title: GAE's appspot.com cache-control header - HTTP STATUS 304
body: <p>I have a lot mouseover images on my GAE development (Java). I hosted it at appspot.com. The current cache-control header I got = no-cache, re-validation. So, when the image hovered and mouse out , it will reload the image and then this is where latency comes...</p>
  
  <p>I am not sure how to deal with this. Any help please (Java solution)?</p>
  
  <p>Edited ==></p>
  
  <p>appengine.xml</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;appengine-web-app xmlns="http://appengine.google.com/ns/1.0"&gt;
      &lt;application&gt;s~xxxxxx&lt;/application&gt;
  
      &lt;version&gt;1&lt;/version&gt;
  
      &lt;static-files&gt;
          &lt;include path="/images/**" expiration="1d" /&gt;
          &lt;include path="/scripts/**" expiration="1d" /&gt;
          &lt;include path="/stylesheets/**" expiration="1d" /&gt;
          &lt;include path="/*.p12" expiration="1d" /&gt;
          &lt;include path="/favicon.ico" expiration="1d" /&gt;
      &lt;/static-files&gt;
  
      &lt;threadsafe&gt;true&lt;/threadsafe&gt;
  
      &lt;warmup-requests-enabled&gt;true&lt;/warmup-requests-enabled&gt;
  
      &lt;system-properties&gt;
          &lt;property name="java.util.logging.config.file" value="WEB-INF/logging.properties"/&gt;
      &lt;/system-properties&gt;
  
      &lt;sessions-enabled&gt;true&lt;/sessions-enabled&gt;
  &lt;/appengine-web-app&gt;
  </code></pre>
  
  <p>When the first load the image (<a href="http://xxx.appspot.com/images/myicon.png" rel="nofollow noreferrer">http://xxx.appspot.com/images/myicon.png</a>) after deployment, I will get something like this. There are 2 cache-controls... I guess "no-cache" cache-control replaced the earlier private cache-control.</p>
  
  <p><img src="https://i.stack.imgur.com/l7gg3.png" alt="Response Header1"></p>
  
  <p>But then if I refresh that page again, it will go back http 1.1 304 Not Modified.</p>
  
  <p><img src="https://i.stack.imgur.com/FTmdj.png" alt="Response Header2"></p>