Usage of the methods of Throwable requires that the class be extended and that a subclass of Throwable will have access to the methods of its superclass. Throwable has four constructors:
Also, as a superclass, Throwable has several methods which are available to all classes which inherit from it:
printStackTrace()—Prints the string return by toString() followed by the execution stack trace showing the sequence of a method invocations that led to the exception being thrown