java实现md5和sha1加密类

md5为32位大写字母格式，
sha1为40位大写字母格式，

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;


/** * Created by leif on 2016/3/30 0030. */
public class utility {
    /** * 实现32位大写字母格式的md5加密 * @param m * @return */
    public static String md5(String m) {
        MessageDigest md5;
        char hexDigits[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
        String mi = new String();
        try {
            md5 = MessageDigest.getInstance("MD5");
            md5.update(m.getBytes());
            byte[] bb = md5.digest();
            int j = 0;
            char[] ll = new char[bb.length * 2];
            for (int i = 0; i < bb.length; i++) {
                byte nm = bb[i];
                ll[j++] = hexDigits[nm >>> 4 & 0xf];
                ll[j++] = hexDigits[nm & 0xf];
            }
            mi = new String(ll);
        } catch (NoSuchAlgorithmException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return mi;
    }
    /** * 实现40位大写字母格式的SHA加密 * @param m * @return */
    public static String sha(String m) {
        MessageDigest md5;
        char hexDigits[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
        String mi = new String();
        try {
            md5 = MessageDigest.getInstance("SHA");
            md5.update(m.getBytes());
            byte[] bb = md5.digest();
            int j = 0;
            char[] ll = new char[bb.length * 2];
            for (int i = 0; i < bb.length; i++) {
                byte nm = bb[i];
                ll[j++] = hexDigits[nm >>> 4 & 0xf];
                ll[j++] = hexDigits[nm & 0xf];
            }
            mi = new String(ll);
        } catch (NoSuchAlgorithmException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return mi;
    }
    //测试
    public static void main(String[] args) {
        String m = new String("admin"); 
        System.out.println(sha(md5(m)));
    }
}