JList 从组件面板放置在表单上没有响应

Question

好的，我正在使用 IntelliJ 开发一个简单的 sqlite 数据库程序。我对这个平台很陌生。我在窗体上放置了一个 JList 组件并将其命名为 list1。现在，当我尝试用字符串填充它时，我使用了向量和列表模型，但我看不到任何数据。我认为它没有与 IntelliJ 创建的 JList 连接。我看过通过代码完成所有操作的示例，但我想知道如何使用设计时放置的 JList。我想在循环遍历 sqlite 数据后按下一个按钮并填充列表。我知道我不是那么好，但这是我目前所拥有的：

public class mainForm {
    private JPanel panelMain;
    private JButton button1;
   // private Vector vStatic = new Vector();

/////LOOK HERE ->
    DefaultListModel listModel;
    JList list1;




    public mainForm() {

        button1.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {

               // JOptionPane.showMessageDialog(null, "This really sucks!!");
                Connection c;
                Statement stmt;
                listModel = new DefaultListModel();

                try {

                    Class.forName("org.sqlite.JDBC");
                    c = DriverManager.getConnection("jdbc:sqlite:javacarl.db");
                  //  c.setAutoCommit(true);
                    JOptionPane.showMessageDialog(null, "Open Success!");
                    stmt = c.createStatement();
                    ResultSet res = stmt.executeQuery("SELECT * FROM CARL");
                  //  int i = 0;
                   res.next();

/////LOOK HERE ->
                     while (res.next()) {
                       listModel.addElement(res.getString("JOB"));
                   }
                    JList list1 = new JList(listModel);
                    list1.updateUI();
                    stmt.close();
                    c.close();
                } catch (Exception e1) {
                    JOptionPane.showMessageDialog(null, "Operation Not A Successful!"+e1);
                    System.exit(0);
                }
                JOptionPane.showMessageDialog(null, "Operation Success!");

            }
        });

    }


    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {

                new mainForm().createAndShowUI();
            }
        });

        Connection c;
        Statement stmt;
        try {
            Class.forName("org.sqlite.JDBC");
            c = DriverManager.getConnection("jdbc:sqlite:javacarl.db");
            JOptionPane.showMessageDialog(null, "Opened database successfully!");
            stmt = c.createStatement();
            String sql = "CREATE TABLE IF NOT EXISTS CARL " +
                    "(ID INTEGER PRIMARY KEY AUTOINCREMENT," +
                    " JOB            TEXT    NOT NULL, " +
                    " DATE           TEXT    NOT NULL, " +
                    " MATERIAL       REAL    NOT NULL, " +
                    " LABOR          REAL    NOT NULL, " +
                    " SUBTOTAL       REAL    NOT NULL, " +
                    " TAX            REAL, " +
                    " TOTAL          REAL, " +
                    " DEPAMT         REAL, " +
                    " AMTPAID        REAL)";

            stmt.executeUpdate(sql);

            stmt.close();
            //  c.commit();
            c.close();
        } catch (Exception e) {
            JOptionPane.showMessageDialog(null, e.getClass().getName() + ": " + e.getMessage());
            System.exit(0);
        }

        // JOptionPane.showMessageDialog(null, "Table Created successfully!" );
    }

    private void createAndShowUI() {

        Toolkit t;
        Dimension s;
        JFrame frame = new JFrame("MainForm");
        frame.setContentPane(new mainForm().panelMain);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setPreferredSize(new Dimension(750, 500));
        t = Toolkit.getDefaultToolkit();
        s = t.getScreenSize();
        frame.setLocation(s.width / 4 - frame.getWidth() / 2, s.height / 4 - frame.getHeight() / 2);
        initComponents(frame);
        frame.pack();
        frame.setVisible(true);

    }


    private void initComponents(JFrame frame) {
        JMenu menu1 = new JMenu("File");
        JMenuItem deleteall = new JMenuItem("Delete all records");
        JMenuItem addjob = new JMenuItem("Add Job");
        JMenuItem exit1 = new JMenuItem("Exit");
        menu1.add(deleteall);
        menu1.add(addjob);
        menu1.add(exit1);

        addjob.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                Connection c;
                Statement stmt;

                try {
                    Class.forName("org.sqlite.JDBC");
                    c = DriverManager.getConnection("jdbc:sqlite:javacarl.db");
                    c.setAutoCommit(false);
                    stmt = c.createStatement();
                    //String sql = "DELETE FROM CARL";

                    String sql = "INSERT INTO CARL (JOB,DATE,MATERIAL,LABOR,SUBTOTAL,TAX,TOTAL,DEPAMT,AMTPAID) " +
                         "VALUES ('Disaster on goodrich rd!','03/03/2020', 1000.00, 100.00, 1100.00,11.00,0,0,0 );";
                    //stmt.executeUpdate(sql);
                   // sql = "DELETE FROM sqlite_sequence WHERE name = 'CARL'";
                    stmt.executeUpdate(sql);
                    c.commit();
                    stmt.close();
                    c.close();
                } catch (Exception e1) {
                    JOptionPane.showMessageDialog(null, "New record failed!");
                    System.exit(0);
                }
                JOptionPane.showMessageDialog(null, "New record inserted!");

                //  JFileChooser chooser = new JFileChooser();
                //  chooser.showOpenDialog(null);

            }

        });

        deleteall.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                Connection c;
                Statement stmt;

                try {
                    Class.forName("org.sqlite.JDBC");
                    c = DriverManager.getConnection("jdbc:sqlite:javacarl.db");
                    c.setAutoCommit(false);
                    stmt = c.createStatement();
                    String sql = "DELETE FROM CARL";
                    stmt.executeUpdate(sql);
                    sql = "DELETE FROM sqlite_sequence WHERE name = 'CARL'";
                    stmt.executeUpdate(sql);
                    c.commit();
                    stmt.close();
                    c.close();
                } catch (Exception e1) {
                    JOptionPane.showMessageDialog(null, "Deletion failed!");
                    System.exit(0);
                }
                JOptionPane.showMessageDialog(null, "All records deleted!");

            }

        });

        exit1.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                System.exit(0);

            }

        });

        JMenuBar jmb = new JMenuBar();
        jmb.add(menu1);
        frame.setJMenuBar(jmb);
        //  report.addItemListener((ItemListener) this);

    }



}

Answer 1

我可以post这里的代码对我有用：

public void updateJList() {

    Connection c;
    Statement stmt;
    try {
        Class.forName("org.sqlite.JDBC");
        c = DriverManager.getConnection("jdbc:sqlite:javajobs.db");
        stmt = c.createStatement();
        ResultSet res = stmt.executeQuery("SELECT * FROM JOBS ORDER BY ID DESC");
        model.clear();
        while (res.next()) {
            model.addElement(res.getInt("ID") + "*-- " + res.getString("DATE") +"  -- " + res.getString("NAME")
                    + " -- Job Desc: " + res.getString("JOB") + " -- Labor = "
                    + res.getBigDecimal("LABOR")+ " -- Mat = " + res.getString("MATERIAL") + " -- Total = "
                    + res.getBigDecimal("TOTAL"));
        }
        stmt.close();
        c.close();
    } catch (Exception e1) {
        JOptionPane.showMessageDialog(null, "Operation JList load Not Successful!" + e1);
    }
}

JList 从组件面板放置在表单上没有响应

JList placed on form from component palette not responding

java

swing

jlist

defaultlistmodel