JAVA-Inverse a number

Q. Write a program in JAVA to inverse a number taken from user.

Using Buffered Reader Class:
import java.io.*;
class inverse1
{
public static void main(String args[])throws IO Exception
{
 int n,rev=0;
BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
System.out.println("enter a no.= ");
n=Integer.parseInt(br.readLine());
while(n!=0)
{
rev=rev*10;
rev=rev+n%10;
n=n/10;
}
System.out.print("reverse no is= "+a);
}

}
Output:
enter a no.= 123
reverse no is= 321

Using Scanner Class:
import java.util.Scanner;
class inverse2
{
public static void main(String args[])
{
 int n,a=0,x;
Scanner sc=new Scanner(System.in);
System.out.println("enter a no.= ");
n=sc.nextInt();
while(n>0)
{
x=n%10;
a=a*10+x;
n=n/10;
}
System.out.print("reverse no is= "+a);
}

}
Output:
enter a no.= 123
reverse no is= 321

/*if you have any problem, comment below*/