一些基础的关于java jdbc的程序代码
package edu;
import java.awt.Rectangle;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.List;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
public class CountryInfoGui implements ActionListener {
private JFrame jFrame;
private JPanel jContentPane;
private JLabel lblName = null;
private JTextField tfName = null;
private JLabel lblRegion = null;
private JComboBox cbRegion = null;
private JLabel lblArea = null;
private JTextField tfArea = null;
private JLabel lblPopu = null;
private JTextField tfPopu = null;
private JLabel lblGdp = null;
private JTextField tfGDP = null;
private JButton btnAdd = null;
private JButton btnDel = null;
private JButton btnModify = null;
private JButton btnQuery = null;
private JButton btnUpPage = null;
private JButton btnDownPage = null;
private JTable table = null;
TableModel tm = null;
JScrollPane jsp = null;
private JTextField getTfName() {
if (tfName == null) {