title: Installing openjdk-7-jre on ubuntu 10.04 - Package openjdk-7-jre has no installation candidate
body: <p>I'm trying to install openjdk-7 on my ubuntu but I'm getting the following error:</p>
  
  <pre><code>$ sudo apt-get install openjdk-7-jre
  Reading package lists... Done
  Building dependency tree       
  Reading state information... Done
  Package openjdk-7-jre 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
  E: Package openjdk-7-jre has no installation candidate
  </code></pre>
  
  <p>I suppose I'm missing some repos or something like that but I was unable to find any reference where and what.</p>