Multiple Keys to Single Value Map Java

Question

I think my question is similar to this one: How to implement a Map with multiple keys? but with an important difference. In that question (if my understanding of it is corre

Answer 1

It sounds to me like you're looking for a nested HashMap. This could work, but my gut says implementing such a monster would be a terrible idea, both performance-wise and sanity-wise.

How you could initialize it:

    HashMap> nestedHashMap = new HashMap>();

Adding values:

    Key1 first;
    Key2 second;
    Value data;
    HashMap tempMap = new HashMap();
    tempMap.put(second, data);
    nestedHashMap.put(first, tempMap);

Getting data back out:

    Key1 first;
    Key2 second;
    Value data;
    data = nestedHashMap.get(first).get(second);

Disclaimer: This code hasn't been tested, it just came off the top of my head.