SolrJ and Custom Solr Handler - solr

Question

I am trying to implement a simple custom request handler in Solr 7.3. I needed some clarifications on the methods available via the Solr Java API.
As per my understanding, I have extended my Java Class with "SearchHandler" and then overridden the "handleRequestBody" method. I am trying to understand the flow from the beginning. Here is a sample query in the browser.
http://localhost:8983/solr/customcollection/customhandler?
q=John&fl=id,last_name&maxRows=10
1) Once you enter the above query in the browser and press
"return" the Solr customhandler will be triggered. It will look
for the necessary jars from where the handler is created.
2) Once it finds the main class it will execute the following
method, which is overridden from the "SearchHandler" parent
class.
public void handleRequestBody(SolrRequest req, SolrResponse
resp) throws Exception
3) The SolrRequest req object will hold all the Solr Parameters
on the query, in this case, q,fl and maxRows.
4) Using the following code I unpack these parameters.
SolrParams params = req.getParams();
String q = params.get(CommonParams.Q);
String fl = params.getParams(CommonParams.FL);
String rows = params.get(CommonParams.ROWS);
5)I create a Solr object that let's me connect to my Solr Cloud
String zkHostString = "localhost:5181";
SolrClient solr = new
CloudSolrClient.Builder().withZkHost(zkHostString).build();
6) Here is where I need help
a) How do I use the unpacked Solr Parameters from the
original query and make a call to the "solr" object to
return results.
b) How do I make use of the "resp" object?
c) Most of the examples that I found on the internet show
how to print the results to STDOUT. However, since I am
using a custom handler I would like to display the results
back to the user (in this case, SOLR Admin or the browser).```
Any help is truly appreciated.
Thanks
public class SolrQueryTest extends
org.apache.solr.handler.component.SearchHandler {
String zkHostString = "localhost:5181";
SolrClient solr = new
CloudSolrClient.Builder().withZkHost(zkHostString).build();
private static final Logger log =
Logger.getLogger(SolrQueryTest.class.getName());
public void handleRequestBody(SolrRequest req, SolrResponse
resp) throws Exception {
SolrParams params = req.getParams();
String q = params.get(CommonParams.Q);
String rows = params.get(CommonParams.ROWS);
SolrQuery query = new SolrQuery(q);
query.setShowDebugInfo(true);
query.set("indent", "true");
// need to know how to call SOLR using the above query
parameters
//Once the response is received how to send it back to the
browser and NOT STDOUT
}
}