invoke a method using Javassist

Javassist is used to change existing classes or generate new ones programmatically. Its reflective capabilities are used during the transformation of existing classes to find out details about the class being transformed.

The reflective capabilities of javassist are similar to those of the reflection api, but javassist has no way to invoke methods (unless you generate code that invokes those methods of course).

What you could do, is use javassist to transform the main method of your ReflectionClass such that the timing code is added dynamically, i.e. you could build a primitive profiler with it. Then you could leave the timing code out of the source file of ReflectionClass and add it at run-time when the class is loaded into the JVM.

Another approach would be to generate a class that 'invokes 100 objects' as you say, but timing it wouldn't be very interesting because it would run just as fast as regular java bytecode.