Map in Map in Guava

Question

I have some code with Map> objects, which works (it is instantiated as a HashMap of HashMaps), but I wonder whether there is

Answer 1

Take a look at Guava's Table interface.

Its documentation example seems to overlap quite a bit with your use-case:

Typically, when you are trying to index on more than one key at a time, you will wind up with something like Map>, which is ugly and awkward to use. Guava provides a new collection type, Table, which supports this use case for any "row" type and "column" type.