title: Unable to install java9 on ubuntu
body: <p>I already have java8 working but when I try to install java9 this is what happens everytime:</p>
  
  <pre><code>sudo apt-get install oracle-java9-installer
  </code></pre>
  
  <blockquote>
    <p>Reading package lists... Done Building dependency tree        Reading
    state information... Done Package oracle-java9-installer is not
    available, but is referred to by another package. This may mean that
    the package is missing, has been obsoleted, or is only available from
    another source</p>
    
    <p>E: Package 'oracle-java9-installer' has no installation candidate</p>
  </blockquote>