java - Troubles with simple animation on image -

im trying make image (alien.png) move around screen randomly , once hits walls comes back. im have trouble can't find way upload image , make bounce around. have far i'm getting lot of errors

package animationdemo;   import java.awt.graphics; import java.awt.image; import java.awt.toolkit;  import javax.swing.jpanel; import java.awt.*; import java.awt.event.*; import javax.swing.*;  public class animationdemo extends jframe {   public animationdemo() {      image alien;     alien = toolkit.getdefaulttoolkit().getimage("alien.png");         timer timer = new timer(50, this);     timer.start();   }   public static void main(string[] args) {     animationdemo frame = new animationdemo();     frame.settitle("animationdemo");     frame.setdefaultcloseoperation(jframe.exit_on_close);     frame.setsize(300, 300);     frame.setvisible(true);   } }  class movingmessagepanel extends jpanel implements actionlistener {   public int xcoordinate = 20;   public int ycoordinate = 20;   public int xdir=5;     public int ydir=5;     public void actionperformed(actionevent e) {     repaint();   }    @override   public void paintcomponent(graphics g) {     super.paintcomponent(g);      if (xcoordinate > getwidth()) xdir*=-1;     if (ycoordinate > getheight()) ydir*=-1;     if (xcoordinate <0) xdir*=-1;     if (ycoordinate <0) ydir*=-1;     xcoordinate += xdir;     ycoordinate += ydir;     g.drawimage(alien,xcoordinate,ycoordinate,this);   } } 

heres of errors

animationdemo.java:18: error: cannot find symbol     alien = toolkit.getdefaulttoolkit().getimage("alien.png");             ^   symbol:   variable toolkit   location: class animationdemo animationdemo.java:19: error: incompatible types: animationdemo cannot converted actionlistener         timer timer = new timer(50, this);                                     ^ animationdemo.java:52: error: cannot find symbol     g.drawimage(alien,xcoordinate,ycoordinate,this);                 ^   symbol:   variable alien   location: class movingmessagepanel note: messages have been simplified; recompile -xdiags:verbose full output 3 errors 

i'm not sure why can't find toolkit thought imported i'm not sure why not recognizing alien png on g.drawimage

the errors self explanatory:

animationdemo.java:18: error: cannot find symbol     alien = toolkit.getdefaulttoolkit().getimage("alien.png");             ^   symbol:   variable toolkit   location: class animationdemo 

you're capitalizing toolkit wrong. have precise , careful avoid these errors.

animationdemo.java:19: error: incompatible types: animationdemo cannot converted actionlistener         timer timer = new timer(50, this);                                     ^ 

animationdemo class not implement actionlistener, , can't use such.

animationdemo.java:52: error: cannot find symbol     g.drawimage(alien,xcoordinate,ycoordinate,this);                 ^   symbol:   variable alien   location: class movingmessagepanel 

the alien variable not visible in program because declared in constructor or method , not in class.