ArrayList with Polymorphism for Shape Management

In this problem: You will create Circle and Rectangle classes implementing a Shape interface, store them in an ArrayList, and perform filtering and sorting by area.

Learning Objective: Understand practical data manipulation combining polymorphism with dynamic lists

Overview

Store multiple different objects in an ArrayList using an interface type and process them uniformly through polymorphism. Implement filtering by area threshold and sorting using the Streams API.

Specifications

Shape Interface

• Defines a double getArea() method

Circle Class (implements Shape)

• Field: double radius
• Constructor: Takes radius
• getArea(): Returns Math.PI * radius * radius
• toString(): Format "Circle(radius=X.X, area=Y.YY)" (area to 2 decimal places)

Rectangle Class (implements Shape)

• Fields: double width, double height
• Constructor: Takes width and height
• getArea(): Returns width * height
• toString(): Format "Rectangle(width=X.X, height=Y.Y, area=Z.ZZ)" (area to 2 decimal places)

Main Class

1. Add Circles and Rectangles to ArrayList<Shape>:
   • new Circle(5.0)
   • new Rectangle(3.0, 4.0)
   • new Circle(2.0)
   • new Rectangle(6.0, 3.0)
   • new Circle(4.0)
2. Print "All shapes:" followed by each shape on a separate line
3. Print an empty line
4. Filter shapes with area >= 15.0 and sort by area ascending
5. Print "Shapes with area >= 15.00 (sorted):" followed by matching shapes

Output Format

All shapes:
Circle(radius=5.0, area=78.54)
Rectangle(width=3.0, height=4.0, area=12.00)
Circle(radius=2.0, area=12.57)
Rectangle(width=6.0, height=3.0, area=18.00)
Circle(radius=4.0, area=50.27)

Shapes with area >= 15.00 (sorted):
Rectangle(width=6.0, height=3.0, area=18.00)
Circle(radius=4.0, area=50.27)
Circle(radius=5.0, area=78.54)