大家帮找一个毛病，为什么窗体中没有调用数据库的内容？
本人初学者，大家帮找一下存在什么问题，为什么窗体中没有调用数据库的内容？
我找了半天也没找到呀，数据库用的是mysql,能够正常连接呀!可就是搞不懂
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[code=Java][/code]
package test;

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;
import java.sql.*;


public class Example10_9 extends JFrame implements ActionListener{

/**
* @
*/
public static Connection connectMYSql(String url,String username,String password){
Connection con = null;
try{
// 加载驱动程序
Class.forName("com.mysql.jdbc.Driver");
}catch(Exception e){
e.printStackTrace();return null;
}
try{
con = DriverManager.getConnection(url,username,password);
}catch(SQLException e){
e.printStackTrace();return null;
}
return con;
}
String title[] = {"考号","姓名","成绩","地址","简历"};
JTextField txtNo = new JTextField(8);
JTextField txtName = new JTextField(10);
JTextField txtScore = new JTextField(3);
JTextField txtAddr = new JTextField(30);
JTextArea txtResume = new JTextArea();
JButton prev = new JButton("前一个");
JButton next = new JButton("后一个");
JButton first = new JButton("第一个");
JButton last = new JButton("最后一个");
Statement sql;
ResultSet rs;
Example10_9(Connection connect){//构造方法
super("考生信息查看窗口");
setSize(450,350);
try{
sql = connect.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
rs = sql.executeQuery("SELECT * FROM ksInfo");
Container con = getContentPane();
con.setLayout(new BorderLayout(0,6));
JPanel p[] = new JPanel[4];
for(int i = 0;i < 4;i++){
p[i] = new JPanel(new FlowLayout(FlowLayout.LEFT,8,0));
p[i].add(new JLabel(title[i]));
}
p[0].add(txtNo);
p[1].add(txtName);
p[2].add(txtScore);
p[3].add(txtAddr);
JPanel p1 = new JPanel(new GridLayout(4,1,0,8));
JScrollPane jsp = new JScrollPane(txtResume,JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
jsp.setPreferredSize(new Dimension(300,60));
for(int i = 0;i < 4;i++){
p1.add(p[i]);
}
JPanel p2 = new JPanel(new FlowLayout(FlowLayout.LEFT,10,0));
p2.add(new JLabel(title[4]));
p2.add(jsp);
JPanel p3 = new JPanel();
p3.add(prev);
p3.add(next);
p3.add(first);
p3.add(last);
prev.addActionListener(this);
next.addActionListener(this);
first.addActionListener(this);
last.addActionListener(this);
rs.first();
readRecord();
}catch(Exception e){e.printStackTrace();}
setVisible(true);
}
public void modifyRecord(Connection connect){
String stuNo = (String)JOptionPane.showInputDialog(null,"请输入考生考号","输入考号对话框",JOptionPane.PLAIN_MESSAGE,null,null,"");
try{
sql = connect.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
rs = sql.executeQuery("SELECT * FROM ksInfo");
Container con = getContentPane();
con.setLayout(new BorderLayout(0,6));
JPanel p[] = new JPanel[4];
for(int i = 0;i < 4;i++){
p[i] = new JPanel(new FlowLayout(FlowLayout.LEFT,8,0));
p[i].add(new JLabel(title[i]));
}
p[0].add(txtNo);
p[1].add(txtName);
p[2].add(txtScore);
p[3].add(txtAddr);
JPanel p1 = new JPanel(new GridLayout(4,1,0,8));
JScrollPane jsp = new JScrollPane(txtResume,JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
jsp.setPreferredSize(new Dimension(300,60));