Yes, it's supposed to throw NPE for the reasons stated a couple times in this thread. That's by design, not accident. The "official" version in java.lang.Objects (JDK 7+) does the same thing.
Cheers, Paul On Tue, May 6, 2014 at 4:00 PM, Duncan Jones <dun...@wortharead.com> wrote: > On 6 May 2014 20:41, Phil Steitz <phil.ste...@gmail.com> wrote: > > On 5/6/14, 10:09 AM, sebb wrote: > >> On 6 May 2014 14:27, Benedikt Ritter <brit...@apache.org> wrote: > >>> Hi Thiago, > >>> > >>> > >>> 2014-05-06 14:53 GMT+02:00 Thiago Andrade <thia...@gmail.com>: > >>> > >>>> Hello people, > >>>> > >>>> Analizing the JIRA issue > https://issues.apache.org/jira/browse/LANG-1008the > >>>> contributors noticed that NumberUtils.max/min methods all have the > same > >>>> problem: > >>>> They all throw an IllegalArgumentException when according to the > official > >>>> documentation (Oracle|Sun) says that a NullPointerException must be > thrown > >>>> when an argument must not be null. > >>>> > >>> This is not a problem imho. It is a question of API design. > >> +1 > >> > >>> I don't now an > >>> offical documentation that say when IAE or NPE _must_ be thrown. > Sun/Oracle > >>> at some point decided to throw NPE when ever a null reference is > passed to > >>> a method that doesn't accept null inputs. I don't feel this is right, > since > >>> a null input is also an illegal argument. Why make a differenciation? > IMHO > >>> NPE should be reserved to the JVM, when a method is called on a null > >>> reference, but that's just my opinion. > >>> > >> +1. > >> > >> NPE used to mean a bug had occurred rather than the user had provided > bad input. > >> > >> Using NPE for a parameter that must not be null confuses things. > >> > >>>> However according to Apache Commons Lang Developer Guide, these > methods are > >>>> all correct. This guide says that "When throwing an exception to > indicate a > >>>> bad argument, always try to throw IllegalArgumentException, even if > the > >>>> argument was null. Do not throw NullPointerException.". > >>>> > >>> Since [lang] is currently designed this way, I'd rather deal with this > >>> issue for 4.0. We can then revisit our initial decision to only throw > IAE > >>> an maybe align it to what the JDK now does. If you want to file an > issue, > >>> my opinion is, that it should be fix version 4.0. Changing the > exceptions > >>> that are thrown now may break clients (although I think there are very > few > >>> use cases where one should catch IAE or NPE). > >> If Commons ever decide to switch to NPE (I hope not) then it is > >> imperative that the message is 100% clear that the problem is with a > >> method argument, and which argument is at fault. > >> > >> Otherwise we will likely find ourselves fielding bug reports about > >> Commons code when it is the caller that is at fault. > >> Even then, I suspect some reporters will just see the NPE and assume > >> that the Commons code has a bug. > >> > >> If an argument is invalid, throw IAE. > >> IMO it does not make sense to throw NPE for some invalid arguments and > >> not others. > >> What Sun/Oracle perhaps should have done was introduce an > >> "InvalidNullArgumentException" > >> > >> The Javadoc (1.7) says: > >> > >> Thrown when an application attempts to use null in a case where an > >> object is required. These include: > >> > >> Calling the instance method of a null object. > >> Accessing or modifying the field of a null object. > >> Taking the length of null as if it were an array. > >> Accessing or modifying the slots of null as if it were an array. > >> Throwing null as if it were a Throwable value. > >> > >> Applications should throw instances of this class to indicate other > >> illegal uses of the null object. > >> <<< > >> > >> I suppose "illegal use of the null object" could be taken to mean > >> passing null to a non-nullable parameter, but I think that is > >> stretching it too far. > > > > +1 to everything above. The "illegal use of the null object" bit is > > an unfortunate choice of words as it seems to have opened the door > > to the s/IAE/NPE debate. I am OK with "throw NPE early when you > > know it is going to happen further down" approach when API doc does > > not specify behavior, but I prefer APIs that document their > > preconditions clearly and throw IAE when actual parameters violate > > those preconditions. > > > > Phil > > If consensus continues to be in the direction of IAE, do we consider > changing the behaviour of Validate.notNull() in 4.0? This currently > throws a NPE. > > Duncan > > > >> > >>>> This mail was sent in order to discuss around and make decisions to > solve > >>>> this dilemma where the Java official specification says X and the > Apache > >>>> official specification says Y. > >>>> > >>> Can you please provide a lnk to the official specification you're > refering > >>> to? ;-) > >>> > >>> Regards, > >>> Benedikt > >>> > >>> > >>>> My sincere thanks for your time and consideration, > >>>> > >>>> -- > >>>> Thiago Andrade > >>>> > >>> > >>> > >>> -- > >>> http://people.apache.org/~britter/ > >>> http://www.systemoutprintln.de/ > >>> http://twitter.com/BenediktRitter > >>> http://github.com/britter > >> --------------------------------------------------------------------- > >> 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 > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org > For additional commands, e-mail: dev-h...@commons.apache.org > >
