draw line

package drawingProgram;

import java.awt.BasicStroke;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Rectangle;
import java.awt.Shape;

import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;

import java.awt.event.MouseMotionAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseAdapter;
import java.awt.geom.Line2D;
import java.awt.image.ImageObserver;
import java.text.AttributedCharacterIterator;

public class MainDrawingFrame extends JFrame {

    private JPanel contentPane;
    private int xLoc = 0;
    private int yLoc = 0;
    private JLabel blackSpot;
    private int lastX = 0;
    private int lastY = 0;

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

    /**
     * Create the frame.
     */
    public MainDrawingFrame() {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 450, 300);
        contentPane = new JPanel();
        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
        setContentPane(contentPane);
        contentPane.setLayout(null);


        final DrawingPanel drawingPanel = new DrawingPanel();
        drawingPanel.addMouseMotionListener(new MouseMotionAdapter() {
            public void mouseDragged(MouseEvent e) {

                xLoc = e.getX();
                yLoc = e.getY();

                blackSpot = new JLabel("");
                blackSpot.setOpaque(true);
                blackSpot.setBounds(xLoc, yLoc, 1, 1);
                blackSpot.setBackground(Color.black);
                drawingPanel.add(blackSpot);
                drawingPanel.repaint();


                lastX = xLoc;
                lastY = yLoc;


            }

        });

        drawingPanel.setBounds(10, 11, 414, 240);
        contentPane.add(drawingPanel);
        drawingPanel.setLayout(null);


    }



    class DrawingPanel extends JPanel {

        protected void paintComponent(Graphics g) {

            g.drawLine(lastX,lastY,xLoc,yLoc); // draw a line

        }
    }

}