NullPointerException
public
class
NullPointerException
extends RuntimeException
java.lang.Object | ||||
↳ | java.lang.Throwable | |||
↳ | java.lang.Exception | |||
↳ | java.lang.RuntimeException | |||
↳ | java.lang.NullPointerException |
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 stack trace was not writable.
Summary
Public constructors | |
---|---|
NullPointerException()
Constructs a |
|
NullPointerException(String s)
Constructs a |
Inherited methods | |
---|---|
Public constructors
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 |
String : the detail message. |