<p>I'd like something like a generic, re-usable <code>getPosition()</code> method that will tell me the number of bytes read from the starting point of the stream.  Ideally, I would prefer this to work with all InputStreams, so that I don't have to wrap each and every one of them as I get them from disparate sources.</p>

<p>Does such a beast exist?  If not, can anyone recommend an existing implementation of a counting <code>InputStream</code>?</p>

No.
```
InputStream
```
is intended to handle potentially infinite amounts of data, so a counter would get in the way. In addition to wrapping them all, you might be able to do something with aspects.