CircleDriver Program

import java.util.Scanner;

public class CircleDriver

{

public static void main(String[] args)

{

Scanner stdIn = new Scanner(System.in);

Circle big = new Circle();

Circle small = new Circle();

System.out.println("");

System.out.print("Big : ");

big.print();

System.out.println("");

System.out.print("Small : ");

small.print();

System.out.println(" ");

double bigRadius;

System.out.print("Enter the radius of a big circle : ");

bigRadius = stdIn.nextDouble();

big.resize(bigRadius);

double smallRadius;

System.out.print("Enter the radius of small circle : ");

smallRadius = stdIn.nextDouble();

small.resize(smallRadius);

System.out.println("");

System.out.print("Big : ");

big.print();

System.out.println("");

System.out.print("Small : ");

small.print();

System.out.println("");

if (big.equals(small))

System.out.println(" big equals small ");

else

System.out.println(" big does not equals small ");

System.out.println("");

Circle bigCopy = big.clone();

System.out.print("BigCopy : ");

bigCopy.print();

System.out.println("");

if (bigCopy.equals(big))

System.out.println(" bigCopy equals big ");

else

System.out.println(" bigCopy does not equals big ");

System.out.println("");

}

}

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Main topics:

Writing Classes

Declaring / Using Instance Variables

Writing Instance Methods

Accessors and Mutators

public vs private

Exercise

This week we will be practicing writing a class from scratch which includes the standard accessor and mutator methods. In addition careful attention to the public and private specifiers will be made.

Getting Started

To start this exercise, you should:

1. Open eclipse and start a new Java project named Lab02

2. Add a Class (named Circle) to this project, You will be creating the contents of this class from scratch.

3. Add a Class (named CircleDriver) to this project, and copy the contents of the CircleDriver file provided into it.

Requirements

Circle.java A simple class which models a circle by its one defining characteristic, which is its radius. Your Circle class must adhere to the following:

1. All instance variables must be private

2. On creation all Circles have a radius of 1, and their radius is never allowed to become negative.

3. Include the standard public accessor(s)

4. Include the standard private mutator(s)

5. All access of instance data by the other instance methods is made via the accessors and mutators.

6. Contain a method void resize(double newRadius) which allows a client of the class to set the calling Circle objects radius.

7. Contain a method Circle clone() which creates and return a reference to a copy of the calling Circle object.

8. Contain a method boolean equals(Circle guest) which returns whether or not guest has the same radius as the calling Circle object.

9. Contain a method void print() which displays the calling Circle objects radius to the screen in some reasonable report format.

10. Look for and fix any compilation errors.

11. Remember that you can not run this class, there is no main

CircleDriver.java A simple driver class to test the Circle class, provided for you. This class is complete and must not be modified:

1. Look for and fix any compilation errors.

2. Run your driver class and check the output and make sure it is correct