Java Solr SolrJ get id value of the newly indexed file

Question

I have an entity, which I want to link to an indexed file uploaded to solr via SolrJ. Preferably it would be a field on the entity with the file's entry id as value. Thing is - I don't know how to get that id after it just being uploaded. Here is the code:

            //File tempFile;
            //MultipartFile file;
            tempFile = File.createTempFile(prefix, postfix);
            file.transferTo(tempFile);
            ContentStreamUpdateRequest req = new ContentStreamUpdateRequest("/update/extract");
            req.addFile(tempFile, file.getContentType());
            req.setAction(AbstractUpdateRequest.ACTION.COMMIT, true, true);
            NamedList list = solrClient.request(req);
            System.out.println(list);
            //{responseHeader={status=0,QTime=1328}}
            tempFile.delete();

Answer 1

The solution was to create id myself and set it like this:

req.setParam("literal.id", UUID.randomUUID().toString());