android - Filtering in RecyclerView takes long -

i testing set of 5000 objects. use custom comparator(myownsort) sort values based on business logic.

    public filter getfilter() {     if (_filter == null) {         _filter = new filter() {              @override             protected filterresults performfiltering(charsequence constraint) {                 string chartext = constraint.tostring();                 filterresults filterresults = new filterresults();                  // clear data                 visibledata.clear();                 (string title : data) {                     if (title.startswith(chartext)) {                         visibledata.add(title);                     }                  }                  myownsort.setsearchstring(chartext);                 collections.sort(visibledata, myownsort);             }              filterresults.count=visibledata.size();             filterresults.values=visibledata;              return filterresults;         }          @override         protected void publishresults (charsequence constraint, filterresults results){              notifydatasetchanged();         }     } ; }  return _filter; 

}

this takes somewhere between 200 1600ms depending on android device. takes long when start typing filter data data filtered large. keep typing more, dataset narrows down , faster. see, performfiltering ran in background thread, not block ui thread. results don't show not snappy. normal? there can improve this? if not how can make experience better? edit: added customcomparator class.

class customcomparator implements comparator<string> {     private string _searchstring;      public customsearchstringcomparator(string searchstring) {         _searchstring = searchstring;     }      public void setsearchstring(string searchstring) {         _searchstring = searchstring;     }      @override     public int compare(string lhs, string rhs) { int res = customcompare(lhs, rhs);          // alphabetic         if (res == 0) {             res = alphacompare(lhs, rhs);         }          return res;     }      private int customcompare(string lhs, string rhs) {             string lhstitle = lhs.tolowercase(locale.getdefault());             string rhstitle = rhs.tolowercase(locale.getdefault());              string[] lhsnames = lhstitle.split("\\s+");             string lhsfirstname = lhsnames[0];             string lhslastname = lhsnames.length > 1 ? lhsnames[1] : "";              // if there middle name...             if (lhsnames.length > 2) {                 lhslastname = lhsnames[2];             }              string[] rhsnames = rhstitle.split("\\s+");             string rhsfirstname = rhsnames[0];             string rhslastname = rhsnames.length > 1 ? rhsnames[1] : "";              // if there middle name...             if (rhsnames.length > 2) {                 rhslastname = rhsnames[2];             }              boolean lhsfirstnamecontains = lhsfirstname.startswith(_searchstring);             boolean rhsfirstnamecontains = rhsfirstname.startswith(_searchstring);             boolean lhslastnamecontains = lhslastname.startswith(_searchstring);             boolean rhslastnamecontains = rhslastname.startswith(_searchstring);              if (lhsfirstnamecontains == rhsfirstnamecontains) {                 if (lhslastnamecontains == rhslastnamecontains) {                     return 0;                 } else {                     return rhslastnamecontains ? 1 : -1;                 }             } else {                 return rhsfirstnamecontains ? 1 : -1;             }     }     private int alphacompare(string lhs, string rhs) {         return string.case_insensitive_order.compare(lhs, rhs);     } 

split("\s+") culprit creating pattern every time regex evaluation. since needed simple split based on whitespace, used apache commons split method. basic split , faster , dramatically reduced time half.