jfinal 使用类里的方法

package demo;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

import com.jfinal.core.Controller;

public class HelloController extends Controller {

    public static byte[] getKeyedDigest(byte[] buffer, byte[] key) {
        try {
            MessageDigest md5 = MessageDigest.getInstance("MD5");
            md5.update(buffer);
            return md5.digest(key);
        } catch (NoSuchAlgorithmException e) {
        }
        return null;
    }

    public static String getKeyedDigest(String strSrc, String key) {
        try {
            MessageDigest md5 = MessageDigest.getInstance("MD5");
            md5.update(strSrc.getBytes("UTF8"));

            String result="";
            byte[] temp;
            temp=md5.digest(key.getBytes("UTF8"));
            for (int i=0; i<temp.length; i++){
                result+=Integer.toHexString((0x000000ff & temp[i]) | 0xffffff00).substring(6);
            }

            return result;

        } catch (NoSuchAlgorithmException e) {

            e.printStackTrace();

        }catch(Exception e)
        {
          e.printStackTrace();
        }
        return null;
    }

    /**
     * @param args
     */

    public void index() {
        String mi;
        String s = "prodid=8096&agentid=123&backurl=&returntype=2&orderid=agentid1405210000&mobilenum=13811528470&source=esales&mark=&merchantKey=111111";
        mi=HelloController.getKeyedDigest(s,"");
        renderText("mi:"+mi);
        }

}