String is still a type of Object (requiring GC handling of reference counters), as you can do Object[] o = stringArray.clone(); without casting. (other way not so)
https://www.javaspecialists.eu/archive/Issue124.html says there is hardly any difference, so I don't think we need to fight this one out and can just go with the cleanest code :) On 16 February 2018 at 11:22, sebb <seb...@gmail.com> wrote: > On 16 February 2018 at 10:01, Stian Soiland-Reyes <st...@apache.org> wrote: >> I agree in general for .clone() on objects - and I'm trying to move >> away from using .clone() in that Commons RDF fluent mutable/immutable >> builder (See COMMONSRDF-49). >> >> But this is an Object[] - a native type. > > Huh? > > The code says String[], which is native as it's final. > > Object[] may not be native > >> I must admit I am not sure what is really the preferred way - I >> thought .clone() is best as the VM can copy an array natively however >> it wants, while with Arrays.copyOf it might have to check if length is >> the same before doing anything clever. > > In the specific case of String[] it might be OK to use clone, but in > general it's better to use the proper JVM methods and not try to > second-guess how efficient they are. > >> On 13 February 2018 at 18:58, Gilles <gil...@harfang.homelinux.org> wrote: >>> On Tue, 13 Feb 2018 18:40:13 +0000, sebb wrote: >>>> >>>> On 13 February 2018 at 09:31, Gilles <gil...@harfang.homelinux.org> wrote: >>>>> >>>>> On Tue, 13 Feb 2018 00:16:13 +0000 (UTC), st...@apache.org wrote: >>>>>> >>>>>> >>>>>> Repository: commons-csv >>>>>> Updated Branches: >>>>>> refs/heads/CSV-216 637ad2d7a -> f66a83901 >>>>>> >>>>>> >>>>>> CSV-216: Avoid Arrays.copyOf() >>>>> >>>>> >>>>> >>>>> Why? >>>> >>>> >>>> Agreed >>>> >>>>>> as .clone() will do >>>>> >>>>> >>>>> >>>>> We should rather avoid using "clone()". >>>> >>>> >>>> Again: why? >>> >>> >>> There are many discussions about this topic on the web.[1] >>> My point is that using "clone()" is not good advice. >>> >>> Gilles >>> >>> [1] E.g. http://vojtechruzicka.com/java-cloning-problems/ >>> >>> >>>> It's not clear why Arrays.copyOf(0 is considered bad, nor why clone() >>>> is considered bad. >>>> >>>> >>>>> Gilles >>>>> >>>>> >>>>>> -- at least until someone tries to do >>>>>> .withValue(x) in an out-of-range column >>>>>> >>>>>> >>>>>> Project: http://git-wip-us.apache.org/repos/asf/commons-csv/repo >>>>>> Commit: >>>>>> http://git-wip-us.apache.org/repos/asf/commons-csv/commit/f66a8390 >>>>>> Tree: http://git-wip-us.apache.org/repos/asf/commons-csv/tree/f66a8390 >>>>>> Diff: http://git-wip-us.apache.org/repos/asf/commons-csv/diff/f66a8390 >>>>>> >>>>>> Branch: refs/heads/CSV-216 >>>>>> Commit: f66a83901bd026369a2e8d522bd567eb2ef3f8c0 >>>>>> Parents: 637ad2d >>>>>> Author: Stian Soiland-Reyes <st...@apache.org> >>>>>> Authored: Fri Feb 9 16:49:51 2018 +0000 >>>>>> Committer: Stian Soiland-Reyes <st...@apache.org> >>>>>> Committed: Tue Feb 13 00:14:52 2018 +0000 >>>>>> >>>>>> >>>>>> >>>>>> ---------------------------------------------------------------------- >>>>>> src/main/java/org/apache/commons/csv/CSVRecord.java | 4 ++-- >>>>>> 1 file changed, 2 insertions(+), 2 deletions(-) >>>>>> >>>>>> >>>>>> ---------------------------------------------------------------------- >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> http://git-wip-us.apache.org/repos/asf/commons-csv/blob/f66a8390/src/main/java/org/apache/commons/csv/CSVRecord.java >>>>>> >>>>>> >>>>>> ---------------------------------------------------------------------- >>>>>> diff --git a/src/main/java/org/apache/commons/csv/CSVRecord.java >>>>>> b/src/main/java/org/apache/commons/csv/CSVRecord.java >>>>>> index 979119f..2be5c49 100644 >>>>>> --- a/src/main/java/org/apache/commons/csv/CSVRecord.java >>>>>> +++ b/src/main/java/org/apache/commons/csv/CSVRecord.java >>>>>> @@ -199,7 +199,7 @@ public class CSVRecord implements Serializable, >>>>>> Iterable<String> { >>>>>> public final CSVRecord immutable() { >>>>>> if (isMutable()) { >>>>>> // Subclass is probably CSVMutableRecord, freeze values >>>>>> - String[] frozenValue = Arrays.copyOf(values, >>>>>> values.length); >>>>>> + String[] frozenValue = values.clone(); >>>>>> return new CSVRecord(frozenValue, mapping, comment, >>>>>> recordNumber, characterPosition); >>>>>> } else { >>>>>> return this; >>>>>> @@ -260,7 +260,7 @@ public class CSVRecord implements Serializable, >>>>>> Iterable<String> { >>>>>> if (isMutable()) { >>>>>> return this; >>>>>> } >>>>>> - String[] newValues = Arrays.copyOf(values, >>>>>> values.length); >>>>>> + String[] newValues = values.clone(); >>>>>> return new CSVMutableRecord(newValues, mapping, comment, >>>>>> recordNumber, characterPosition); >>>>>> } >>> >>> >>> >>> --------------------------------------------------------------------- >>> To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org >>> For additional commands, e-mail: dev-h...@commons.apache.org >>> >> >> >> >> -- >> Stian Soiland-Reyes >> http://orcid.org/0000-0001-9842-9718 >> >> --------------------------------------------------------------------- >> 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 > -- Stian Soiland-Reyes http://orcid.org/0000-0001-9842-9718 --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org For additional commands, e-mail: dev-h...@commons.apache.org
