Like you, I was under the impression that generics were erased and you were out of luck at runtime! After the type conversion burn at the top of this thread, I started to dig in and found this article. I have experimented with it and it works great. As it turns out, this is probably about all anyone would want to glean anyway.
Scott On Wed, Sep 24, 2008 at 3:15 PM, Laurie Harper <[EMAIL PROTECTED]> wrote: > I stand corrected -- and thanks for the link; I've never seen this > documented before. Very interesting... > > L. > > > [EMAIL PROTECTED] wrote: > >> >> http://www.google.com/gwt/n?eosr=on&q=Reflection+generics+Java+&source=m&hl=en&ei=ZWfZSODxI5nYqAKR1t53&sa=X&oi=blended&ct=res&cd=4&rd=1&u=http%3A%2F%2Ftutorials.jenkov.com%2Fjava-reflection%2Fgenerics.html >> >> On 9/23/08, Laurie Harper <[EMAIL PROTECTED]> wrote: >> >>> Sounds reasonable until you remember two words: type erasure. There is >>> no way to 'glean the generic type' of a collection at runtime. >>> >>> L. >>> >>> Gabriel Belingueres wrote: >>> >>>> I agree too. >>>> >>>> 2008/9/23 stanlick <[EMAIL PROTECTED]>: >>>> >>>>> I agree totally! If the TypeDeterminer had called getEmployees() >>>>> <which >>>>> it >>>>> clearly did for iterator> *and* had bothered to glean the generic type >>>>> of >>>>> the key, it would have recognized the action expected the key to of >>>>> type >>>>> String. If the data type is specifically spelled out and the framework >>>>> decides a type diametrically opposed, this is a problem.:teeth: >>>>> >>>>> >>>>> >>>>> Gabriel Belingueres-2 wrote: >>>>> >>>>>> AFAIK, OGNL does not have any support for generics, but even if it >>>>>> would support it, I would prefer that it wont be too smart, for >>>>>> example in: >>>>>> >>>>>> <s:property value="aMap[abc].id"/> >>>>>> >>>>>> I prefer that abc be treated as an action property and call method >>>>>> getAbc() than coerce it to the string 'abc'. >>>>>> >>>>>> 2008/9/23 <[EMAIL PROTECTED]>: >>>>>> >>>>>>> Those are all good points, but when my collection was expressly >>>>>>> declared >>>>>>> to >>>>>>> be a Map<String, Employee> I would sort of expect the key to be a >>>>>>> String! >>>>>>> When the framework "guesses" for a different type (feature?) and your >>>>>>> application fails; all the discussion about valid number systems is >>>>>>> sort >>>>>>> of >>>>>>> meaningless. >>>>>>> >>>>>>> Scott >>>>>>> >>>>>>> On Mon, Sep 22, 2008 at 7:53 PM, Gabriel Belingueres >>>>>>> <[EMAIL PROTECTED]>wrote: >>>>>>> >>>>>>> I don't know but I hope not, since I don't want my expressions to >>>>>>>> reduce to different data types depending if there is a number or not >>>>>>>> in them! >>>>>>>> Even if abc would reduce to the string 'abc', the expression 0xabc >>>>>>>> reduce to an Integer (have tested it), since it is an hexadecimal >>>>>>>> number. >>>>>>>> >>>>>>>> 2008/9/22 <[EMAIL PROTECTED]>: >>>>>>>> >>>>>>>>> I expected the conversion facility or iterator key to be smart >>>>>>>>> enough >>>>>>>>> >>>>>>>> to >>>>>>>> >>>>>>>>> recognize my Map<String, Employee> and setup the internal key >>>>>>>>> variable >>>>>>>>> accordingly. Do you suppose it would have worked if my Map had >>>>>>>>> >>>>>>>> contained >>>>>>>> >>>>>>>>> 'abc':emp1, 'def':emp2, 'ghi':emp3? >>>>>>>>> >>>>>>>>> Peace, >>>>>>>>> Scott >>>>>>>>> >>>>>>>>> On Mon, Sep 22, 2008 at 3:47 PM, Gabriel Belingueres >>>>>>>>> <[EMAIL PROTECTED]>wrote: >>>>>>>>> >>>>>>>>> Interesting. Seems it is a feature, as documented in [1]. >>>>>>>>>> >>>>>>>>>> Tested it myself: >>>>>>>>>> <s:property value="1234h.class.name" /> >>>>>>>>>> <s:property value="1234b.class.name" /> >>>>>>>>>> <s:property value="1234F.class.name" /> >>>>>>>>>> <s:property value="1234L.class.name" /> >>>>>>>>>> <s:property value="1234d.class.name" /> >>>>>>>>>> <s:property value="(1234).class.name" /> >>>>>>>>>> >>>>>>>>>> The last one (Integer) didn't work without the ( ), which I don't >>>>>>>>>> >>>>>>>>> know >>>>>>>> >>>>>>>>> if this is a necessity or a bug. >>>>>>>>>> What about Short and Byte data type? it doesn't say... >>>>>>>>>> >>>>>>>>>> However, I think is NOT a bug that employees[1234F].id returns >>>>>>>>>> nothing, since the map key is a string and you need to quote it >>>>>>>>>> accordingly. >>>>>>>>>> >>>>>>>>>> [1] >>>>>>>>>> >>>>>>>>>> >>>>>>>> http://www.ognl.org/2.6.9/Documentation/html/LanguageGuide/basicExpressions.html#constants >>>>>>>> >>>>>>>>> 2008/9/22 stanlick <[EMAIL PROTECTED]>: >>>>>>>>>> >>>>>>>>>>> I encountered a very strange situation today. I had the >>>>>>>>>>> following >>>>>>>>>>> >>>>>>>>>> in >>>>>>>> a >>>>>>>> >>>>>>>>> web >>>>>>>>>> >>>>>>>>>>> page: >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> <s:iterator value="employees"> >>>>>>>>>>> <s:textfield name="employees[%{key}].id .../> >>>>>>>>>>> >>>>>>>>>>> where the get method in my action was: >>>>>>>>>>> >>>>>>>>>>> public Map<String,Employee> getEmployees() >>>>>>>>>>> >>>>>>>>>>> The employee id 7932F was being interpreted as 7932! The >>>>>>>>>>> trailing >>>>>>>>>>> >>>>>>>>>> "F" >>>>>>>> >>>>>>>>> was >>>>>>>>>> >>>>>>>>>>> apparently being considered a literal for FLOAT and was being >>>>>>>>>>> >>>>>>>>>> trimmed >>>>>>>> off >>>>>>>> >>>>>>>>> the String. >>>>>>>>>>> >>>>>>>>>>> When I wrapped the variable in quotes is worked >>>>>>>>>>> >>>>>>>>>>> <s:textfield name="employees[ '%{key' }].id .../> >>>>>>>>>>> >>>>>>>>>>> Does this appear to be a bug? >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> -- >>>>>>>>>>> View this message in context: >>>>>>>>>>> >>>>>>>>>> >>>>>>>> http://www.nabble.com/Custom-tag-and-map-backed-action-tp19614086p19614086.html >>>>>>>> >>>>>>>>> Sent from the Struts - User mailing list archive at Nabble.com. >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> --------------------------------------------------------------------- >>>>>>>> >>>>>>>>> To unsubscribe, e-mail: [EMAIL PROTECTED] >>>>>>>>>>> For additional commands, e-mail: [EMAIL PROTECTED] >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> --------------------------------------------------------------------- >>>>>>>>>> To unsubscribe, e-mail: [EMAIL PROTECTED] >>>>>>>>>> For additional commands, e-mail: [EMAIL PROTECTED] >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> --------------------------------------------------------------------- >>>>>>>> To unsubscribe, e-mail: [EMAIL PROTECTED] >>>>>>>> For additional commands, e-mail: [EMAIL PROTECTED] >>>>>>>> >>>>>>>> >>>>>>>> --------------------------------------------------------------------- >>>>>> To unsubscribe, e-mail: [EMAIL PROTECTED] >>>>>> For additional commands, e-mail: [EMAIL PROTECTED] >>>>>> >>>>>> >>>>>> >>>>>> -- >>>>> View this message in context: >>>>> >>>>> http://www.nabble.com/Custom-tag-and-map-backed-action-tp19614086p19629362.html >>>>> Sent from the Struts - User mailing list archive at Nabble.com. >>>>> >>>>> >>>>> --------------------------------------------------------------------- >>>>> To unsubscribe, e-mail: [EMAIL PROTECTED] >>>>> For additional commands, e-mail: [EMAIL PROTECTED] >>>>> >>>>> >>>>> >>> --------------------------------------------------------------------- >>> To unsubscribe, e-mail: [EMAIL PROTECTED] >>> For additional commands, e-mail: [EMAIL PROTECTED] >>> >>> >>> > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > >
