Hy hab grad einen alten JavaSpecialists Newsletter gelesen und dabei bin ich durch einen Nebensatz auf eine Klasse gekommen die das Problem behebt.
ThreadMXBean
https://docs.oracle.com/javase/7/docs/api/java/lang/management/ThreadMXBean.html
Returns the total CPU time for the current thread in nanoseconds. The returned value is of nanoseconds precision but not necessarily nanoseconds accuracy. If the implementation distinguishes between user mode time and system mode time, the returned CPU time is the amount of time that the current thread has executed in user mode or system mode.
This is a convenient method for local management use and is equivalent to calling:
getThreadCpuTime(Thread.currentThread().getId());