java - Running the same select query multiple times with different parameters: Mysql -

i have java program needs iterate through hashmap parameters used query mysql database. code follows:

iterator<entry<string, double>>it = ws.entryset().iterator(); connection con = null;  while(it.hasnext())   {     entry<string, double>pairs = it.next();     preparedstatement ps = con.preparestatement("select doc_freq lookup word=?");     ps.setstring(1, pairs.getkey());     resultset rs = ps.executequery(); } 

the process of repeatedly accessing database every iteration of loop (which 500 times) slowing down application. there way can send these parameters @ once access database once?

considering ws map, can single query way:

connection con = getconnection(); set<string> ks = ws.keyset();  if (ks.size() > 0) {     stringbuilder instatement = new stringbuilder("?");     (int = 1; < ks.size(); i++) {         instatement.append(", ?");     }      preparedstatement ps = con.preparestatement("select doc_freq lookup word in (" + instatement.tostring() + ")");      int k = 1;     (string key : keyset) {         ps.setstring(k++, key);     }     resultset rs = ps.executequery(); }