title: ETag format w3c
body: <p>We use ETag header for syncronization on server and it corresponds to entities 'int version' field in DB.
  According to w3c docs:
  <a href="http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html" rel="nofollow">http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html</a>
  Examples:</p>
  
  <pre><code>  ETag: "xyzzy"
    ETag: W/"xyzzy"
    ETag: ""
  </code></pre>
  
  <p>It means that ETag inside double quotes.
  So if I want to send it to client it should be done like:</p>
  
  <pre><code>int version = 2;
  response.setHeader(HttpHeaders.ETAG, String.format("\"%s\"", version));
  </code></pre>
  
  <p>Or:</p>
  
  <pre><code> int version = 2;
   response.setHeader(HttpHeaders.ETAG, String.format("%s", version));
  </code></pre>
  
  <p>In first case I get:</p>
  
  <pre><code>HTTP/1.1 200 OK
  ...
  ETag: 2
  </code></pre>
  
  <p>In second:</p>
  
  <pre><code>HTTP/1.1 200 OK
  ...
  ETag: "2"
  </code></pre>
  
  <p>Which way is more w3c compliant?</p>