Java

import java.applet.*;
import java.awt.*;
public class MainClass extends Applet implements Runnable {

	private static final long serialVersionUID = 1L;
	Thread thread = new Thread(this);
	boolean running=true;
	Player p;
	Image dbImage;
	Graphics dbg;
	public void init()
	{
		setSize(800,800);
		p = new Player(this);
	}
	public void start(){thread.start();}
	public void destroy(){running=false;}
	public void stop(){running=false;}
	public void run()
	{
		while(running)
		{
			repaint();
			p.update(this);
			try
			{
				Thread.sleep(5);
				
			}
			catch(InterruptedException e)
			{
				System.out.println("ERROR HAS OCCURED");
		}
		}
		
		}
	public void update(Graphics g){
		dbImage = createImage(400,400);
		dbg = dbImage.getGraphics();
		paint(dbg);
		g.drawImage(dbImage,0,0,this);
	}
	public void paint(Graphics g){
			p.paint(g, this);
		}
	}

import java.awt.*;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
public class Player implements KeyListener {
	private int x=200;
	private int y=200;
	private int radius=20;
	private int velX=0;
	private int velY=0;
	private URL url;
	private Image player;
	
	public Player(MainClass mc){
		url = mc.getDocumentBase();
		player = mc.getImage(url,"mario.jpg");
	}
	
	public void update(MainClass mc){
		mc.addKeyListener(this);
		x+=velX;
		y+=velY;
	}
	public void paint(Graphics g, MainClass mc){
	g.drawImage(player, x, y, mc);
	}
	@Override
	public void keyTyped(KeyEvent e) {
	
		
	}
	@Override
	public void keyPressed(KeyEvent e) {
		switch(e.getKeyCode()){
		case KeyEvent.VK_RIGHT:{
			velX=5;
			break;
		}
		case KeyEvent.VK_LEFT:{
			velX=-5;
			break;
		}
		case KeyEvent.VK_UP:{
			velY=-5;
			break;
		}
		case KeyEvent.VK_DOWN:{
			velY=5;
			break;
		}
		
		}
		
		
	}
	@Override
	public void keyReleased(KeyEvent e) {
		switch(e.getKeyCode()){
		case KeyEvent.VK_RIGHT:{
			velX=0;
			break;
		}
		case KeyEvent.VK_LEFT:{
			velX=-0;
			break;
		}
		case KeyEvent.VK_UP:{
			velY=-0;
			break;
		}
		case KeyEvent.VK_DOWN:{
			velY=0;
			break;
		}
		
	}
		
	}

}