Modify the GeometricObject class to implement the Comparable interface, and defi

Question

Modify the GeometricObject class to implement the Comparable interface, and define a static max method in the GeometricObject class for finding the larger of two GeometricObject objects. Write a test program that uses the max method to find the larger of two circles and the larger of two rectangles.

GeometricObject:
public abstract class GeometricObject {
private String color = "white";
private boolean filled;
private java.util.Date dateCreated;

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

/** Construct a geometric object with color and filled value */
protected GeometricObject(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,
so, the get method name is 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;
}

/** Return a string representation of this object */
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();
}

Example of a comparator:
import java.util.Comparator;

public class GeometricObjectComparator
implements Comparator<GeometricObject>, java.io.Serializable {
public int compare(GeometricObject o1, GeometricObject o2) {
double area1 = o1.getArea();
double area2 = o2.getArea();

if (area1 < area2)
return -1;
else if (area1 == area2)
return 0;
else
return 1;
}
}

Example of Max.java:
public class Max {
/** Return the maximum between two objects */
public static Comparable max(Comparable o1, Comparable o2) {
if (o1.compareTo(o2) > 0)
return o1;
else
return o2;
}
}

Example of another Max.java:
public class Max1 {
/** Return the maximum between two objects */
public static <E extends Comparable<E>> E max(E o1, E o2) {
if (o1.compareTo(o2) > 0)
return o1;
else
return o2;
}
}

Explanation / Answer

import java.util.Date; public abstract class GeometricObject implements Comparable{ private String color = "white"; private boolean filled; private Date dateCreated; protected GeometricObject(){ dateCreated = new Date(); } public String getColor(){ return color; } public void setColor (String color){ this.color = color; } public boolean isFilled (){ return filled; } public void setFilled (boolean filled){ this.filled = filled; } public Date getDateCreated(){ return dateCreated; } public abstract double getArea(); public abstract double getPerimeter(); public int compareTo(Object o1){ if (getArea() == ((GeometricObject) o1).getArea()) return 0; else if (getArea()>((GeometricObject)o1).getArea()) return 1; else return -1; } public static void max (Object o,Object o1){ if (((GeometricObject)o).compareTo(o1)==1){ System.out.println("The First Object is larger than the Second Object"); } else if (((GeometricObject)o).compareTo(o1)==0){ System.out.println("Both Object is equal"); } else { System.out.println("The First Object is smaller than the Second"); } } } Circle.java public class Circle extends GeometricObject { private double radius; public Circle (double radius){ this.radius=radius; } public double getArea(){ return radius*radius*Math.PI; } public double getPerimeter(){ return radius*Math.PI*2; } public double getRadius (){ return radius; } public double getDiameter(){ return 2*radius; } public void setRadius(double radius){ this.radius=radius; } } Rectangle public class Rectangle extends GeometricObject { private double width,height; public double getArea(){ return width*height; } public double getPerimeter(){ return (width+height)*2; } public void setWidth(double width){ this.width=width; } public void setHeigth(double height){ this.height=height; } public double getWidth (){ return width; } public double getHeight (){ return height; } public Rectangle (double width,double height){ this.width=width; this.height=height; } }

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