- java.lang.Object
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- java.lang.Throwable
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- java.lang.Exception
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- java.lang.RuntimeException
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- java.lang.NullPointerException
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- All Implemented Interfaces:
Serializable
public class NullPointerException extends RuntimeException
Thrown when an application attempts to usenullin 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
nullobject.NullPointerExceptionobjects 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
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Constructor Summary
Constructors Constructor Description NullPointerException()Constructs aNullPointerExceptionwith no detail message.NullPointerException(String s)Constructs aNullPointerExceptionwith the specified detail message.
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Method Summary
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Methods declared in class java.lang.Throwable
addSuppressed, fillInStackTrace, getCause, getLocalizedMessage, getMessage, getStackTrace, getSuppressed, initCause, printStackTrace, printStackTrace, printStackTrace, setStackTrace, toString
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Constructor Detail
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NullPointerException
public NullPointerException()
Constructs aNullPointerExceptionwith no detail message.
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NullPointerException
public NullPointerException(String s)
Constructs aNullPointerExceptionwith the specified detail message.- Parameters:
s- the detail message.
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