my reason for the code is because the IteratorUtils methods return iterators of arbitrary objects and i really don't want the underlying collection. i just want to set up some array sizes based on the list size, but i am not going to perform any operation on the list itself, just iterate through it.
my specific example is an html table with an database resultset (returned as a Collection) as its backing. i have a 'select all' button for the table. i want to load an array with the selected items. i use the IteratorUtils class to rip through a Collection that is the data to look for checked items. so all i ever see is an iterator, i never get the collection itself, and i don't need to either. but, if the 'select all' button is pressed, i need to load the array with defaults for the entire size of the Collection. i am not going to use the Collection, i just want to know how big it is so i can create a loop and populate an array. it is an obscure issue i agree, but i cannot see a reason not to support the functionality either. if you rely on the IteratorUtil class for arbitrary list iteration, you need something like this (and actually several other Collection methods) to allow arbitrary lists to be as robust as a typical Collection. it seems reasonable to add functionality to a common API even for less common uses. steve -----Original Message----- From: Janek Bogucki [mailto:[EMAIL PROTECTED] Sent: Friday, March 19, 2004 6:21 PM To: Jakarta Commons Users List Subject: Re: [collections] collections size On Fri, 2004-03-19 at 19:26, matthew.hawthorne wrote: > I understand the underlying idea behind your suggestion, but I don't > quite get the use case. Why create conditional llogic to get the size > of an arbitrary list, when you'd then have to implement the same > conditional logic to get the items out of the list? > > If your goal is to treat all lists in a similar way, I think you'd be > better of doing something like: > > public static Collection toCollection(Object list) { > if(list instanceof Collection) > return list > else if (list instanceof Map) > return ((Map)list).entrySet() > else > return Arrays.asList(list) > } While I agree with the idea of using a Collection view of the object when you want to do Collection things on the object, there is a precedent for this sort of approach in o.a.c.collections in the form of CollectionUtils.get(Object, int). This could be used to get the items out of the 'list' although performance would suffer in some cases. Edited JavaDoc: Returns the index-th value in object. Supports: Map List Object Array Collection Iterator or Enumeration public static Object get(Object object, int index) -Janek --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] Learn more about Paymentech's payment processing services at www.paymentech.com THIS MESSAGE IS CONFIDENTIAL. This e-mail message and any attachments are proprietary and confidential information intended only for the use of the recipient(s) named above. If you are not the intended recipient, you may not print, distribute, or copy this message or any attachments. If you have received this communication in error, please notify the sender by return e-mail and delete this message and any attachments from your computer. ~2 --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
