有没有大神能帮忙加个背景图片啊？拜托拜托

新手，不会加背景图片，勉强加了个丑炸了的背景颜色，拜托各位大神了。给个方法也行啊！下附代码（小白，写的很粗糙，望各位见谅）。
package Login;
import Login.Logincd;

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class Login extends JFrame
{
    private JPanel panel=new JPanel();
    private JPanel panel1=new JPanel();
    private JPanel panel2=new JPanel();
    private JPanel panel3=new JPanel();
    private JLabel l1=new JLabel("登录名");
    private JLabel l2=new JLabel("密码");
    private JTextField f1=new JTextField(11);
    private JTextField f2=new JTextField(11);
    private JButton jbtBack=new JButton("重置");
    private JButton jbtOK=new JButton("登录");
    private JButton jbtCancel=new JButton("取消");
    public Login()
    {  
        
        setLayout(new BorderLayout(5,8));
        add(panel1,BorderLayout.NORTH);
        add(panel2,BorderLayout.CENTER);
        add(panel3,BorderLayout.SOUTH);
        panel1.add(l1);
        panel1.add(f1);
        panel2.add(l2);
        panel2.add(f2);
        panel3.add(jbtOK);
        panel3.add(jbtBack);
        panel3.add(jbtCancel);
        
        panel.add(panel1);
        panel.add(panel2);
        panel.add(panel3);
        add( panel);
        
        panel.setBackground(new Color(255,182,193));
        panel1.setBackground(new Color(255,182,193));
        panel2.setBackground(new Color(255,182,193));
        panel3.setBackground(new Color(255,182,193));
        jbtOK.addActionListener(new Enter());
        jbtBack.addActionListener(new ReWrite() );
        jbtCancel.addActionListener(new Close());
        
    }
    public static void main (String[] args)
    {
        Login frame=new  Login();
         frame.setTitle("登录框");
         frame.setSize(250,230);
         frame.setLocationRelativeTo(null);
         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         frame.setVisible(true);
         
    }
   
    class Enter implements ActionListener{
        
        
          public void actionPerformed(ActionEvent e)
          {  
            
              if((f1.getText()).equals("abc")&&(f2.getText()).equals("123"))
                      {
                    JOptionPane.showMessageDialog( null,"登录成功,管理员登录!");
                    Login.this.setVisible(false);
                    Logincd.initGUI();
                  
                      }
              else if ((f1.getText()).equals("ABC") && (f2.getText()).equals("123456")) {
                          JOptionPane.showMessageDialog(null, "登录成功，用户登录！");
                          Login.this.setVisible(false);
                          Logincd.initGUI();  
              }
                else JOptionPane.showMessageDialog(null, "登录失败，请重新登录!");
           
          }
         }
         class ReWrite implements ActionListener{
          public void actionPerformed(ActionEvent e)
          {
           f1.setText("");
           f2.setText("");
           f1.requestFocus();
          }
         }
         class Close implements ActionListener{
         public void actionPerformed(ActionEvent e)
            {
                JButton bt=(JButton)e.getSource();
                if(bt.equals(jbtCancel));
                System.exit(0);
               
            }
            }
         
}