HashMap StackOverflow error when it refer back to itself

import java.util.*;

public class HashMapStackOverflow {
  public static void main(String[] args) throws Exception {
    HashMap<String, Object> map = new HashMap<>();
    map.put("self", map);
    System.out.println(map.hashCode());
  }
}

AbstractMap.hashCode is as below, it will sum up all the hash code for all the entry.

public int hashCode() {
int h = 0;
Iterator<Entry<K,V>> i = entrySet().iterator();
while (i.hasNext())
h += i.next().hashCode();
return h;
}


the hash map entry will be calculate the key and value hash code.

Entry.hashCode
public final int hashCode() {
return Objects.hashCode(getKey()) ^ Objects.hashCode(getValue());
}


when compile the hash code for the value which exactly is the map itself. then the infinite cycle is happen.

Objects.hashCode

public static int hashCode(Object o) { return o != null ? o.hashCode() : 0; }

Exception in thread "main" java.lang.StackOverflowError
at java.util.HashMap$Entry.hashCode(HashMap.java:847)
    at java.util.AbstractMap.hashCode(AbstractMap.java:494)
    at java.util.Objects.hashCode(Objects.java:96)
    at java.util.HashMap$Entry.hashCode(HashMap.java:847)
    at java.util.AbstractMap.hashCode(AbstractMap.java:494)
    at java.util.Objects.hashCode(Objects.java:96)
    at java.util.HashMap$Entry.hashCode(HashMap.java:847)
    at java.util.AbstractMap.hashCode(AbstractMap.java:494)
    at java.util.Objects.hashCode(Objects.java:96)