private void updateDisplay() {

        new Thread(
                () -> {
                        if (catalogue == null)
                            throw new Error("Internal error: catalogue not set");
                        if (displayArea == null)
                            throw new Error(
                                    "Internal error: display area not set");
                        // Then do the display
                        value = 0;
                        Document doc = displayArea.getDocument();
                        // For each item in the stock, add it to the description
                        // list and the total value
                        List<String> list = new ArrayList<String>();
                        try {
                            doc.remove(0, doc.getLength());
                            for (String name : catalogue.getEntryNames()) {
                                list.add(name);
                            }
                            list.parallelStream().forEach(n -> {
                                try {

                                    IEntry entry = catalogue.getEntry(n);
                                    Product product = entry.getProduct();
                                    int quantity = entry.getQuantity();
                                    String text = product.getName() + "@"
                                            + product.getPrice() + ": " + quantity
                                            + "\n";
                                    doc.insertString(doc.getLength(), text, null);
                                    value += quantity * product.getPrice();
                                } catch (Exception e) {
                                    // TODO Auto-generated catch block
                                    e.printStackTrace();
                                }
                            });

                            doc.insertString(doc.getLength(), "Total value: "
                                    + value, null);
                        } catch (RemoteException exn) {
                            throw new Error("Remote failure: " + exn);
                        } catch (BadLocationException e) {
                            throw new Error(
                                    "Internal error: bad text location in GUI");
                        }

                }).start();
    }