jlist的位置和大小

Question

嗨，先生，我对我的程序感到困惑，我怎么能找到并调整我的JList等等。我现在正在使用FlowLayout（）;但我不能调整大小并找到JList等，这是我的代码到目前为止。任何建议的人

public static void main(String args [])
    {

        brie t1 = new brie();
                t1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        t1.setSize(300,200);
        t1.setVisible(true);
        t1.setLocationRelativeTo(null);
                t1.setResizable(false);
    }
    String namep [] = {"Chocolate", "Cake", "Candy", "Ice Cream", "Snacks"};
    int pricep [] = {1, 2, 3, 4, 5};
    JPanel panel2 = new JPanel();
    JLabel l = new JLabel("Enter your payment");
    JTextField f = new JTextField(15);
    JButton tru = new JButton("Yes");
    JFrame w = new JFrame("pay");
    JList lst = new JList(namep);
    JLabel l2 = new JLabel("Enter Quantity");
    JTextField t1 = new JTextField(10);
    JLabel l3 = new JLabel();
    JButton b2 = new JButton("Exit");
        JButton b1 = new JButton("Compute");

    double tet;
    Container cong = getContentPane();
    String namep1,totallist;
    double otpc;
        int paym,tot = 0;
        int quan,pricep1;
    int x,grandtotal,change;



    public brie(){

        totallist = "";
        namep1 = "";
//      t1.setEditable(false);
        t1.setText("");             
        cong.setLayout(new FlowLayout());
                new JScrollPane(lst).setSize(30,30);
                cong.add(new JScrollPane(lst));
        cong.add(l2);
        cong.add(t1);
        cong.add(b1);
        cong.add(b2);   
        cong.add(l3);

        b1.addActionListener(this);
        b2.addActionListener(this);
        tru.addActionListener(this);


        lst.setSelectedIndex(0);
        lst.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
        lst.addListSelectionListener(new ListSelectionListener()
                {
            public void valueChanged(ListSelectionEvent e)
                        {
                t1.setEditable(true);
                x = lst.getSelectedIndex();
            }
        });