1 public class MD5Util { 2     public static String getMD5(String s) { 3         char hexDigits[] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 4                 'A', 'B', 'C', 'D', 'E', 'F'}; 5         byte[] btInput = s.getBytes(); 6         // 获得MD5摘要算法的 MessageDigest 对象 7         MessageDigest mdInst = null; 8         try { 9             mdInst = MessageDigest.getInstance("MD5");10         } catch (NoSuchAlgorithmException e) {11             // TODO Auto-generated catch block12             e.printStackTrace();13         }14         // 使用指定的字节更新摘要15         mdInst.update(btInput);16         // 获得密文17         byte[] md = mdInst.digest();18         // 把密文转换成十六进制的字符串形式19         int j = md.length;20         char str[] = new char[j * 2];21         int k = 0;22         for (int i = 0; i < j; i++) {23             byte byte0 = md[i];24             str[k++] = hexDigits[byte0 >>> 4 & 0xf];25             str[k++] = hexDigits[byte0 & 0xf];26         }27         return new String(str);28     }29 }