I know someone would reply with some Java 8 lamba... but that will never be
as easy to ready as a method name like isEmpty or hasSomething...
Gary
On Sat, Jan 28, 2017 at 2:33 PM, Matt Benson <gudnabr...@gmail.com> wrote:
> Like Bene, this feels a little off to me. Just for argument's sake, let's
> look at:
>
> Optional.ofNullable(foo).map(Object::toString).filter(
> StringUtils::isNotBlank).isPresent();
>
> Assuming you're on Java 8, of course. It's a bit long, but not horrible.
> What about, in a Java 8-compatible version of [lang], an
> Optionals/OptionalUtils class?
>
> public class OptionalUtils {
>
> public static Optional<String> toString(Object o) {
> return map(o, Object::toString);
> }
>
> static <T, R> Optional<R> map(T t, Function<? super T, ? extends R> fn) {
> return Optional.ofNullable(t).map(fn);
> }
> }
>
> Then your test could be shortened to:
>
> OptionalUtils.toString(foo).filter(StringUtils::isNotBlank).isPresent();
>
> Just thinking "out loud",
> Matt
>
> On Sat, Jan 28, 2017 at 11:08 AM, Gary Gregory <garydgreg...@gmail.com>
> wrote:
>
> > If you look at the link Matt provided, that handles arrays and
> collection,
> > but not Object.toString()
> >
> > Gary
> >
> > On Jan 28, 2017 1:13 AM, "Benedikt Ritter" <brit...@apache.org> wrote:
> >
> >
> > > Am 28.01.2017 um 02:53 schrieb Gary Gregory <garydgreg...@gmail.com>:
> > >
> > > The simplest examples I have on hand are instances of Path and URI
> which
> > > can be built with an empty string. I want to know if these are "empty".
> > For
> > > the app I am now on for example, a Path or null and "" should be
> treated
> > > the same. Same for a URI.
> >
> > I don’t think it is a good idea to define emptiness based on the return
> > value of Object.toString(). Consider the following:
> >
> > isEmpty(null) -> true
> > isEmpty(„“) -> true
> > isEmpty(new URI(„“)) -> true
> >
> > But:
> >
> > isEmpty(Collections.emptyList()) -> false
> > isEmpty(new int[0]) -> false
> >
> > This is because toString() has nothing to do with emptiness. For this
> > reason I think it would be better to have explicitly typed method
> overloads
> > for the use cases you’re thinking about:
> >
> > boolean isEmpty(Path)
> > boolean isEmpty(URI)
> >
> > I’m not sure whether this belong to [lang]. The first looks like it
> belongs
> > to [io] while the second would better fit into [net]…
> >
> > Benedikt
> >
> > >
> > > Gary
> > >
> > > On Fri, Jan 27, 2017 at 5:37 PM, Matt Sicker <boa...@gmail.com> wrote:
> > >
> > >> That's an interesting use case, though I've never come across a
> > toString()
> > >> implementation that would be affected. Can you go into more detail?
> > >>
> > >> On 27 January 2017 at 16:04, Gary Gregory <garydgreg...@gmail.com>
> > wrote:
> > >>
> > >>> _Like_ that except that our Log4j version does not do the case I
> want:
> > >>> object.toString().
> > >>>
> > >>> Gary
> > >>>
> > >>> On Fri, Jan 27, 2017 at 1:58 PM, Matt Sicker <boa...@gmail.com>
> wrote:
> > >>>
> > >>>> Something like this?
> > >>>>
> > >>>> https://github.com/apache/logging-log4j2/blob/master/
> > >>>> log4j-core/src/main/java/org/apache/logging/log4j/core/
> > >>>> util/Assert.java#L43
> > >>>>
> > >>>> On 27 January 2017 at 15:54, Gary Gregory <garydgreg...@gmail.com>
> > >>> wrote:
> > >>>>
> > >>>>> Hi All,
> > >>>>>
> > >>>>> There are certain kinds of objects, _descriptor_ kind of objects
> that
> > >>>> would
> > >>>>> benefit from isEmpty semantics. These kind of objects can describe
> > >>>> complex
> > >>>>> command line arguments and other kind of configuration objects.
> > >>>>>
> > >>>>> I'd like to add with this pseudo code:
> > >>>>>
> > >>>>> boolean isEmpty(Object) {
> > >>>>> return object == null ? true : isEmpty(object.toString());
> > >>>>> }
> > >>>>>
> > >>>>> Thoughts?
> > >>>>>
> > >>>>> Same idea of isBlank(), isNotEmpty() and so on.
> > >>>>>
> > >>>>> Gary
> > >>>>>
> > >>>>> --
> > >>>>> E-Mail: garydgreg...@gmail.com | ggreg...@apache.org
> > >>>>> Java Persistence with Hibernate, Second Edition
> > >>>>> <https://www.amazon.com/gp/product/1617290459/ref=as_li_
> > >>>>> tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1617290459&
> > >>>>> linkCode=as2&tag=garygregory-20&linkId=
> > >> cadb800f39946ec62ea2b1af9fe6a2
> > >>> b8>
> > >>>>>
> > >>>>> <http:////ir-na.amazon-adsystem.com/e/ir?t=
> > >> garygregory-20&l=am2&o=1&a=
> > >>>>> 1617290459>
> > >>>>> JUnit in Action, Second Edition
> > >>>>> <https://www.amazon.com/gp/product/1935182021/ref=as_li_
> > >>>>> tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1935182021&
> > >>>>> linkCode=as2&tag=garygregory-20&linkId=
> > >> 31ecd1f6b6d1eaf8886ac902a24de4
> > >>>> 18%22
> > >>>>>>
> > >>>>>
> > >>>>> <http:////ir-na.amazon-adsystem.com/e/ir?t=
> > >> garygregory-20&l=am2&o=1&a=
> > >>>>> 1935182021>
> > >>>>> Spring Batch in Action
> > >>>>> <https://www.amazon.com/gp/product/1935182951/ref=as_li_
> > >>>>> tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1935182951&
> > >>>>> linkCode=%7B%7BlinkCode%7D%7D&tag=garygregory-20&linkId=%7B%
> > >>>>> 7Blink_id%7D%7D%22%3ESpring+Batch+in+Action>
> > >>>>> <http:////ir-na.amazon-adsystem.com/e/ir?t=
> > >> garygregory-20&l=am2&o=1&a=
> > >>>>> 1935182951>
> > >>>>> Blog: http://garygregory.wordpress.com
> > >>>>> Home: http://garygregory.com/
> > >>>>> Tweet! http://twitter.com/GaryGregory
> > >>>>>
> > >>>>
> > >>>>
> > >>>>
> > >>>> --
> > >>>> Matt Sicker <boa...@gmail.com>
> > >>>>
> > >>>
> > >>>
> > >>>
> > >>> --
> > >>> E-Mail: garydgreg...@gmail.com | ggreg...@apache.org
> > >>> Java Persistence with Hibernate, Second Edition
> > >>> <https://www.amazon.com/gp/product/1617290459/ref=as_li_
> > >>> tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1617290459&
> > >>> linkCode=as2&tag=garygregory-20&linkId=
> cadb800f39946ec62ea2b1af9fe6a2
> > b8>
> > >>>
> > >>> <http:////ir-na.amazon-adsystem.com/e/ir?t=
> garygregory-20&l=am2&o=1&a=
> > >>> 1617290459>
> > >>> JUnit in Action, Second Edition
> > >>> <https://www.amazon.com/gp/product/1935182021/ref=as_li_
> > >>> tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1935182021&
> > >>> linkCode=as2&tag=garygregory-20&linkId=
> 31ecd1f6b6d1eaf8886ac902a24de4
> > >> 18%22
> > >>>>
> > >>>
> > >>> <http:////ir-na.amazon-adsystem.com/e/ir?t=
> garygregory-20&l=am2&o=1&a=
> > >>> 1935182021>
> > >>> Spring Batch in Action
> > >>> <https://www.amazon.com/gp/product/1935182951/ref=as_li_
> > >>> tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1935182951&
> > >>> linkCode=%7B%7BlinkCode%7D%7D&tag=garygregory-20&linkId=%7B%
> > >>> 7Blink_id%7D%7D%22%3ESpring+Batch+in+Action>
> > >>> <http:////ir-na.amazon-adsystem.com/e/ir?t=
> garygregory-20&l=am2&o=1&a=
> > >>> 1935182951>
> > >>> Blog: http://garygregory.wordpress.com
> > >>> Home: http://garygregory.com/
> > >>> Tweet! http://twitter.com/GaryGregory
> > >>>
> > >>
> > >>
> > >>
> > >> --
> > >> Matt Sicker <boa...@gmail.com>
> > >>
> > >
> > >
> > >
> > > --
> > > E-Mail: garydgreg...@gmail.com | ggreg...@apache.org
> > > Java Persistence with Hibernate, Second Edition
> > > <https://www.amazon.com/gp/product/1617290459/ref=as_li_tl?
> > ie=UTF8&camp=1789&creative=9325&creativeASIN=1617290459&link
> > Code=as2&tag=garygregory-20&linkId=cadb800f39946ec62ea2b1af9fe6a2b8>
> > >
> > > <http:////ir-na.amazon-adsystem.com/e/ir?t=garygregory-20&l=
> > am2&o=1&a=1617290459>
> > > JUnit in Action, Second Edition
> > > <https://www.amazon.com/gp/product/1935182021/ref=as_li_tl?
> > ie=UTF8&camp=1789&creative=9325&creativeASIN=1935182021&link
> > Code=as2&tag=garygregory-20&linkId=31ecd1f6b6d1eaf8886ac902a24de418%22>
> > >
> > > <http:////ir-na.amazon-adsystem.com/e/ir?t=garygregory-20&l=
> > am2&o=1&a=1935182021>
> > > Spring Batch in Action
> > > <https://www.amazon.com/gp/product/1935182951/ref=as_li_tl?
> > ie=UTF8&camp=1789&creative=9325&creativeASIN=1935182951&link
> > Code=%7B%7BlinkCode%7D%7D&tag=garygregory-20&linkId=%7B%7Bli
> > nk_id%7D%7D%22%3ESpring+Batch+in+Action>
> > > <http:////ir-na.amazon-adsystem.com/e/ir?t=garygregory-20&l=
> > am2&o=1&a=1935182951>
> > > Blog: http://garygregory.wordpress.com
> > > Home: http://garygregory.com/
> > > Tweet! http://twitter.com/GaryGregory
> >
> >
> > ---------------------------------------------------------------------
> > To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org
> > For additional commands, e-mail: dev-h...@commons.apache.org
> >
>
--
E-Mail: garydgreg...@gmail.com | ggreg...@apache.org
Java Persistence with Hibernate, Second Edition
<https://www.amazon.com/gp/product/1617290459/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1617290459&linkCode=as2&tag=garygregory-20&linkId=cadb800f39946ec62ea2b1af9fe6a2b8>
<http:////ir-na.amazon-adsystem.com/e/ir?t=garygregory-20&l=am2&o=1&a=1617290459>
JUnit in Action, Second Edition
<https://www.amazon.com/gp/product/1935182021/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1935182021&linkCode=as2&tag=garygregory-20&linkId=31ecd1f6b6d1eaf8886ac902a24de418%22>
<http:////ir-na.amazon-adsystem.com/e/ir?t=garygregory-20&l=am2&o=1&a=1935182021>
Spring Batch in Action
<https://www.amazon.com/gp/product/1935182951/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1935182951&linkCode=%7B%7BlinkCode%7D%7D&tag=garygregory-20&linkId=%7B%7Blink_id%7D%7D%22%3ESpring+Batch+in+Action>
<http:////ir-na.amazon-adsystem.com/e/ir?t=garygregory-20&l=am2&o=1&a=1935182951>
Blog: http://garygregory.wordpress.com
Home: http://garygregory.com/
Tweet! http://twitter.com/GaryGregory
