Hi there, maybe eliminating those who can be divided by 2 will be better?

after checking if n == 2, we can examine from 3, and 4, 6, 8, 10, ... are not needed.

(n could be divided by 2 if it can be divided by 4, 6, 8, 10, ...)

Since then, we could increase our count by 2.

boolean isPrime(int n){
    if (n == 2)
        return true;
    if (n < 2 || n % 2 == 0) 
        return false;
    for (int i = 3; i <= (int) Math.sqrt(n); i += 2){
        if (n % i == 0)
            return false;
    }
    return true;
}