Refactor and add ut for ClassUtils

[bowenliang123]

Why are the changes needed?

• add unit tests for ClassUtils
• refactor ClassUtils.createInstance method with DynConstructors
• move classIsLoadable method to ReflectUtils.isClassLoadable, refeactor to use DynClasses

How was this patch tested?

• Add some test cases that check the changes thoroughly including negative and positive cases if possible

• Add screenshots for manual tests if appropriate

• Run test locally before make a pull request

[codecov-commenter]

Codecov Report

Merging #4887 (c39f9a0) into master (07e590a) will not change coverage.
The diff coverage is 0.00%.

@@          Coverage Diff           @@
##           master   #4887   +/-   ##
======================================
  Coverage    0.00%   0.00%           
======================================
  Files         557     557           
  Lines       30705   30694   -11     
  Branches     3997    3993    -4     
======================================
+ Misses      30705   30694   -11     

Impacted Files	Coverage Δ
...src/main/scala/org/apache/spark/ui/EngineTab.scala	0.00% <0.00%> (ø)
...mon/src/main/scala/org/apache/kyuubi/Logging.scala	0.00% <0.00%> (ø)
...main/scala/org/apache/kyuubi/util/ClassUtils.scala	0.00% <0.00%> (ø)

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more

[bowenliang123]

Can I move the isClassLoadable method from kyuubi-util-scala's ReflectUtils to kyuubi-util's DynClasses as a static method for Java as well ? @pan3793

[pan3793]

Can I move the isClassLoadable method from kyuubi-util-scala's ReflectUtils to kyuubi-util's DynClasses as a static method for Java as well ? @pan3793

It's fine if other places can benefit from it, but since Java does not support the default value, it should be broken into multi-methods

[bowenliang123]

Can I move the isClassLoadable method from kyuubi-util-scala's ReflectUtils to kyuubi-util's DynClasses as a static method for Java as well ? @pan3793

It's fine if other places can benefit from it, but since Java does not support the default value, it should be broken into multi-methods

OK, let's leave it in Scala module for now. As for Java, it's handy to use workaround DynClasses.builder().loader(cl).impl(className).orNull().build() != null for checking the class loadable.

[bowenliang123]

Thanks, merged to master.