Generic bounds with pre-generics raw types

问题

I've got a Collection with the element type of <K extends Comparable<K>> because it's ordered.

I'm trying to use Joda LocalTime with this collection - e.g. MyCollection<LocalTime>. Unfortunately, apparently Joda is pre-generics; LocalTime implements raw Comparable.

I'm getting the compiler error

Bound mismatch: The type LocalTime is not a valid substitute 
for the bounded parameter <K extends Comparable<K>> of the type Interval<K>

I would expect this to work with just a warning, as it's quite possible to assign a raw type to a typed variable.

Why doesn't this work, and what can I do about it?

Here's a minimal code sample:

class Holder<K extends Comparable<K>> { }
class WTF extends Holder<LocalTime> { }

回答1:

You could create a wrapper class around LocalTime which implements Comparable<K> and passes through all the method calls.

来源：https://stackoverflow.com/questions/4221431/generic-bounds-with-pre-generics-raw-types