title: Importing Java libraries into C#
body: <p>So, I have written my code to .zip files in C#, but when I import the libraries I have the following:</p>
  
  <pre><code>Using java.util;
  Using java.util.zip;
  Using java.io;
  </code></pre>
  
  <p>But, these are underlined in red, with the error message, <code>The type or namespace "java" could not be found</code></p>
  
  <p>Is there some reference I need to add?</p>