Estimating Size of files downloaded from portal

[Anonymous User]

Using the Runtime SDK there appears to only be one way to ascertain the size of a portal item for download (in this case I am downloading a TPK or GeoTIFF file for use in our application).  So essentially this forces you to cycle through the InputStream twice.  Once to get the size of the file and then a second time to download.  Obviously this is a waste of time and resources.  Anyone know of a way to access portal items and get content-length as you might do with an httpconnection?  I guess the complication is that if you go outside of the runtime sdk it is using Rest and you would have to provide credentials a second time, even though you are already doing this via the SDK.  It would be a lot nicer if you could just use the "item" to ascertain the file size.  Anybody out there have any ideas?

PortalItem item = PortalItem.fetchItem(portal, itemID);

InputStream inputStream = item.fetchData();

long fileLength;

byte[] buf = new byte[16384];

int len, size = 0;

while ((len = inputStream.read(buf)) != -1) {

  size += len;

}

inputStream.close();

fileLength = size;

[AlexanderNohe1]

I am not entirely sure as I have not had an opportunity to test this myself, but I believe this will change in the Quartz release with PortalItem.getSize()

PortalItem| arcgis-android

Currently, the Quartz release is in Beta.  You can get started with the Quartz Beta release here:

ArcGIS Runtime SDK for Android | ArcGIS for Developers

[AlexanderNohe1]

This post from stack overflow might be helpful as well since rather than just calculating the length, you can write to the output byte array at the same time:

public byte[] readBytes(InputStream inputStream) throws IOException {
  // this dynamically extends to take the bytes you read
  ByteArrayOutputStream byteBuffer = new ByteArrayOutputStream();

  // this is storage overwritten on each iteration with bytes
  int bufferSize = 1024;
  byte[] buffer = new byte[bufferSize];

  // we need to know how may bytes were read to write them to the byteBuffer
  int len = 0;
  while ((len = inputStream.read(buffer)) != -1) {
  byteBuffer.write(buffer, 0, len);
  }

  // and then we can return your byte array.
  return byteBuffer.toByteArray();
}

Android - getting from a Uri to an InputStream to a byte array? - Stack Overflow