When writing something like
doit(43, 44, "hello");
the compiler knows which overloaded method is to be called. When I want to do the same via reflection, I need to find out myself, that the method is
doit(Integer, double, CharSequence...);
and obtain it via something like
Class[] types = {Integer.class, double.class, CharSequence[].class};
declaringClass.getDeclaredMethod("doit", types);
I wonder if there's already something allowing me to write just
Method m = getMethod(declaringClass, "doit", 43, 44, "hello");
I wonder if somebody did this already, as the JLS is a bit complicated in this respect.
Actually, behaving exactly like the compiler is impossible as in Phase 1 the compiler accepts only methods matching without boxing and unboxing. When calling my hypothetical getMethod from above, the distinction between primitives and their wrappers is already lost (because of autoboxing when passing arguments via varargs). This problem seems to have no solution, so let's ignore it.
As suggested in an answer, BeanUtils.invokeMethod comes close. It's supposed to find the best match, whatever it means. Looking at MethodUtils.getMatchingAccessibleMethod shows that
- it knows nothing about varargs
- it's non-deterministic
so I'm looking for something better.