Question

The class docs state that Entrys cannot be modified via .setValue(...) but also caveat that put(...) works fine.

Does that mean put(...) will work fine when iterating over the collection views like navigableKeySet() (i.e., not result in a ConcurrentModificationException), as long as no structural modifications (i.e., adding a new key) are made?

I’m in the middle of testing it out, but if I’m unable to break the iteration, I’d still like some verification that it’s working fine (instead of me being unable to break it).

Answer 1

The javadocs for TreeMap state:

A structural modification is any operation that adds or deletes one or more mappings; merely changing the value associated with an existing key is not a structural modification.

Therefore one can assume that changing the values associated with a given key while iterating over the set of keys is allowed.