private static List<String> getDocIds(String fileName) {
        try {
            FileInputStream fstream = new FileInputStream(fileName);
            DataInputStream in = new DataInputStream(fstream);
            BufferedReader br = new BufferedReader(new InputStreamReader(in));
            String strLine;

            List<String> docIds = new ArrayList<>();
            while ((strLine = br.readLine()) != null) {
                docIds.add(strLine);
            }
            in.close();
            return docIds;
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }
This is used for testing and benchmarking rpc docsum interface.
time vespa-summary-benchmark file-containing-docids connectionspec summary-class repetitions threads
fx ' time vespa-summary-benchmark feed.xml tcp/localhost:19115 keyvaluesummary 10000 32'

@author baldersheim
vespaclient-java/src/main/java/com/yahoo/vespasummarybenchmark/VespaSummaryBenchmark.java