Hi Eamonn,
Thanks for the explanation. I tried your suggestion:
ClassLoadingMXBean.class.getMethod("getLoadedClassCount") and it works
great. This saves me some extra coding. :)
Thanks,
Jennifer
Eamonn McManus wrote:
> Jennifer,
>
> The problem is that the interface ClassLoadingMXBean is public but the
> implementation class sun.management.ClassLoadingImpl is not. This
> means that the method ClassLoadingMXBean.getLoadedClassCount() is
> accessible but the method
> sun.management.ClassLoadingImpl.getLoadedClassCount() is not. If you
> wrote ((sun.management.ClassLoadingImpl) clBean).getLoadedClassCount()
> instead of just clBean.getLoadedClassCount() then it would not
> compile, and reflection doesn't do anything different.
>
> If you write ClassLoadingMXBean.class.getMethod("getLoadedClassCount")
> then it should work. (Because getMethod is varargs you don't need the
> second argument.)
>
> Regards,
> Éamonn McManus/ · /JMX Spec Lead/ ·
> /http://weblogs.java.net/blog/emcmanus/
>
>
> Jennifer Chou wrote:
>> Hi,
>>
>> I'm trying use method.invoke(..) on the MXBeans but I'm getting
>> IllegalAccessException on some but not all the MXBeans. Anybody know
>> why? And how to get around this problem?
>>
>> java.lang.management.ClassLoadingMXBean clBean =
>> ManagementFactory.getClassLoadingMXBean();
>> java.lang.reflect.Method method =
>> clBean.getClass().getMethod("getLoadedClassCount", (Class[]) null);
>> method.invoke(clBean, (Object[]) null);
>>
>> These get IllegalAccessException:
>> ClassLoadingMXBean
>> CompilationMXBean
>> GarbageCollectorMXBean
>> MemoryMXBean
>> MemoryMXBean
>>
>> These allow me to use method.invoke():
>> OperatingSystemMXBean
>> MemoryUsage
>>
>> Jennifer
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