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
