Map with multi values

Question

I basically want 2 values on 1 map if possible or something equivalent. I want to store this info

Map<K,V1,V2> sample = new HasMap<K,V1,V2>
(Key - caller) = 26
(value 1 - callee) = 55
(value 2 - seconds) = 550
sample(26,55,550)

the only other way i see how i can do this is

Map(k, arraylist(v2))

having the position in the arraylist as V1 but this will take forever to search if i would want to find what callers have called a specific callee.

i have also read this HashMap with multiple values under the same key but i do not understand how to do this.

The accepted answer of the question you've mentioned contains all you need. Read it carefully, and ask if you don't understand something *specific*. — aga, Nov 05 '13 at 12:03

score 2 · Answer 1 · answered Nov 05 '13 at 12:09

Create a bean for your value like below

  class Value {
    VariableType val1;
    VariableType val2;
    ...
    }

Then we can create a map like below

Map<K,Value> valueSample = new HashMap<K,Value>();
valueSample .put(new K(), new Value());

We need to set the value in Value calss by setter or constructor

score 0 · Answer 2 · answered Nov 05 '13 at 12:02

0

If all values are <V1, V2> you can use Entry as value:

Map<K,Map.Entry<V1,V2>> sample = new HasMap<K,Map.Entry<V1,V2>>();

Create Entry<V1,V2> and put it with the relevant key.

Another solution (and even better one) is to create your own value class.

answered Nov 05 '13 at 12:02

BobTheBuilder

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score 0 · Answer 3 · answered Nov 05 '13 at 12:02

You can do like this.

  Map<Integer,List<Integer>> map = new HashMap<Integer,List<Integer>>();
  List<Integer> list =new ArrayList<Integer>();
  list.add(55);
  list.add(550);
  //Adding value to the map
  map.put(26, list);

  //getting value from map
  List<Integer> values = map.get(26);

score 0 · Accepted Answer · answered Nov 05 '13 at 12:04

0

One solution is to create a wrapper object (it was given in the discussion link that you have in your question) to hold values v1 and v2:

class ValueWrapper {
V1Type v1;
V2Type v2;
...
}

Now you can map your keys to the instances of this wrapper:

Map<K,ValueWrapper> sample = new HashMap<K,ValueWrapper>();
sample.put(new K(), new ValueWrapper());

answered Nov 05 '13 at 12:04

Debojit Saikia

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i just didnt understand how to implement it from that link but it is clearer now after your explanation. thank you – BigApeWhat Nov 05 '13 at 12:12
if you could. how would i iterate over the valuewrapper class because k = 26 can have many valuewrapper classes. – BigApeWhat Nov 05 '13 at 13:09
this answer might help you: http://stackoverflow.com/questions/19495155/how-to-get-hashmap-values-depends-on-key/19495337#19495337 – Debojit Saikia Nov 05 '13 at 13:14

Map with multi values

4 Answers4