title: JAVA_HOME is not defined correctly in Groovy
body: <p>I install groovy in ubuntu and when i run groovy command in terminal i saw the bellowing error:</p>
  
  <pre><code>groovy: JAVA_HOME is not defined correctly, can 
  not execute: /usr/local/java/jdk1.8.0_20/bin/java
  </code></pre>
  
  <p>what should i do to solve this?</p>