When trying to set parameter of type byte[] in Google Endpoints object a String is excpected

Question

I created an Object which is sent through Google Cloud Endpoints. Among its parameters there is one parameter of type byte[] with its getter and setter methods.

The problem is when I want to set the byte[] parameter in my app it expects somehow a parameter of type String? Does it want me to encode the byte array or what is the reason for that strange error?

When I get the parameter from the dataObject it is of type byte[] and everything is fine. I am really confused!

My Object is DataPackage defined in my Backend

 ...
 private byte[] imageThumbnail;

 public void setImageThumbnail(byte[] imageThumbnail) {
    this.imageThumbnail = imageThumbnail;
}

public byte[] getImageThumbnail() {
    return imageThumbnail;
}

Then in my app I try to set the imageByteArray

 dataPackage.setImageThumbnail(byteThumbnail); // gives error that String is expected

And this works fine

 dataPackage.getImageThumbnail() // is of type byte[]

Could you post the relevant code and any related LogCat messages printed out? — Jay Snayder, Jan 09 '15 at 20:23
I solved it by not using the datastore to save images at all. You could use the endpoints to send images when you decode them to a Base64 String but sooner or later you will find out that it takes a lot of time(1 Mb ~ 10 Seconds) to up or download the image. I recommend to use the Blobstore with a Servlet for any images it's way more faster and not in your Upload/Download Qouta! — Marcel_marcel1991, Mar 28 '15 at 20:04

score 2 · Answer 1 · edited May 23 '17 at 12:32

While it may not be your first choice, is it possible to use the byte[] constructor for a string and pass it that? An example of how to do so can be found here

Essentially the relevant part of that question/answer is this:

byte[] b = {(byte) 99, (byte)97, (byte)116}; //This could also be your byte array
String s = new String(b, "US-ASCII"); // US-ASCII might need to be something else

and then the opposite process:

String s = "some text here"; //The string from dataPackage.getImageThumbnail()
byte[] b = s.getBytes("UTF-8"); //Might need to be some other byte formatting

Happy coding! Leave a comment if you have any questions.

Good useful information, though it does not address the OP question. It is kind of sad that the best answer Marcel found to what seems a simple question was `don't do that`. — Jesse Chisholm, Apr 14 '17 at 16:58

score -1 · Answer 2 · edited May 23 '17 at 12:25

You should decode and encode using the Base64 class of from the Android framework.

String encodedBitArray = Base64.encodeToString(imageThumbnail, Base64.DEFAULT);

byte[] decodedArray = Base64.decode(encodedBitArray, Base64.DEFAULT);

If you want to convert the byte array to a Bitmap you need to do the following :

Bitmap bitmap = BitmapFactory.decodeByteArray(byteArray, 0, byteArray.length);

SO example

When trying to set parameter of type byte[] in Google Endpoints object a String is excpected

2 Answers2