user1 user1 - 1 year ago 100
Java Question

Whats the difference between Java.Net.Uri and Android.Net.Uri

I am trying to get a

from a
object like so:

File file = new File("/sdcard/MyFolder/MyFile.txt");
var androidUri = Android.Net.Uri.FromFile(file).ToString();
var javaUri = file.ToURI().ToString();

this returns the following values:

androidUri = "file:///sdcard/MyFolder/MyFile.txt"
javaUri = "file:/sdcard/MyFolder/MyFile.txt"

so my question is whats the difference between the
are these two values supposed to be different? When should they be used?


I found the two documentation pages Java.Net.Uri and Android.Net.Uri and both say:

Builds and parses URI references which conform to RFC 2396.

Therefore surely this is a bug and they should return the same string?

Answer Source

The difference is that Android.Net.Uri is Google's own implementation of RFC 2396.

Android.Net.Uri is immutable, hence it is thread-safe. Their implementation is also, according to the comments in the source, more forgiving. So while Java.Net.Uri would throw an Exception you attempt to use a garbage Uri, the Android implementation would just return you a Uri with that garbage.

As far as I can tell, Android.Net.Uri will only throw NullPointerException and seemingly no other exceptions. While the Java.Net.Uri implementation will throw other exceptions such as URISyntaxException and IllegalArgumentException

Otherwise they seem very similar.

The Uri you get file:/sdcard/MyFolder/MyFile.txt is valid, and when throwing it through I get following:

java> String uri = "file:/sdcard/MyFolder/MyFile.txt";
java> import*
java> URI urr = new URI(uri); urr = file:/sdcard/MyFolder/MyFile.txt
java> urr.getScheme();
java.lang.String res2 = "file"
java> urr.getPath();
java.lang.String res3 = "/sdcard/MyFolder/MyFile.txt"