private String fileUrl() {
   String url =
       host
           + "/mkfile/"
           + size
           + "/mimeType/"
           + UrlSafeBase64.encodeToString(mime)
           + "/fname/"
           + UrlSafeBase64.encodeToString(f.getName());
   final StringBuilder b = new StringBuilder(url);
   if (key != null) {
     b.append("/key/");
     b.append(UrlSafeBase64.encodeToString(key));
   }
   if (params != null) {
     params.forEach(
         new StringMap.Consumer() {
           public void accept(String key, Object value) {
             b.append("/");
             b.append(key);
             b.append("/");
             b.append(value);
           }
         });
   }
   return b.toString();
 }
 // @Test
 public void t3() {
   String bucket = "gotwo-thumbnail:0/101150/20150525/2015052517442692838357_750.jpg";
   System.out.println(BASE64.encrypt(bucket));
   System.out.println(Base64.encodeToString(bucket.getBytes(), Base64.DEFAULT));
   System.out.println(UrlSafeBase64.encodeToString(bucket));
 }