Java NullPointerException
NullPointerException is a kind of unchecked exception
that occurs when an application attempts to use null in a
case where an object is required. It is also known as runtime time exception,
which occurs while running a program. This type of exception is internal to
the application and extends the java.lang.RuntimeException that is
inherited from java.lang.Exception
class.
NullPointerException must bethrown when an application attempts to use null
in a case where an object is required. These include:
- Calling the instance method
of a
nullobject. - Accessing or modifying the
field of a
nullobject. - Taking the length of
nullas if it were an array.
Read more at:
http:/www.roseindia.net/java/exceptions/exception.shtml