[App A] Renaming the fields responsible for showing the messages from the server

  public static final int NUMBER_OF_BEATS = 16;

  private final List<BeatInstrument> instruments;

  private JList<String> incomingList;

  private JList<String> messages;

  private JTextField userMessage;

  private ArrayList<JCheckBox> checkboxList;

  private int nextNum;

  private final Vector<String> listVector = new Vector<>();

  private final Vector<String> incomingMessages = new Vector<>();

  private String userName;

  private ObjectOutputStream out;

  private ObjectInputStream in;

    buttonBox.add(userMessage);

    incomingList = new JList<>();

    incomingList.addListSelectionListener(new MyListSelectionListener());

    incomingList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);

    JScrollPane theList = new JScrollPane(incomingList);

    buttonBox.add(theList);

    incomingList.setListData(listVector); // no data to start with

    messages = new JList<>();

    messages.addListSelectionListener(new MyListSelectionListener());

    messages.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);

    buttonBox.add(new JScrollPane(messages));

    messages.setListData(incomingMessages); // no data to start with

    Box nameBox = new Box(BoxLayout.Y_AXIS);

    for (BeatInstrument instrument : instruments) {

  public class MyListSelectionListener implements ListSelectionListener {

    public void valueChanged(ListSelectionEvent le) {

      if (!le.getValueIsAdjusting()) {

        String selected = incomingList.getSelectedValue();

        String selected = messages.getSelectedValue();

        if (selected != null) {

          // now go to the map, and change the sequence

          boolean[] selectedState = otherSeqsMap.get(selected);

          String nameToShow = (String) obj;

          checkboxState = (boolean[]) in.readObject();

          otherSeqsMap.put(nameToShow, checkboxState);

          listVector.add(nameToShow);

          incomingList.setListData(listVector);

          incomingMessages.add(nameToShow);

          messages.setListData(incomingMessages);

        }

      } catch (IOException | ClassNotFoundException ex) {

        ex.printStackTrace();