Jackson serialization ignore empty values or null

Question

I m currently using jackson 2 1 4 and I m having some trouble ignoring fields when I m converting an object to a JSON string   Here s my class which acts as the object to be converted   public class JsonOperation    public static class Request        JsonInclude Include NON EMPTY      String requestType      Data data   new Data         public static class Data            JsonInclude Include NON EMPTY          String username          String email          String password          String birthday          String coinsPackage          String coins          String transactionId          boolean isLoggedIn           public static class Response        JsonInclude Include NON EMPTY      String requestType   null      Data data   new Data         public static class Data            JsonInclude Include NON EMPTY          enum ErrorCode   ERROR INVALID LOGIN  ERROR USERNAME ALREADY TAKEN  ERROR EMAIL ALREADY TAKEN            enum Status   ok  error             Status status          ErrorCode errorCode          String expiry          int coins          String email          String birthday          String pictureUrl          ArrayList  lt Performer gt  performer              And here s how I convert it   ObjectMapper mapper   new ObjectMapper    mapper setVisibility PropertyAccessor FIELD  Visibility ANY    JsonOperation subscribe   new JsonOperation     subscribe request requestType    login    subscribe request data username    Vincent   subscribe request data password    test     Writer strWriter   new StringWriter    try       mapper writeValue strWriter  subscribe request     catch  JsonGenerationException e           TODO Auto-generated catch block     e printStackTrace      catch  JsonMappingException e           TODO Auto-generated catch block     e printStackTrace      catch  IOException e           TODO Auto-generated catch block     e printStackTrace       Log d  JSON   strWriter toString      Here s the output     data    birthday  null  coins  null  coinsPackage  null  email  null  username   Vincent   password   test   transactionId  null  isLoggedIn  false   requestType   login     How can I avoid those null values  I only want to take required information for the  subscription  purpose   Here s exactly the output that I m looking for     data    username   Vincent   password   test    requestType   login     I also tried  JsonInclude Include NON NULL  and put all my variables to null  but it didn t work either  Thanks for your help guys

User · Answer

You need to add import com fasterxml jackson annotation JsonInclude   Add     JsonInclude JsonInclude Include NON NULL    on top of POJO   If you have nested POJO then    JsonInclude JsonInclude Include NON NULL    need to add on every values   NOTE  JAXRS  Jersey  automatically handle this scenario 2 6 and above

User · Answer

You can also set the global option   objectMapper setSerializationInclusion JsonInclude Include NON NULL

User · Answer

Code bellow may help if you want to exclude boolean type from serialization either    JsonInclude JsonInclude Include NON ABSENT

User · Answer

You have the annotation in the wrong place - it needs to be on the class  not the field  i e     JsonInclude Include NON NULL    or Include NON EMPTY  if that fits your use case  public static class Request                As noted in comments  in versions below 2 x the syntax for this annotation is     JsonSerialize include   JsonSerialize Inclusion NON NULL     or JsonSerialize Inclusion NON EMPTY   The other option is to configure the ObjectMapper directly  simply by calling  mapper setSerializationInclusion Include NON NULL     for the record  I think the popularity of this answer is an indication that this annotation should be applicable on a field-by-field basis   fasterxml

User · Answer

I was having similar problem recently with version 2 6 6     JsonInclude JsonInclude Include NON NULL    Using above annotation either on filed or class level was not working as expected  The POJO was mutable where I was applying the annotation  When I changed the behaviour of the POJO to be immutable the annotation worked its magic    I am not sure if its down to new version or previous versions of this lib had similar behaviour but for 2 6 6 certainly you need to have Immutable POJO for the annotation to work    objectMapper setSerializationInclusion JsonInclude Include NON NULL     Above option mentioned in various answers of setting serialisation inclusion in ObjectMapper directly at global level works as well but  I prefer controlling it at class or filed level    So if you wanted all the null fields to be ignored while JSON serialisation then use the annotation at class level but if you want only few fields to ignored in a class then use it over those specific fields  This way its more readable  amp  easy for maintenance if you wanted to change behaviour for specific response

User · Answer

Or you can use GSON  https   code google com p google-gson    where these null fields will be automatically removed   SampleDTO java  public class SampleDTO        String username      String email      String password      String birthday      String coinsPackage      String coins      String transactionId      boolean isLoggedIn          getters setters     Test java  import com google gson Gson   public class Test        public static void main String   args            SampleDTO objSampleDTO   new SampleDTO            Gson objGson   new Gson            System out println objGson toJson objSampleDTO              OUTPUT     isLoggedIn  false    I used gson-2 2 4

User · Answer

Also you can try to use    JsonSerialize include JsonSerialize Inclusion NON NULL    if you are dealing with jackson with version below 2   1 9 5  i tested it  you can easily use this annotation above the class  Not for specified for the attributes  just for class decleration

User · Answer

For jackson 2 x   JsonInclude JsonInclude Include NON NULL    just before the field

[java] Jackson serialization: ignore empty values (or null)

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