primes.java

来自「webwork source」· Java 代码 · 共 65 行

package webwork.examples;

import webwork.action.Action;
import webwork.action.ActionSupport;

public class Primes extends ActionSupport
{
   private int start = 1;
   private int end = 1000;
   private boolean[] primes;

   public void setStart(int start)
   {
      this.start = start;
   }

   public int getStart()
   {
      return start;
   }

   public void setEnd(int end)
   {
      this.end = end;
   }

   public int getEnd()
   {
      return end;
   }

   public boolean[] getPrimes()
   {
      return primes;
   }

   protected boolean isPrime(int number)
   {
      if (number == 1 || number % 2 == 0 && number > 2)
      {
         return false;
      }
      for (int i = 3; i < Math.sqrt(number); i += 2)
      {
         if (number % i == 0)
         {
            return false;
         }
      }
      return true;
   }

   protected String doExecute()
   {
      primes = new boolean[end - start + 1];
      for (int i = start; i <= end; i++)
      {
         primes[i - start] = isPrime(i);
      }
      return Action.SUCCESS;
   }
}