It’s often the case that java.lang.Object is the most accurate type for a method argument. This situation complicates type checking, which impacts performance.

Method and variable handles vs. Java reflection To truly understand MethodHandles and VarHandles —what they do and why they are useful—it’s helpful to know a few things about reflection in Java.

You'd either include the paths in your invocations of javac and java with the -cp command line switch, or if you're using a build tool or IDE, it'll have its own method of managing the classpath.