Databse connected successfully but there are something wrong in my procedur

Question

hi
i am writing a small java application that use Microsoft SQL Server 2000 .the test application show that i am successful connect to the database.
But in my application when my press the query button ,the resulte cannot append on the textrea, i am double about it .Can anyone help me out of this??thanks !! the fllowing are my code:
import java.awt.*;
import java.awt.event.*;
import java.sql.*;
public class jdbc //main class
{  public static void main(String args[])
     GUI gui=new GUI();//GUI
     gui.pack(); //excute GUI
class GUI extends Frame implements ActionListener
     TextArea text;Panel panel; TextField sno;Button btn;
     GUI()//
     super("made by yaowu");
          setLayout(new BorderLayout());
     setBackground(Color.cyan);
     setVisible(true); text=new TextArea();
     btn=new Button("query");
     sno=new TextField(16);
     panel=new Panel();
     panel.add(new Label("entre the id of student（include10number）"));
panel.add(sno);panel.add(btn);
     add("North",panel);add("Center",text);
     text.setEditable(false);btn.addActionListener(this);
     addWindowListener(new WindowAdapter(){
     public void windowClosing(WindowEvent e)
          setVisible(false);
          System.exit(0);}});}
          public void actionPerformed(ActionEvent e){
          if(e.getSource()==btn)// when press
               {text.setText("rusult"+'\n');
               try{
               Liststudent();
               catch(SQLException ee){}
public void Liststudent() throws SQLException//connct with database
     String xh,xm,xb,nl,em,tl;
     try{
     Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver").newInstance();
     catch(ClassNotFoundException e){e.printStackTrace();
System.out.println("Error Trace in getConnection() : " + e.getMessage());}
catch(java.lang.InstantiationException e)
          catch(java.lang.IllegalAccessException e)
String url="jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=mydata";
String user="";
String password="";
Connection con= DriverManager.getConnection(url,user,password); //
     Statement sql=con.createStatement();//creat Statement
     ResultSet rs=sql.executeQuery("select* from xsqk"); //xsqk table
     while(rs.next()) //ptint the result
          {   xh =rs.getString("id");
               xm=rs.getString("name");
          xb=rs.getString("sex");
               nl=rs.getString("age");
em=rs.getString("E�Mail");
tl=rs.getString("tl");
          if(xh.trim().equals(sno.getText().trim()))
               text.append('\n'+"id"+" "+"name"+" "+"sex"+" "+"age"+" "+"E-Mail"+" "+"tl"+'\n');
               text.append('\n'+xh+" "+xm+" "+xb+" "+nl+" "+em+" "+tl+'\n');
}

Answer 1

Something is wrong but your code doesn't care: catch(SQLException ee){}What happens if there is an SQL exception? Nothing. That's probably what happened. Try this to find out: catch(SQLException ee){ee.printStackTrace();}