具有不同原始数据成员但方法相同的Java子类

Question

I'm writing a Ray Tracer and I have a Vec3 class which is a typical math vector with 3 coordinates: X, Y, and Z. I've also created a Color class that holds 3 components: R, G, and B. After writing a decent amount of code, I started to notice that Color is basically a Vec3. I started to write a lot of the same methods for Color as I did for Vec3. Seeing that DRY code is the way to go, I wanted to merge the two classes so I didn't have to keep writing the same code for both classes.

As it stands, here are the classes:

class Vec3{
    public static final int X=0,Y=1,Z=2;
    double components[];
    ...
    // Constructors and Methods
}

class Color extends Vec3{
    public static final int R=0,G=1,B=2;
    int components[];
    ...
    // Constructors and Methods
}

The only difference between the two classes is that a Vec3 uses doubles for its components and a Color uses ints. Other than the type of data, all of the methods are exactly the same. My original inclination was to try and make a BaseVec3 class of generic type T and then just declare the type in the subclasses. But, of course, a generic requires a class, not a primitive.

Is there any way I can have a single method code-base but with different primitive data types?

Edit: I should probably note that I have been programming in Python and C for a while and it's been a while since I've touched Java. So, my first instinct answer to this question is NO .

Answer 1

I'm not 100% sure of what you're asking, but if your code is as you've shown, don't you have what you want? In your code, Color extends Vec3 . Due to this statement, a Color object can be treated as a Vec3 object; all methods from Vec3 are inherited by Color and methods which take an arg of type Vec3 will accept args of type Color.

Answer 2

Each primitive has its corresponding class. For example, Integer for int . Java can autobox them, ie convert them automatically.

However, I don't think using inheritance is appropriate in this case. What if you Vec3 implementation change? What if you decide to make you members private (as you should)?

Answer 3

EDIT - I see your comment about generics at the end. Isn't that what autoboxing is for?

Couldn't you just use a generic like this?

public abstract class GenericVector<T> {
    private final T x, y, z;

    public GenericVector(T x, T y, T z) {
        this.x=x;
        this.y=y;
        this.z=z;
    }

    public T getX() { return x; }
    public T getY() { return y; }
    public T getZ() { return z; }
}