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Monday, 6 March 2017

Chapter 32 Exercise 3, Introduction to Java Programming, Tenth Edition Y. Daniel LiangY.

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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