Question

Sample JSON data from Facebook

{
    "1111111" : {
         "home" : false,
         "activities" : "some value"
    },

    "2222222" : {
         "home" : false,
         "activities" : "some value again"
    }
}

public class Profile{
    private boolean home;
    private String activities;

    // generated setter getter

    public static void main(String[] args) throws JsonParseException, JsonMappingException, IOException {
        ObjectMapper mapper = new ObjectMapper();
        Profile mainProfile = mapper.readValue(new File("data.json"), Profile.class);

        System.out.println(mainProfile.getActivities().size());
    }
}

Run above file will produce this error.

Unrecognized field "1111111" (Class com.analysis.structure.Profile), not marked as ignorable

The problem I’m facing is that how to map that “1111111” value to a variable in a class? If I use @JsonIgnoreProperties(ignoreUnknown=true), it will totally ignore all the josn data, since the first data does not have any tag to map to. How should I map this type of json data into Java using Jackson JSON?

Answer 1

That does not map to POJOs cleanly, so maybe you should rather bind it to a Map, where key is of type String, and value some POJO type?