java.lang.NullPointerException
        at java.io.Reader.<init>(Unknown Source)
        at java.io.InputStreamReader.<init>(Unknown Source)
        at game.level.LevelLoader.load(LevelLoader.java:14)
        at game.Game.<init>(Game.java:25)
        at game.Main.initObjects(Main.java:128)
        at game.Main.<init>(Main.java:25)
        at game.Main.main(Main.java:160)
Exception in thread "main" java.lang.NullPointerException
        at game.Game.tick(Game.java:42)
        at game.Main.tick(Main.java:100)
        at game.Main.loop(Main.java:55)
        at game.Main.<init>(Main.java:26)
        at game.Main.main(Main.java:160)

Thread t = new Thread(runnableObject);

t.start();

public class ECamera 
{
   // Image to draw
   protected Image bg;

   // Position of the camera
   protected float camX, camY;

   // Width and height of image
   protected float bgWidth, bgHeight;

   // Game container to get screen width/height
   protected GameContainer gc;
   
   /**
    * Create new Camera with background image
    * 
    * @param gc the game container
    * @param bg the background image
    */
   public ECamera(GameContainer gc, Image bg)
   {
      this.bg = bg;

      bgWidth =  bg.getWidth();
      bgHeight = bg.getHeight();

      camX = camY = 0;

      this.gc = gc;
   }

   /**
    * Centers on the x, y coordinate given. If the camera comes to an edge of 
    * the image, the camera stops
    * 
    * @param x x-position to center on
    * @param y y-position to center on
    */
   public void centerOn(float x, float y)
   {
      camX = x - (gc.getWidth()  / 2);
      camY = y - (gc.getHeight() / 2);

      if (camX < 0) 
         camX = 0;
      if (camX + gc.getWidth() > bgWidth) 
         camX = bgWidth - gc.getWidth();

      if (camY < 0) 
         camY = 0;
      if (camY + gc.getHeight() > bgHeight) 
         camY = bgHeight - gc.getHeight();
   }
   
   /**
    * Draw the background
    */
   public void draw()
   {
      this.draw(camX, camY);
   }
   
   /**
    * Draw the background using an offset separate of the camera
    * 
    * @param offsetX x-offset to use
    * @param offsetY y-offset to use
    */
   public void draw(float offsetX, float offsetY)
   {   if (bg != null)
         gc.getGraphics().drawImage(bg, 0, 0, offsetX, offsetY, offsetX + gc.getWidth(), offsetY + gc.getHeight());
   }
   
   /**
    * Translates all graphics relative to the camera
    */
   public void translateGraphics()
   {
      gc.getGraphics().translate(-camX, -camY);
   }
   
   /**
    * Undoes translateGraphics(). Use before drawing anything that is 
    * independent of camera position, like HUD's
    */
   public void untranslateGraphics()
   {
      gc.getGraphics().translate(camX, camY);
   }
}

import org.newdawn.slick.GameContainer;
import org.newdawn.slick.Image;

public class Camera 
{
   // Image to draw
   protected Image bg;

   // Position of the camera
   protected float camX, camY;

   // Width and height of image
   protected float bgWidth, bgHeight;

   // Game container to get screen width/height
   protected GameContainer gc;

   /**
    * Create new Camera
    * 
    * @param gc the game container
    * @param bg the background image
    */
   public Camera(GameContainer gc, Image bg)
   {
      this.bg = bg;

      bgWidth =  bg.getWidth();
      bgHeight = bg.getHeight();

      camX = camY = 0;

      this.gc = gc;
   }

   /**
    * Centers on the x, y coordinate given. If the camera comes to
    * an edge of the image, the camera stops
    * 
    * @param x x position to center on
    * @param y y position to center on
    */
   public void centerOn(float x, float y)
   {
      camX = x - gc.getWidth()  / 2;
      camY = y - gc.getHeight() / 2;

      if(camX < 0) 
         camX = 0;
      if(camX + gc.getWidth() > bgWidth) 
         camX = bgWidth - gc.getWidth();

      if(camY < 0) 
         camY = 0;
      if(camY + gc.getHeight() > bgHeight) 
         camY = bgHeight - gc.getHeight();
   }
   
   /**
    * Centers on the x coordinate given. Use so the camera
    * only accounts for horizontal movement
    * 
    * @param x x position to center on
    */
   public void centerOnX(float x)
   {
      camX = x - gc.getWidth()  / 2;

      if(camX < 0) 
         camX = 0;
      if(camX + gc.getWidth() > bgWidth) 
         camX = bgWidth - gc.getWidth();

   }
   
   /**
    * Centers on the y coordinate given. Use so the camera
    * only accounts for vertical movement
    * 
    * @param y y position to center on
    */
   public void centerOnY(float y)
   {
      camY = y - gc.getHeight() / 2;

      if(camY < 0) 
         camY = 0;
      if(camY + gc.getHeight() > bgHeight) 
         camY = bgHeight - gc.getHeight();
   }
   
   /**
    * Draw the background
    */
   public void draw()
   {
      this.draw(camX, camY);
   }
   
   /**
    * Draw the background using an offset separate of the camera
    * 
    * @param offsetX x offset to use
    * @param offsetY y offset to use
    */
   public void draw(float offsetX, float offsetY)
   {
      gc.getGraphics().drawImage(bg, 0, 0, offsetX, offsetY, 
            offsetX + gc.getWidth(), offsetY + gc.getHeight());
   }
   
   /**
    * Translates all graphics relative to the camera
    */
   public void translateGraphics()
   {
      gc.getGraphics().translate(-camX, -camY);
   }
   
   /**
    * Undoes translateGraphics(). Use before drawing anything
    * that is independent of camera position, like HUD's.
    */
   public void untranslateGraphics()
   {
      gc.getGraphics().translate(camX, camY);
   }
}

Camera cam;
Image bg;
Image player;
float px, py;   // Player coordinates

public void init(GameContainer gc)
{
    bg = new Image("Image path");
    player = new Image("Image path");
    cam = new Camera(gc, bg);

    px = py = 0;
}

public void render(GameContainer gc, Graphics g)
{
    cam.centerOn(x, py);
    cam.draw();
    cam.translateGraphics();

    g.drawImage(player, x, y);
}

public void update(GameContainer gc, int delta)
{
    // Move player and stuff
}

graphics = buffer.getDrawGraphics();
graphics.drawImage (bi, 0, 0, null);