Most simple code to populate JTable from ResultSet

Question

I googled the whole day and no luck. I call getnPrintAllData() method after pressing OK button. So the code is:

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();         }     } } 

My testResultSet() method is working properly. Now, how to change my code so that it works, or what is the most simple code to make DefaultTableModel from ResultSet ? Thanks in advance.

Edit: I am reciving java.lang.IllegalStateException: SQLite JDBC: inconsistent internal state error.

Answer 1

I think the simplest way to build a model from an instance of ResultSet, could be as follows.

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));  } 

The method 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);  } 

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UPDATE

Do you like to use javax.swing.SwingWorker? Do you like to use the try-with-resources statement?

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");     }  } 

Answer 2

I think this is the Easiest way to populate a table with ResultSet with a method like

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

And a very simple method can be made as

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)     {     } }