See this page for more details about the Collections API:
https://lucene.apache.org/solr/guide/8_5/collections-api.html

• HTTP Request (URL):
  http://localhost:8983/solr/admin/collections?action=CLUSTERSTATUS&omitHeader=true&wt=xml&indent=true
  
  Output:
  <response> <lst name="cluster"> <lst name="collections"> <lst name="collection1"> <str name="pullReplicas">0</str> <str name="replicationFactor">2</str> <lst name="shards"> <lst name="shard1"> <str name="range">80000000-ffffffff</str> <str name="state">active</str> <lst name="replicas"> <lst name="core_node3"> <str name="core">collection1_shard1_replica_n1</str> <str name="base_url">http://192.168.2.33:8984/solr</str> <str name="node_name">192.168.2.33:8984_solr</str> <str name="state">active</str> <str name="type">NRT</str> <str name="force_set_state">false</str> </lst> <lst name="core_node5"> <str name="core">collection1_shard1_replica_n2</str> <str name="base_url">http://192.168.2.33:8983/solr</str> <str name="node_name">192.168.2.33:8983_solr</str> <str name="state">active</str> <str name="type">NRT</str> <str name="force_set_state">false</str> <str name="leader">true</str> </lst> </lst> </lst> <lst name="shard2"> <str name="range">0-7fffffff</str> <str name="state">active</str> <lst name="replicas"> <lst name="core_node7"> <str name="core">collection1_shard2_replica_n4</str> <str name="base_url">http://192.168.2.33:8984/solr</str> <str name="node_name">192.168.2.33:8984_solr</str> <str name="state">active</str> <str name="type">NRT</str> <str name="force_set_state">false</str> <str name="leader">true</str> </lst> <lst name="core_node8"> <str name="core">collection1_shard2_replica_n6</str> <str name="base_url">http://192.168.2.33:8983/solr</str> <str name="node_name">192.168.2.33:8983_solr</str> <str name="state">active</str> <str name="type">NRT</str> <str name="force_set_state">false</str> </lst> </lst> </lst> </lst> <lst name="router"> <str name="name">compositeId</str> </lst> <str name="maxShardsPerNode">2</str> <str name="autoAddReplicas">false</str> <str name="nrtReplicas">2</str> <str name="tlogReplicas">0</str> <int name="znodeVersion">6</int> <arr name="aliases"> <str>collection_1_alias</str> </arr> <str name="configName">_default</str> </lst> </lst> <lst name="aliases"> <str name="collection_1_alias">collection1</str> </lst> <arr name="live_nodes"> <str>192.168.2.33:8983_solr</str> <str>192.168.2.33:8984_solr</str> </arr> </lst> </response>
  
• Java sample:
  private void getClusterStatus(final int jettyPort) throws IOException { final String url = "http://localhost:" + jettyPort + "/solr/admin/collections?action=CLUSTERSTATUS"; final HttpGet request = new HttpGet(url); try (final CloseableHttpClient client = HttpClientBuilder.create().build(); final CloseableHttpResponse response = client.execute(request)) { final HttpEntity entity = response.getEntity(); System.out.println(IOUtils.toString(entity.getContent(), "UTF-8")); // close the content stream. EntityUtils.consumeQuietly(entity); } }