Class HeadlessException

java.lang.Object

java.lang.Throwable

java.lang.Exception

java.lang.RuntimeException

java.lang.UnsupportedOperationException

java.awt.HeadlessException

All Implemented Interfaces:

Serializable

public class HeadlessException
extends UnsupportedOperationException

Thrown when code that is dependent on a keyboard, display, or mouse is called in an environment that does not support a keyboard, display, or mouse. Any code that depends on any of those devices should firstly ensure their availability using the GraphicsEnvironment.isHeadless() method and throw HeadlessException if the latter returns true.

Since:

1.4

See Also:

• GraphicsEnvironment.isHeadless()
• Serialized Form

Constructor Summary

Constructors

Constructor	Description
HeadlessException()	Constructs a new HeadlessException with null as its detail message.
HeadlessException(String msg)	Create a new instance with the specified detailed error message.

Method Summary

Modifier and Type	Method	Description
String	getMessage()	Returns the detail message string of this HeadlessException.

Methods declared in class Throwable

addSuppressed, fillInStackTrace, getCause, getLocalizedMessage, getStackTrace, getSuppressed, initCause, printStackTrace, printStackTrace, printStackTrace, setStackTrace, toString

Modifier and Type	Method	Description
final void	addSuppressed(Throwable exception)	The specified exception is going to be suppressed in order to give priority to this exception (primary exception) and to be appended to the list of suppressed exceptions.
Throwable	fillInStackTrace()	Record in the receiver a walkback from the point where this message was sent.
Throwable	getCause()	Answers the cause of this Throwable, or null if there is no cause.
String	getLocalizedMessage()	Answers the extra information message which was provided when the throwable was created.
StackTraceElement[]	getStackTrace()	Answers an array of StackTraceElement.
final Throwable[]	getSuppressed()	Returns an array of exceptions suppressed, typically by the automatically generated code from the try-with-resources statement, in order to give priority to this exception (primary exception).
Throwable	initCause(Throwable throwable)	Initialize the cause of the receiver.
void	printStackTrace()	Outputs a printable representation of the receiver's walkback on the System.err stream.
void	printStackTrace(PrintStream err)	Outputs a printable representation of the receiver's walkback on the stream specified by the argument.
void	printStackTrace(PrintWriter err)	Outputs a printable representation of the receiver's walkback on the writer specified by the argument.
void	setStackTrace(StackTraceElement[] trace)	Sets the array of StackTraceElements.
String	toString()	Answers a string containing a concise, human-readable description of the receiver.

Methods declared in class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Modifier and Type	Method	Description
protected Object	clone()	Answers a new instance of the same class as the receiver, whose slots have been filled in with the values in the slots of the receiver.
boolean	equals(Object o)	Compares the argument to the receiver, and answers true if they represent the same object using a class specific comparison.
protected void	finalize()	Deprecated, for removal: This API element is subject to removal in a future version. May cause performance issues, deadlocks and hangs.
final Class<? extends Object>	getClass()	Answers the unique instance of java.lang.Class which represents the class of the receiver.
int	hashCode()	Answers an integer hash code for the receiver.
final void	notify()	Causes one thread which is waiting on the receiver to be made ready to run.
final void	notifyAll()	Causes all threads which are waiting on the receiver to be made ready to run.
final void	wait()	Causes the thread which sent this message to be made not ready to run pending some change in the receiver (as indicated by notify or notifyAll).
final void	wait(long time)	Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.
final void	wait(long time, int frac)	Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.

Constructor Details

HeadlessException

public HeadlessException()

Constructs a new HeadlessException with null as its detail message. The default headless message may replace null in some cases, as outlined below.

For such HeadlessException the default headless error message may be auto-generated for some platforms. The text of the default headless message may depend on whether the GraphicsEnvironment is in fact headless. That is, the default headless message is both system and environmentally dependent.

HeadlessException

public HeadlessException(String msg)

Create a new instance with the specified detailed error message. For some platforms the default headless error message may be added at the end of the specified message. The text of the default headless message may depend on whether the GraphicsEnvironment is in fact headless. That is, the default headless message is both system and environmentally dependent.

Parameters:

msg - the error message

Method Details

getMessage

public String getMessage()

Returns the detail message string of this HeadlessException. Depending on the platform the message specified in the constructor may be followed by the default headless error message. The text of the default headless message may depend on whether the GraphicsEnvironment is in fact headless. That is, the default headless message is both system and environmentally dependent.

Overrides:

getMessage in class Throwable

Returns:

the detail message string of this HeadlessException instance (which may be null).