Hello

I ran into this really awkward problem in Map.get() (implemented as HashMap proxied by PersistentMap).
I am calling myMap.get(myKey) but always get null, and myMap.keySet().contains(myKey) also returns false, although myKey is contained in it!
I inspected myMap to see if it contains myKey and indeed it is, and it is mapped to a non-null value. I could easily prove it by iterating over the Map:



Although the loop is indeed entered for every k, myMap.contains(k) is never true. the result for my 2-keyed map is:
false
false

even myMap.containsKey(myMap.keySet().iterator().next()) returns false.

How is this even possible?
Perhaps it is a PersistentMap bug?

Please help
Yuval

Hi,

this sounds indeed very strange. Make sure to check your hashCode and equals implementations. A buggy implementation there could maybe cause the problem.
If you think the implementations of these method are ok you can create a Jira issue and attach a test case.

--Hardy

Hello Hardy

looks like you were right - my hashCode implementation wasn't good enough, because i used my id field for hashCode() and equals(). I changed this and it works fine now, though, i can't really say what's wrong with that in my use case (creating a new entity) - the entity was already persisted so it had an id, in such case i don't understand why is it bad to return id.hashCode()

Anyway thanks for your help
Yuval