Jackson在一个POJO中反序列化了两种不同的Json表示形式

Question

Is it possible to deserialize two different representations in the same pojo object, for example when optional translations can be returned.

For example, this is my pojo:

class LightCustomer {
  enum TITLE {
    Mr, Mrs, Ms
  }
  public TITLE title;
  public String titleLabel;
}

No problem with first available representation :

{
  "title": "Mrs"
}

My second representation with translation :

{
  "title": {
    "value": "Mrs",
    "label": "Madame"
  }
}

There is an way to :

• deserialize "title" or "title.value" in LightCustomer.setTitle() ?
• deserialize "title.label" in LightCustomer.setTitleLabel() ?

Answer 1

You can use @JacksonRootName for the second representation.

@JsonRootName(value = "title")
class LightCustomer {
  enum TITLE {
    Mr, Mrs, Ms
  }
  public TITLE title;
  public String label;
}

Configure the ObjectMapper instance with

mapper.configure(Feature.UNWRAP_ROOT_VALUE, true); //version 1.9

or

mapper.configure(DeserializationFeature.UNWRAP_ROOT_VALUE, true); //version 2

You can use different ObjectMapper instance for example. I'm not entirely sure if it is a good idea though. Perhaps a better way: create custom serializer/deserializer that allow both representation to be handled by a single instance of ObjectMapper.