Why does java native HashMap in clojure run slowly? -

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i associate key hash map 10000000 time. here's java code , output：

import java.util.hashmap;  public class testmap {     public static void main(string[] args) {         hashmap<integer, integer> mp = new hashmap<integer, integer>();         long  start = system.currenttimemillis();         (int = 0; < 10000000; i++) {             mp.put(1, 1);         }         long end = system.currenttimemillis();         system.out.println("elapsed time: " + (end - start) + " msecs");     } }   $ javac testmap.java && java -cp . testmap elapsed time: 38 msecs

and call java clojure in repl:

user=> (import java.util.hashmap) java.util.hashmap user=> (def mp (hashmap.)) #'user/mp user=>  (time (dotimes [n 10000000] (.put mp 1 1))) "elapsed time: 10024.797 msecs" nil

both code same thing, clojure version runs exstreamly slow!!

what's problem?

add type hint better:

user> (import 'java.util.hashmap) java.util.hashmap user> (def mp (hashmap.)) #'user/mp user> (time (dotimes [n 10000000] (.put mp 1 1))) "elapsed time: 13932.248126 msecs" nil user> (time (dotimes [n 10000000] (.put ^hashmap mp 1 1))) "elapsed time: 117.915992 msecs" nil

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