how to call the class again if the user enter wrong input using keyboard

Question

package simple;

import java.io.BufferedReader;    
import java.io.InputStreamReader;     
class AreaofCircle{    
    public static void main(String args[]){    
        float PI = 3.1416f;    
        int r=0;    
        String rad;     
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); 
        System.out.println("Radius?");   
        try{    
            rad = br.readLine(); 
            r = Integer.parseInt(rad); 
            System.out.println("Circle area is: " + PI*r*r + " Permieter: " +PI*2*r); 
        }
        catch(Exception e){
            System.out.println("Write an integer number"); 
            AreaofCircle a = new AreaofCircle(); 
        }
    }
}

Here in this code , assume user enter some string using keyboard, at that point in try block it shows exception and it comes to catch block,

And i want to show the details of error and want to push back user to that code again, how this is possible, Plz help me regarding this.

Answer 1

int allowedAttempts=0;
while(true) 
{
   try{    
       rad = br.readLine(); 
       r = Integer.parseInt(rad); 
       System.out.println("Circle area is: " + PI*r*r + " Permieter: " +PI*2*r); 
       break;
       }
       catch(Exception e){
            System.out.println("Write an integer number"); 
            allowedAttempts++;
            if(allowedAttempts==3){
                    System.out.println("No More attempts allowed");break;
                }
        }
}

You can use integer variable, and prompt upto specific number of attempts.