Since HashSet is not thread-safe, getting a Set from ConcurrentHashMap which is thread-safe.

Author: Greg Williams

okhttp3-persistent-cookiejar/src/main/java/com/franmontiel/persistentcookiejar/cache/SetCookieCache.java

@@ -17,9 +17,10 @@
 package com.franmontiel.persistentcookiejar.cache;
 
 import java.util.Collection;
-import java.util.HashSet;
+import java.util.Collections;
 import java.util.Iterator;
 import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 
 import okhttp3.Cookie;
 
@@ -28,7 +29,7 @@ public class SetCookieCache implements CookieCache {
     private Set<IdentifiableCookie> cookies;
 
     public SetCookieCache() {
-        cookies = new HashSet<>();
+        cookies = Collections.newSetFromMap(new ConcurrentHashMap<IdentifiableCookie, Boolean>());
     }
 
     @Override