How to implement CompositeMap class structure in java which is available in the Jakarta Apache Commons Collections?

[gatekeeper]

DataMap is a class structure that maps a single key to multiple values.

I'm supposed to design a class structure called JoinMap which keeps a pair of keys of two DataMaps.

As far as I understood, a JoinMap is meant to join data from two DataMaps into a single view. It somehow reminds of the CompositeMap class structure available in the Jakarta Apache Commons Collections.

Any idea how I should implement this ? Does anyone know how a CompositeMap actually works? Any idea would be appreciated. Thanks.

[JavaPF]

Hello gatekeeper, welcome to the forums.

Sorry for the late reply but it doesn't look like anyone has had any experience with CompositeMap before.

Does this link help you?

Java Doc for CompositeMap

[henry]

hello,
I am not sure whether you need a compositeMap or not...all you need is a data structure with a key that would map to the pair of keys of your two other maps..is this correct?
If this is it, then there are many ways to do this...you can define a map which contains keys that points to pairs of keys.
There are other ways..but if you want to stick with maps, this might work for you.