billing.java
这是计费类，我已经完成了系统登录的编码，它在框架中完美运行，但是我输入了用户名和密码，访问数据库未被检测到。
公共类计费{
Connection con;
Statement st;
ResultSet rs;
JFrame f = new JFrame ("User Login");
JLabel l = new JLabel ("Username:");
JLabel l1 = new JLabel ("Password:");
JTextField t = new JTextField(10);
JTextField t1 = new JTextField(10);
JButton b = new JButton("Login");
public billing()
{
connect();
frame();
}
public void connect()
{
try{
String driver = "sun.jdbc.odbc.JdbcOdbc.Driver";
Class.forName(driver);
String db = "jdbc:odbc:dbB";
con = DriverManager.getConnection(db) ;
st = con.createStatement();
}
catch(Exception ex)
{
}
}
public void frame()
{
f.setSize (600,400);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setVisible(true);
JPanel p = new JPanel();
p.add(l);
p.add(t);
p.add(l1);
p.add(t1);
p.add(b);
f.add(p);
b.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e)
{
try
{
String user = t.getText().trim();
String pass = t1.getText().trim();
String sql ="select user,pass from Table2 where username ='"+user+" ' and password =' "+pass+" ' "; // sql code
rs = st.executeQuery(sql);
}
abstract
int count = 0;
while(rs.next())
{
count = count +1;
}
if (count == 1)
{
JOptionPane.showMessageDialog(null, "Successfully Login");
}
else if (count > 1)
{
JOptionPane.showMessageDialog(null, "Duplicate Account, Access Denied");
}
else
{
JOptionPane.showMessageDialog(null, "User Not Found");
}
}
catch (Exception ex)
{
}
}
});
}
public static void main (String[] args){
new billing();
}
}
请帮助...这很令人困惑，我不知道我哪里出错了..