Command pattern demo

CommandClasses_Action.java

package CommandClasses;

/**
 * @author Ari
 * @version 1.0
 * command interface
 */
public interface Action {
  public void exec();
}

CommandClasses_Bicycle.java

package CommandClasses;

/**
 * @author Ari
 * @version 1.0
 * receiver class
 */
public class Bicycle {

  private int gear = 1;

  public int getGear() {
    return gear;
  }

  public void setGear(int gear) {
    this.gear = gear;
  }

  public void goLeft(){
    System.out.println("L");
  }

  public void goRight(){
    System.out.println("R");
  }



}

CommandClasses_Cyclist.java

package CommandClasses;

import java.util.ArrayList;
import java.util.List;

/**
 * @author Ari
 * @version 1.0
 * invoker class
 */
public class Cyclist {

  private List<Action> actionList = new ArrayList<Action>();

  public void setAction(Action action){
    actionList.add(action);
  }

  public void rideBike(){
    for(Action action: actionList){
      action.exec();
    }
    actionList.clear();
  }

}

CommandClasses_DecreaseGear.java

package CommandClasses;

/**
 * @author Ari
 * @version 1.0
 * concrete command
 */
public class DecreaseGear implements Action {

  private Bicycle bicycle;

  public DecreaseGear(Bicycle bicycle) {
    this.bicycle = bicycle;
  }

  @Override
  public void exec() {
    int gear = bicycle.getGear();
    if(gear > 1) gear--;
    bicycle.setGear(gear);
    System.out.println("gear down to " + gear);


  }
}

CommandClasses_IncreaseGear.java

package CommandClasses;

/**
 * @author Ari
 * @version 1.0
 * concrete command
 */
public class IncreaseGear implements Action {

  private Bicycle bicycle;

  public IncreaseGear(Bicycle bicycle) {
    this.bicycle = bicycle;
  }

  @Override
  public void exec() {
    int gear = bicycle.getGear();
    if(gear<9) bicycle.setGear(gear++);
    System.out.println("gear up to " + gear);
  }
}

CommandClasses_LeftTurn.java

package CommandClasses;

/**
 * @author Ari
 * @version 1.0
 * concrete command
 */
public class LeftTurn implements Action {

  private Bicycle bicycle;

  public LeftTurn(Bicycle bicycle) {
    this.bicycle = bicycle;
  }

  @Override
  public void exec() {
    bicycle.goLeft();
  }
}

CommandClasses_RightTurn.java

package CommandClasses;

/**
 * @author Ari
 * @version 1.0
 * concrete command
 */
public class RightTurn implements Action {

  private Bicycle bicycle;

  public RightTurn(Bicycle bicycle) {
    this.bicycle = bicycle;
  }

  @Override
  public void exec() {
    bicycle.goRight();
  }
}