by a null parameter, move that logic to the event handler creation time.

For additional information, see item 9 in the Java SE 6 Compatibility guide.