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Deserializing nested polymorphic types does not work

See original GitHub issue
        use = JsonTypeInfo.Id.NAME,
        include = JsonTypeInfo.As.PROPERTY,
        property = "type")
        @JsonSubTypes.Type(value = Car.class, name = "car"),
        @JsonSubTypes.Type(value = Truck.class, name = "truck")
public abstract class Vehicle {
    protected String make;
    protected String model;
    protected String type;

    // no-arg constructor, getters and setters
public class Truck extends Vehicle {
    private double payloadCapacity;

     // no-arg constructor, getters and setters
        use = JsonTypeInfo.Id.NAME,
        include = JsonTypeInfo.As.PROPERTY,
        property = "status")
        @JsonSubTypes.Type(value = CarLite.class, name = "lite"),
        @JsonSubTypes.Type(value = CarWeight.class, name = "weight")
public class Car extends Vehicle {
    protected int seatingCapacity;
    protected double topSpeed;
    protected String status;

     // no-arg constructor, getters and setters
public class CarLite extends Car {
    private String lite;

     // no-arg constructor, getters and setters
public class CarWeight extends Car {
    private int weight;

    // no-arg constructor, getters and setters
public static void main(String[] args) throws IOException {
        ObjectMapper objectMapper = new ObjectMapper();

        String json = "[\n" +
                "        {\n" +
                "            \"type\": \"car\",\n" +
                "            \"make\": \"Mercedes-Benz\",\n" +
                "            \"model\": \"S500\",\n" +
                "            \"seatingCapacity\": 5,\n" +
                "            \"topSpeed\": 250.0,\n" +
                "            \"status\": \"lite\",\n" +
                "            \"lite\": \"#ccc\"\n" +
                "        },\n" +
                " \n" +
                "        {\n" +
                "            \"type\": \"truck\",\n" +
                "            \"make\": \"Isuzu\",\n" +
                "            \"model\": \"NQR\",\n" +
                "            \"payloadCapacity\": 7500.0\n" +
                "        }\n" +
                "    ]";

        List<Vehicle> v = objectMapper.readValue(json, new TypeReference<List<Vehicle>>() {});

Exception in thread "main" com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException: Unrecognized field "lite" (class models.Car), not marked as ignorable (6 known properties: "topSpeed", "seatingCapacity", "model", "type", "make", "status"])

Using jackson 2.9.5

Issue Analytics

  • State:closed
  • Created 5 years ago
  • Comments:12 (5 by maintainers)

github_iconTop GitHub Comments

pedrovinivcommented, May 3, 2020

@raderio Hi. I know it’s been a couple of time. But I was facing the same issue and I developed a custom JsonDeserializer to workaround this limitation. The idea is to support multiple discriminator fields when deserializing the JSON. checkout the repository:

cowtowncodercommented, Dec 30, 2018

@raderio I am sure other libraries can implement it. I have no interest in implementing, or using my limited time on documenting why I think it is not worth the hassle. If you truly want to figure it out that’s fine of course. It may be fun exercise.

One starting point would be figuring out how polymorphic deserialization actually works. JsonDeserializer and TypeDeserializer are main abstractions that handle interaction between “regular” deserializer (which handles content) and type deserializer that handles extracting of type id from json content to figure out which content deserializer to call.

Read more comments on GitHub >

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