Map of Maps data structure

Question

The MultiValueMap class (Apache commons collections) makes it easy to work with a Map whose values are Collections. I\'m looking for a a class that makes it easy to work wit

Answer 1

The regular Map collection works for this:

    Map> mapOfMaps = new LinkedHashMap>();
    Object newObject = new String("object as string");
    mapOfMaps.put(newObject, new LinkedHashMap());
    Map objectMap = mapOfMaps.get(newObject);

In fact, if you're not worried about type safety, you can put whatever you want into the value section:

    Map mapOfWhatever = new LinkedHashMap();
    Object newObject = new String("object as string");
    mapOfWhatever.put(newObject, new LinkedHashMap());
    Map objectMap = (Map) mapOfWhatever.get(newObject);