HI Sabra, If there is collection type as a return, then you MUST return empty collection object of instead of null. But if you expect POJO as a return, then it would be better to return null instead of empty object. Because if it returns empty object instead of null, then some one get misunderstand who is going to use that API and will try to consume that as expected output. Then there may be more problems. You may not be the only one who consume your backend api.
*Harsha Thirimanna* Associate Tech Lead; WSO2, Inc.; http://wso2.com * <http://www.apache.org/>* *email: **[email protected]* <[email protected]>* cell: +94 71 5186770 * *twitter: **http://twitter.com/ <http://twitter.com/afkham_azeez>* *harshathirimannlinked-in: **http: <http://lk.linkedin.com/in/afkhamazeez>**//www.linkedin.com/pub/harsha-thirimanna/10/ab8/122 <http://www.linkedin.com/pub/harsha-thirimanna/10/ab8/122>* *Lean . Enterprise . Middleware* On Wed, Jul 13, 2016 at 12:42 AM, Rasika Perera <[email protected]> wrote: > Hi Sabra > > , > > I think you need to handle this error at jaggery level. > > Considering a method returning a user object the client code should not be >> able to proceed further if there is no user. > > In this case, -1 for returning NULL. When there is an error, > unless > it is recoverable locally you > *should* > convey it to the upper layers. In your case, If you cannot return a > user object it is more intuitive to return an exception such as > UserManagerException. > > By returning NULL, you cannot make it mandatory to handle exception. Your > client code will not be aware of NULL unless the developer reads your > implementation class OR the documentation. Try to avoid > NullPointerException > as much as possible. > > In your client code(Jaggery) you can catch this error with try{ } > catch(error){ }. Found this blogpost [1] which discusses on jaggery error > handling. > AFAIK Jaggery will wrap java exceptions with ScriptException object. > > Regards, > Rasika > > [1] > http://ruchirawageesha.blogspot.com/2013/04/error-handling-in-jaggery.html > > On Tue, Jul 12, 2016 at 2:17 PM, Abimaran Kugathasan <[email protected]> > wrote: > >> There are good enough discussion in Stackoverflow [1], [2] and [3]. You >> could return null, empty object or throw exception in the case of data not >> available. >> >> It's also depends on the type of the Object you are supposed to return, >> if it's a ArrayList/Map, then returning empty ArrayList/Map is better than >> returning null, but, in case of Model object, I think, returning null is >> better than retuning a mock object of that class. >> >> >> [1] : >> http://programmers.stackexchange.com/questions/120355/is-it-better-to-return-null-or-empty-values-from-functions-methods-where-the-ret >> [2] : >> http://stackoverflow.com/questions/1626597/should-functions-return-null-or-an-empty-object >> [3] : >> http://programmers.stackexchange.com/questions/228287/returning-null-or-a-empty-value-throw-exception >> >> On Tue, Jul 12, 2016 at 12:03 PM, Jayanga Kaushalya <[email protected]> >> wrote: >> >>> Hi, >>> >>> In my opinion, returning an empty object is far better. It will reduce >>> unnecessary null checks and will stop the code from going on different >>> paths. And code quality wise also I think returning empty is cleaner. >>> For example: >>> >>> *List list = getList();* >>> >>> *for (Item item : list) {// Do logic.* >>> *// This will not execute if the list is empty.* >>> *}* >>> >>> Is much cleaner than >>> >>> *List list = getList();* >>> *if (list == null) {* >>> *// Handle the logic.* >>> *// Now this is a different code path.* >>> *}* >>> >>> Thanks! >>> >>> *Jayanga Kaushalya* >>> Software Engineer >>> Mobile: +94777860160 >>> WSO2 Inc. | http://wso2.com >>> lean.enterprise.middleware >>> >>> On Tue, Jul 12, 2016 at 10:05 AM, Sabra Ossen <[email protected]> wrote: >>> >>>> Hi Chamila, >>>> >>>> I checked from findbugs and it didn't return an error. Is returning an >>>> empty object a practice followed in WSO2? >>>> >>>> On Tue, Jul 12, 2016 at 9:25 AM, Chamila Wijayarathna < >>>> [email protected]> wrote: >>>> >>>>> Hi Sabra, >>>>> >>>>> AFAIK when we return a null from a method, find bugs show it as an >>>>> error (please check this) and to fix this we use empty objects. So I think >>>>> the returning null is not something we should do. >>>>> >>>>> Thank You! >>>>> >>>> >>>> >>>> >>>> -- >>>> *Sabra Ossen* >>>> *Software Engineer* >>>> Email: [email protected] >>>> Mobile: +94 767 837356 >>>> >>>> _______________________________________________ >>>> Dev mailing list >>>> [email protected] >>>> http://wso2.org/cgi-bin/mailman/listinfo/dev >>>> >>>> >>> >>> _______________________________________________ >>> Dev mailing list >>> [email protected] >>> http://wso2.org/cgi-bin/mailman/listinfo/dev >>> >>> >> >> >> -- >> Thanks >> Abimaran Kugathasan >> Senior Software Engineer >> >> Email : [email protected] >> Mobile : +94 773922820 >> >> <http://stackoverflow.com/users/515034> >> <http://lk.linkedin.com/in/abimaran> >> <http://www.lkabimaran.blogspot.com/> <https://github.com/abimarank> >> <https://twitter.com/abimaran> >> >> >> _______________________________________________ >> Dev mailing list >> [email protected] >> http://wso2.org/cgi-bin/mailman/listinfo/dev >> >> > > > -- > With Regards, > > *Rasika Perera* > Software Engineer > M: +94 71 680 9060 E: [email protected] > LinkedIn: http://lk.linkedin.com/in/rasika90 > > WSO2 Inc. www.wso2.com > lean.enterprise.middleware > > _______________________________________________ > Dev mailing list > [email protected] > http://wso2.org/cgi-bin/mailman/listinfo/dev > >
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