Example of batching and multi-threading Solr updates

SolrUpdater.java

public static class SolrUpdater implements Runnable {
  private final UpdateRequest req = new UpdateRequest();
  private final SolrServer solr;
  private final BlockingQueue<String> strings;
  private final AtomicLong id;
  private final int batchSize = 100;
  private volatile int batchedUpdates = 0;

  public SolrUpdater(SolrServer solr, BlockingQueue<String> strings,
      AtomicLong id) {
    this.solr = solr;
    this.strings = strings;
    this.id = id;
  }

  @Override
  public void run() {
    while(true) {
      String text = strings.take();
      SolrInputDocument doc = new SolrInputDocument();
      doc.setField("id", "doc-" + id.getAndIncrement());
      doc.setField("text", text);
      req.add(doc);
      batchedUpdates++;
      if(batchedUpdates >= batchSize) {
        req.process(solr);
        req.clear();
      }
    }
  }
}