java.lang.ArrayIndexOutOfBoundsException: 420

Preciso de ajuda pra resolver isso aqui toda vez tento iniciar acontece esse erro
Exception in thread “main” java.lang.ArrayIndexOutOfBoundsException: 420
at com.gcstudios.world.World.(World.java:25)
at com.gcstudios.main.Game.(Game.java:49)
at com.gcstudios.main.Game.main(Game.java:108)
World
package com.gcstudios.world;

import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;

import javax.imageio.ImageIO;

public class World {

private Tile[]tiles;
public static int WIDTH,HEIGHT;

public World(String path){
try {
BufferedImage map = ImageIO.read(getClass().getResource(path));
int[] pixels = new int[map.getWidth()* map.getHeight()];
WIDTH = map.getWidth();
HEIGHT = map.getHeight();
tiles = new Tile[map.getWidth()* map.getHeight()];
map.getRGB(0, 0, map.getWidth(), map.getHeight(), pixels, 0, map.getWidth());
for(int xx =0; xx < map.getWidth(); xx++){
for(int yy =0; yy < map.getHeight(); yy++){
int pixelAtual = pixels [xx +(yy*map.getWidth())];

			if (pixelAtual == 0xFF000000){
				//Chão
				tiles[xx = (yy*WIDTH)] = new FloorTile(xx*32,yy*32,Tile.TILE_FLOOR);
			}else if(pixelAtual == 0xFFFFFFFF){
				//Parede
				tiles[xx = (yy*WIDTH)] = new FloorTile(xx*32,yy*32,Tile.TILE_WALL);
			}else if(pixelAtual == 0xFF0026FF){
				//Player
				tiles[xx = (yy*WIDTH)] = new FloorTile(xx*32,yy*32,Tile.TILE_FLOOR);
			}else {
				tiles[xx = (yy*WIDTH)] = new FloorTile(xx*32,yy*32,Tile.TILE_FLOOR);
			}
		}
	}
		
} catch (IOException e) {
		e.printStackTrace();
	}
}
public void render(Graphics g){
	for (int xx =0;xx < WIDTH; xx++){
		for (int yy =0;yy < HEIGHT; yy++){
			Tile tile =tiles [xx +(yy*WIDTH)];
			tile.render(g);
		}
	}
}

}
Main
package com.gcstudios.main;

import java.awt.Canvas;

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.image.BufferStrategy;
import java.awt.image.BufferedImage;
import java.util.ArrayList;
import java.util.List;

import javax.swing.JFrame;

import com.gcstudios.entidades.Entity;
import com.gcstudios.entidades.Player;
import com.gcstudios.graficos.Spritesheet;
import com.gcstudios.world.World;

public class Game extends Canvas implements Runnable,KeyListener{

private static final long serialVersionUID = 1L;
public static JFrame frame;
private Thread thread;
private boolean isRunning = true;
private final int WIDTH = 240;
private final int HEIGHT = 120;
private final int SCALE = 4;

private BufferedImage image;

public List<Entity> entities;
public static Spritesheet spritesheet;

public World world;

private Player player;

public Game ( ) {
	addKeyListener(this);
	setPreferredSize(new Dimension (WIDTH*SCALE,HEIGHT*SCALE));
	initFrame();
	//Inicializando Objeto
	image = new BufferedImage(160,120,BufferedImage.TYPE_INT_RGB);
	entities = new ArrayList<Entity>();
	spritesheet = new Spritesheet("/wFRJj.png");
	world = new World("/map.png");
    player = new Player(0,0,32,32,spritesheet.getSprite(0,0,32,32) 	);
	entities.add(player);
}

public void initFrame(){
	frame = new JFrame ("Game #1");
	frame.add(this);
	frame.setResizable(false);
	frame.pack();
	frame.setLocationRelativeTo(null);
	frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	frame.setVisible(true);
}

public synchronized void start(){
	thread = new Thread(this);
	isRunning = true;
	thread.start();
	
}

public void tick (){
	  for (int i = 0; i < entities.size(); i++){
		  Entity e = entities.get(i);
		  if(e instanceof Player){
			  e.tick();
		  }
	  }
	}

public void render(){
	BufferStrategy bs = this.getBufferStrategy();
	if (bs  == null) {
		this.createBufferStrategy(3);
		return;
	}
	
	Graphics g = image.getGraphics();
	g.setColor(new Color (0,0,255) );
	g.fillRect(0, 0, WIDTH, HEIGHT);
	
	//rederiazaçao
	//Graphics2D 2g =(Graphics2D) g;
	 for (int i = 0; i < entities.size(); i++){
		 Entity e = entities.get(i);
		  e.render(g);
	 }
		  
	g.dispose();
	g = bs.getDrawGraphics();
	g.drawImage(image,0,0,WIDTH*SCALE,HEIGHT*SCALE,null);
	bs.show();

}

public synchronized void stop(){
	
}
public static void  main (String agrs [ ] ) {
              Game game = new Game();
              game.start();
}

public void run() {

	long lastTime = System.nanoTime();
	double amountOfTicks = 60.0;
	double ns = 1000000000 / amountOfTicks;
	double delta = 0;
	int frames = 0;
	double timer =System.currentTimeMillis();
		while(isRunning){
		    long now = System.nanoTime();
		    delta+= (now - lastTime) / ns;
		    lastTime= now;
		    if(delta >= 1){
		    	tick();
		    	render();
		    	frames++; 
		    	delta --;
		    }
		    
		    if(System.currentTimeMillis() - timer >= 1000 ){
		    	 System.out.println("FPS: "+ frames );
		    	 frames = 0;
		    	 timer+=1000;
		    }
	}
	
}
@Override
public void keyPressed(KeyEvent e) {
	if (e.getKeyCode() == KeyEvent.VK_D){
		player.right =true;
	}else if(e.getKeyCode()== KeyEvent.VK_A){
		player.left =true;
	}
	
	if (e.getKeyCode() == KeyEvent.VK_W){
		player.up =true;
	}else if(e.getKeyCode()== KeyEvent.VK_S){
		player.down =true;
	}
}

@Override
public void keyReleased(KeyEvent e) {
	if (e.getKeyCode() == KeyEvent.VK_D){
		player.right =false;
	}else if(e.getKeyCode()== KeyEvent.VK_A){
		player.left =false;
	}
	
	if (e.getKeyCode() == KeyEvent.VK_W){
		player.up =false;
	}else if(e.getKeyCode()== KeyEvent.VK_S){
		player.down =false;
	}
}

@Override
public void keyTyped(KeyEvent arg0) {
	// TODO Auto-generated method stub
	
}

}

Estas a tentar ler/escrever na posição 420 de um array que não tem tamanho tão grande.

Quando postar código, usa a formatação do fórum:
formatacao-forum

Curiosidade, esse exercício é de onde?
Já teve mais gente com problemas no mesmo código.

Dentro de cada if você está alterando o valor de xx.