Facade パターン

 package driving;
 class Car{
     private int speed;
     private int distance;
     Car(){
         this.speed = 0;
         this.distance = 0;
     }
     void setSpeed(int speed){
         this.speed = speed;
     }
     void run(int minutes){
         this.distance += minutes * this.speed;
     }
     int getDistance(){
         return this.distance;
     }
 }

 package driving;
 class Driver{
     private Car car;
     Driver(Car car){
         this.car = car;
     }
     void pushPedal(int speed){
         this.car.setSpeed(speed);
     }
     void drive(int minutes){
         this.car.run(minutes);
     }
 }

 package driving;
 public class DrivingSimulator{
     public void simulate(){
         Car c    = new Car();
         Driver d = new Driver(c);
         d.pushPedal(700);
         d.drive(30);
         d.pushPedal(750);
         d.drive(20);
         System.out.println("The travel distance is " + c.getDistance() + " m.");
     }
 }

 import driving.DrivingSimulator;
 public class FacadeTest{
     public static void main(String[] argv){
         new DrivingSimulator().simulate();
     }
 }