从 ResultSet 填充 JTable 的最简单代码

java sqlite swing jtable defaulttablemodel

2022-09-01 03:28:20

我用谷歌搜索了一整天，没有运气。我在按下确定按钮后调用方法。所以代码是：getnPrintAllData()

public class DatabaseSQLiteConnection {
    Connection conn = null;
    PreparedStatement statement = null;
    ResultSet res = null;

    public DatabaseSQLiteConnection(){
        try{
            Class.forName("org.sqlite.JDBC");
            conn = DriverManager.getConnection("jdbc:sqlite:test.sqlite");
            statement = conn.prepareStatement("SELECT * from product_info;");
        }
        catch(Exception e){
            e.printStackTrace();
        }
    }   

    public void getnPrintAllData(){
        String name, supplier, id;
        DefaultTableModel dtm = new DefaultTableModel();
        Window gui = new Window(); //My JPanel class        
        try{
            res = statement.executeQuery();
            testResultSet(res);
            ResultSetMetaData meta = res.getMetaData();
            int numberOfColumns = meta.getColumnCount();
            while (res.next())
            {
                Object [] rowData = new Object[numberOfColumns];
                for (int i = 0; i < rowData.length; ++i)
                {
                    rowData[i] = res.getObject(i+1);
                }
                dtm.addRow(rowData);
            }
            gui.jTable1.setModel(dtm);
            dtm.fireTableDataChanged();
            //////////////////////////

        }
        catch(Exception e){
            System.err.println(e);
            e.printStackTrace();
        }
        finally{
            try{
                res.close();
                statement.close();
                conn.close();
            }
            catch(Exception e){
                e.printStackTrace();
            }
        }
    }    

    public void testResultSet(ResultSet res){
        try{
            while(res.next()){
                System.out.println("Product ID: "+ res.getInt("product_id"));
                System.out.println("Product name: "+ res.getString("product_name"));
                System.out.println("Supplier: "+ res.getString("supplier"));
            }        
        }
        catch(Exception e){
            e.printStackTrace();
        }
    }
}

我的方法工作正常。现在，如何更改我的代码以使其正常工作，或者最简单的代码是什么？提前致谢。testResultSet()DefaultTableModelResultSet

编辑：我正在接收错误。java.lang.IllegalStateException: SQLite JDBC: inconsistent internal state

答案 1

我认为从的实例构建模型的最简单方法如下。ResultSet

public static void main(String[] args) throws Exception {
    // The Connection is obtained

    ResultSet rs = stmt.executeQuery("select * from product_info");

    // It creates and displays the table
    JTable table = new JTable(buildTableModel(rs));

    // Closes the Connection

    JOptionPane.showMessageDialog(null, new JScrollPane(table));

}

方法：buildTableModel

public static DefaultTableModel buildTableModel(ResultSet rs)
        throws SQLException {

    ResultSetMetaData metaData = rs.getMetaData();

    // names of columns
    Vector<String> columnNames = new Vector<String>();
    int columnCount = metaData.getColumnCount();
    for (int column = 1; column <= columnCount; column++) {
        columnNames.add(metaData.getColumnName(column));
    }

    // data of the table
    Vector<Vector<Object>> data = new Vector<Vector<Object>>();
    while (rs.next()) {
        Vector<Object> vector = new Vector<Object>();
        for (int columnIndex = 1; columnIndex <= columnCount; columnIndex++) {
            vector.add(rs.getObject(columnIndex));
        }
        data.add(vector);
    }

    return new DefaultTableModel(data, columnNames);

}

更新

你喜欢使用javax.swing.SwingWorker吗？是否要使用“资源试用”语句？

public class GUI extends JFrame {

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                new GUI().setVisible(true);
            }
        });
    }

    private final JButton button;
    private final JTable table;
    private final DefaultTableModel tableModel = new DefaultTableModel();

    public GUI() throws HeadlessException {

        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);

        table = new JTable(tableModel);
        add(new JScrollPane(table), BorderLayout.CENTER);

        button = new JButton("Load Data");
        button.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                new SwingWorker<Void, Void>() {
                    @Override
                    protected Void doInBackground() throws Exception {
                        loadData();
                        return null;
                    }
                }.execute();
            }
        });
        add(button, BorderLayout.PAGE_START);

        setSize(640, 480);
    }

    private void loadData() {
        LOG.info("START loadData method");

        button.setEnabled(false);

        try (Connection conn = DriverManager.getConnection(url, usr, pwd);
                Statement stmt = conn.createStatement()) {

            ResultSet rs = stmt.executeQuery("select * from customer");
            ResultSetMetaData metaData = rs.getMetaData();

            // Names of columns
            Vector<String> columnNames = new Vector<String>();
            int columnCount = metaData.getColumnCount();
            for (int i = 1; i <= columnCount; i++) {
                columnNames.add(metaData.getColumnName(i));
            }

            // Data of the table
            Vector<Vector<Object>> data = new Vector<Vector<Object>>();
            while (rs.next()) {
                Vector<Object> vector = new Vector<Object>();
                for (int i = 1; i <= columnCount; i++) {
                    vector.add(rs.getObject(i));
                }
                data.add(vector);
            }

            tableModel.setDataVector(data, columnNames);
        } catch (Exception e) {
            LOG.log(Level.SEVERE, "Exception in Load Data", e);
        }
        button.setEnabled(true);

        LOG.info("END loadData method");
    }

}

答案 2

我认为这是使用ResultSet填充表格的最简单方法，例如

FillTable(MyTable, "select * Customers;");

一个非常简单的方法可以做成

public void FillTable(JTable table, String Query)
{
    try
    {
        CreateConnection();
        Statement stat = conn.createStatement();
        ResultSet rs = stat.executeQuery(Query);

        //To remove previously added rows
        while(table.getRowCount() > 0) 
        {
            ((DefaultTableModel) table.getModel()).removeRow(0);
        }
        int columns = rs.getMetaData().getColumnCount();
        while(rs.next())
        {  
            Object[] row = new Object[columns];
            for (int i = 1; i <= columns; i++)
            {  
                row[i - 1] = rs.getObject(i);
            }
            ((DefaultTableModel) table.getModel()).insertRow(rs.getRow()-1,row);
        }

        rs.close();
        stat.close();
        conn.close();
    }
    catch(InstantiationException | IllegalAccessException | SQLException e)
    {
    }
}