porsche.java

java2 primer plus一书源程序

public class Porsche
{
    public static final int TIPTRONIC = 1;

    // Attributes
    private int horsePower = 450;
    private int maximumSpeed = 220;
    private int numberOfDoors = 2;
    private String paint = "Yellow";
    private int turbos = 2;
    private int gasCapacity = 15;
    private int oilCapacity = 5;
    private int transmission = TIPTRONIC;
    private boolean nos;

    // State attributes
    private boolean turbo1Engaged = false;
    private boolean turbo2Engaged = false;
    private boolean nosEnabled = false;
    private boolean running = false;
    private int currentSpeed;
    private int currentGas;
    private int currentOil;

    public Porsche()
    {
    }

    public void start()
    {
        running = true;
    }

    public void stop()
    {
        running = false;
    }

    public boolean isRunning()
    {
        return running;
    }

    public void accelerate()
    {
        // Check to see if we are running or not
        if( running == false )
        {
            return;
        }

        // Create a variable representing how much we are going to 
        // accelerate this second
        int increment = 15;

        // Check the turbos; they add 5mph per second acceleration
        if( turbo1Engaged )
        {
            increment += 5;
        }
        if( turbo2Engaged )
        {
            increment += 5;
        }

        // Check the NOS; it represents 15mph per second
        if( nos )
        {
            increment += 15;
        }

        // Increment the current speed
        currentSpeed += increment;
        if( currentSpeed > maximumSpeed ) currentSpeed = maximumSpeed;
    }

    public void decelerate()
    {
        currentSpeed -= 20;
        if( currentSpeed < 0 ) currentSpeed = 0;
    }

    public void engageTurbos()
    {
        turbo1Engaged = true;
        turbo2Engaged = true;
    }

    public void disengageTurbos()
    {
        turbo1Engaged = false;
        turbo2Engaged = false;
    }

    public void engageNOS()
    {
        nos = true;
        maximumSpeed += 50;
    }

    public void disengageNOS()
    {
        nos = false;
        maximumSpeed -= 50;
    }

    public int getCurrentSpeed()
    {
        return currentSpeed;
    }

    public String toString()
    {
        return "A shiny new " + paint + " Porsche!";
    }

    public static void main( String[] args )
    {
        Porsche p = new Porsche();
        System.out.println( "My new car: " + p );
        p.start();
        System.out.println( "Current speed: " + p.getCurrentSpeed() );
        for( int i=0; i<20; i++ )
        {
            if( i == 5 )
            {
                p.engageTurbos();
            }
            else if( i == 14 )
            {
                p.engageNOS();
            }
            p.accelerate();
            System.out.println( "Current speed: " + p.getCurrentSpeed() );
        }
        p.disengageNOS();
        p.disengageTurbos();
        while( p.getCurrentSpeed() > 0 ) 
        {
            p.decelerate();
            System.out.println( "Current speed: " + p.getCurrentSpeed() );
        }
        p.stop();
    }
}