rollnumfinder.java

JDBC Sample

import java.sql.*;
import java.awt.*;
import java.awt.event.*;
public class RollNumFinder extends Frame implements ActionListener
{
   Label l1=new Label("Name");
   Label l2=new Label("Roll Number");
   TextField tf1=new TextField("",11);
   TextField tf2=new TextField("",22);
   Button bt=new Button("Find");
   public RollNumFinder()
   {
   	super("Roll Number Finder");
   	setSize(300,200);
   	init_setup();
   	setVisible(true);
   	addWindowListener(new WindowAdapter(){public void windowClosing(WindowEvent e){System.exit(0);}});
   	}
   public static void main(String args[])
   {
   	RollNumFinder roll=new RollNumFinder();
   }
   public void init_setup()
   {
   	setLayout(new GridLayout(2,1));
   	Panel p1=new Panel();
   	p1.add(l1);
   	p1.add(tf1);
   	p1.add(bt);
   	add(p1);
   	Panel p2=new Panel();
   	p2.add(l2);
   	p2.add(tf2);
   	add(p2);
   	bt.addActionListener(this);
   }
   	public void actionPerformed(ActionEvent e)
   	{
   	 if(e.getActionCommand()=="Find")
   	   process();
   	}
    public void process()
    {
      	try
	   {
		   ResultSet r;
		   String ps;
		   Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
	       Connection c=DriverManager.getConnection("jdbc:odbc:stud_dts");
		   ps="select ID from stud where NAME like ?";
		   PreparedStatement st=c.prepareStatement(ps);
		   st.setString(1,tf1.getText().trim());
		   r=st.executeQuery();
		   tf2.setForeground(Color.black);
		   r.next();
		   if(r.getRow()==0)
		   {
		     tf2.setForeground(Color.red);
		     tf2.setText("Not Exist");
		    }
		   else
		     tf2.setText(r.getString("ID")); 
		/* Statement st=c.createStatement();
		   r=st.executeQuery(ps);
		   while(r.next())
		   {
		   	if(r.getString(2).equals(tf1.getText()))
		   	  {
		   	  	tf2.setText(r.getString(1));
		   	    break;
		      }
		   	else	
		   	  tf2.setText("Not Exist");
		   }
		*/
		   	r.close();
		   	c.close();
		   
	   }
	   catch(SQLException e)
	   {
		   System.out.println("SQL ERROR:"+e);
	   }
	   catch(Exception e)
	   {
		   System.out.println("ERROR:"+e);
	   }
    } 
   	
}