AssertionError

AI-generated Key Takeaways

• AssertionError signals that an assertion has failed during program execution.

• It extends the Error class and provides various constructors to initialize with different data types as detail messages.

• Detail messages are string conversions of the provided values, as defined in the Java Language Specification.

• An AssertionError can be constructed with a cause, which is another Throwable that led to the assertion failure.

• It inherits methods from Throwable for stack trace handling, cause retrieval, and message formatting.

public class AssertionError extends Error

Thrown to indicate that an assertion has failed.

The seven one-argument public constructors provided by this class ensure that the assertion error returned by the invocation:

     new AssertionError(expression)
 

has as its detail message the string conversion of expression (as defined in section 15.18.1.1 of The Java™ Language Specification), regardless of the type of expression.

Public Constructor Summary

	AssertionError() Constructs an AssertionError with no detail message.
	AssertionError(Object detailMessage) Constructs an AssertionError with its detail message derived from the specified object, which is converted to a string as defined in section 15.18.1.1 of The Java™ Language Specification.
	AssertionError(boolean detailMessage) Constructs an AssertionError with its detail message derived from the specified boolean, which is converted to a string as defined in section 15.18.1.1 of The Java™ Language Specification.
	AssertionError(char detailMessage) Constructs an AssertionError with its detail message derived from the specified char, which is converted to a string as defined in section 15.18.1.1 of The Java™ Language Specification.
	AssertionError(int detailMessage) Constructs an AssertionError with its detail message derived from the specified int, which is converted to a string as defined in section 15.18.1.1 of The Java™ Language Specification.
	AssertionError(long detailMessage) Constructs an AssertionError with its detail message derived from the specified long, which is converted to a string as defined in section 15.18.1.1 of The Java™ Language Specification.
	AssertionError(float detailMessage) Constructs an AssertionError with its detail message derived from the specified float, which is converted to a string as defined in section 15.18.1.1 of The Java™ Language Specification.
	AssertionError(double detailMessage) Constructs an AssertionError with its detail message derived from the specified double, which is converted to a string as defined in section 15.18.1.1 of The Java™ Language Specification.
	AssertionError(String message, Throwable cause) Constructs a new AssertionError with the specified detail message and cause.

Inherited Method Summary

From class java.lang.Throwable

synchronized final void	addSuppressed(Throwable exception) Appends the specified exception to the exceptions that were suppressed in order to deliver this exception.
synchronized Throwable	fillInStackTrace() Fills in the execution stack trace.
synchronized 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.
String	getMessage() Returns the detail message string of this throwable.
StackTraceElement[]	getStackTrace() Provides programmatic access to the stack trace information printed by printStackTrace().
synchronized 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.
synchronized 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(PrintWriter s) Prints this throwable and its backtrace to the specified print writer.
void	printStackTrace(PrintStream s) Prints this throwable and its backtrace to the specified print stream.
void	setStackTrace(StackTraceElement[] stackTrace) Sets the stack trace elements that will be returned by getStackTrace() and printed by printStackTrace() and related methods.
String	toString() Returns a short description of this throwable.

From class java.lang.Object

Object	clone() Creates and returns a copy of this Object.
boolean	equals(Object obj) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class<?>	getClass() Returns the unique instance of Class that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait(long timeout, int nanos) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait(long timeout) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait() Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object.

Public Constructors

public AssertionError ()

Constructs an AssertionError with no detail message.

public AssertionError (Object detailMessage)

Constructs an AssertionError with its detail message derived from the specified object, which is converted to a string as defined in section 15.18.1.1 of The Java™ Language Specification.

If the specified object is an instance of Throwable, it becomes the cause of the newly constructed assertion error.

Parameters

detailMessage	value to be used in constructing detail message

See Also

• Throwable.getCause()

public AssertionError (boolean detailMessage)

Constructs an AssertionError with its detail message derived from the specified boolean, which is converted to a string as defined in section 15.18.1.1 of The Java™ Language Specification.

Parameters

detailMessage	value to be used in constructing detail message

public AssertionError (char detailMessage)

Constructs an AssertionError with its detail message derived from the specified char, which is converted to a string as defined in section 15.18.1.1 of The Java™ Language Specification.

Parameters

detailMessage	value to be used in constructing detail message

public AssertionError (int detailMessage)

Constructs an AssertionError with its detail message derived from the specified int, which is converted to a string as defined in section 15.18.1.1 of The Java™ Language Specification.

Parameters

detailMessage	value to be used in constructing detail message

public AssertionError (long detailMessage)

Constructs an AssertionError with its detail message derived from the specified long, which is converted to a string as defined in section 15.18.1.1 of The Java™ Language Specification.

Parameters

detailMessage	value to be used in constructing detail message

public AssertionError (float detailMessage)

Constructs an AssertionError with its detail message derived from the specified float, which is converted to a string as defined in section 15.18.1.1 of The Java™ Language Specification.

Parameters

detailMessage	value to be used in constructing detail message

public AssertionError (double detailMessage)

Constructs an AssertionError with its detail message derived from the specified double, which is converted to a string as defined in section 15.18.1.1 of The Java™ Language Specification.

Parameters

detailMessage	value to be used in constructing detail message

public AssertionError (String message, Throwable cause)

Constructs a new AssertionError with the specified detail message and cause.

Note that the detail message associated with cause is not automatically incorporated in this error's detail message.

Parameters

message	the detail message, may be null
cause	the cause, may be null