String _serverUrl="http://www.baidu.com/";
String _filename="picture.jpg";
String mDeadLine=3600;
String SecretKey="你的secretkey";
try {
String DownloadUrl =_serverUrl+_filename + "?e=" + mDeadLine;
byte[] DownloadSign = HmacSHA1Encrypt(DownloadUrl, SecretKey);// 这个方法参见我的上传demo
String DownloadEncodedSign = UrlSafeBase64.encodeToString(DownloadSign);
String DownloadToken = AccessKey + ':'+ DownloadEncodedSign;
DownloadUrl += "&token=" + DownloadToken;
Log.e(TAG, "DownloadUrl*******:" + DownloadUrl);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}