question: public abstract int compare ( String source , String target ) ;
target:  Compares the source string to the target string according to the collation rules for this Collator.  Returns an integer less than, equal to or greater than zero depending on whether the source String is less than, equal to or greater than the target string.  See the Collator class description for an example of use. <p> For a one time comparison, this method has the best performance. If a given String will be involved in multiple comparisons, CollationKey.compareTo has the best performance. See the Collator class description for an example using CollationKeys.