Hi David,
The current converter implementation actually has (some) support for this
already via the TypeReference-based APIs. Basically this generic
information is preserved if you create a subclass for your type, and the
way to do this is by creating an (anonymous) TypeReference subclass.
You can find an example in the ConverterMapTest.testGenericMapConversion()
[1]
Basically what that test does is convert this map:
Map<Integer, String> m1 = Collections.singletonMap(42, "987654321");
into a Map<String, Long>. So the number 42 needs to be converted into a
String and the string "987654321" needs to be converted into a long.
An anonymous TypeReference subclass is used to tell the converter to do
this:
Map<String, Long> m2 = converter.convert(m1).to(new
TypeReference<Map<String, Long>>(){});
Then at then end of the test you'll see that the correct converted types
are being converted to are asserted.
So in your case you should be able to specify the conversion as:
TopDTO<BottomDTO> dto = converter.convert(someMap).to(new
TypeReference<TopDTO<BottomDTO>>(){});
Hope this works for you :) The implementation of TypeReference-based APIs
isn't completely finished, so if you find an issue, let us know!
Cheers,
David
[1]
https://svn.apache.org/viewvc/felix/trunk/converter/src/test/java/org/apache/felix/converter/impl/ConverterMapTest.java?view=markup#l54
On 24 August 2016 at 18:21, David Leangen <[email protected]> wrote:
>
> Hi!
>
> I’m having a bit of trouble, so am fishing for ideas. Maybe there is a
> simple answer.
>
> If I convert from Map—>DTO, and the DTO has in its tree a generic field,
> how can I tell the converter the correct type so that it does not get
> converted as a Map?
>
> Example:
>
> BottomDTO {
> public String a;
> public String b;
>
> MiddleDTO<T> {
> public T bottom;
> }
>
> TopDTO<T> {
> public MiddleDTO<T> middle;
> }
>
> If I just do this, then Map is used for the value of bottom, which will
> cause a ClassCastException sometime later during execution:
>
> // Convert from Map to TopDTO<BottomDTO>
> converter.convert(someMap).to(TopDTO.class);
>
>
> Thanks!
> =David
>
>
>
