用筛法求之N内的素数

import java.util.Scanner;


/**
 * 
 * <p>
 * Description：用筛法求之N内的素数，其中N是有用户输入的数字
 * <p>
 * <p>
 * Copyright：copyright (c) 2013
 * <p>
 * <p>
 * Create Date：2013-12-13
 * <p>
 * <p>
 * Company：ShangHai University
 * <p>
 * 
 * @author WANGXU
 * @version Id: TestPrime.java,v1.1,WANGXU Exp
 */
public class TestPrime {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
while (in.hasNextInt()) {
int num = in.nextInt();
for (int i = 2; i <= num; i++) {
if (isPrimeNumber(i)) {
System.out.println(i);
}
}
}
}


public static boolean isPrimeNumber(int num) {
for (int i = 2; i <= num / 2; i++) {
if (num % i == 0) {
return false;
}
}
return true;
}
}