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Polymorphic type lost when using `@JsonValue`

See original GitHub issue

When suppressing all getters but one with @JsonIgnore and choosing to use a byte array for serialization (marking its getter with @JsonValue), the typing of the object is changed to “[B”, which is deserialized to a byte array. I would have expected verbose typing and usage of the constructor marked with @JsonCreator that accepts the byte array to construct the object on deserialization. The behavior is as expected when choosing more fields for serialization, which is redundant data in this case.

Running jackson-databind 2.7.4 on Java 1.8.0_91.

Configuration of the ObjectMapper:

private final ObjectMapper mapper;
public JsonFilter() {
    this.mapper = new ObjectMapper();
    mapper.configure(SerializationFeature.FAIL_ON_EMPTY_BEANS, false);

Serialization: mapper.writeValueAsString(message) Deserialization: mapper.readValue(json, RemoteCall.class)

Getter and field:

/** @serial */
private byte[] apdu;

public byte[] getBytes() {
    return apdu.clone();


public CommandAPDU(@JsonProperty(value = "bytes") byte[] apdu) {
    this.apdu = apdu.clone();
    LOG.v("com.ubitricity.devices.common.pal.CommandAPDU creator (1)");

Serializes to "args":[["[B","AKQEAAnw8fLz9AAAAgA="],["",{"instanceId":"b0e15098-f49e-4328-b072-fc5df42799bd","className":"com.ubitricity.devices.common.tasks.ResponseReceiver"}]] where “args” is an Object array field of the enclosing object.

Issue Analytics

  • State:closed
  • Created 7 years ago
  • Comments:5 (3 by maintainers)

github_iconTop GitHub Comments

cowtowncodercommented, Sep 28, 2016

Ok, one minor change to code: it should be:

public CommandAPDU(byte[] apdu) {
    this.apdu = apdu.clone();
    LOG.v("com.ubitricity.devices.common.pal.CommandAPDU creator (1)");

that is, ensure it’s delegating Creator, NOT property-one.

That’s not the main problem, but once serialization works, this is what would prevent deser.

It also looks like I can actually fix this for 2.8, and no new API is needed.

ondersoncommented, Jun 16, 2017


Either fix #1385 or #466 causes problem in CAMEL-11308

Downgrade of jackson2 dependency to 2.8.3 resolves the issue.

Could you check this cross reference?

Read more comments on GitHub >

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