Find the amstrong numbers upto the given limit in Java

//Generate Amstrong Number upto limit
import java.io.*;
class AmstrongNum
{
int sum=0,rem,t;
void check(int num)
{
System.out.println("The following numbers are amstrong numbers:");

for(int i=1;i<num;i++)
{
t= i;
while( t !=0 )
{
rem= t % 10;
sum = sum + rem*rem*rem;
t = t/10;
}
if( sum == i)
System.out.println(i+"\n");
sum=0;
}
}
public static void main(String args[])throws IOException
{
AmstrongNum am= new AmstrongNum();
int n;
BufferedReader b= new BufferedReader(new InputStreamReader(System.in));
System.out.println(" Enter the range upto which u want to find amstrong numbers:");
n=Integer.parseInt(b.readLine());
am.check(n);
}
}