How to find prime numbers in java by jayanthi ganesh

import java.util.*;

public class loop {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int i,j, flag, count=0;
int a = sc.nextInt();
int b = sc.nextInt();
for (i=a; i<=b; i++)
{
if (i==1 || i==0)
continue;
flag=1;
for(j=2; j<=i/2; ++j)
{
if (i%j == 0)
{
flag=0;
break;
}
}
if (flag==1)
++count;
}
System.out.println(count);
}
}