question: public static List sortMapByValue ( Map map , Locale locale ) { List listSorted = Collections . EMPTY_LIST ; if ( ( map != null ) && ! map . isEmpty ( ) ) { Map mapReverse = reverseStringMap ( map ) ; List sortedKey = sortKeyInMap ( mapReverse , locale ) ; listSorted = new ArrayList ( sortedKey . size ( ) ) ; Iterator iter = sortedKey . iterator ( ) ; while ( iter . hasNext ( ) ) { String key = ( String ) iter . next ( ) ; listSorted . addAll ( ( Set ) mapReverse . get ( key ) ) ; } } return listSorted ; }
target:  Sorts keys in a map ordered by its value (String).