Whats wrong with is this code? Need it asap. Thank you!

import java.util.*;

public class CircleDemo{ //Instance Variables private double PI = 3.1459; private double radius; private String colour;

//Constructor public CircleDemo ( ) { } public double getRadius() { return radius; } public String getColour() { return colour; } public double getArea() { return PI*radius*radius; } public double getCircumference() { return 2*PI*radius; } public String toString() { String str = radius + colour + (PI*radius*radius) + (2*PI*radius); return str; } public static void main(String[] args) { Scanner kb = new Scanner(System.in); //System.out.println(""); double radius = kb.nextDouble(); String colour = kb.nextLine(); CircleDemo info = new CircleDemo(radius, colour); System.out.println(info.toString()); } }