java - Number of Users Join At Time Case Scenarios? -

i need know same action perform @ time different users case scenarios.

for ex : 1 room there.users continuously joins room , leaves room @ time.and 1 more case no of users try join same room @ time.

how handle above example cases in java synchronization or else.please suggest me best case handle this?

i did 1 sample.please see below sample code once :

public class sample{      private arraylist<string> players = new arraylist<string>();     public synchronized void joinroom(string name)     {         players.add(name);         //do     }      public synchronized void leaveroom(string name)     {         for(string uname : players){             if(uname.equals(name))             {                 players.remove(uname);//here there possibility concurrent modification exception.if gets how solve             }         }         //do     } } 

but didn't know cases handle using above sample code or not.please suggest me 1 best handle cases?

thanks in advance.

you use concurrentskiplistset this. handle synchronization , more efficiently.the concurrentskiplistset allows concurrent reads , writes.

regarding concurrent modification exception, use iterator:

iterator<string>  iter = players.iterator();  while(iter.hasnext()){    if(iter.next().equals(name)){     iter.remove();     break;   } }