Selenium using Java - The path to the driver executable must be set by the webdriver.gecko.driver system property
<p>I am trying to launch Mozilla but still I am getting this error:</p>

<blockquote>
  <p>Exception in thread "main" java.lang.IllegalStateException: The path to the driver executable must be set by the webdriver.gecko.driver system property; for more information, see <a href="https://github.com/mozilla/geckodriver" rel="noreferrer">https://github.com/mozilla/geckodriver</a>. The latest version can be downloaded from <a href="https://github.com/mozilla/geckodriver/releases" rel="noreferrer">https://github.com/mozilla/geckodriver/releases</a></p>
</blockquote>

<p>I am using <code>Selenium 3.0.01</code> Beta version and <code>Mozilla 45</code>. I have tried with <code>Mozilla 47</code> too. but still the same thing.</p>