Didnt think to use a TreeMap - good idea! When accessed via the Map interface the difference you perceive is one of implementation efficiency - the SequencedHashMap uses a HashMap internally - and it entries also have references that will preserve the list order, while a TreeMap uses a tree internally which of course can be traversed in order.
According to the docs, the HashMap will give you a "fast O(1) search time" for lookups while the TreeMap has "guaranteed log(n) time" - so I guess for a huge collection the HashMap would be faster. That said I doubt your requirements approach anything like the size needed for a noticable difference in lookup time, and HashMaps are noted to be quite heavy when it comes to memory use so Id say the TreeMap is a better choice. :-) -----Original Message----- From: O_Parthasarathy Kesavaraj [mailto:[EMAIL PROTECTED] Sent: Tuesday, 8 July 2003 13:48 To: 'Struts Users Mailing List' Subject: RE: Urgent!!!Sorting Problem while loading from HashMap Thanks Navjot and Andrew.. Meanwhile i tried to convert it to TreeMap.It is working fine..But Andrew.. what is the difference between TreeMap and SequencedHashMap b'coz TreeMap itself is giving me the list in order of how i have stored Regds Partha > ---------- > From: Andrew Hill[SMTP:[EMAIL PROTECTED] > Reply To: Struts Users Mailing List > Sent: Tuesday, July 08, 2003 10:45 AM > To: Struts Users Mailing List > Subject: RE: Urgent!!!Sorting Problem while loading from HashMap > > HashMaps will rearrange stuff internally and will NOT preserve the > original > order (see the j2se javadocs for details). > > There is a class in commons-collections (which should already be on your > classpath as struts (1.1 anyway) uses this library) called > SequencedHashMap - try using this instead as it preserves the order in > which > stuff was added to the hashmap and uses this order in its iterator. > > (This was introduced in commons-collections 2.0 so if your using an older > version you may need to upgrade the jar with the latest. > > Heres the javadoc for it: > http://jakarta.apache.org/commons/collections/api/org/apache/commons/colle > ctions/SequencedHashMap.html > > -----Original Message----- > From: O_Parthasarathy Kesavaraj [mailto:[EMAIL PROTECTED] > Sent: Tuesday, 8 July 2003 13:17 > To: 'Struts Users Mailing List' > Subject: Urgent!!!Sorting Problem while loading from HashMap > > > Hi > I am loading a html:select box with property as the key in the HashMap( ID > corresponding to the value which is displayed) and labelproperty as the > value.When i am fetching from the database i am sorting by the value and > then only loading in the HashMap.But when i see the select box the values > are not sorted..which makes my form not so userfriendly...Kindly help to > display sorted when i am loading from a HashMap...(When i load using an > araylist it displays the values in the order i have stored and there is no > sorting problem) > > Thanks in Advance > Regds > Partha > > --------------------------------------------------------------------- > 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]
