Jackson JSON do not wrap attributes of nested object
14,382
Jackson 1.9 has introduced JsonUnwrapped
annotation which does what you are looking for.
Comments
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kurochenko almost 2 years
I've got following classes:
public class Container { private String name; private Data data; } public class Data { private Long id; }
When I serialize
Container
class using Jackson I get{"name":"Some name","data":{"id":1}}
But I need the result to be:
{"name":"Some name","id":1}
Is it possible (without adding
Container.getDataId()
method)? If so, how to do it?
update
I've tried to create custom
JsonSerializer<Data>
but the result was same as beforepublic class JsonDataSerializer extends JsonSerializer<Data> { private static Logger logger = Logger.getLogger(JsonDataSerializer.class); @Override public void serialize(Data value, JsonGenerator jgen, SerializerProvider provider) throws IOException,JsonProcessingException { Long id = (value.getId() == null) ? 0l : value.getId(); jgen.writeStartObject(); jgen.writeNumberField("id", id); jgen.writeEndObject(); logger.debug("Data id " + id + " serialized to JSON."); } }
I've also tried to add
@JsonSerialize
annotation aboveData
class, then above getter inContainer
class. As I mentioned before without any success. My serializer is used, logger logs message.
update 2
When I remove
writeStartObject()
andwriteEndObject()
then no JSON is returnesd, onlyHTTP Status 500
error and no exception is thrown except of what I found in debug output.DEBUG: org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerExceptionResolver - Resolving exception from handler [com.example.DataController@16be8a0]: org.springframework.http.converter.HttpMessageNotWritableException: Could not write JSON: Can not write a field name, expecting a value; nested exception is org.codehaus.jackson.JsonGenerationException: Can not write a field name, expecting a value DEBUG: org.springframework.web.servlet.mvc.annotation.ResponseStatusExceptionResolver - Resolving exception from handler [com.example.DataController@16be8a0]: org.springframework.http.converter.HttpMessageNotWritableException: Could not write JSON: Can not write a field name, expecting a value; nested exception is org.codehaus.jackson.JsonGenerationException: Can not write a field name, expecting a value DEBUG: org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver - Resolving exception from handler [com.example.DataController@16be8a0]: org.springframework.http.converter.HttpMessageNotWritableException: Could not write JSON: Can not write a field name, expecting a value; nested exception is org.codehaus.jackson.JsonGenerationException: Can not write a field name, expecting a value
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kurochenko over 12 yearsThanks for reply! I've tried to do what you've written (see updated question), but unfortunately the result is same as before.