MainClass.java Source code

Introduction

Here is the source code for MainClass.java

Source

/*
 * Output:
 */

import java.io.BufferedReader;
import java.io.InputStreamReader;

public class MainClass {

    public static void main(String args[]) {
        try {

            InputStreamReader isr = new InputStreamReader(System.in);
            BufferedReader br = new BufferedReader(isr);

            while (true) {

                System.out.print("Radius? ");

                String str = br.readLine();
                double radius;
                try {
                    radius = Double.valueOf(str).doubleValue();
                } catch (NumberFormatException nfe) {
                    System.out.println("Incorrect format!");
                    continue;
                }

                if (radius <= 0) {
                    System.out.println("Radius must be positive!");
                    continue;
                }

                double area = Math.PI * radius * radius;
                System.out.println("Area is " + area);
                return;
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}