CODEWITHSUNDEEP
javaguava
tripleblep
tripleblep

Reputation: 540

Retrieving specific values in Multimap

I'm using a Multimap that has two values per key. Below is the code I'm using to get each value separately:

The first bit of code gets the first object value:

for(Object object : map.get(object))
{
    return object
}

Then, I'm using another method to retrieve the other value. This method takes the first object as an argument:

for(Object object : team.get(object))
{
    if(object != initialObject)
    {
        return object;
    }
}

This seems like a 'hackish' way of doing things, so is there any way for me to get the values more easily?

Upvotes: 2

Views: 9488

Answers (3)

Vladi
Vladi

Reputation: 1990

for getting all the values for the same key the most easiest way to do it will be :

    Iterator iterator = multimap.get(key).iterator();
    System.out.println("first element: " + iterator.next());
    System.out.println("second element: " + iterator.next());
    System.out.println("third element: " + iterator.next());

And so on

another option if you want to get all the elements without know how much elements there

  Iterator iterator = multimap.get(key).iterator();
   int index=1;
   while (iterator.hasNext()) {
    System.out.println(index +" element: " + iterator.next()); 
     index++;
        }

Upvotes: 0

Alan Stokes
Alan Stokes

Reputation: 18964

If you're using Guava, Iterables#get is probably what you want - it returns the Nth item from any iterable, example:

Multimap<String, String> myMultimap = ArrayListMultimap.create();

// and to return value from position:
return Iterables.get(myMultimap.get(key), position);

If you're using a ListMultimap then it behaves very much like a map to a List so you can directly call get(n).

Upvotes: 7

Andrea Bergia
Andrea Bergia

Reputation: 5552

Collection<Object> values = map.get(key);
checkState(values.size() == 2, String.format("Found %d values for key %s", values.size(), key));

return values.iterator().next(); // to get the first

Iterator<Object> it = values.iterator();
it.next(); // move the pointer to the second object
return it.next(); // get the second object

Upvotes: 3

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