How to get the _search_shards informations with Java API

Elastic Stack Elasticsearch
1

I want to get in programmatic way the data that is available through
/IDXNAME/TYPENAME/_search_shards?routing=route2

Sadly this is not documented in Java API. However I have found that there is a method
client().admin().cluster().searchShards(clusterSearchShardsRequest)
with code like:

ClusterSearchShardsRequest clusterSearchShardsRequest 
= new   ClusterSearchShardsRequest();
                clusterSearchShardsRequest.routing("route2");

                try {
                    DiscoveryNode[] discoveryNodes = client().admin().cluster()
                            .searchShards(clusterSearchShardsRequest)
                            .get()
                            .getNodes();
                    for (int i=0; i<=discoveryNodes.length; i++){
                        System.out.print("\n\n\n"+discoveryNodes[i].toString()+"\n\n\n");
                    }

                } catch (InterruptedException e) {
                    e.printStackTrace();
                } catch (ExecutionException e) {
                    e.printStackTrace();
                }

However the clusterSearchShardsRequestinitialization is incorrect here so for a given (client,index,type). How can one fix this code to give the _search_shard informations?

How can I get the _search_shards functionality with Java API?