MOXy performance - PrivilegedAccessHelper

[plutext]

Describe the bug

MOXy is approx 10 times slower than glassfish in unmarshalling in my application

in my testing, 67% of time is spent in the two org.eclipse.persistence.internal.security.PrivilegedAccessHelper.getClassForName methods

There are classes not being found in the hashmap (since they aren't primitives but rather, my XJC generated classes), so 66.5% of time is spent in java.lang.Class.forName().

In my testing, caching the results of the class lookups reduces time taken by 75% (test run time down from 400 secs to 100 secs).

To Reproduce

EclipseLink versions tested include 2.5.2, 2.7.4, 3.0.2, 4.0.2

Somewhat related https://bugs.eclipse.org/bugs/show_bug.cgi?id=447342