java中求質數的方法

//:DoPrimeNum.java
/**
 *
 * <p>Title:Print Prime Number </p>
 * <p>Description: make some prime number and print</p>
 * <p>Copyright: Copyright (c) 2004</p>
 * <p>Company: </p>
 * @author 還是一條魚
 * @version 1.0
 */
class DoPrimeNum {
 
  public static void main(String[] args) {
    int a;
    for (int i = 1; i < 1000; i++) {
      for (a = 2; a <= (int)i/2; a++) {
        if (i % a == 0) {
          break;
        }

      }
      if (a > (int)i/2 ) {
        System.out.println(i);
      }
    }
  }
}