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COP-3804 Intermediate Java Programming Final Date: Aug, 7th 2007 Grade: _____/100
(This final consists of three pages)
Name: _______________________________________________ Last 4 digits PantherID: __________
We are given the following classes: an abstract class Animal, an interface Whistler, another interface
Fyable and a concrete class Parrot that inherits from class Animal and implements interfaces Whistler and
Flyable. Complete implementations for these classes and interfaces are provided below.
Class Animal has two abstract methods eat() and
whoAmI(), that concrete (non-abstract) classes need to
implement.
public abstract class Animal{
private String id;
public Animal( ){
id = "";
}
public Animal( String id ){
this.id = id;
}
public void setId( String id ){
this.id = id;
}
public String getId( ){
return id;
}
public abstract void eat( );
public abstract void whoAmI( );
}
Interface Whistler has one method to be implemented
by classes inheriting from it.
public interface Whistler{
int LOUD = 10;
int LOW = 0;
void whistle( );
}
Interface Flyable allows a class to implement the
flying behavior; that class needs to implement: fly,
canFly and isAbleToFly methods.
public interface Flyable{
void fly( );
void canFly( boolean can );
boolean isAbleToFly( );
}
Class Parrot implements abstract methods eat() and
whoAmI() from class Animal, and also method
whistle() from interface Whistler (see next column).
public class Parrot extends Animal
implements Whistler, Flyable {
private int intensity;
private boolean flies;
public Parrot( ){
intensity = LOW;
flies = true;
}
public Parrot( int intensity, String id ){
super(id);
this.intensity = intensity;
flies = true;
}
public Parrot( boolean flies, int intensity, String id ){
super(id);
this.intensity = intensity;
this.flies = flies;
}
public void setIntensity( int intensity ){
this.intensity = intensity;
}
public int getIntensity( ){
return intensity;
}
public void eat( ){
System.out.println( "Parrot "+getId()+" eating." );
}
public void whoAmI( ){
System.out.println( "I'm parrot "+getId()+"." );
}
public void whistle( ){
String intStr = "loudly";
if ( intensity < LOUD )
intStr = "lowly";
System.out.println( "Parrot "+getId()+
" whistling "+intStr+"." );
}
public void fly( ){
if ( isAbleToFly() )
System.out.println( "Parrot "+getId()+" is flying." );
else
System.out.println( "Parrot "+getId()+
" wished it could fly." );
}
public void canFly( boolean can ){
flies = can;
}
public boolean isAbleToFly( ){
return flies;
}
}
