使用MVC将ArrayList转换为JList

Question

I have 3 classes.
ImpAppModel:

/* String array for saving members in the friendlist*/
public ArrayList<String> friendList = new ArrayList(10);

/**
 * Method for retrieving elements (added friends) in the array for use in 
 * GUI.
 * @return the elements in the ArrayList
 */
public ArrayList friendList() {
    //method filling the array with 1 testing record
    friendList.add(1, "petr");
    return friendList;
}

I have viewing appPanel class (generated by fellow NetBeans GUI Builder):

        Users.setModel(new javax.swing.AbstractListModel() {
        String[] strings = {"User1", "User2", "User3", "User4", "User5"};

        @Override
        public int getSize() {
            return strings.length;
        }

        @Override
        public Object getElementAt(int i) {
            return strings[i];
        }
    });
    /**
 * Method for setting users to display in GUI (variable JList Users)
 * @param user parameter for supplying JList
 */
public void setUser(JList user){
    this.Users = user;
}

And finally I have controlling ImpAppContorller class:

private final GuiPanel appPanel;
private final ImpAppModel impAppModel;
/**
 * Main constructor method, creates variables for saving links on Data and 
 * GUI.
 * @param appPanel Ensures communication between GUI panel and controller.
 * @param impAppModel Ensures communication between Model and controller.
 */
public ImpAppController(GuiPanel appPanel, ImpAppModel impAppModel) {

    this.appPanel = appPanel;
    this.impAppModel = impAppModel;

    appPanel.setUser(impAppModel.friendList.toArray());
}

And I have a Error: incopatible types: Object[] cannot be converted to Jlist.
The question is (And yes, I did my research, the solutions I found weren't suitable for use in MVC pattern) how do I implement controller (or modify model/view) to supply JList with elements from arrayList using the controller class while maintaining the MVC pattern.
/Edit: I have heavy suspision that my problems are caused by setUser method in GUI class, but the question remains the same.

Answer 1

A JList contains its data in the form of a ListModel . Define the data for your Jlist with the setModel() member.

It's obviously not meaningful to cast an array to a Model object but there is a convenient class DefaultListModel that you can use to import an array to the model. So in your appPanel class you can add

public void setUserData(Object [] data){
    DefaultListModel model = new DefaultListModel();
    model.copyInto(data);
    Users.setModel(model); // Users must exist
}

Answer 2

appPanel.setUser(JList user) method accepts object of type JList whereas in appPanel.setUser(impAppModel.friendList.toArray()); you are passing an array type.

You should do something like appPanel.setUser(new JList(impAppModel.friendList.toArray()));

Or provide an overloaded setUser(String[] arr) method in AppPanel class which takes an array and create JList object internally.