Enums Implementing Interface Are Rejected By Verifier (java.lang.verifyerror)

I'm using enums for units of different physical quantities, like meter and miles for the DISTANCE. To use them in a generic way there is an interface Unit which has the method conv

Solution 1:

This part seems key:

returning 'Reference: java.lang.Enum[]', but expected from declaration 'Reference: com.example.app.Unit[]

So you are returning an enum array when you should be returning a unit array. Change either the return type of the method, or simply pack the DistanceUnit values into a list to fix the problem.

I would recommend using List<Unit> as your return type instead of Unit[]. See this for reference. To do so, call Arrays.asList(DistanceUnit.values()) when instantiating your list.

Solution 2:

Just looked into the stacktrace a little more and it says:

returning 'Reference: Enum[]', but expected from declaration 'Reference: Unit[]'

in getAllUnits()

Casting the returned enums of getAllUnits() to Unit[] manually fixed the issue although there is a hint:

Casting 'DistanceUnit.values()' to 'Unit[]'is redundant