Vehicle.java

/*
 * 練習問題2.13 p.58
 * Vehicleクラスのフィールドをprivateにして、フィールドに対するアクセッサーメソッドを追加しなさい。
 * どのフィールドが変更を許すメソッドを持ち、どのフィールドがそのようなメソッドを持つべきではないですか。
 */

package ch02.ex02_13;

// id, nextID以外は変更できて良いと思う。

public class Vehicle
{
    private double currentSpeed;
    private double currentDirection;
    private String owner;

    private static int nextID = 1;
    private final int id;

    public String getOwner()
    {
        return owner;
    }

    public void setOwner(String newOwner)
    {
        owner = newOwner;
    }

    public double getCurrentSpeed()
    {
        return currentSpeed;
    }

    public void setCurrentSpeed(double speed)
    {
        currentSpeed = speed;
    }

    public double getCurrentDirection()
    {
        return currentDirection;
    }

    public void setCurrentDirection(double direction)
    {
        currentDirection = direction;
    }

    public Vehicle()
    {
        id = nextID++;
        ;
    }

    public Vehicle(String ownerName)
    {
        id = nextID++;
        owner = ownerName;
    }

    public String toString()
    {
        String desc = "owner: " + owner;

        return desc;
    }

    public static int showCurrentID()
    {
        // まだ識別番号が一度も使われていない場合は0を返す
        return nextID - 1;
    }

    /**
     * @param args
     */
    public static void main(String[] args)
    {

        Vehicle testVehicle1 = new Vehicle("Bob");
        testVehicle1.setCurrentSpeed(3.5);
        testVehicle1.setCurrentDirection(1.2);
        System.out.println("Id: " + testVehicle1.id);
        System.out.println("Current speed: " + testVehicle1.getCurrentSpeed());
        System.out.println("Current direction: "
                + testVehicle1.getCurrentDirection());
        System.out.println("Owner: " + testVehicle1.getOwner());

        System.out.println("");

        System.out.println("MAX used ID: " + Vehicle.showCurrentID());

        System.out.println("");

        System.out.println(testVehicle1);

    }

}