OpenJDK 1.23 · java.lang.NullPointerException · APIdia, the JavaDoc alternative

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 suppression were disabled and/or the stack trace was not writable.

Field Summary

Modifier and Type	Field and Description
private transient String	extendedMessage
private transient int	extendedMessageState
private static final long	serialVersionUID Hides java.lang.RuntimeException.serialVersionUID.

Constructor Summary

Access	Constructor and Description
public	NullPointerException() Constructs a `NullPointerException` with no detail message.
public	NullPointerException(String the detail message. s) Constructs a `NullPointerException` with the specified detail message.

Method Summary

Modifier and Type	Method and Description
public synchronized Throwable	fillInStackTrace() Overrides java.lang.Throwable.fillInStackTrace. Fills in the execution stack trace.
private native String	getExtendedNPEMessage() Get an extended exception message.
public String	Returns: the detail message string, which may be `null`. getMessage() Overrides java.lang.Throwable.getMessage. Returns the detail message string of this throwable.

Field Detail

extendedMessage	back to summary
private transient String extendedMessage

extendedMessageState	back to summary
private transient int extendedMessageState

serialVersionUID	back to summary
private static final long serialVersionUID Hides java.lang.RuntimeException.serialVersionUID. Annotations @Serial

Constructor Detail

NullPointerException	back to summary
public NullPointerException() Constructs a `NullPointerException` with no detail message.

NullPointerException back to summary

NullPointerException	back to summary
public NullPointerException(String s) Constructs a `NullPointerException` with the specified detail message. Parameters s:String the detail message.

public NullPointerException(String s)

Constructs a NullPointerException with the specified detail message.

Parameters

s:String: the detail message.

Method Detail

fillInStackTrace back to summary

fillInStackTrace	back to summary
public synchronized Throwable fillInStackTrace() Overrides java.lang.Throwable.fillInStackTrace. Doc from java.lang.Throwable.fillInStackTrace. Fills in the execution stack trace. This method records within this `Throwable` object information about the current state of the stack frames for the current thread. If the stack trace of this `Throwable` is not writable, calling this method has no effect. Returns:Throwable a reference to this `Throwable` instance.

public synchronized Throwable fillInStackTrace()

Overrides java.lang.Throwable.fillInStackTrace.

Doc from java.lang.Throwable.fillInStackTrace.

Fills in the execution stack trace. This method records within this Throwable object information about the current state of the stack frames for the current thread.

If the stack trace of this Throwable is not writable, calling this method has no effect.

Returns:Throwable: a reference to this Throwable instance.

getExtendedNPEMessage	back to summary
private native String getExtendedNPEMessage() Get an extended exception message. This returns a string describing the location and cause of the exception. It returns null for exceptions where this is not applicable.

getMessage back to summary

getMessage	back to summary
public String getMessage() Overrides java.lang.Throwable.getMessage. Returns the detail message string of this throwable. If a non-null message was supplied in a constructor it is returned. Otherwise, an implementation specific message or `null` is returned. Implementation Note If no explicit message was passed to the constructor, and as long as certain internal information is available, a verbose description of the null reference is returned. The internal information is not available in deserialized NullPointerExceptions. Returns:String the detail message string, which may be `null`.

public String getMessage()

Overrides java.lang.Throwable.getMessage.

Returns the detail message string of this throwable.

If a non-null message was supplied in a constructor it is returned. Otherwise, an implementation specific message or null is returned.

Implementation Note

If no explicit message was passed to the constructor, and as long as certain internal information is available, a verbose description of the null reference is returned. The internal information is not available in deserialized NullPointerExceptions.

Returns:String: the detail message string, which may be null.