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
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 suppression were disabled and/or the stack trace was not writable.
- Since:
- 1.0
- See Also:
- Serialized Form
Constructor Summary
| Constructor | Description |
|---|---|
NullPointerException() | Constructs a |
NullPointerException(String s) | Constructs a |
Method Summary
Methods declared in class java.lang.Throwable
addSuppressed, fillInStackTrace, getCause, getLocalizedMessage, getMessage, getStackTrace, getSuppressed, initCause, printStackTrace, printStackTrace, printStackTrace, setStackTrace, toString Methods declared in 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.