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 aThrowable
value.
Applications should throw instances of this class to indicate
other illegal uses of the null
object.
NullPointerException
objects may be constructed by the
virtual machine as if suppression were disabled and/or the
stack trace was not writable.
- Since:
- 1.0
- See Also:
- Serialized Form
-
Constructor Summary
Constructors Constructor Description NullPointerException()
Constructs aNullPointerException
with no detail message.NullPointerException(String s)
Constructs aNullPointerException
with the specified detail message. -
Method Summary
Methods declared in class java.lang.Throwable
addSuppressed, fillInStackTrace, getCause, getLocalizedMessage, getMessage, getStackTrace, getSuppressed, initCause, printStackTrace, printStackTrace, printStackTrace, setStackTrace, toString
-
Constructor Details
-
NullPointerException
public NullPointerException()Constructs aNullPointerException
with no detail message. -
NullPointerException
Constructs aNullPointerException
with the specified detail message.- Parameters:
s
- the detail message.
-