Multiple indexes for a Java Collection - most basic solution?

Question

I\'m looking for the most basic solution to create multiple indexes on a Java Collection.

Required functionality:

• When a Value is removed, all index en

Answer 1

Basically a solution based on multiple hash maps would be possible, but in this case all of them have to be keped up-to-date manually. A very simple integrated solution can be found here: http://insidecoffe.blogspot.de/2013/04/indexable-hashmap-implementation.html