I’ve seen a different approach in libraries like Mockito and Hamcrest that split up utility classes by category, then they use a tool to copy all the static stuff to generated aggregate classes.
On Sun, Sep 6, 2020 at 09:23 Xeno Amess <xenoam...@gmail.com> wrote: > > I am not a big fan of extending Static Utility classes. And Joshua > > Bloch is not either from his book "Effective Java"... > > > > Yep I'm sure he will never like this lol. > > > > Melloware <melloware...@gmail.com> 于2020年9月6日周日 下午10:18写道： > > > > > I am not a big fan of extending Static Utility classes. And Joshua > > > Bloch is not either from his book "Effective Java"... > > > > > > See: https://www.informit.com/articles/article.aspx?p=1216151&seqNum=4 > > > > > > > > > On 9/6/2020 10:06 AM, Xeno Amess wrote: > > > > class AUtil { > > > > public static String getStringA() { > > > > return "A"; > > > > } > > > > } > > > > > > > > class ExtendedAUtil extends AUtil { > > > > public static String getStringABCDE() { > > > > return "ABCDE"; > > > > } > > > > } > > > > > > > > public class Main { > > > > public static void main(String[] args) { > > > > System.out.println(ExtendedAUtil.getStringA()); > > > > System.out.println(ExtendedAUtil.getStringABCDE()); > > > > } > > > > } > > > > > > > > Maybe it's better to add some runnable codes :) > > > > > > > > Xeno Amess <xenoam...@gmail.com> 于2020年9月6日周日 下午10:05写道： > > > > > > > >> Well sometimes we want to extend(or modify) some behaviors of one Util > > > >> Class.That is why I don't want the constructor be private. > > > >> For example, there be a AUtil: > > > >> > > > >> public class AUtil{ > > > >> public static String getStringA(){ > > > >> return "A"; > > > >> } > > > >> } > > > >> > > > >> then some people need a function that returns "ABCDE". > > > >> Actually "ABCDE" is useless for any other repos, so we can never pass > > > the > > > >> pr to put the getABCDE function to AUtil. > > > >> And that people also need the getStringA function. > > > >> So there be a way: > > > >> > > > >> public class ExtendedAUtil extends{ > > > >> public static String getStringABCDE(){ > > > >> return "ABCDE"; > > > >> } > > > >> } > > > >> > > > >> In this way that people can use ExtendedAUtil as an extended AUtil. > > > >> I admit that might be sugar and tricky, but it will help shorten the > > > codes. > > > >> BUT if we make the AUtil have only private constructor, then we cannot > > > do > > > >> such things, as class who have private constructors only cannot be > > > extended. > > > >> > > > >> Melloware <melloware...@gmail.com> 于2020年9月6日周日 下午9:55写道： > > > >> > > > >>> That is why I love Lombok's @UtilityClass. > > > >>> > > > >>> https://projectlombok.org/features/experimental/UtilityClass > > > >>> > > > >>> It enforces a static class is truly static by making the constructor > > > >>> private and throwing an exception, making sure all methods are > static, > > > >>> marking the class as Final etc. > > > >>> > > > >>> > > > >>> On 9/6/2020 9:53 AM, Xeno Amess wrote: > > > >>>>> Inheritance in Java on the static side is > > > >>>> not the same as on the instance side > > > >>>> > > > >>>> Yep, I know it. It will not override but just, hiding. > > > >>>> I admit it might confuse people sometimes. > > > >>>> > > > >>>>> subclassing a class that only > > > >>>> provides static methods is no help. > > > >>>> > > > >>>> Well actually I personally use it for a shortcut or something. > > > >>>> Of course we can do this by fork/wrap the static functions one by > one, > > > >>> but > > > >>>> extending it directly can make the codes shorter. > > > >>>> > > > >>>> Gary Gregory <garydgreg...@gmail.com> 于2020年9月6日周日 下午9:48写道： > > > >>>> > > > >>>>> On Sun, Sep 6, 2020 at 9:44 AM Xeno Amess <xenoam...@gmail.com> > > > wrote: > > > >>>>> > > > >>>>>> The idea behind not making *Util constructors private is that it > > > makes > > > >>>>>> people be able to extend that class. > > > >>>>>> for example: > > > >>>>>> > > > >>>>>> > > > >>> > > > > https://github.com/apache/commons-lang/blob/master/src/main/java/org/apache/commons/lang3/StringUtils.java#L9627 > > > >>>>> > > > >>>>> I have not see a use case that requires instances of classes that > > > only > > > >>>>> provide static methods in a long time, like the Javadoc mentions, > > > there > > > >>>>> used to be JavaBean tools that needed this, and some UI builders > > > IIRC, > > > >>> but > > > >>>>> I do not see a case of it today. Inheritance in Java on the static > > > >>> side is > > > >>>>> not the same as on the instance side, so subclassing a class that > > > only > > > >>>>> provides static methods is no help. > > > >>>>> > > > >>>>> Gary > > > >>>>> > > > >>>>> > > > >>>>>> Gary Gregory <garydgreg...@gmail.com> 于2020年9月6日周日 下午9:39写道： > > > >>>>>> > > > >>>>>>> The idea behind making *Util constructors private is that it does > > > not > > > >>>>>> make > > > >>>>>>> sense to instantiate a class that only has static methods. > > > >>>>>>> > > > >>>>>>> Gary > > > >>>>>>> > > > >>>>>>> > > > >>>>>>> On Sun, Sep 6, 2020 at 12:49 AM Xeno Amess <xenoam...@gmail.com> > > > >>>>> wrote: > > > >>>>>>>> for example: can we make its constructor public instead of > > > private? > > > >>>>>>>> > > > >>> --------------------------------------------------------------------- > > > >>> 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 > > > > > > > > -- Matt Sicker <boa...@gmail.com>
