title: Spring boot application shows file download option when serving static content
body: <p>I have a spring boot application in which I have some static files kept inside <code>resources/static</code> directory. One of them is a swagger directory. The file system layout looks as follows:</p>
  
  <pre><code>resources
  - static
    - swagger
      - index.html
  </code></pre>
  
  <p>Now if I send request to my webapp with URI <code>localhost:8080/swagger/index.html</code> then it serves the file correctly. However, if I send request to <code>localhost:8080/swagger</code> then the webapp shows a file download box with an empty binary file named <code>swagger</code>. </p>
  
  <p>In my opinion second URI should actually serve the <code>index.html</code> file automatically. How do I fix this behavior?</p>