A vector class in Java

Vector.java

package ca.mitmaro.cs4751.a03;

public class Vector {

	public static class Vector2D extends Vector {

		public Vector2D(Vector v) {
			this(v.components[Vector.X], v.components[Vector.Y]);
		}
		
		public Vector2D(double x, double y) {
			super(new double[]{x, y});
		}

		public Vector2D() {
			super(2);
		}

		public double getX() {
			return this.components[Vector.X];
		}
		
		public double getY() {
			return this.components[Vector.Y];
		}

		public void setX(double value) {
			this.components[Vector.X] = value;
		}
		public void setY(double value) {
			this.components[Vector.Y] = value;
		}

		public Vector2D getPerpendicular() {
			return new Vector2D(-this.getX(), this.getY());
		}
	}
	public static class Vector3D extends Vector {
		
		public Vector3D(Vector v) {
			this(v.components[Vector.X], v.components[Vector.Y], v.components[Vector.Z]);
		}
		
		public Vector3D(double x, double y, double z) {
			super(new double[]{x, y, z});
		}

		public Vector3D() {
			super(3);
		}

		public double getX() {
			return this.components[Vector.X];
		}
		
		public double getY() {
			return this.components[Vector.Y];
		}

		public double getZ() {
			return this.components[Vector.Z];
		}

		public void setX(double value) {
			this.components[Vector.X] = value;
		}
		
		public void setY(double value) {
			this.components[Vector.Y] = value;
		}

		public void setZ(double value) {
			this.components[Vector.Z] = value;
		}

		public static Vector3D crossProduct(Vector3D a, Vector3D b) {
			return new Vector3D (
				a.getY() * b.getZ() - a.getZ() * b.getY(),
				a.getZ() * b.getX() - a.getX() * b.getZ(),
				a.getX() * b.getY() - a.getY() * b.getX()
			);
			
		}
	}
	
	public static final int X = 0;
	public static final int Y = 1;
	public static final int Z = 2;
	
	protected final double[] components;
	
	public Vector(double[] components) {
		this.components = components;
	}
	
	public Vector(int numberComponents) {
		this.components = new double[numberComponents];
	}
	
	public void mulitply(double d) {
		for (int i = 0; i < this.components.length; i++) {
			this.components[i] = this.components[i] * d;
		}
		
	}

	public void divide(double d) {
		for (int i = 0; i < this.components.length; i++) {
			this.components[i] = this.components[i] / d;
		}
	}
	
	public void setComponent(int component, int value) {
		this.components[component] = value;
	}
	
	public void checkVectorDimensions(Vector v) {
		if (this.components.length != v.components.length) {
			throw new RuntimeException(Vector.class.getName() + " are of different size");
		}
	}

	public double magnitude() {
		double value = 0;
		for (int i = 0; i < this.components.length; i++) {
			value += this.components[i] * this.components[i];
		}
		
		return Math.sqrt(value);
	}
	
	public static Vector add(Vector a, Vector b) {
		
		a.checkVectorDimensions(b);
		
		double[] newComponents = new double[a.components.length]; 
		
		for (int i = 0; i < newComponents.length; i++) {
			newComponents[i] = a.components[i] + b.components[i];
		}
		
		return new Vector(newComponents);
	}
	
	public static Vector subtract(Vector a, Vector b) {

		a.checkVectorDimensions(b);
		
		double[] newComponents = new double[a.components.length]; 
		
		for (int i = 0; i < newComponents.length; i++) {
			newComponents[i] = a.components[i] - b.components[i];
		}
		
		return new Vector(newComponents);
	}
	
	public static double dotProduct(Vector a, Vector b) {
		double result = 0;
		
		a.checkVectorDimensions(b);
		
		for (int i = 0; i < a.components.length; i++) {
			result += a.components[i] * b.components[i];
		}
		
		return result;
	}
	
}