title: How to run external jar functions in spark-shell
body: <p>I created a jar package from a project by this file-tree:</p>
  
  <pre><code>build.sbt
  src/main
  src/main/scala
  src/main/scala/Tester.scala
  src/main/scala/main.scala
  </code></pre>
  
  <p>where Tester is a class by a function (name is print()) and main has an object to run that prints "Hi!" (from spark documention)
  created a jar file by sbt successfully and worked well in spark-submit</p>
  
  <p>now I wanna add it into spark-shell and use Tester class as a class to create objects and ...
  I added the jar file into spark-default.conf but:</p>
  
  <pre><code>scala&gt; val t = new Tester();
  &lt;console&gt;:23: error: not found: type Tester
         val t = new Tester();
  </code></pre>