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 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
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.