java - Keylistener not working for JPanel -

i trying when 1 of arrow keys pressed using keylistener in jpanel class. here code:

public class testpanel extends jpanel implements keylistener{      public testpanel(){         this.addkeylistener(this);         this.setfocusable(true);         this.requestfocusinwindow();     }      public void keypressed(keyevent e) {         if (e.getkeycode() == keyevent.vk_right) {             system.out.println("right");          }          if (e.getkeycode() == keyevent.vk_left) {             system.out.println("left");         }      }      public void keytyped(keyevent e) {}     public void keyreleased(keyevent e) {} } 

my main method adds new instance of panel frame , displays it. need add keylistener jframe? in case, difficult , inefficient, make work jpanel if possible. know doing wrong?

edit: key bindings code not work either:

public class gamepanel extends jpanel implements actionlistener{  //constructor public gamepanel(){      setupkeybinding();     this.setfocusable(true);     this.requestfocusinwindow();   }  private void setupkeybinding() {     int condition = jcomponent.when_in_focused_window;     inputmap inmap = getinputmap(condition);     actionmap actmap = getactionmap();      inmap.put(keystroke.getkeystroke(keyevent.vk_left, 0), "left");     actmap.put("left", new leftaction()); }  private class leftaction extends abstractaction {         public void actionperformed(actionevent e) {           system.out.println("test");        } }  public void actionperformed(actionevent e) {     //some other game info } }  

can tell me why doesnt work either? (my second action listener other stuff needed game)

if search problem, you'll see asked , has been solved many times.

• keylisteners need on focused component work. 1 solution give component focus after first making focusable.
• better long shot use key bindings. google tutorial on this.

please have @ answer this question more on this, including many of gory details.