java.lang
Class NullPointerException

java.lang.Object
  java.lang.Throwable
      java.lang.Exception
          java.lang.RuntimeException
              java.lang.NullPointerException

public class NullPointerException
extends RuntimeException

Thrown when attempting to use null where an object is required. The Virtual Machine automatically throws this exception for the following:

• Calling an instance method on a null object
• Accessing or modifying a field of a null object
• Taking the array length of a null array
• Accessing or modifying the slots of a null array
• Throwing a null Throwable
• Synchronizing on a null object

Applications should also throw NullPointerExceptions whenever null is an inappropriate parameter to a method.

Constructor Summary

NullPointerException()
Create an exception without a message.

NullPointerException(String s)
Create an exception with a message.

Method Summary

Methods inherited from class java.lang.Throwable

getCause, getLocalizedMessage, getMessage, initCause, printStackTrace, printStackTrace, printStackTrace, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

NullPointerException

public NullPointerException()

Create an exception without a message.

NullPointerException

public NullPointerException(String s)

Create an exception with a message.

Parameters:

s - the message