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
nullobject. - Accessing or modifying the field of a
nullobject. - Taking the length of
nullas if it were an array. - Accessing or modifying the slots of
nullas if it were an array. - Throwing
nullas if it were aThrowablevalue.
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. |