java.lang.UnsupportedOperationException при добавлении элемента в список

Question

Я пытаюсь создать настольное приложение с Netbeans и шаблоном управления моделью для моего экзамена по программированию. Мне приходится управлять кроватью и завтраком, и у меня возникают проблемы с добавлением комнаты в архив (я использую фиктивный Дао) (я также перевожу код на английский, чтобы вы лучше поняли, поэтому извините если я забуду некоторые слова или некоторые слова неверны)

public class ControlDialogAddRoom {

    private Action actionAddRoom = new ActionAddRoom();


    public Action getActionAddRoom() {
        return actionAddRoom;
    }

 private class ActionAddRoom extends AbstractAction{

        public ActionAddRoom (){
            this.putValue(Action.NAME, "Add room");
            this.putValue(Action.SHORT_DESCRIPTION, "Add a room");
        }
    @Override
        public void actionPerformed(ActionEvent e) {
            Bed bed= (Bed)Application.getInstance().getModel().getBean(Constants.BED);

                Room roomAdded = checkFields(bed);
                if(roomAdded != null){
                    //i wrote this just to make sure that the program was getting the right text from the fields
                    System.out.println(roomAdded.toString());
                    bed.addRoom(roomAdded);
                    Application.getInstance().getFrame().showInfo("Room correctly added!");
                    Applicazione.getInstance().getDialogRoomAdded().initFields();
                }

            }

Теперь я вставлю метод checkField. name и code - это два JTextFields, цена и numberOfBeds - это два JSpinner. поле Jspinner для цены также дает мне некоторые ошибки, если я оставлю номер по умолчанию 1.

private Room checkFields(Bed){
            StringBuilder errors = new StringBuilder();
            String roomCode = Application.getInstance().getDialogAddRoom().getFieldCode();
            String roomName = Application.getInstance().getDialogAddRoom().getFieldName();
            float price= (Float)Application.getInstance().getDialogAddRoom().getSpinnerPrice();
            int numberOfBeds = (Integer)Application.getInstance().getDialogAddRoom().getSpinnerNumberOfBeds();
            if(roomCode.isEmpty()){
                errors.append("\nThe code cant be empty");
            }
            for(Room room : bed.getRooms()){
                if(room.getCode().equals(roomCode)){
                    errors.append("\nThere's already a room with that code");
                }
            }            
            if(roomName.isEmpty()){
                errors.append("\nThe field name can't be empty");
            }                    
            if(!(errors.toString()).isEmpty()){

          Application.getInstance().getFrame().showErrors(errors.toString());
                return null;
            }
            return new Room(roomName, roomCode, numberOfBeds, price);
        }

ошибка цены:

          Exception in thread "AWT-EventQueue-0" java.lang.ClassCastException: java.lang.Integer cannot be cast to java.lang.Float

Основная ошибка в строке кода bed.addRoom(roomAdded);

в классе Бед это простой метод, который работал много раз для меня. у меня есть список комнат, и я просто добавляю новую комнату:

 private List<Room> rooms = new ArrayList<>();

public void addRoom(Room room){
        this.rooms.add(room);
    }

Я получаю следующий стек на выходе

Exception in thread "AWT-EventQueue-0" java.lang.UnsupportedOperationException

    at java.util.AbstractList.add(AbstractList.java:148)
    at java.util.AbstractList.add(AbstractList.java:108)
    at it.unibas.bedandbreakfast.model.Bed.addRoom(Sistema.java:27)
    at it.unibas.bedandbreakfast.control.ControlDialogAddRoom$ActionAddRoom.actionPerformed(ControlDialogAddRoom.java:51)
    at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022)
    at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2348)
    at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
    at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
    at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
    at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:289)
    at java.awt.Component.processMouseEvent(Component.java:6533)
    at javax.swing.JComponent.processMouseEvent(JComponent.java:3324)
    at java.awt.Component.processEvent(Component.java:6298)
    at java.awt.Container.processEvent(Container.java:2236)
    at java.awt.Component.dispatchEventImpl(Component.java:4889)
    at java.awt.Container.dispatchEventImpl(Container.java:2294)
    at java.awt.Component.dispatchEvent(Component.java:4711)
    at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4888)
    at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4525)
    at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4466)
    at java.awt.Container.dispatchEventImpl(Container.java:2280)
    at java.awt.Window.dispatchEventImpl(Window.java:2746)
    at java.awt.Component.dispatchEvent(Component.java:4711)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)
    at java.awt.EventQueue.access$500(EventQueue.java:97)
    at java.awt.EventQueue$3.run(EventQueue.java:709)
    at java.awt.EventQueue$3.run(EventQueue.java:703)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:90)
    at java.awt.EventQueue$4.run(EventQueue.java:731)
    at java.awt.EventQueue$4.run(EventQueue.java:729)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:109)
    at java.awt.WaitDispatchSupport$2.run(WaitDispatchSupport.java:184)
    at java.awt.WaitDispatchSupport$4.run(WaitDispatchSupport.java:229)
    at java.awt.WaitDispatchSupport$4.run(WaitDispatchSupport.java:227)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.awt.WaitDispatchSupport.enter(WaitDispatchSupport.java:227)
    at java.awt.Dialog.show(Dialog.java:1084)
    at java.awt.Component.show(Component.java:1671)
    at java.awt.Component.setVisible(Component.java:1623)
    at java.awt.Window.setVisible(Window.java:1014)
    at java.awt.Dialog.setVisible(Dialog.java:1005)
    at it.unibas.bedandbreakfast.view.DialogAddRoom.showWindow(DialogAddRoom.java:151)
    at it.unibas.bedandbreakfast.control.ControlPanelMenu$ActionAddRoom.actionPerformed(ControlPanelMenu.java:65)
    at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022)
    at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2348)
    at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
    at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
    at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
    at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:289)
    at java.awt.Component.processMouseEvent(Component.java:6533)
    at javax.swing.JComponent.processMouseEvent(JComponent.java:3324)
    at java.awt.Component.processEvent(Component.java:6298)
    at java.awt.Container.processEvent(Container.java:2236)
    at java.awt.Component.dispatchEventImpl(Component.java:4889)
    at java.awt.Container.dispatchEventImpl(Container.java:2294)
    at java.awt.Component.dispatchEvent(Component.java:4711)
    at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4888)
    at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4525)
    at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4466)
    at java.awt.Container.dispatchEventImpl(Container.java:2280)
    at java.awt.Window.dispatchEventImpl(Window.java:2746)
    at java.awt.Component.dispatchEvent(Component.java:4711)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)
    at java.awt.EventQueue.access$500(EventQueue.java:97)
    at java.awt.EventQueue$3.run(EventQueue.java:709)
    at java.awt.EventQueue$3.run(EventQueue.java:703)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:90)
    at java.awt.EventQueue$4.run(EventQueue.java:731)
    at java.awt.EventQueue$4.run(EventQueue.java:729)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)

я правда не понимаю, что не так ??? я почти уверен, что проблема в строке кода bed.addRoom(roomAdded);

EDIT: Я изменил некоторые строки в действии, и теперь это работает, но я все еще хотел бы знать, что я делал неправильно раньше. Я добавил это

    public void actionPerformed(ActionEvent e) {
            Bed bed= (Bed)Application.getInstance().getModel().getBean(Constants.BED);

            //ADDED THE FOLLOWING LINE            
            List<Room> allTheRooms = new ArrayList<>(bed.getRooms());

            Room roomAdded = checkFields(bed);
            if(roomAdded != null){
                   System.out.println(roomAdded.toString());

                   //ADDED THE FOLLOWING TWO LINES
                    allTheRooms.add(addedRoom);
                    bed.setRooms(allTheRooms);

                    Application.getInstance().getFrame().showInfo("Room correctly added!");

как сказал пользователь @ xerx593 в комментариях, похоже, что информация о типе потерялась