Java Reference
In-Depth Information
import customer.service.PhoneHandler;
public class FieldDemo
{
public static void main(String [] args)
{
int call = 1;
switch(call)
{
case PhoneHandler.LOCAL :
System.out.println(“Dial 9”);
break;
case PhoneHandler.LONG_DISTANCE :
System.out.println(“Dial 8”);
break;
case PhoneHandler.COLLECT :
System.out.println(“Dial 0”);
break;
}
}
}
Extending Interfaces
An interface can extend another interface, similarly to the way that a class can
extend another class. The extends keyword is used to extend an interface, and
the child interface inherits the methods of the parent interface.
The following SportsListener interface is extended by HockeyListener and
FootballListener interfaces.
//Filename: SportsListener.java
public interface SportsListener
{
public void setHomeTeam(String name);
public void setVisitingTeam(String name);
}
//Filename: FootballListener.java
public interface FootballListener extends SportsListener
{
public void homeTeamScored(int points);
public void visitingTeamScored(int points);
public void endOfQuarter(int quarter);
}
//Filename: HockeyListener.java
