In order for the code bellow to work:

► 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 (binary):

final String UPDATE_REQUEST_PATH = "/update";

final String[] solrUrl = { "http://localhost:8983/solr" };

final String collectionName = "collection1";

// org.apache.solr.common.params.CollectionAdminParams.COLLECTION = "collection";

final CloudSolrClient cloudSolrClient = new CloudSolrClient.Builder(Arrays.asList(solrUrl)).build();

cloudSolrClient.setDefaultCollection(collectionName);

// adding documents [/update] [ContentStreamUpdateRequest::addContentStream]
{
    final String contentStream = "<add><doc><field name=\"id\">4</field><field name=\"dynamicField1_s\">dynamic_field1 1</field><field name=\"field1\">field1 1</field></doc></add>";
    final String contentType = "application/xml;charset=UTF-8";

    final ByteArrayStream byteArrayStream = new ByteArrayStream(contentStream.getBytes(StandardCharsets.UTF_8), null);
    byteArrayStream.setContentType(contentType);

    final ModifiableSolrParams modifiableSolrParams = new ModifiableSolrParams();

    modifiableSolrParams.add(CollectionAdminParams.COLLECTION, collectionName);

    final ContentStreamUpdateRequest contentStreamUpdateRequest = new ContentStreamUpdateRequest(UPDATE_REQUEST_PATH);

    contentStreamUpdateRequest.addContentStream(byteArrayStream);
    contentStreamUpdateRequest.setParams(modifiableSolrParams);
    contentStreamUpdateRequest.setMethod(METHOD.POST);

    final NamedList<Object> response = cloudSolrClient.request(contentStreamUpdateRequest);

    System.out.println(response);
}

cloudSolrClient.close();