java - Efficient way of mimicking hibernate criteria on cached map -


i have wrote code cach table in memory (simple java hashmap). 1 of code trying replace find objects based on criteria. receives multiple field parameters , if fields not empty , not null, being added part of hibernate query criteria.

to replace this, thinking is

  1. for each valid param (not null , no empty) create hashset satisfy criteria.
  2. once done making hashsets valid criteria, call set.retainall(second_set) on sets. @ end, have set intersection of valid criteria.

does sound best approach or there better way implement ?

edit

though, original post still valid , looking answer. ended implementing in following way. reason kind cumbersome sets since after creating sets, had first figure out set non empty retainall called. resulting in lots of if-else statements. current implementation this

private list<myobj> getcachedobjs(long criteria1, string criteria2, string criteria3) {     list<myobj> results = new arraylist<>();     int totalactivefilters = 0;      if (criteria1 != null){         totalactivefilters++;     }      if (!stringutil.isblank(criteria2)){         totalactivefilters++;     }      if (!stringutil.isblank(criteria3)){         totalactivefilters++;     }      (map.entry<long, myobj> objentry : objcache.entryset()){         myobj obj = objentry.getvalue();          int matchedfilters = 0;          if (criteria1 != null) {             if (obj.getcriteria1().equals(criteria1)) {                 matchedfilters++;             }         }          if (!stringutil.isblank(criteria2)){             if (obj.getcriteria2().equals(criteria2)){                 matchedfilters++;             }         }          if (!stringutil.isblank(criteria3)){             if (game.getcriteria3().equals(criteria3)){                 matchedfilters++;             }         }          if (matchedfilters == totalactivefilters){             results.add(obj);         }     }     return results; }


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