Simple prime number generator in java

SieveOfEratosthenes.java

import java.util.BitSet;

public class SieveOfEratosthenes {

    /**
     * @param args
     */
    public static void main(final String[] args) {
        final int length = 2000000;
        final BitSet sieve = new BitSet(length);
        long sum = 0;

        sieve.flip(2, sieve.size());

        for (int i = 0; i < sieve.size(); i++) {
            if (sieve.get(i)) {
                for (int j = i * 2; j < sieve.size(); j += i) {
                    sieve.set(j, false);
                }
            }
        }

        for (int i = 0; i < sieve.size(); i++) {
            if (sieve.get(i)) {
                sum += i;
            }
        }

        System.out.println(sum);
    }
}