import java.security.MessageDigest;        import java.security.NoSuchAlgorithmException;                public class MD5 {                    public static String getMD5(String content) {                try {                    MessageDigest digest = MessageDigest.getInstance("MD5");                    digest.update(content.getBytes());                    return getHashString(digest);                                    } catch (NoSuchAlgorithmException e) {                    e.printStackTrace();                }                return null;            }                        private static String getHashString(MessageDigest digest) {                StringBuilder builder = new StringBuilder();                for (byte b : digest.digest()) {                    builder.append(Integer.toHexString((b >> 4) & 0xf));                    builder.append(Integer.toHexString(b & 0xf));                }                return builder.toString();            }        }