program for calculating area of circle in java

import java.io.*;
class simple_area_circle
{
    public static void main(String args[])
    {
        try
        {
            int r;
            float pie=3.14f,a;
            DataInputStream cin=new DataInputStream(System.in);
            System.out.println("Enter a radius to calculate area of circle");
            r=Integer.parseInt(cin.readLine());
            a=r*r*pie;
            System.out.println("area of circle with radius "+r+" is = "+a);
        }
        catch(Exception e)
        {
            System.out.println("Wrong data");
        }
    }
}