I have a TreeSet and a custom comparator. I get the values from server according to the changes in the stock
ex: if time=0 then server will send all the entries on the stock (unsorted) if time=200 then server will send entries added or deleted after the time 200(unsorted)
In client side i am sorting the entries. My question is which is more efficient
1> fetch all entries first and then call addAll method or 2> add one by one
there can be millions of entries.
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private static Map<Integer, KeywordInfo> hashMap = new HashMap<Integer, KeywordInfo>();
private static Set<Integer> sortedSet = new TreeSet<Integer>(comparator);
private static final Comparator<Integer> comparator = new Comparator<Integer>() {
public int compare(Integer o1, Integer o2) {
int integerCompareValue = o1.compareTo(o2);
if (integerCompareValue == 0) return integerCompareValue;
KeywordInfo k1 = hashMap.get(o1);
KeywordInfo k2 = hashMap.get(o2);
if (null == k1.getKeyword()) {
if (null == k2.getKeyword())
return integerCompareValue;
else
return -1;
} else {
if (null == k2.getKeyword())
return 1;
else {
int compareString = AlphaNumericCmp.COMPARATOR.compare(k1.getKeyword().toLowerCase(), k2.getKeyword().toLowerCase());
//int compareString = k1.getKeyword().compareTo(k2.getKeyword());
if (compareString == 0)
return integerCompareValue;
return compareString;
}
}
}
};
now there is an event handler which gives me an ArrayList of updated entries, after adding them to my hashMap i am calling
final Map<Integer, KeywordInfo> mapToReturn = new SubMap<Integer, KeywordInfo>(sortedSet, hashMap);
The actual implementation is a linked list, so add one by one will be faster if you do it right. And i think in the near future this behaviour wont be change.
For your problem a Statefull comparator may help.