What do you even mean by "access", in terms of a smartphone? How do you expect to be able to extract the values, and what would you do with them? When you say "code", do you mean some programming language? Are you trying to create an app or something?
If this were a regular Linux system, with access to a shell and arbitrary programs, and you just needed some way to extract the text values, then I'd suggest something like xmlstarlet
$ xmlstarlet sel -T -t -v '//string[@name="base_uri"]' -n file.xml
But I have no idea what's possible on android. I agree that you should go to the androidquestions forums for this. And be sure to define your needs clearly.