Nested Json to Map using Jackson

Question

I\'m trying to dynamically parse some JSON to a Map. The following works well with simple JSON

        String easyString = \"{\\\"name\\\":\\\"mkyong\\\", \         


        

Answer 1

Wrap your Map into a dumb object as container, like this:

public class Country {
  private final Map<String,Map<String,Set<String>>> citiesAndCounties=new HashMap<>;

  // Generate getters and setters and see the magic happen.
}

The rest is just working with your Object mapper, example Object mapper using Joda module:

public static final ObjectMapper JSON_MAPPER=new ObjectMapper().
          disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES).
          setSerializationInclusion(JsonInclude.Include.NON_NULL).
          disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS).
          registerModule(new JodaModule());

// Calling your Object mapper
JSON_MAPPER.writeValueAsString(new Country());

Hope that helps ;-)

Answer 2

I think the error occurs because the minute Jackson encounters the { character, it treats the remaining content as a new object, not a string. Try Object as map value instead of String.

public static void main(String[] args) throws IOException {

    Map<String,String> map = new HashMap<String,String>();
    ObjectMapper mapper = new ObjectMapper();

    map = mapper.readValue(x, new TypeReference<HashMap>(){});

    System.out.println(map);
}

output

{glossary={title=example glossary, GlossDiv={title=S, GlossList={GlossEntry={ID=SGML, SortAs=SGML, GlossTerm=Standard Generalized Markup Language, Acronym=SGML, Abbrev=ISO 8879:1986, GlossDef={para=A meta-markup language, used to create markup languages such as DocBook., GlossSeeAlso=[GML, XML]}, GlossSee=markup}}}}}