Is there a clean way to determine whether a core exists?

[Dean Thompson]

The ping command gives me a 500 status if the core exists, or a 404 if  
it doesn't.  For example, when I hit

    http://doom:8983/solr/content_item_representations_20081201/admin/ping
I see

    HTTP ERROR: 500

    INTERNAL_SERVER_ERROR

    RequestURI=/solr/admin/ping

    Powered by Jetty://

(Obviously I'm using Jetty.  Moving to Tomcat is on our list.)

I could depend on this behavior, but that seems ugly, so I decided to  
try a "probe query" instead.

I am using the Solrj client library.  Unfortunately, for core non- 
existence or any other problem, Solrj uses an unhelpful catch-all  
exception:

    /** Exception to catch all types of communication / parsing  
issues associated with talking to SOLR
      *
      * @version $Id: SolrServerException.java 555343 2007-07-11  
17:46:25Z hossman $
      * @since solr 1.3
      */
    public class SolrServerException extends Exception {
        ...
    }

So I have wound up, thus far, with the following code:

    private boolean solrCoreExists(String url)
        throws SolrException, MalformedURLException,  
SolrServerException
    {
        try {
            SolrQuery solrQuery = new SolrQuery();
            solrQuery.setQuery("xyzzy=plugh");
            new CommonsHttpSolrServer(url).query(solrQuery);
            return true;
        } catch (SolrServerException e) {
            if (e.getCause() != null &&  
e.getCause().getMessage().startsWith("Not Found")) {
                return false;
            } else {
                throw e;
            }
        }
    }

Hopefully there's a better solution?

Dean