[Solved] Why iterators are not a solution for CuncurentModificationException?

Question

From https://docs.oracle.com/javase/7/docs/api/java/util/ConcurrentModificationException.html

For example, it is not generally permissible for one thread to modify a Collection while another thread is iterating over it. In general, the results of the iteration are undefined under these circumstances. Some Iterator implementations (including those of all the general purpose collection implementations provided by the JRE) may choose to throw this exception if this behavior is detected.

You will need to implement some sort of synchronization yourself to avoid the exception. You may consider using Collections.synchronizedList and only operating on the list through that view.

Accepted Answer

From https://docs.oracle.com/javase/7/docs/api/java/util/ConcurrentModificationException.html

For example, it is not generally permissible for one thread to modify a Collection while another thread is iterating over it. In general, the results of the iteration are undefined under these circumstances. Some Iterator implementations (including those of all the general purpose collection implementations provided by the JRE) may choose to throw this exception if this behavior is detected.

You will need to implement some sort of synchronization yourself to avoid the exception. You may consider using Collections.synchronizedList and only operating on the list through that view.