title: Draw in an image inside panel
body: <p>I have a panel with two buttons. I'm trying to insert an image inside the panel and I want to draw lines inside the image after clicking on a button. I have used the below code but this doesn't seem to work.</p>
  
  <pre><code>public class Try_Panel extends JFrame {
    // start attributes
    private JPanel jPanel1 = new JPanel(null, true);
    private JButton jButton1 = new JButton();
    private JButton jButton2 = new JButton();
    // end attributes
  
    public Try_Panel(String title) {
      // Frame-Init
      super(title);
      setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
      int frameWidth = 300; 
      int frameHeight = 300;
      setSize(frameWidth, frameHeight);
      Dimension d = Toolkit.getDefaultToolkit().getScreenSize();
      int x = (d.width - getSize().width) / 2;
      int y = (d.height - getSize().height) / 2;
      setLocation(x, y);
      setResizable(false);
      Container cp = getContentPane();
      cp.setLayout(null);
      // start components
  
      jPanel1.setBounds(48, 24, 209, 145);
      jPanel1.setOpaque(false);
      cp.add(jPanel1);
      jButton1.setBounds(88, 208, 75, 25);
      jButton1.setText("jButton1");
      jButton1.setMargin(new Insets(2, 2, 2, 2));
      jButton1.addActionListener(new ActionListener() { 
        public void actionPerformed(ActionEvent evt) { 
          jButton1_ActionPerformed(evt);
        }
      });
      cp.add(jButton1);
      jButton2.setBounds(184, 208, 75, 25);
      jButton2.setText("jButton2");
      jButton2.setMargin(new Insets(2, 2, 2, 2));
      jButton2.addActionListener(new ActionListener() { 
        public void actionPerformed(ActionEvent evt) { 
          jButton2_ActionPerformed(evt);
        }
      });
      cp.add(jButton2);
      // end components
  
      setVisible(true);
    } // end of public Try_Panel
  
    // start methods
    public void jButton1_ActionPerformed(ActionEvent evt) {
        BufferedImage image=new BufferedImage(jPanel1.getWidth(), jPanel1.getHeight(), BufferedImage.TYPE_3BYTE_BGR);
          JLabel l=new JLabel(new ImageIcon(image));
          Graphics graphics = image.getGraphics();
          Graphics2D g = (Graphics2D) graphics;
          g.fillRect(0, 0, image.getWidth(), image.getHeight());
          g.setColor(Color.BLUE);
          g.drawLine(0, 0, 300, 400);
          jPanel1.add(l);
    } // end of jButton1_ActionPerformed
  
    public void jButton2_ActionPerformed(ActionEvent evt) {
      // TODO add your code here
    } // end of jButton2_ActionPerformed
  
    // end methods
  
    public static void main(String[] args) {
      new Try_Panel("Try_Panel");
    } // end of main
  
  } // end of class Try_Panel
  </code></pre>
  
  <p>The biggest problem is the same code worked in my other class. </p>