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Asked: 2026-05-14T02:46:52+00:00

public abstract class MyAbs implements Comparable<MyAbs> This would work but then I would be

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public abstract class MyAbs implements Comparable<MyAbs>

This would work but then I would be able to compare class A and B with each other if they both extend MyAbs. What I want to accomplish however is the exact opposite.

So does anyone know a way to get the generic type to be the own class? Seemed like such a simple thing at first…

Edit:

To explain it a little further with an example. Say you have an abstract class animals, then you extend it with Dogs and ants.

I wouldn’t want to compare ants with Dogs but I however would want to compare one dog with another. The dog might have a variable saying what color it is and that is what I want to use in the compareTo method. However when it comes to ants I would rather want to compare ant’s size than their color.

Hope that clears it up. Could possibly be a design flaw however.

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1 Answer

  1. Editorial Team

    Most straightforward would be:

    public abstract class MyAbs<T> implements Comparable<T>

    Perhaps more usefully, you go Enum style:

    public abstract class MyAbs<THIS extends MyAbs<THIS>> implements Comparable<THIS>

    You may possibly be able to ignore the issue:

    public abstract class MyAbs

    An external Comparator feels more natural to me (that is to say, don’t have a natural order).

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