concurrentmodification

This question already has an answer here: Why is a ConcurrentModificationException thrown and how to debug it 6 answers I have this code below, and I'm getting a ConcurrentModificationException by executing the following line: filterCardsToDevice(getCollection()); the code: private List<MyClass> filterCardsToDevice(Collection<MyClass> col) { final List<MyClass> newList = new ArrayList<MyClass>(); for (MyClass myObj : col) { long id = myObj.getId(); if (id < 0 || id > 0xFFFFFFFFl) { // just a log here } else { newList.add(myObj); } } return newList; } private final Map<Long, MyClass> map = new

i have a grid from where users select the row , when a row is clicked then its id is sending to my action class AddBookToSession.java and after wards it is returning a list into my jsp page invoice.jsp I am getting error java.util.ConcurrentModificationException ,when users selects a row from my grid. I read this similar question ,But still i am not able to solve my problem. My problem is : Why i am getting java.util.ConcurrentModificationException Error and how can I solve this issue. Please help me to solve this problem. Error in console: Dec 10, 2012 11:37:30 PM org.apache.catalina.core

Exception in thread "main" java.util.ConcurrentModificationException Squash the PC dirties the room Violet. The room's state is now dirty Lily the animal growls The Animal Lily left the room and goes to Green through the west door. at java.util.HashMap$HashIterator.nextEntry(HashMap.java:793) at java.util.HashMap$KeyIterator.next(HashMap.java:828) at homework5.Room.critReactRoomStateChange(Room.java:76) at homework5.PC.play(PC.java:121) at homework5.Main.main(Main.java:41) Java Result: 1 That is the error I receive. My method looks like public void critReactRoomStateChange(String command, PC

SITUATION: I have a TreeSet of custom Objects and I have also used a custom Comparator. I have created an iterator to use on this TreeSet. TreeSet<Custom> ts=new TreeSet<Custom>(); Iterator<Custom> itr=ts.iterator(); while(itr.hasNext()){ Custom c=itr.next(); //Code to add a new element to the TreeSet ts } QUESTION: Well I want to know that if I add a new element to the TreeSet within the while loop, then will that new element get sorted immediately. In other words, if I add a new element within the while loop and it is less than the one which I am currently holding in c, then in the next

I am getting the a ConcurrentModificationException from my cooldown timer. I use a thread to reduce the values every second like this: public class CoolDownTimer implements Runnable { @Override public void run() { for (String s : playerCooldowns.keySet()) { playerCooldowns.put(s, playerCooldowns.get(s) - 20); if (playerCooldowns.get(s) <= 0) { playerCooldowns.remove(s); } } } } So every second it should reduce every players cooldown by 20, but the problem is that I a getting the CME every couple hours while running the program, especially when lots of people are online. How do I make it so

I have the following code which throws ConcurrentModificationException because I am using two different iterators on the same list and one of them is modifying the list. So, the second iterator throws the exception when reading the list because some other iterator has modified the list. List<Integer> list = new ArrayList<>(); populate(list);//A method that adds integers to list ListIterator<Integer> iterator1 = list.listIterator(); ListIterator<Integer> iterator2 = list.listIterator(); while (iterator1.hasNext()) { if(iterator1.next() < 5) iterator1.remove(); } while (iterator2.hasNext()){ if