JDBC prog-2

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

class studdetfrm extends JFrame implements ActionListener
{
Connection con=null;
Integer i=0,j;
JLabel sid,sname,sclg,scpi;
JTextField txtid,txtnm,txtcol,txtcpi;
JButton cmdnxt,cmdprvs,cmdadd,cmdupdat;
String selectqr;
Statement stmt;
ResultSet rset;


public studdetfrm(String s)
{
super(s);

try

{
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
}
catch(Exception e)
{
System.out.println("ads");
}

try
{
con=DriverManager.getConnection("jdbc:odbc:stud_db");

}
catch(SQLException se)
{
System.out.println(se);
}
System.out.println("connection successful......");



Container c=getContentPane();
c.setLayout(new GridLayout(5,2));

sid=new JLabel("ID");
sname=new JLabel("Name");
sclg=new JLabel("College");
scpi=new JLabel("CPI");

txtid=new JTextField();
txtnm=new JTextField();
txtcol=new JTextField();
txtcpi=new JTextField();

//cmdnxt=new JButton("Next");
//cmdnxt.addActionListener(this);
//cmdprvs=new JButton("Previous");
//cmdprvs.addActionListener(this);
cmdadd=new JButton("Add");
cmdadd.addActionListener(this);
cmdupdat=new JButton("Update");
cmdupdat.addActionListener(this);

c.add(sid);
c.add(txtid);
//c.add(cmdnxt);
c.add(sname);
c.add(txtnm);
//c.add(cmdprvs);
c.add(sclg);
c.add(txtcol);
c.add(scpi);
c.add(txtcpi);
c.add(cmdadd);
c.add(cmdupdat);

try
{

selectqr = "select * from stud_info";
        stmt = con.createStatement();
rset = stmt.executeQuery(selectqr);
rset.next();
txtid.setText(rset.getString(1));
txtnm.setText(rset.getString(2));
txtcol.setText(rset.getString(3));
txtcpi.setText(rset.getString(4));

}
catch(SQLException se)
{
System.out.println(se);
}



}
public void actionPerformed(ActionEvent ae)
{
String s=ae.getActionCommand();
System.out.println(s);
/*if(s=="Next")
{
try
{
rset.next();
txtid.setText(rset.getString(1));
txtnm.setText(rset.getString(2));
txtcol.setText(rset.getString(3));
txtcpi.setText(rset.getString(4));

}
catch(Exception e)
{
System.out.println("error:"+e);
}
}
else if(s=="Previous")
{
try
{
rset.previous();
txtid.setText(rset.getString(1));
txtnm.setText(rset.getString(2));
txtcol.setText(rset.getString(3));
txtcpi.setText(rset.getString(4));

}
catch(Exception e)
{
System.out.println("error:"+e);
}

}
else*/

if(s=="Add")
{
try
{
Integer id=Integer.parseInt(txtid.getText());
Integer cpi=Integer.parseInt(txtcpi.getText());
String str="insert into stud_info values( " +id + ",'"+txtnm.getText()+"','"+txtcol.getText()+"', "+ cpi+")";

System.out.println(str);
stmt = con.createStatement();
stmt.executeUpdate(str);
System.out.println("data added successfully....");
}
catch(Exception e)
{
System.out.println("error:"+e);
}
}
else if(s=="Update")
{
try
{
Integer id=Integer.parseInt(txtid.getText());
Integer cpi=Integer.parseInt(txtcpi.getText());
String str="update stud_info SET (stud_name='" +txtnm.getText ()+"',stud_college='"+txtcol.getText()+"', stud_cpi="+cpi+") where stud_id="+id;

System.out.println(str);
stmt = con.createStatement();
stmt.executeUpdate(str);

System.out.println("Update Successfully....");

}
catch(Exception e)
{
System.out.println("error:"+e);
}
}

else
{
System.out.println("asd");
}

}
}

class studpg
{
public static void main(String[] s)
{
studdetfrm f= new studdetfrm("student detail page");
f.setSize(400,400);
f.setVisible(true);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}