Signals that an object cannot be serialized. It is thrown when serialization is attempted on an instance of a class that does not implement the Serializable interface. Note that it is also thrown when an attempt is made to serialize a Serializable object that refers to (or contains) an object that is not Serializable. A subclass of a class that is Serializable can prevent itself from being serialized by throwing this exception from its writeObject( ) and/or readObject( ) methods.

Figure 9-34. java.io.NotSerializableException

public class NotSerializableException extends ObjectStreamException {
// Public Constructors
     public NotSerializableException( );  
     public NotSerializableException(String classname);  
}