title: Cannot open declaration on Eclipse(Source not found) - HttpServlet.class
body: <p>I am Trying to open declaration on Eclipse Neon.1(Mac OS X).</p>
  
  <p>open other classes such as PrintWriter.class is working fine but when I open httpServlet.class's declaration. Source can't be found.</p>
  
  <p>below is screenshots of what I am struggling now. I've searched for this problem but I couldn't find a solution. please help.</p>
  
  <p><a href="https://i.stack.imgur.com/4z0dE.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/4z0dE.png" alt="enter image description here"></a></p>
  
  <p><a href="https://i.stack.imgur.com/LW7O0.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/LW7O0.png" alt="source not found"></a></p>
  
  <p><a href="https://i.stack.imgur.com/aazj8.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/aazj8.png" alt="Jar files imported"></a></p>