Where does the ConcurrentModificationException occur?

Question

I occassionally(random) get a ConcurrentModificationException in my app with the following exception message:

 java.util.ConcurrentModificationException
            at java.util.AbstractList$SimpleListIterator.next(AbstractList.java:62)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterator.next(AbstractList.java:201)
            at java.util.AbstractList$SubAbstractList$SubAbstractListIterat

My code is relatively large and Lists/Maps all used in different places. The exception message doesn't tell where the exception is occuring. How can i find out where the exception occurs so i can solve it?

score 0 · Answer 1 · answered Apr 10 '15 at 09:21

0

After getting each item from Iterator remove it from the Iterator .

iterator.remove();

It will avoid ConcurrentModificationException

answered Apr 10 '15 at 09:21

Don Chakkappan

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I don't know what code to post because the exception message doesn't tell where the exception occurs. I can't post all the code for different reasons. – MeesterPatat Apr 10 '15 at 09:38

Where does the ConcurrentModificationException occur?

1 Answers1