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)	Appends the specified exception to the exceptions that were suppressed in order to deliver this exception.
Throwable	fillInStackTrace()	Fills in the execution stack trace.
Throwable	getCause()	Returns the cause of this throwable or null if the cause is nonexistent or unknown.
String	getLocalizedMessage()	Creates a localized description of this throwable.
StackTraceElement[]	getStackTrace()	Provides programmatic access to the stack trace information printed by Throwable.printStackTrace().
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.
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	printStackTrace(PrintStream s)	Prints this throwable and its backtrace to the specified print stream.
void	printStackTrace(PrintWriter s)	Prints this throwable and its backtrace to the specified print writer.
void	setStackTrace(StackTraceElement[] stackTrace)	Sets the stack trace elements that will be returned by Throwable.getStackTrace() and printed by Throwable.printStackTrace() and related methods.
String	toString()	Returns a short description of this throwable.

Methods declared in class Object

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

Modifier and Type	Method	Description
protected Object	clone()	Creates and returns a copy of this object.
boolean	equals(Object obj)	Indicates whether some other object is "equal to" this one.
protected void	finalize()	Deprecated, for removal: This API element is subject to removal in a future version. Finalization is deprecated and subject to removal in a future release.
final Class<?>	getClass()	Returns the runtime class of this Object.
int	hashCode()	Returns a hash code value for this object.
final void	notify()	Wakes up a single thread that is waiting on this object's monitor.
final void	notifyAll()	Wakes up all threads that are waiting on this object's monitor.
final void	wait()	Causes the current thread to wait until it is awakened, typically by being notified or interrupted.
final void	wait(long timeoutMillis)	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
final void	wait(long timeoutMillis, int nanos)	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

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).