title: How to keep variable content over multiple requests?
body: <p>I want to build a log file in memory using a <code>StringBuilder</code>, so I have a </p>
  
  <pre><code>private StringBuilder logFile = new StringBuilder();
  </code></pre>
  
  <p>in my controller class. Later than I append log lines to that object.</p>
  
  <p>But after each request it is cleared. How do I keep the contents during multiple requests/views? What's the best approach?</p>