java.lang
Class NullPointerException

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

All Implemented Interfaces:

Serializable

public class NullPointerException
extends RuntimeException   

Thrown when an application attempts to use null in a case where an object is required. These include:

• Calling the instance method of a null object.
• Accessing or modifying the field of a null object.
• Taking the length of null as if it were an array.
• Accessing or modifying the slots of null as if it were an array.
• Throwing null as if it were a Throwable value.

Applications should throw instances of this class to indicate other illegal uses of the null object.

Since:

JDK1.0

See Also:

Serialized Form

Constructor Summary

NullPointerException ()
Constructs a NullPointerException with no detail message.

NullPointerException (String s)
Constructs a NullPointerException with the specified detail message.

Method Summary

Methods inherited from class java.lang.Throwable

fillInStackTrace , getCause , getLocalizedMessage , getMessage , getStackTrace , initCause , printStackTrace , printStackTrace , printStackTrace , setStackTrace , toString

Methods inherited from class java.lang.Object

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

Constructor Detail

NullPointerException

public NullPointerException()

Constructs a NullPointerException with no detail message.

NullPointerException

public NullPointerException(String    s)

Constructs a NullPointerException with the specified detail message.

Parameters:

s - the detail message.