Liferay showing HotDeployment and ClassCast Exception
<p>I am getting the following error while building project in 
Liferay</p>

<blockquote>
  <p>Antjava.lang.ClassCastException:
  com.liferay.docs.guestbook.model.impl.GuestbookImpl cannot be cast to
  com.liferay.docs.guestbook.model.Guestbook    at
  com.liferay.docs.guestbook.service.persistence.GuestbookPersistenceImpl.findByGroupId(GuestbookPersistenceImpl.java:1541)
    at
  com.liferay.docs.guestbook.service.persistence.GuestbookPersistenceImpl.findByGroupId(GuestbookPersistenceImpl.java:1483)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)</p>
</blockquote>