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 a Throwable
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 {@linkplain Throwable#Throwable(String,
Throwable, boolean, boolean) suppression were disabled and/or the
stack trace was not writable}.
Public Constructor Summary
Inherited Method Summary
From class
java.lang.Throwable
synchronized
final
void
|
addSuppressed( Throwable exception)
Appends the specified exception to the exceptions that were
suppressed in order to deliver this exception.
|
synchronized
Throwable
|
|
synchronized
Throwable
|
getCause()
Returns the cause of this throwable or null if the
cause is nonexistent or unknown.
|
String
|
|
String
|
getMessage()
Returns the detail message string of this throwable.
|
StackTraceElement[]
|
|
synchronized
final
Throwable[]
|
getSuppressed()
Returns an array containing all of the exceptions that were
suppressed, typically by the try -with-resources
statement, in order to deliver this exception.
|
synchronized
Throwable
|
initCause( Throwable cause)
Initializes the cause of this throwable to the specified value.
|
void
|
printStackTrace()
Prints this throwable and its backtrace to the
standard error stream.
|
void
|
|
void
|
|
void
|
|
String
|
toString()
Returns a short description of this throwable.
|
From class
java.lang.Object
Object
|
clone()
Creates and returns a copy of this Object .
|
boolean
|
equals( Object obj)
Compares this instance with the specified object and indicates if they
are equal.
|
void
|
finalize()
Invoked when the garbage collector has detected that this instance is no longer reachable.
|
final
Class<?>
|
getClass()
Returns the unique instance of Class that represents this
object's class.
|
int
|
hashCode()
Returns an integer hash code for this object.
|
final
void
|
notify()
Causes a thread which is waiting on this object's monitor (by means of
calling one of the wait() methods) to be woken up.
|
final
void
|
notifyAll()
Causes all threads which are waiting on this object's monitor (by means
of calling one of the wait() methods) to be woken up.
|
String
|
toString()
Returns a string containing a concise, human-readable description of this
object.
|
final
void
|
wait(long timeout, int nanos)
Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the
specified timeout expires.
|
final
void
|
wait(long timeout)
Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the
specified timeout expires.
|
final
void
|
wait()
Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object.
|
Public Constructors
public
NullPointerException
()
Constructs a NullPointerException
with no detail message.
public
NullPointerException
(String s)
Constructs a NullPointerException
with the specified
detail message.