Could one calculate the hashes for each entry, sort them, and then generate the hash for the collection?
On Thu, 7 Mar 2024 at 06:59, Mark Struberg <strub...@yahoo.de.invalid> wrote: > > The question to me is how we can make it more robust. > In a Collection (but actually also in most lists) the order in which you get > the values (Iterator or get(i)) is not deterministic. It can be different in > one list than in another - even if they contain the exact same items. > > Not yet sure how to work around this. We can probably try to sort it first, > but then again, if they do not implement Comparable it won't help much. Or do > a containsElement based on reflection as well - but that would be rather slow. > > Same with Maps. There is a good reason why the key at least should implement > equals/hashCode. If this is not the case, then we are not able to implement > this properly I fear. > > Any ideas? > > LieGrue, > strub > > > Am 06.03.2024 um 15:53 schrieb Gary Gregory <garydgreg...@gmail.com>: > > > > Ah, right, custom "non-equalable" _inside_ Collections and Maps... > > > > For the diff, I'd suggest you test and iterable over a Collection > > instead of a List. > > > > Then you'd need a separate test and traversal for Map instances. > > > > (Still no common super-interface in Java 21 for Collections and Maps...) > > > > Gary > > > > On Wed, Mar 6, 2024 at 7:40 AM Mark Struberg <strub...@yahoo.de.invalid> > > wrote: > >> > >> Hi Gregory! > >> > >> I did try this out and figured that I didn't think it though. Maybe I need > >> to go a few steps back and explain the problem: > >> > >> I have the following constellation > >> > >> public class SomeInnerDTO {int field..} // NOT implements equals! > >> public class TheOuterDTO{ List<SomeInnerDTO> innerList;..} > >> > >> My problem is that reflectionEquals (which I use in a unit test) tries to > >> introspect fields even in java.util.classes. And for getting the values of > >> those classes it tries to call a setAccessible(true); > >> And obviously here it fails. There is a ticket already open [1] which > >> sugggests to use trySetAccessible. But I fear that will still do nothing > >> and you won't get access to those inner knowledge inside > >> java.util.LinkedList etc. > >> > >> And using equals() on the List sadly won't help either, as the > >> SomeInnerDTO would also get compared with equals(), but that will > >> obviously use identity comparison only :( > >> > >> > >> What I did for now (running all tests with a few projects right now, but > >> looks promising): > >> > >> diff --git > >> a/src/main/java/org/apache/commons/lang3/builder/EqualsBuilder.java > >> b/src/main/java/org/apache/commons/lang3/builder/EqualsBuilder.java > >> index ff5276b04..cf878da40 100644 > >> --- a/src/main/java/org/apache/commons/lang3/builder/EqualsBuilder.java > >> +++ b/src/main/java/org/apache/commons/lang3/builder/EqualsBuilder.java > >> @@ -978,6 +978,16 @@ public EqualsBuilder reflectionAppend(final Object > >> lhs, final Object rhs) { > >> if (bypassReflectionClasses != null > >> && (bypassReflectionClasses.contains(lhsClass) || > >> bypassReflectionClasses.contains(rhsClass))) { > >> isEquals = lhs.equals(rhs); > >> + } else if (testClass.isAssignableFrom(List.class)) { > >> + List lList = (List) lhs; > >> + List rList = (List) rhs; > >> + if (lList.size() != rList.size()) { > >> + isEquals = false; > >> + return this; > >> + } > >> + for (int i = 0; i < lList.size(); i++) { > >> + reflectionAppend(lList.get(i), rList.get(i)); > >> + } > >> } else { > >> > >> I'm rather sure this is still not enough and there are plenty other cases > >> to consider. Like e.g. handling Maps etc. > >> But at least that's the direction I try to approach it right now. And of > >> course this new part should potentially also be enabled by a flag... > >> > >> Will keep you updated. > >> > >> txs and LieGrue, > >> strub > >> > >> > >> [1] https://issues.apache.org/jira/browse/LANG-1711 > >> > >>> Am 06.03.2024 um 13:18 schrieb Gary Gregory <garydgreg...@gmail.com>: > >>> > >>> This sounds like a good idea to try. I would call the option something > >>> else > >>> though. We would not skip calling equals if it is defined right? How about > >>> "useEqualsIfPresent". > >>> > >>> Gary > >>> > >>> On Wed, Mar 6, 2024, 5:03 AM Mark Struberg <strub...@yahoo.de.invalid> > >>> wrote: > >>> > >>>> Hi! > >>>> > >>>> I have a question about EqualsBuilder#reflectionEquals. From Java9 > >>>> onwards > >>>> we get more and more nasty module problems. Mainly because the code tries > >>>> to recurse into java.util.* classes as well. > >>>> I know that I can use setBypassReflectionClasses for those. But wouldn't > >>>> it be fine to have an additional switch to 'skipOnCustomEquals' or > >>>> similar? > >>>> > >>>> The idea is to only use reflection on classes which do not provide their > >>>> own equals method. One can test this imo rather easily by checking > >>>> whether > >>>> classInQuestion.getMethod("equals", Object.class).getDeclaringClass() != > >>>> Object.class > >>>> Do that for lhs and rhs and if both fit the criteria -> invoke equals > >>>> > >>>> Wdyt of that idea? Worth trying or is there already a better solution? > >>>> With the new flag we can make sure that we do not change the current > >>>> behaviour for existing use cases. > >>>> > >>>> LieGrue, > >>>> strub > >>>> > >>>> > >>>> --------------------------------------------------------------------- > >>>> To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org > >>>> For additional commands, e-mail: dev-h...@commons.apache.org > >>>> > >>>> > >> > >> > >> --------------------------------------------------------------------- > >> To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org > >> For additional commands, e-mail: dev-h...@commons.apache.org > >> > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org > > For additional commands, e-mail: dev-h...@commons.apache.org > > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org > For additional commands, e-mail: dev-h...@commons.apache.org > --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org For additional commands, e-mail: dev-h...@commons.apache.org