Java Grafica tipo barras

import java.awt.Color;
import java.awt.EventQueue;
import java.awt.Graphics;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.JButton;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;


public class GraficaBarras extends JFrame {

    private JPanel contentPane;
    private JTextField tf3;
    private JTextField tf1;
    private JTextField tf2;
    private boolean bandera=false;

    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    GraficaBarras frame = new GraficaBarras();
                    frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    /**
     * Create the frame.
     */
    public GraficaBarras() {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 800, 600);
        contentPane = new JPanel();
        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
        setContentPane(contentPane);
        contentPane.setLayout(null);
        
        JLabel lblPartido = new JLabel("Partido 1:");
        lblPartido.setBounds(46, 39, 61, 14);
        contentPane.add(lblPartido);
        
        JLabel lblPartido_1 = new JLabel("Partido 2:");
        lblPartido_1.setBounds(46, 69, 61, 14);
        contentPane.add(lblPartido_1);
        
        JLabel lblPartido_2 = new JLabel("Partido 3:");
        lblPartido_2.setBounds(46, 103, 61, 14);
        contentPane.add(lblPartido_2);
        
        tf1 = new JTextField();
        tf1.setBounds(117, 36, 86, 20);
        contentPane.add(tf1);
        tf1.setColumns(10);
        
        tf2 = new JTextField();
        tf2.setBounds(117, 66, 86, 20);
        contentPane.add(tf2);
        tf2.setColumns(10);
        
        tf3 = new JTextField();
        tf3.setBounds(117, 97, 86, 20);
        contentPane.add(tf3);
        tf3.setColumns(10);
        
        JButton btnGraficar = new JButton("Graficar");
        btnGraficar.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                bandera=true;
                repaint();
            }
        });
        btnGraficar.setBounds(45, 138, 107, 37);
        contentPane.add(btnGraficar);
    }
    
    
    public void paint(Graphics g)
    {
        super.paint(g);
        if (bandera==true)
        {
            String s1=tf1.getText();
            String s2=tf2.getText();
            String s3=tf3.getText();
            int v1=Integer.parseInt(s1);
            int v2=Integer.parseInt(s2);
            int v3=Integer.parseInt(s3);
            int mayor=retornarMayor(v1,v2,v3);
            
            int largo1=v1*400/mayor;
            int largo2=v2*400/mayor;
            int largo3=v3*400/mayor;

            g.setColor(new Color(255,0,0));
            g.fillRect(100,250,largo1,40);
            g.drawString("Partido 1", 10, 270);            

            g.setColor(new Color(0,128,0));
            g.fillRect(100,300,largo2,40);
            g.drawString("Partido 2", 10, 320);            

            g.setColor(new Color(0,0,255));
            g.fillRect(100,350,largo3,40);
            g.drawString("Partido 3", 10, 370);            
            
        }
    }
    
    private int retornarMayor(int v1,int v2,int v3)
    {
        if (v1>v2 && v1>v3)
            return v1;
        else
            if (v2>v3)
                return v2;
            else
                return v3;
    }
       
}