How can I determine the total number of documents in a Solr index using Solrj?
After hours of searching on my own, I actually have an answer (given below); I'm only posting this question so others can find the solution more easily.
Your answer of sending the query *:*
is probably the best, most general solution. Especially if you are using SolrCloud. However, there is an alternate solution, the Solr Core Admin API