Custom deserializer example in Jackson

Bean.java

class Bean {
    @JsonDeserialize(using=RrDeserializer.class)
    public final Object rr;

    public static class RrDeserializer extends JsonDeserializer<Object> implements ResolvableDeserializer {
        JsonDeserializer<Object> sampleRefResponseDeserializer;

        @Override
        public Object deserialize(JsonParser jp, DeserializationContext ctxt) throws IOException, JsonProcessingException {
            JsonToken token = jp.getCurrentToken();
            switch (token) {
                case FIELD_NAME:
                case START_OBJECT:
                    return sampleRefResponseDeserializer.deserialize(jp, ctxt);

                case VALUE_NUMBER_INT:
                    return jp.getNumberValue().longValue(); // should be optimal, whatever it is

                default:
                    throw ctxt.mappingException(Object.class, token);
            }
        }

        @Override
        public void resolve(DeserializationContext ctxt) throws JsonMappingException {
            sampleRefResponseDeserializer =
                    ctxt.findRootValueDeserializer(ctxt.getTypeFactory().constructType(SampleRefResponse.class));
        }
    }

    @JsonCreator
    public Bean(
            @JsonProperty("rr") Object rr) {
        this.rr = rr;
    }
}