添加项目后刷新JList Java

Question

I'm trying to create simple addressbook with Java, I have JList that contain people's name, after successfully create person, the name of person will be show on JList, but it still didn't working.

Here's My AddressBookGUI code:

public class AddressBookGUI extends JFrame {
    // GUI components  
    private DefaultListModel<String> namaPeople = new DefaultListModel<>();
    private JList<String> nameList = new JList<>(namaPeople);

    public AddressBookGUI() {
        JScrollPane listPane = new JScrollPane(nameList);
        getContentPane().add(listPane, BorderLayout.NORTH);
    }

    public static void addPerson(Person info) {
      // insert new Person's Name to JList
      // ERROR's Here
      DefaultListModel<String> namaPeople = new DefaultListModel<>();
      namaPeople.addElement(info.getName());
    }
}

Answer 1

You try to create a new DefaultListModel instance in the static method while you should use which one which exists if you want to add a Person and not overwriting the existing list.
Just use the namaPeople instance field to add it the new Person .
And remove also the static modifier here :

public static void addPerson(Person info) 

because it prevents the method from accessing to a instance field.

public class AddressBookGUI extends JFrame {
    // GUI components  
    private DefaultListModel<String> namaPeople = new DefaultListModel<>();
    private JList<String> nameList = new JList<>(namaPeople);

    public AddressBookGUI() {
        JScrollPane listPane = new JScrollPane(nameList);
        getContentPane().add(listPane, BorderLayout.NORTH);
}

public void addPerson(Person info) {
    // insert new Person's Name to JList
    namaPeople.addElement(info.getName());
}