title: Update Java Exception List
body: <p>I need to add URL to Java exception sites. I found a way to add using powershell but i need to add only if the url is not yet added.</p>
  
  <p>i tried the following code below. but it always adds. i need to add the URL only if it does not exist.</p>
  
  <pre class="lang-js prettyprint-override"><code>$site = "somesite.com"
  Add-Content -Path "$env:USERPROFILE\AppData\LocalLow\Sun\Java\Deployment\security\exception.sites" -Value "$site"
  </code></pre>
  
  <p>the specified URL is added only if it does not exist in the list already</p>