I must admit to playing a bit of devil's advocate here ;-) with my laundry list of sizeable kind of objects but I am sure you get my point: As soon as we add a method like this, the we will get requests for adding more to it release after release. I'm not against it, but it make you wonder about adding a Sizeable interface ;-)
Gary On Fri, Aug 17, 2018 at 10:33 AM Alexander Tsvetkov < alexander.tsvetkov...@gmail.com> wrote: > Hi Gary, > > Yes, you can make the argument that the user might expect *every* class > with a length(), size() or isEmpty() method to be covered by the > implementation, but IMO as long as the Javadoc clearly states what is > supported and what is not, then it's better to have at least a partial > implementation that covers the more common use-cases than nothing at all. > I'll be happy to hear what others think about this though. > > Regarding your examples: > - StringBuffer and StringBuilder are already covered by the current > implementation, since they both implement CharSequence. > - Buffer - Not sure about this one. Input from others is appreciated here. > - File, Path, Clob, Lob, AtomicReference, ZipFile - I doubt that these can > be considered common use-cases, but I may be a bit affected by what we need > this method for. We have an implementation in our code base that is used > for: > 1) Ignoring empty fields when serializing objects to YAML and JSON > without checking their type. > 2) Resolving values of placeholders in a generic way. The types of the > objects is still limited to strings, lists and maps, however. > Other people may use similar methods for other things, but from what I've > seen (in our projects and in Spring), most people use such methods to check > "simple" objects like the ones covered in the current implementation. > > Best regards, > Alexander > > > 2018-08-17 19:01 GMT+03:00 Gary Gregory <garydgreg...@gmail.com>: > > > If we open that Pandora's box, then I want to add: > > > > - File, empty if length is 0 > > - Path, empty if name length is 0 > > - Buffer, what? > > - StringBuffer > > - StringBuilder > > - java.sql.Clob > > - java.sql.Lob > > - The content of an AtomicReference > > - ZipFile > > - on and on for anything that has a "size()" or "length" or "length()" > > > > ? > > > > Gary > > > > > > On Fri, Aug 17, 2018 at 2:43 AM Alexander Tsvetkov < > > alexander.tsvetkov...@gmail.com> wrote: > > > > > Hi all, > > > > > > First of all, apologies if I have messed something up - this is my > first > > > attempt at contributing to Apache. > > > > > > With that said, I'd like to propose adding two new methods to Commons > > > Lang's ObjectUtils class: > > > - isEmpty() > > > - isNotEmpty() > > > > > > These would check whether the object is empty (or not empty > respectively) > > > based on its type: > > > - CharSequence - Considered empty if its length is zero. > > > - Array - Considered empty if its length is zero. > > > - Collection - Considered empty if it has zero elements. > > > - Map - Considered empty if it has zero key-value mappings. > > > The object would be considered "not-empty" if its type is not one of > the > > > types mentioned above. > > > > > > There is an already existing method that does exactly this in Spring's > > > ObjectUtils (see > > > > > > https://github.com/spring-projects/spring-framework/blob/ > > 2ac23badee02697c5eb87c46f955387b32a0d581/spring-core/src/ > > main/java/org/springframework/util/ObjectUtils.java#L134 > > > ), > > > but I think it would be helpful to people (myself and my team included) > > if > > > there was a similar method in Commons Lang's ObjectUtils. That way we > > > wouldn't have to add a dependency to Spring or re-implement the method > in > > > our code base. > > > > > > What do you think? > > > > > > I've opened a JIRA ticket and a GitHub pull request as well: > > > https://issues.apache.org/jira/browse/LANG-1411 > > > https://github.com/apache/commons-lang/pull/342 > > > > > > Best regards, > > > Alexander > > > > > >
