The type SnakeGame must implement the inherited abstract method KeyListener.keyReleased(KeyEvent)

i am trying to create a snake type game and despite my best efforts at "implementing" KeyListener, i get the error message at class SnakeGame- "The type SnakeGame must implement the inherited abstract method KeyListener.keyReleased(KeyEvent)".

I am new to java and cannot think of a possible way to fix this, i've looked for tutorials on how to implement KeyListener properly, and tried everything i can think of.
Any kind of help is appreciated.

Here is my code-

import java.awt.*;
import javax.swing.*;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
public class SnakeGame implements KeyListener {
public JFrame board;
public static void main(String[] args) {
SnakeGame sm = new SnakeGame();
sm.initGUI();
}
public void initGUI() {
JFrame board = new JFrame("Snake");
board.addKeyListener(this);
board.setFocusable(true);
board.setFocusTraversalKeysEnabled(false);
board.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
board.setLocationRelativeTo(null);
board.setVisible(true);
board.pack();
board.setSize(300, 300);
}
KeyListener listener = new KeyAdapter() {
public void keyPressed(KeyEvent e) {
int keyCode = e.getKeyCode();
switch (keyCode) {
case KeyEvent.VK_UP:
System.out.println("you pressed up");
break;
case KeyEvent.VK_LEFT:
System.out.println("you pressed left");
break;
case KeyEvent.VK_RIGHT:
System.out.println("you pressed right");
break;
case KeyEvent.VK_DOWN:
System.out.println("you pressed down");
}
}
};

}

You should be able to hover over the error(it should be showing you the error on the class def 'SnakeGame') and then press 'Add unimplemented methods' or just simply define that method in your class body.

If you want to implement KeyListener in your class then you need to implement all the method of the KeyListener interface in your class. Which means you need to implement keyPressed, keyTyped and keyReleased as methods in your class you have not done that.

Instead you are trying to use a KeyAdapter and override a single method of the adapter, but you are doing this incorrectly.

So to fix your problem, don't implement KeyListener. Your class definition should be:

//public class SnakeGame implements KeyListener {
public class SnakeGame {

And then now you can use the KeyAdapter as follows:

public void initGUI() {
KeyListener listener =  new KeyAdapter() {
public void keyPressed(KeyEvent e) {
int keyCode = e.getKeyCode();
switch (keyCode) {
case KeyEvent.VK_UP:
System.out.println("you pressed up");
break;
case KeyEvent.VK_LEFT:
System.out.println("you pressed left");
break;
case KeyEvent.VK_RIGHT:
System.out.println("you pressed right");
break;
case KeyEvent.VK_DOWN:
System.out.println("you pressed down");
}
}
};
JFrame board = new JFrame("Snake");
//board.addKeyListener(this);
board.addKeyListener(listener);

This is a better approach they trying to have you class implement KeyListener, because you can have a different KeyAdapter for each component.

However, if you really want to know how to implement a KeyListener in a class then read the section from the Swing tutorial on How to Write a KeyListener for a working example.

Keep a link to the Swing tutorial handy for all Swing basics.

Also, note you should not be using a KeyListener to listen for key events for you game. Instead you should be using Key Bindings. The tutorial also has a section on How to Use Key Bindings.