Prime Number in Java

Here is the code of the Program

import java.io.*;

class PrimeNumber {
public static void main(String[] args) throws Exception{
  int i;
  BufferedReader bf = new BufferedReader(
            new InputStreamReader(System.in));
  System.out.println("Enter number:");
  int num = Integer.parseInt(bf.readLine());
  System.out.println("Prime number: ");
  for (i=1; i < num; i++ ){
    int j;
    for (j=2; j<i; j++){
      int n = i%j;
      if (n==0){
        break;
      }
    }
    if(i == j){
      System.out.print("  "+i);
    }
  }
}
}