Problem in drawing a line in Java Application Program

Question

Hi,
I am trying to draw a line after a message is displayed on the screen. But the line is not at all coming on the screen while running. but I can see a red line is appearing on the screen first and and it is getting overridden.
There is something wrong in the concept what I understood about graphics.Can anybody help to
understand where the problem is ?
Here is the part of the code which used to draw line.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.table.*;
import java.io.*;
import java.sql.*;
import java.util.*;
import java.util.Date.*;
import java.text.*;
import java.lang.*;
import MyPack.*;
class chalan_pay extends JFrame
JTextField jt1,jt2,jt3,jt4,jt5;
JLabel jlh,jl1,jl2,jl3,jl4,jl5,jl10;
JButton bt1,bt2,bt3;
Choice ch1,ch2,ch3,ch4;
Connection con = null;
int i1no,i2no,i3no,i4no,itno;
String idate;
public chalan_pay()
getContentPane().setLayout(null);
jt1= new JTextField(5);
jt1.setBounds(110,150,50,20);
jt2= new JTextField(10);
jt2.setBounds(400,150,100,20);
jt3= new JTextField(3);
jt3.setBounds(590,150,30,20);
jt4= new JTextField(2);
jt4.setBounds(750,150,30,20);
jlh= new JLabel();
jlh.setText("CHALLAN DETAILS");
jlh.setBounds(300,50,200,20);
jl1= new JLabel();
jl1.setText("IGM No. ");
jl1.setBounds(50,150,100,20);
jl2= new JLabel();
jl2.setText("IGM Date ");
jl2.setBounds(340,150,100,20);
jl3= new JLabel();
jl3.setText("Line No. ");
jl3.setBounds(530,150,100,20);
jl4= new JLabel();
jl4.setText("Subline No. ");
jl4.setBounds(680,150,100,20);
jl10= new JLabel();
jl10.setBounds(100,200,300,20);
ch1= new Choice();
ch1.setBounds(170,150,150,20);
getContentPane().add(ch1);
ch1.addItemListener(new Opt1());
bt1= new JButton("Exit");
bt1.setBounds(200,600,100,20);
getContentPane().add(bt1);
bt1.addActionListener(new Ex());
try
con=db_connect.getConnection();
Statement st1 = con.createStatement();
ResultSet rs1 = st1.executeQuery("select igm_no,to_char(igm_dt,'DD-MON-YY'),line_no,subline_no from "+
"det_item order by igm_no");
while(rs1.next())
ch1.addItem(String.valueOf(rs1.getInt(1))+" "+rs1.getString(2)+" "+
String.valueOf(rs1.getInt(3))+" "+String.valueOf(rs1.getInt(4)));
rs1.close();
st1.close();
catch(Exception e){e.printStackTrace();}
getContentPane().add(jlh);
getContentPane().add(jl1);
getContentPane().add(jt1);
getContentPane().add(jl2);
getContentPane().add(jt2);
getContentPane().add(jl3);
getContentPane().add(jt3);
getContentPane().add(jl4);
getContentPane().add(jt4);
getContentPane().add(jl10);
setSize(900,700);
setVisible(true);
show();
public void paint(Graphics g)
g.setColor(Color.red);
g.drawLine(0,300,600,300);
class Ex implements ActionListener
public void actionPerformed(ActionEvent evt)
if(evt.getSource() == bt1)
dispose();
return;
This code is incomplete. The program is compiled and Ran. I am unable to see the Line.
Is it because , I am using contentPane ?. Please help me to cake it clear.
mjava

Answer 1

I have no idea what JTutor is, but if it tells you to override paint() in Swing, it's not worth its disk space.
[http://java.sun.com/docs/books/tutorial/uiswing/painting/closer.html] clearly says that for all practical purposes paintComponent will be the only method that you will ever need to override.