java - 如何解决 "Keystrokes is not abstract and does not override ab. method"

Question

我正在学习 Java 编程，正在尝试从书中编译以下代码。当我尝试编译代码时出现此错误

Keystrokes is not abstract and does not override abstract method 
    keyTyped (java.awt.event.KeyEvent) in java.awt.event.KeyListener.

另外，我相信这是不相关的，但书上还告诉我将这段代码添加到源代码中(某个地方？):

pnl.add ( field) ;
pnl.add (txtArea);

当我这样做时，我得到一个标识符“预期错误”。

程序代码:

import javax.swing.*;
import java.awt.event.*;

  class Keystrokes extends JFrame implements KeyListener
  {
   JPanel pnl = new JPanel(); 

  public static void main (String[ ] args){
      Keystrokes gui = new Keystrokes();
    }

    JTextField field = new JTextField ( 38 );
    JTextArea txtArea = new JTextArea (5, 38);

 public Keystrokes()
    {
     super( "Swing window");
     setSize( 500,200);
     setDefaultCloseOperation( EXIT_ON_CLOSE );
     add(pnl);
     field.addKeyListener (this );

     setVisible( true );
    }

    public void keyPressed(KeyEvent event )
    {
        txtArea.setText("Key Pressed");
        throw new UnsupportedOperationException("Not supported yet.");
    }

    public void KeyTyped (KeyEvent event ) {
        throw new UnsupportedOperationException("Not supported yet.");
        txtArea.append("\nCharacter : " + event.getKeyChar() );
    }

    public void keyReleased ( KeyEvent event) 
    {
        int keyCode = event.getKeyCode();
       txtArea.append("\nKey Code : " + event.getKeyCode() );
       textArea.append("\nKey Text : " + event.getKeyText(keyCode));
    }
}

Answer 1

您的方法KeyTyped应该是keyTyped。大小写很重要。