Does an implementation of this method exists in solr ?
i don;t think so.
If not, is it difficult to develop new instructions for solr ? where I must start to do so ?
it will be easy to add. take a look at a simple SolrRequestHandler: http://svn.apache.org/repos/asf/lucene/solr/trunk/src/java/org/apache/solr/handler/IndexInfoRequestHandler.java this gets the IndexReader and writes out some stuff.
