java.lang
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 a Throwable
value.
Applications should throw instances of this class to indicate
other illegal uses of the null
object.
- Since:
- JDK1.0
- See Also:
- Serialized Form
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.
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