Line with different line styles(Dashed,Dotted,etc) in Java

filename: Line.java 

import java.awt.BasicStroke;
import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;

class Surface extends JPanel { //Class Surface

    private void doDrawing(Graphics g) {
        
        Graphics2D g2a = (Graphics2D) g; //Line g2a
        Graphics2D g2d = (Graphics2D) g; //Line g2d

        float[] dash1 = {2f, 0f, 2f}; //Line 2
        float[] dash2 = {1f, 1f, 1f}; //Line 3
        float[] dash3 = {4f, 0f, 10f};  //Line 4
        float[] dash4 = {4f, 4f, 1f}; //Line 5
        
        g2d.drawLine(20, 40, 250, 40);
        
        g2a.setStroke(new BasicStroke(3));
        g2a.drawLine(20,240,250,240);



        BasicStroke bs1 = new BasicStroke(1, BasicStroke.CAP_BUTT,
                BasicStroke.JOIN_ROUND, 10.0f, dash1, 4f);

        BasicStroke bs2 = new BasicStroke(1, BasicStroke.CAP_BUTT,
                BasicStroke.JOIN_ROUND, 1.0f, dash2, 2f);

        BasicStroke bs3 = new BasicStroke(1, BasicStroke.CAP_BUTT,
                BasicStroke.JOIN_ROUND, 1.0f, dash3, 2f);

        BasicStroke bs4 = new BasicStroke(1, BasicStroke.CAP_BUTT,
                BasicStroke.JOIN_ROUND, 1.0f, dash4, 2f);



        g2d.setStroke(bs1);
        g2d.drawLine(20, 80,250, 80);

        g2d.setStroke(bs2);
        g2d.drawLine(20, 120, 250, 120);

        g2d.setStroke(bs3);
        g2d.drawLine(20, 160, 250, 160);

        g2d.setStroke(bs4);
        g2d.drawLine(20, 200, 250, 200);

    }

    @Override
    public void paintComponent(Graphics g) {

        super.paintComponent(g);
        doDrawing(g);
    }
}

public class line extends JFrame { //Class Line

    public line() {

        initUI();
    }
    
    private void initUI() {
        
        setTitle("Line Styles");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        add(new Surface());

        setSize(280, 280);
        setLocationRelativeTo(null);        
    }

    public static void main(String[] args) {

        SwingUtilities.invokeLater(new Runnable() {

            @Override
            public void run() {

                line bs = new line();
                bs.setVisible(true);
            }
        });
    }

Output