How to avoid ConcurrentModificationException when iterating over a map and changing values?

Question

I\'ve got a map containing some keys (Strings) and values (POJOs)

I want to iterate through this map and alter some of the data in the POJO.

The current code

Answer 1

Try using ConcurrentHashMap.

From JavaDoc,

A hash table supporting full concurrency of retrievals and adjustable expected concurrency for updates.

For ConcurrentModificationException to occur, generally:

it is not generally permissible for one thread to modify a Collection while another thread is iterating over it.