Transform a set into a map using the current lambda API

[Sam Pullara]

Also, you could use groupingBy, but it returns a list since it doesn't
know that your keys are unique:

        Map<String, List<Property>> map =
properties.stream().collect(groupingBy(p -> p.name));

Sam

On Tue, Mar 26, 2013 at 1:12 PM, Sam Pullara <sam at sampullara.com> wrote:
>         HashMap<String, Property> map =
> properties.stream().collect(HashMap<String, Property>::new, (m, p) ->
> m.put(p.name, p), Map::putAll);
>
> The convenience methods for toMap() collectors have the key/value reversed.
>
> Sam
>
> On Tue, Mar 26, 2013 at 11:18 AM, Marcos Antonio
> <marcos_antonio_ps at hotmail.com> wrote:
>>
>> Hello!
>>
>> Suppose this simple POJO:
>>
>> public class Property
>> {
>>     public String name;
>>     public Object value;
>>     @Override
>>     public boolean equals(Object obj)
>>     {
>>         if (this == obj)
>>         {
>>             return true;
>>         }
>>         if (obj == null || getClass() != obj.getClass())
>>         {
>>             return false;
>>         }
>>
>>         Property another = (Property) obj;
>>         return name.equals(another.name);
>>     }
>>     @Override
>>     public int hashCode()
>>     {
>>         return name.hashCode();
>>     }
>> }
>>
>> and a set of them:
>>
>> Set<Property> properties = ...
>>
>> using the current lambda API, what's the easiest way to transform this set
>> in a map
>>
>> Map<String, Property> names = ...
>>
>> where the map key is the name field of the Property object and the map value
>> is the Property object itself?
>>
>> Thank you.
>>
>> Marcos
>>