java 버튼 만들었는데 보이지가 않아요

import java.awt.*;
import java.awt.event.*;

import javax.swing.JFrame;

public class A01 extends JFrame implements WindowListener
{
  
    public static void main(String[] args)//창생성
    {
        A01 f = new A01();
        
        f.setSize(300,300);       
        f.setVisible(true);
        
       
    } 
   
    //버튼
     Button btn1, btn2, btn3;
     public void init()
    {
      
        btn1 = new Button("버튼1");
        btn1.setBounds(10,10,100,20);
        add(btn1);
        
        
    }
   
    public A01()//캠버스 생성
    { 
//여기에 init()를 추가하세요
//의문점 쪽지주세요     
     init();
        MyCanvas mc = new MyCanvas();
        add("Center", mc);
        addWindowListener(this);
       
    }
   
    /*class paint2
    {
        MyCanvas2 mc2 = new MyCanvas2();
        add("Center", mc2);       
    }
   
    class MyCanvas2 extends Canvas//이미지출력캔버스
    {
        public void paint(Graphics g)
        {
            Toolkit myToolkit2 = Toolkit.getDefaultToolkit();
            Image myImage = myToolkit2.getImage("c:kaka.jpg");
            g.drawImage(myImage , 0, 0, this);
       
        }
    }*/
           
    class MyCanvas extends Canvas//이미지출력캔버스
    {
        public void paint(Graphics g)
        {
            Toolkit myToolkit = Toolkit.getDefaultToolkit();
            Image myImage = myToolkit.getImage("c:/android.jpg");
            g.drawImage(myImage , 0, 0,300,300, this);
       
        }
    }
   
    public void windowOpened(WindowEvent e) {}//윈도우리스너
    public void windowClosing(WindowEvent e) {
        System.exit(0);
    }
    public void windowClosed(WindowEvent e) {}
    public void windowIconified(WindowEvent e) {}
    public void windowDeiconified(WindowEvent e) {}
    public void windowActivated(WindowEvent e) {}
    public void windowDeactivated(WindowEvent e) {}
   
      
}

//문]
//버튼 만들었는데 보이지가 않아요