I'm having trouble getting a Java program to compile properly. Can someone tell me what is wrong and how to fix it? When I try to run TestGeometricThing, I get an error message I have never seen before. Here are the files I am working with:

GeometricThing.java

public abstract class GeometricThing {

private String color = "white"; private boolean filled; private java.util.Date dateCreated;

/** Construct a default geometric object */ protected GeometricThing() { dateCreated = new java.util.Date(); }

/** Construct a geometric object with color and filled value */ protected GeometricThing(String color, boolean filled) { dateCreated = new java.util.Date(); this.color = color; this.filled = filled; }

/** Return color */ public String getColor() { return color; }

/** Set a new color */ public void setColor(String color) { this.color = color; }

/** Return filled. Since filled is boolean, * the get method is named isFilled */ public boolean isFilled() { return filled; }

/** Set a new filled */ public void setFilled(boolean filled) { this.filled = filled; }

/** Get dateCreated */ public java.util.Date getDateCreated() { return dateCreated; }

@Override public String toString() { return "created on " + dateCreated + " color: " + color + " and filled: " + filled; }

/** Abstract method getArea */ public abstract double getArea();

/** Abstract method getPerimeter */ public abstract double getPerimeter();

}

Square.java

public class Square extends GeometricThing{

double side = 1.0; ////default value of 1.0

Square(double side){

this.side=side;//specific side } @Override public double getArea() {

return side*side; //returns area of square }

@Override public double getPerimeter() {

return 4*side; //returns peremeter of square } public double getSide() { return side; //returns length of side }

public String toString(){

return "side of sqare is "+side; //display side }

}

Rectangle.java

public class Rectangle extends GeometricThing {

private double width; private double height;

public Rectangle() { }

public Rectangle(double width, double height) { this.width = width; this.height = height; }

/** Return width */ public double getWidth() { return width; }

/** Set a new width */ public void setWidth(double width) { this.width = width; }

/** Return height */ public double getHeight() { return height; }

/** Set a new height */ public void setHeight(double height) { this.height = height; }

@Override /** Return area */ public double getArea() { return width * height; }

@Override /** Return perimeter */ public double getPerimeter() { return 2 * (width + height); } }

Circle.java

public class Circle extends GeometricThing {

private double radius;

public Circle() { }

public Circle(double radius) { super("red", false); this.radius = radius; }

/** Return radius */ public double getRadius() { return radius; }

/** Set a new radius */ public void setRadius(double radius) { this.radius = radius; }

@Override /** Return area */ public double getArea() { return radius * radius * Math.PI; }

/** Return diameter */ public double getDiameter() { return 2 * radius; }

@Override /** Return perimeter */ public double getPerimeter() { return 2 * radius * Math.PI; }

/* Print the circle info */ public void printCircle() { System.out.println("The circle is created " + getDateCreated() + " and the radius is " + radius); }

}

TestGeometricThing.java

import java.util.ArrayList;

import java.util.Collections;

import java.util.List; public class TestGeometricThing { static double sumOfArea = 0; static List list = new ArrayList(); public static void main(String[] args) { GeometricThing geoThing1 = new Circle(5); GeometricThing geoThing2 = new Rectangle(5, 3); GeometricThing geoThing3 = new Square(5);

System.out.println("The two objects have the same area? " + equalArea(geoThing1, geoThing2));

System.out.println("Circle"); displayGeometricThing(geoThing1);

System.out.println("Rectangle"); displayGeometricThing(geoThing2);

System.out.println("Square"); displayGeometricThing(geoThing3);

System.out.println("Do circle and rectangle have same area? " + equalArea(geoThing1, geoThing3));

list.add(geoThing1); list.add(geoThing2); list.add(geoThing3);

double sum = sumArea(list); System.out.println("Sum of area: " + sum);

GeometricThing obj = findBiggestThing(list); System.out.println("Biggest area of thing is: " + obj.getArea()); } public static boolean equalArea(GeometricThing object1,GeometricThing object2) { return object1.getArea() == object2.getArea(); }

public static void displayGeometricThing(GeometricThing object) { System.out.println("The area is " + object.getArea()); System.out.println("The perimeter is " + object.getPerimeter()); System.out.println(); } public static double sumArea(List list){ for(int i=0;i list){ List list1 = new ArrayList(); for(int i=0;i