This is a known issue. See more discussion at:
https://community.jboss.org/message/808212
Quoting from the thread:
Yes it is normal.
There have been some changes in JDK8 that prevent
AS7 and current version of EAP6 to start under JDK8. We have many
JDK8 related fixes in WildFly so I would recommend you to use that.As for EAP goes, the start up on JDK8 is fixed in upcoming 6.2 release.