arne-bdt commented on issue #2795: URL: https://github.com/apache/jena/issues/2795#issuecomment-2439653100
> `LiteralLabel `assumes that the datatypes can be compared by reference. LiteralLabel daoes not make such an assumption. `Objects.equals(a, b)` does not compare by reference. The code looks like this:  In my option the root cause of the whole problem is that the implementations of `RDFDatatype` do not override `equals(Object other)` and `hashCode()`. So we indeed rely on reference equality, which I guess is a really bad thing. That is what makes duplicated entries possible in the first place. In the `testUserDefRepeated` from your [PR](https://github.com/apache/jena/pull/2796), I think the types should be equal: ```java RDFDatatype type1 = new BaseDatatype("urn:x-jena-dt:repeated"); RDFDatatype type2 = new BaseDatatype("urn:x-jena-dt:repeated"); // Check precondition assertEquals("Datatypes should be equal", type1, type2); ``` This assert currently fails. I propose to implement `equals()` and `hashCode()` in `BaseDatatype` like this: ```java @Override public boolean equals(Object other) { if(other != null && this.getURI().equals(((BaseDatatype)other).getURI()) && this.getClass().equals(other.getClass())) { return true; } return false; } @Override public int hashCode() { return super.uri.hashCode(); } ``` I am not sure if the implementing class should be part of the equality check. Checking it feels safer. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
