Thread: unable to add elements in jlist

UNable to add elements in jlist
in constructor
getting jlist blank
following is my code :

 private Server ser=null;
    Thread my=null;
    DefaultListModel clients= new DefaultListModel();
 
    public UIServer(Server ser) {
        initComponents();
        this.ser=ser;
        setVisible(true);
       clients = new DefaultListModel();
            for(int i=0;i<=ser.clientsNames.length-1;i++)
                {
 
                    clients.addElement(ser.clientsNames[i]);
                }
            lstClient = new JList(clients);
            lstClient.setModel(clients);
            my= new Thread(this);
        //my.start();
    }

I debugged and im getting values in list model and im using netbeans IDE

class UIServer extends JFrame{
private Server ser=null;
    Thread my=null;
    DefaultListModel clients= new DefaultListModel();
 
    public UIServer(Server ser) {
        initComponents();
        this.ser=ser;
        setVisible(true);
       clients = new DefaultListModel();
            for(int i=0;i<=ser.clientsNames.length-1;i++)
                {
 
                    clients.addElement(ser.clientsNames[i]);
                }
            lstClient = new JList(clients);
            lstClient.setModel(clients);
            add(lstClient);
            setvisible(true);
    }
}
class Server{
public String clientsNames[]={"02","05","10","11","24","28","29","37","43","86"};
public Server(){UIServer o = new UIServer(this);}
}