We haven't been able to upgrade to JIRA 7 yet. Our policy is OpenJDK, followed by OracleJDK.
If OracleJDK is the only supported option then the software vendor (so if this is Altassian) must supply us a statement that none of the chargeable components as per the OracleJDK licence terms in table 1-1 are used, nor do they intend to and if so they will advise us in writing prior to it.
Otherwise we are making BA / IAG liable in the future.
See http://www.oracle.com/technetwork/java/javase/terms/products/index.html
Non-licence compliance with Oracle can be an expensive matter. Otherwise we will have to resort to trying openJDK workarounds