In order for the code bellow to work:

► Make sure to enable Streaming in "solrconfig.xml":
<requestParsers enableStreamBody="true" />
If you want to update this file directly in the Configset, make sure to reload all collections that use the updated Configset.
Please visit this page for more details: http://lucene.apache.org/solr/guide/8_5/requestdispatcher-in-solrconfig.html

► Make sure to update the variables ("solrUrl", "collectionName", ...) with your information.

► Make sure to add the fields "id" and "field1" to your SchemaXml.

To force the commit, make sure to set the property "openSearcher" to true (SolrConfigXml file -> updateHandler -> autoCommit)

Note: You can also force the commit by running the URL: http://localhost:8983/solr/COLLECTION-NAME/update?commit=true

Add documents using the request handler /update (stream.body):
final String UPDATE_REQUEST_PATH = "/update"; final String[] solrUrl = { "http://localhost:8983/solr" }; final String collectionName = "collection1"; // org.apache.solr.common.params.CommonParams.STREAM_BODY = "stream.body"; // org.apache.solr.common.params.CollectionAdminParams.COLLECTION = "collection"; final CloudSolrClient cloudSolrClient = new CloudSolrClient.Builder(Arrays.asList(solrUrl)).build(); cloudSolrClient.setDefaultCollection(collectionName); // adding documents [/update] [ModifiableSolrParams] [stream.body] { final String streamBody = "<add><doc><field name=\"id\">3</field><field name=\"dynamicField1_s\">dynamic_field1 1</field><field name=\"field1\">field1 1</field></doc></add>"; final ModifiableSolrParams modifiableSolrParams = new ModifiableSolrParams(); modifiableSolrParams.add(CommonParams.STREAM_BODY, streamBody); modifiableSolrParams.add(CollectionAdminParams.COLLECTION, collectionName); final UpdateRequest updateRequest = new UpdateRequest(); updateRequest.setParams(modifiableSolrParams); updateRequest.setPath(UPDATE_REQUEST_PATH); updateRequest.setMethod(METHOD.POST); final NamedList<Object> response = cloudSolrClient.request(updateRequest); System.out.println(response); } cloudSolrClient.close();