title: getResourceAsStream() vs FileInputStream
body: <p>I was trying to load a file in a webapp, and I was getting a <code>FileNotFound</code> exception when I used <code>FileInputStream</code>. However, using the same path, I was able to load the file when I did <code>getResourceAsStream()</code>. 
  What is the difference between the two methods, and why does one work while the other doesn't?</p>