Question

I am wondering if there’s an elegant solution for doing this in Java (besides the obvious one – of declaring a different/explicit function. Here is the code:

private static HashMap<String, Integer> nameStringIndexMap 
        = new HashMap<String, Integer>();
private static HashMap<Buffer, Integer> nameBufferIndexMap 
        = new HashMap<Buffer, Integer>();

// and a function
private static String newName(Object object, 
        HashMap<Object, Integer> nameIndexMap){
    ....
}

The problem is that I cannot pass nameStringIndexMap or nameBufferIndexMap parameters to the function. I don’t have an idea about a more elegant solution beside doing another function which explicitly wants a HashMap<String, Integer> or HashMap<Buffer, Integer> parameter.

My question is:
Can this be made in a more elegant solution/using generics or something similar?

Thank you,

Iulian

Answer 1

You could make your function generic too:

private static <E extends Object> String newName(E object, 
        HashMap<E, Integer> nameIndexMap){
    ....
}

This bounds the two parameters of the function together, so for a HashMap<String, Integer> you can only pass String instances as first parameter. This may or may not be what you exactly want: if you only want to get elements from the map, Jon’s solution is simpler, but if you want to add this object to the map, this one is the only choice.