The only problem with SequencedHashMap is that its ordering is based upon the insertion order, not the values of the objects added to it or some Comparator, such as is needed (at least that's how I interpret "ordering by value" from the original requirements).
----- Original Message ----- From: "Arun Thomas" <[EMAIL PROTECTED]> To: "Jakarta Commons Developers List" <[EMAIL PROTECTED]> Sent: Friday, September 12, 2003 12:04 PM Subject: RE: [collections] New Collection You might want to take a look at org.apache.commons.collections.SequencedHashMap which combines, for the most part, the functions of list and map (insertElementAt()) is not available - how does one insert a key, when the value should be at a specific position? The transactional support is definitely not there, but this might give you a better starting point for what you desire. -AMT -----Original Message----- From: Oxley, David [mailto:[EMAIL PROTECTED] Sent: Friday, September 12, 2003 8:07 AM To: '[EMAIL PROTECTED]' Subject: [collections] New Collection Our application has just changed from requiring JDK 1.1 to JDK 1.3 as a minimum. As a result we are looking at switching our implementation of using Hashtable and Vector to using collections. I am going to write a new collection that gives the functionality we require and once I've finished I want to donate it to commons-collections. I would like some comments on where to start (especially as I don't yet know too much about the standard collections API's). The functionality I require is this: 1. Keys and values. ala Hashtable. 2. Ordering by value. ala Vector. 3. Indexing by value. ala Vector's indexOf, elementAt and insertElementAt. 4. Transactions. i.e. Others won't see changes until commit is called. I take it there is no implementation that supplies the above. I was initially thinking of either encapsulating or overriding TreeMap, but I think that would make the indexing part pretty difficult. But now I think I will just encapsulate or override HashMap. Any comments would be gratefully received. Cheers. Dave. [EMAIL PROTECTED] ________________________________________________________________________ This e-mail has been scanned for all viruses by Star Internet. The service is powered by MessageLabs. For more information on a proactive anti-virus service working around the clock, around the globe, visit: http://www.star.net.uk ________________________________________________________________________ --------------------------------------------------------------------- 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]
