Java MD5

public class Md5MessageDigest {private MessageDigest messageDigest;public Md5MessageDigest() throws Exception {messageDigest = MessageDigest.getInstance("MD5");}/** *  * @param message * @return */public String digest(String message) throws Exception {byte[] md5Bytes = messageDigest.digest(message.getBytes());StringBuilder hexStr = new StringBuilder();        for (int i = 0; i < md5Bytes.length; i++) {            int val = ((int)md5Bytes[i]) & 0xff; //转为16进制            if (val < 16) {            hexStr.append("0"); //两位一组            }            hexStr.append(Integer.toHexString(val));        }return hexStr.toString();}}