Performance optimization by using Method.getParameterCount() where possible

[dreis2211]

Hi,

as described in #1848 we could make use of Method.getParameterCount() in order to save some overhead from unnecessary cloning caused by Method.getParameterTypes().

As this is my first contribution to Mockito, let me know if I can do something to help.

Let me know what you think.
Cheers,
Christoph

[codecov-io]

Codecov Report

Merging #1849 into release/3.x will increase coverage by <.01%.
The diff coverage is 92.85%.

@@                Coverage Diff                @@
##             release/3.x    #1849      +/-   ##
=================================================
+ Coverage          86.69%   86.69%   +<.01%     
- Complexity          2505     2506       +1     
=================================================
  Files                314      314              
  Lines               6606     6607       +1     
  Branches             829      829              
=================================================
+ Hits                5727     5728       +1     
  Misses               678      678              
  Partials             201      201

Impacted Files	Coverage Δ	Complexity Δ
...mockito/internal/invocation/InvocationMatcher.java	97.82% <0%> (ø)	26 <0> (+1)	⬆️
.../mockito/internal/invocation/TypeSafeMatching.java	88.23% <100%> (ø)	12 <3> (ø)	⬇️
...o/internal/stubbing/answers/ReturnsArgumentAt.java	100% <100%> (ø)	27 <0> (ø)	⬇️
...a/org/mockito/internal/util/ObjectMethodsGuru.java	100% <100%> (ø)	9 <0> (ø)	⬇️
...nal/creation/instance/ConstructorInstantiator.java	95.77% <100%> (ø)	36 <9> (ø)	⬇️
...ito/internal/util/reflection/FieldInitializer.java	90.56% <100%> (ø)	18 <0> (ø)	⬇️
...java/org/mockito/internal/exceptions/Reporter.java	93.54% <100%> (+0.02%)	93 <5> (ø)	⬇️

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[mockitoguy]

Looks great! I'll merge as soon as the currently built version is published.

[TimvdLippe]

After importing this change into Google, I realized that this change is breaking all downstream Android applications. Should we revert this change similarly to #1845 (see full postmortem at https://github.com/mockito/mockito/wiki/Android-Java-8-%60java.time.Duration%60-postmortem ), given that it does not change our public API?

[dreis2211]

That's very unfortunate.

[mockitoguy]

Should we revert this change similarly to #1845

Absolutely.