Personally i'm a fan of the proposal that was earlier suggested to rethink the response writer API so we can add a generalized SolrParam for overriding the default Content-Type of any response writer, and then letting the example specify "text/plain" as a default to make the tutorial easy to read.
but independent of that (since it's a much bigger issue), why don't we move forward by:
- changing the default mime type for the writer to be "application/json"
- add an init param on the writer to override the mime type used (much like the patch does, but i'm not a fan of the proposed param name nor of making it a simple boolean)
- update the example solrconfig.xml to explicitly use this init param to set the type to "text/plain" with a comment like so...
<queryResponseWriter name="json" class="solr.JSONResponseWriter">
<!-- For the purposes of the tutorial, JSON response are written as
plain text so that it's easy to read in *any* browser.
If you are building applications that consume JSON, just remove
this override to get the default "application/json" mime type.
...which seems like a good compromise all the way around: The default mime type of the writer starts matching the expectations of advanced users, the example configs make the tutorial output easy to read for novices in any browser, and there is clear indication in those example configs how people can change the content type used (crazy people can even use "text/json-x" if they really want to)
(If/when we adding a more general request time mime type over ride param, this init param can still be used as a fallback, so it doesn't really paint us into a corner or anything)