32.3 (Connection dialog) Develop a subclass of BorderPane named DBConnectionPane that enables the user to select or enter a JDBC driver and a URL and to enter a username and password, as shown in Figure 32.28. When the Connect to DB button is clicked, a Connection object for the database is stored in the connection property. You can then use the getConnection() method to return the connection.
import javax.swing.*; import javax.swing.border.EmptyBorder; import javax.swing.border.TitledBorder; import java.sql.*; import java.awt.*; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; public class Exercise03 extends JApplet { private static final long serialVersionUID = 1L; private DBConnectionPanel connectionPanel = new DBConnectionPanel("jdbc:mysql://localhost/javabook", "root", "root"); private JLabel connected; public void init() { add(connectionPanel); } class DBConnectionPanel extends JPanel { private static final long serialVersionUID = 1L; private JComboBox<String> jComboBox = new JComboBox<>(new String[] {"sun.jdbc.odbc.JdbcOdbcDriver", "com.mysql.jdbc.Driver", "oracle.jdbc.driver.OracleDriver"}); private JTextField jTextField1 = new JTextField(20); private JTextField jTextField2 = new JTextField(20); private JTextField jTextField3 = new JTextField(20); private Connection connection; public DBConnectionPanel() { this("", "", ""); } public DBConnectionPanel(String db, String user, String pass) { jTextField1.setText(db); jTextField2.setText(user); jTextField3.setText(pass); JPanel jPanel1 = new JPanel(new BorderLayout(5, 5)); jPanel1.setBorder(new TitledBorder("Enter database information")); JPanel jPanel2 = new JPanel(new GridLayout(4, 1, 5, 5)); jPanel2.add(new JLabel("JDBC Driver")); jPanel2.add(new JLabel("Database URL")); jPanel2.add(new JLabel("Username")); jPanel2.add(new JLabel("Password")); jPanel1.add(jPanel2, BorderLayout.WEST); JPanel jPanel3 = new JPanel(new GridLayout(4, 1, 5, 5)); jPanel3.add(jComboBox); jPanel3.add(jTextField1); jPanel3.add(jTextField2); jPanel3.add(jTextField3); jPanel1.add(jPanel3, BorderLayout.CENTER); JPanel jPanel4 = new JPanel(new BorderLayout(5, 5)); jPanel4.setBorder(new EmptyBorder(5, 5, 5, 5)); connected=new JLabel("No connection"); jPanel4.add(connected, BorderLayout.WEST); JButton jButton = new JButton("Connect to DB"); jPanel4.add(jButton, BorderLayout.EAST); setLayout(new BorderLayout()); add(jPanel1, BorderLayout.CENTER); add(jPanel4, BorderLayout.SOUTH); jButton.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent arg0) { try { Class.forName(jComboBox.getItemAt(jComboBox.getSelectedIndex())); connection = DriverManager.getConnection(jTextField1.getText(), jTextField2.getText(), jTextField3.getText()); connected.setText("Connected"); } catch (Exception ex) { JOptionPane.showMessageDialog(null, ex.getMessage(), "Error", JOptionPane.ERROR_MESSAGE); } } }); } public Connection getConnection() { return connection; } } /** Main method */ public static void main(String[] args) { Exercise03 applet = new Exercise03(); JFrame frame = new JFrame(); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setTitle("Exercise03"); frame.getContentPane().add(applet, BorderLayout.CENTER); applet.init(); applet.start(); frame.pack(); frame.setLocationRelativeTo(null); frame.setVisible(true); } }
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