Java Reference
In-Depth Information
Figure 20.2. The classes
Firework
and
Rocket
each have a static method with the same
signature and same return value.
CHALLENGE 20.4
What does the following program print out?
package com.oozinoz.applications;
import com.oozinoz.units.*;
import com.oozinoz.fireworks.*;
public class ShowStatic implements UnitConstants
{
public static void main(String[] args)
{
Length apogee = (Length) METER.times(75);
Firework r = new Rocket("Byebaby", 13.95, apogee);
System.out.println(r.flies());
}
}
In addition to modifiers, return type, and signature, a method header may include a
throws
clause.
This clause limits some of the exceptions that may occur during the method's
execution.
Exceptions in Methods
A method header may declare that the method throws exceptions. An
exception
in Java is an
instance of any subclass of
Throwable
, including the
Exception
class and the
Error
class. Note that the word exception refers to an instance of
Throwable
but not necessarily to
an instance of
Exception
. Figure 20.3 shows part of the
Throwable
hierarchy.
