Upgrade to my collion detection game, you can not go outside the window + diagonal collisions works better

CollisionUpgrade.java

public class Game extends Canvas implements Runnable
{
 static Thread t;
 public int width = 500, height = 300, playerSize = 10;
 public InputHandler input;
 public Player player = new Player();
 public Box box = new Box();
	 public static void main(String args[])
	 {
		 JFrame frame = new JFrame();
		 Game game = new Game();
		 frame.setResizable(false);
		 frame.setTitle("Game");
		 frame.add(game);
		 frame.pack();
		 frame.setDefaultCloseOperation(3);
		 frame.setLocationRelativeTo(null);
		 frame.setVisible(true);
	 	 t.start();
	}
	 public Game()
	 {
		 Dimension size = new Dimension(width, height);
		 setPreferredSize(size);
		 setMinimumSize(size);
		 setMaximumSize(size);
		 t = new Thread(this, "Game");
		 input = new InputHandler();
		 addKeyListener(input);
	 }
	 public void run()
	 {
		long lastLoopTime = System.nanoTime();
		final long second = 1000000000;
		final int fps = 150;
		while(true)
	        {
			long now = System.nanoTime();
			long updateLength = now - lastLoopTime;
			lastLoopTime = now;
			double delta = updateLength / ((double)second/fps);
			update(delta);
			render();
			try{Thread.sleep((lastLoopTime-System.nanoTime())/1000000+10);}
			catch(Exception ex){}
		}
	 }
	 public void update(double delta)
	 {
		 double speed = delta;
		 int dir = 0;
		 if(input.keys[KeyEvent.VK_W])
		 {
			 	player.setY(player.getY() - speed);
			 	if(player.getY() < 0)player.setY(player.getY() + speed);//this will cancel out movement if you go too far up
			 	dir = 0;
		 }
		 if(input.keys[KeyEvent.VK_S])
		 {
			 	player.setY(player.getY() + speed);
			 	if(player.getY() > height-playerSize)player.setY(player.getY() - speed);//this will cancel out movement if you go too far down
			 	dir = 1;
		 }
		 if(input.keys[KeyEvent.VK_A])
		 {
			 	player.setX(player.getX() - speed);
			 	if(player.getX() < 0)player.setX(player.getX() + speed);//this will cancel out movement if you go too far left
			 	dir = 2;
		 }
		 if(input.keys[KeyEvent.VK_D])
		 {
			 	player.setX(player.getX() + speed);
			 	if(player.getX() > width-playerSize)player.setX(player.getX() - speed);//this will cancel out movement if you go too far right
			 	dir = 3;
		 }
		 if(input.keys[KeyEvent.VK_W] && input.keys[KeyEvent.VK_A]) dir = 4;
		 if(input.keys[KeyEvent.VK_W] && input.keys[KeyEvent.VK_D]) dir = 5;
		 if(input.keys[KeyEvent.VK_S] && input.keys[KeyEvent.VK_A]) dir = 6;
		 if(input.keys[KeyEvent.VK_S] && input.keys[KeyEvent.VK_D]) dir = 7;
		 player.setBounds((int)player.getX(), (int)player.getY(), playerSize, playerSize);
		 box.setBounds((int)box.getX(), (int)box.getY(), playerSize, playerSize);
		 if(player.intersects(box)) 
		 {
			 switch(dir)
			 {
			 	case 0: box.setY(box.getY() - 2);//push up
			 			break;
			 	case 1: box.setY(box.getY() + 2);//push down
			 			break;
			 	case 2: box.setX(box.getX() - 2);//push left
			 			break;
			 	case 3: box.setX(box.getX() + 2);//push right
			 			break;
			 	//Diagonal directions
			 	case 4: box.setY(box.getY() - 2);//push up & left
			 			box.setX(box.getX() - 2);
			 			break;
			 	case 5: box.setY(box.getY() - 2);//push up & right
			 			box.setX(box.getX() + 2);
			 			break;
			 	case 6: box.setY(box.getY() + 2);//push down & left
			 			box.setX(box.getX() - 2);
			 			break;
			 	case 7: box.setY(box.getY() + 2);//push down & right
			 			box.setX(box.getX() + 2);
			 			break;
			 }
		 }
	 }
	  public void render()
	  {
		  BufferStrategy bs = this.getBufferStrategy();
		  if(bs == null)
			{
				createBufferStrategy(2);
				return;
			}
			Graphics g = bs.getDrawGraphics();
			g.clearRect(0, 0, width, height);
			g.setColor(Color.black);
			g.fillRect((int)player.getX(), (int)player.getY(), playerSize, playerSize);
			g.fillRect((int)box.getX(), (int)box.getY(), playerSize, playerSize);
			
			g.dispose();
			bs.show();
	  }
	 
class Player extends Rectangle
{
	private double x = 50;
	private double y = 50;
	public double getX(){return x;}
	public double getY(){return y;}
	public void setX(double x){this.x = x;}
	public void setY(double y){this.y = y;}
}
class Box extends Rectangle
{
	private double x = 100;
	private double y = 100;
	public double getX(){return x;}
	public double getY(){return y;}
	public void setX(double x){this.x = x;}
	public void setY(double y){this.y = y;}
}
class InputHandler implements KeyListener
{
 public boolean[] keys = new boolean[65536];
	public void keyPressed(KeyEvent e)
	{
		int keyCode = e.getKeyCode();
		keys[keyCode] = true;
	}
	public void keyReleased(KeyEvent e)
	{
		int keyCode = e.getKeyCode();
		keys[keyCode] = false;
	}
	public void keyTyped(KeyEvent e)
	{
		int keyCode = e.getKeyCode();
		keys[keyCode] = true;
	}
}
}