org-mode source inclusion line numbers - emacs

Question

Org-mode has a great feature to include source code like this:
#+begin_src java -n
/**
* #param foo
*/
public static void doBar(Baz ba)
{
Collection<String> strings = ba.getStrings(true);
return strings;
}
#+end_src
The -n option shows line numbers.
There's a +n option to have the numbering continue from the last block.
Is there any option to set the starting number? This would be useful for source code snippets where you want the line numbers to correspond to the full file.

Answer 1

This has been added in Org Mode 9. It's now possible to pass numbers to both -n and +n.
So, for example, you could make the example start on line 12 by using the following header:
#+begin_src java -n 12
...
#+end_src

Answer 2

I agree with jco. A long answer to the question could read like the following. But except from the screenshot it's just copy and paste from the manual.
As documented in the Section Literal Examples you can add line numbers to the source blocks and example blocks:
Both in example and in src snippets, you can add a -n switch to the
end of the BEGIN line, to get the lines of the example numbered. The
-n takes an optional numeric argument specifying the starting line number of the block. If you use a +n switch, the numbering from the
previous numbered snippet will be continued in the current one. The +n
can also take a numeric argument. The value of the argument will be
added to the last line of the previous block to determine the starting
line number.
You can also refer to line numbers:
In literal examples, Org will interpret strings like (ref:name) as
labels, and use them as targets for special hyperlinks like [[(name)]]
(i.e., the reference name enclosed in single parenthesis). In HTML,
hovering the mouse over such a link will remote-highlight the
corresponding code line, which is kind of cool.
An example for demonstrating both features is
#+BEGIN_SRC emacs-lisp -n -r
(save-excursion (ref:sc)
(goto-char (point-min))) (ref:jump)
#+END_SRC
In line [[(sc)]] we remember the current position.
[[(jump)][Line (jump)]] jumps to point-min.
It would produce

Answer 3

This answer is out of date, see the other ones
No implemented options that I know of.
A very hacky solution I just tested would be to define yourself the counter org uses for +n to work.
It goes :
#+begin_src emacs-lisp :exports results
;; we need it not be a buffer-local value
(setq-default org-export-last-code-line-counter-value 42)
#+end_src
As the result of being a dirty hack, it only works once, though, for the very first block, but I'm not sure how ±n behaves .
It is evaluated (because of :exports results, without actually exporting anything when I tried) before numbering any other blocks, so it can be anywhere in your buffer.
I guess it wouldn't be very hard to implement, or that it could be done better by someone who actually knows elisp, but I hope it'll help.