https://solr.apache.org/docs/4_6_1/solr-solrj/org/apache/solr/common/cloud/DocRouter.html?is-external=true
DocRouter (Solr 4.6.1 API)
solrapi
https://solr.apache.org/docs/4_6_1/solr-solrj/org/apache/solr/common/cloud/DocRouter.Range.html?is-external=true
DocRouter.Range (Solr 4.6.1 API)
rangesolrapi