How can I use OpenOffice in server mode as a multithreaded service?

Question

What is the experience of working with OpenOffice in server mode? I know OpenOffice is not multithreaded and now I need to use its services in our server.
What can I do

Answer 1

Thanks Bastian. I found another way, based on Bastian's answer. Opening several ports it provides access to create multithreads. But without many ports(enought several) we can improve performence by increase task queue timeout here is a documentation. And one thing again, we decided not to start and stop officeManager on each convertion process.At the end, I solved this task by this approach:

public class JODConverter {

    private static volatile OfficeManager officeManager;
    private static volatile OfficeDocumentConverter converter;

    public static void startOfficeManager(){
        try {

            officeManager = new DefaultOfficeManagerConfiguration()
                    .setOfficeHome(new File('libre office home path'))
                    .setPortNumbers(8100, 8101, 8102, 8103, 8104 )  
                    .setTaskExecutionTimeout(600000L)    // for big files
                    .setTaskQueueTimeout(200000L)        // wait if all port were busy
                    .buildOfficeManager();
            officeManager.start();

            // 2) Create JODConverter converter
            converter = new OfficeDocumentConverter(officeManager);

        } catch (Throwable e){
            e.printStackTrace();
        }
    }

    public static void convertPDF(File inputFile, File outputFile) throws Throwable {

        converter.convert(inputFile, outputFile);
    }

    public static void stopOfficeManager(){
        officeManager.stop();
    }

}

I call JODConverter's convertPDF when convertion is need. It will be stopped only when application was down.