deserialize json using jackson with dynamic field name

问题

I'm trying to deserialize json using jackson, the problem is that field names are not always the same, for instance

One call will give me

{
  id: "blabla"
  aFieldname : { an object if type A} 
}

Another call will give me 

{
  id: "blabla"
  anotherName : { the same kind of object } 
}

I can't predict the name of the field. is it even possible ?

回答1:

You could deserialize the JSON as a Map<String, Object>:

ObjectMapper mapper = new ObjectMapper();

TypeReference<HashMap<String, Object>> typeReference = 
    new TypeReference<HashMap<String, Object>>() {};
Map<String, Object> data = mapper.readValue(json, typeReference);

---

Or you could use @JsonAnySetter:

public class Data {

    private String id;
    private Map<String, Object> unknownFields = new HashMap<>();

    // Getters and setters (except for unknownFields)

    @JsonAnySetter
    public void setUnknownField(String name, Object value) {
        unknownFields.put(name, value);
    }
}

---

If you know the possible names of the property, you could use the @JsonAlias annotation, which was introduced in Jackson 2.9:

public class Data {

    private String id;

    @JsonAlias({ "onePossibleName", "anotherPossibleName" })
    private Foo something;

    // Getters and setters
}

来源：https://stackoverflow.com/questions/51079658/deserialize-json-using-jackson-with-dynamic-field-name