Deserialize JSON to ArrayList<POJO> using Jackson
You can deserialize directly to a list by using the TypeReference
wrapper. An example method:
public static <T> T fromJSON(final TypeReference<T> type,
final String jsonPacket) {
T data = null;
try {
data = new ObjectMapper().readValue(jsonPacket, type);
} catch (Exception e) {
// Handle the problem
}
return data;
}
And is used thus:
final String json = "";
Set<POJO> properties = fromJSON(new TypeReference<Set<POJO>>() {}, json);
TypeReference Javadoc
Another way is to use an array as a type, e.g.:
ObjectMapper objectMapper = new ObjectMapper();
MyPojo[] pojos = objectMapper.readValue(json, MyPojo[].class);
This way you avoid all the hassle with the Type object, and if you really need a list you can always convert the array to a list by:
List<MyPojo> pojoList = Arrays.asList(pojos);
IMHO this is much more readable.
And to make it be an actual list (that can be modified, see limitations of Arrays.asList()
) then just do the following:
List<MyPojo> mcList = new ArrayList<>(Arrays.asList(pojos));
This variant looks more simple and elegant.
CollectionType typeReference =
TypeFactory.defaultInstance().constructCollectionType(List.class, Dto.class);
List<Dto> resultDto = objectMapper.readValue(content, typeReference);