title: ImageIO can't read my file? (input==null)
body: <p>When I try reading the image from my res folder, I get this error:</p>
  
  <pre><code>Exception in thread "main" java.lang.IllegalArgumentException: input == null!
  at javax.imageio.ImageIO.read(Unknown Source)
  at SpritePractice.render(SpritePractice.java:103)
  at SpritePractice.run(SpritePractice.java:71)
  at SpritePractice.start(SpritePractice.java:123)
  at SpritePractice.main(SpritePractice.java:131)
  </code></pre>
  
  <p>The image itself (MarioSpriteSheet.png) is in the res folder, and I spelled the name right. What's the problem here? </p>
  
  <pre><code>BufferedImage spriteSheet = new BufferedImage(WIDTH*2,HEIGHT*2, BufferedImage.TYPE_INT_RGB);
      try
      {
      spriteSheet = ImageIO.read(getClass().getResourceAsStream("/res/MarioSpriteSheet.png"));
      }catch (IOException e)
      {
          e.printStackTrace();
      }
      finally
      {
          pixelsFromImage = ((DataBufferInt) spriteSheet.getRaster().getDataBuffer()).getData();
      }
  </code></pre>