How to (completely) deserialize json into a generic List?

Question

When using an ObjectMapper to transform a json String into an entity, I can make it generic as:

public  E getConvertedAs(Strin         


        

Answer 1

This method can help to read json to an object or collections:

public class JsonUtil {
    private static final ObjectMapper mapper = new ObjectMapper();

    public static <T>T toObject(String json, TypeReference<T> typeRef){
        T t = null;
        try {
            t = mapper.readValue(json, typeRef);
        } catch (IOException e) {
            e.printStackTrace();
        }
        return t;
    }
}

Read json to list:

List<Device> devices= JsonUtil.toObject(jsonString,
                            new TypeReference<List<Device>>() {});

Read json to object:

Device device= JsonUtil.toObject(jsonString,
                                new TypeReference<Device>() {});

Answer 2

public static <E> List<E> fromJson(String in_string, Class<E> in_type) throws JsonParseException, JsonMappingException, IOException{
    return new ObjectMapper().readValue(in_string, new TypeReference<List<E>>() {});
}

Compiles on my computer. Note that I haven't tested it, though.