在Swing中刷新JTable数据

Question

我在同一框架中添加了文本字段和jTable。 从jButton1单击上的文本字段获取值后，我将值插入数据库中，并且jTable中显示了相同的数据。 但是问题是我的表在添加数据后没有得到更新。 我必须evrytime执行该程序以获取表更新。 我已经尝试过Frame.invalidate, Frame.validate, Frame.repaint , tbale.repaint但没有解决，我要去哪里错了，谢谢！

public class mainFrame extends javax.swing.JFrame {

static JTable table;
static Connection connection;
static Statement statement;
static JTable jTable1;
static int count;
static String r;

/**
 * Creates new form mainFrame
 */
public mainFrame() {
    super();

    initComponents();
    setLocation(500, 180);
    try {
        //----------database
        Class.forName("org.sqlite.JDBC");
        connection = null;
        connection = DriverManager.getConnection("jdbc:sqlite:excel.db");
        statement = connection.createStatement();
        statement.executeUpdate("CREATE TABLE IF NOT EXISTS testing (id INTEGER PRIMARY KEY , namexcel string)");

        //--------
        final String queryCheck = "SELECT count(*) from testing";
        final PreparedStatement ps = connection.prepareStatement(queryCheck);
        // ps.setString(1, name);
        final ResultSet resultSet = ps.executeQuery();
        if (resultSet.next()) {
            count = resultSet.getInt(1);
            System.out.println(count);

        }

        String read = "select * from testing";
        ResultSet rs = statement.executeQuery(read);
        Object[][] data = new Object[count][2];
        int i = 0;
        while (rs.next()) {

            for (int c = 0; c < 1; c++) {
                data[i][c] = rs.getString("namexcel");

            }
            i++;

        }

        String[] headers = {"Name"};

        table = new JTable(data, headers);

        jScrollPane2.setViewportView(table);

        //     pack();
    } catch (Exception e) {

    }
}

/**
 * This method is called from within the constructor to initialize the form.
 * WARNING: Do NOT modify this code. The content of this method is always
 * regenerated by the Form Editor.
 */
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">                          
private void initComponents() {

//.....
}// </editor-fold>                        

private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         

    try {
        String link = jTextField1.getText();
        System.out.println("" + link + "");
        jTextField1.setText("");
        File f = new File("" + link + "");
        if (!f.exists()) {
            JOptionPane.showMessageDialog(null, "File Doesnt Exist....!!");

        } else {
            FileInputStream file = new FileInputStream(f);
            XSSFWorkbook workbook = new XSSFWorkbook(file);
            String name = workbook.getSheetName(0);
            System.out.println(name);
            final String queryCheck = "SELECT count(*) from testing WHERE namexcel = ?";
            final PreparedStatement ps = connection.prepareStatement(queryCheck);
            ps.setString(1, name);
            final ResultSet resultSet = ps.executeQuery();
            if (resultSet.next()) {
                final int count = resultSet.getInt(1);
                if (count == 0) {
                    JOptionPane.showMessageDialog(null, "thank you");                        
                    statement.executeUpdate("insert into testing (namexcel) values('" + name + "')");
                mainFrame frame = new mainFrame();
                frame.invalidate();
                frame.validate();

                table.revalidate();

                } else {
                    JOptionPane.showMessageDialog(null, "Name Already exist please select diffrent name of excel");
                }
            }

        }

    } catch (Exception r) {

    }
}                                        

/**
 * @param args the command line arguments
 */
public static void main(String args[]) throws Exception {

    /* Set the Nimbus look and feel */
    //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
    /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
     * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
     */
    try {
        for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
            if ("Windows".equals(info.getName())) {
                javax.swing.UIManager.setLookAndFeel(info.getClassName());
                break;
            }
        }
    } catch (Exception ex) {

    } 
    //</editor-fold>

    /* Create and display the form */
    java.awt.EventQueue.invokeLater(new Runnable() {
        public void run() {
            new mainFrame().setVisible(true);
        }
    });
}


private javax.swing.JButton jButton1;
private javax.swing.JLabel jLabel1;
private javax.swing.JPanel jPanel1;
public static javax.swing.JScrollPane jScrollPane2;
private javax.swing.JTextField jTextField1;

}

以下是inicomponent方法

 private void initComponents() {

    jPanel1 = new javax.swing.JPanel();
    jButton1 = new javax.swing.JButton();
    jLabel1 = new javax.swing.JLabel();
    jTextField1 = new javax.swing.JTextField();
    jScrollPane2 = new javax.swing.JScrollPane();

    setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

    jPanel1.setBorder(javax.swing.BorderFactory.createEtchedBorder());

    jButton1.setText("Add");
    jButton1.addActionListener(new java.awt.event.ActionListener() {
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            jButton1ActionPerformed(evt);
        }
    });

    jLabel1.setFont(new java.awt.Font("Dialog", 1, 11)); // NOI18N
    jLabel1.setText("Add Excel Sheet Link");

    jTextField1.setText("");

    javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
    jPanel1.setLayout(jPanel1Layout);
    jPanel1Layout.setHorizontalGroup(
        jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(jPanel1Layout.createSequentialGroup()
            .addGap(26, 26, 26)
            .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addGroup(jPanel1Layout.createSequentialGroup()
                    .addComponent(jButton1, javax.swing.GroupLayout.PREFERRED_SIZE, 105, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addGap(0, 0, Short.MAX_VALUE))
                .addGroup(jPanel1Layout.createSequentialGroup()
                    .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                        .addComponent(jTextField1)
                        .addGroup(jPanel1Layout.createSequentialGroup()
                            .addComponent(jLabel1)
                            .addGap(0, 0, Short.MAX_VALUE)))
                    .addContainerGap())))
    );
    jPanel1Layout.setVerticalGroup(
        jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(jPanel1Layout.createSequentialGroup()
            .addGap(20, 20, 20)
            .addComponent(jLabel1)
            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
            .addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 13, Short.MAX_VALUE)
            .addComponent(jButton1)
            .addContainerGap())
    );

    javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
    getContentPane().setLayout(layout);
    layout.setHorizontalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(layout.createSequentialGroup()
            .addContainerGap()
            .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                .addComponent(jScrollPane2, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.DEFAULT_SIZE, 350, Short.MAX_VALUE))
            .addContainerGap())
    );
    layout.setVerticalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(layout.createSequentialGroup()
            .addContainerGap()
            .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addGap(18, 18, 18)
            .addComponent(jScrollPane2, javax.swing.GroupLayout.PREFERRED_SIZE, 394, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addContainerGap(20, Short.MAX_VALUE))
    );

    pack();
}

Answer 1

1. 不做table = new JTable(data, headers); 在您的构造函数中。 您正在取消引用拖放的初始表。 确定jScrollPane2.setViewportView(table); 可能已经修复了它（通过将视口设置为新表），但这是不必要的，并且如果您不了解正在发生的情况，还会闻到将来的问题。

2. 而是使用表的模型进行更新。 因此，代替table = new JTable ，执行

    DefaultTableModel model = new DefaultTableModel(data, headers); table.setModel(model); 

   而已。

3. 要更新表，只需在数据库中成功更新后更新模型即可。

    if (successfulInsert) { DefaultTableModel model = (DefaultTableModel)table.getModel(); Object[] row = .... // get the data for the row model.addRow(row); } 

有关更多信息，请参见如何使用表以及如何 创建TableModel和DefaultTableModel API。