Howdy,
I was just looking at Oracle's Javadoc for JPA and it seems that 
LockModeType section is a bit messed up 
(
http://docs.oracle.com/javaee/6/api/javax/persistence/LockModeType.html).
I'm not sure if it's JPA Expert Group or Oracle responsibility to build 
up the Javadoc, but just wanted to sign a problem. Most likely it's 
because of unclosed <code> tag here:
<code>LockModeType.OPTIMISTIC_FORCE_INCREMENT<code>  are the
  following.
Regards,
Piotr