Ignore fields from Java object dynamically while sending as JSON from Spring MVC

Question

I have model class like this  for hibernate   Entity  Table name    user   catalog    userdb    JsonIgnoreProperties ignoreUnknown   true  public class User implements java io Serializable        private Integer userId      private String userName      private String emailId      private String encryptedPwd      private String createdBy      private String updatedBy        Id      GeneratedValue strategy   IDENTITY       Column name    UserId   unique   true  nullable   false      public Integer getUserId             return this userId             public void setUserId Integer userId            this userId   userId              Column name    UserName   length   100      public String getUserName             return this userName             public void setUserName String userName            this userName   userName              Column name    EmailId   nullable   false  length   45      public String getEmailId             return this emailId             public void setEmailId String emailId            this emailId   emailId              Column name    EncryptedPwd   length   100      public String getEncryptedPwd             return this encryptedPwd             public void setEncryptedPwd String encryptedPwd            this encryptedPwd   encryptedPwd             public void setCreatedBy String createdBy            this createdBy   createdBy              Column name    UpdatedBy   length   100      public String getUpdatedBy             return this updatedBy             public void setUpdatedBy String updatedBy            this updatedBy   updatedBy            In Spring MVC controller  using DAO  I am able to get the object  and returning as JSON Object    Controller public class UserController         Autowired     private UserService userService        RequestMapping value     getUser  userId    method   RequestMethod GET       ResponseBody     public User getUser  PathVariable Integer userId  throws Exception            User user   userService get userId           user setCreatedBy null           user setUpdatedBy null           return user            View part is done using AngularJS  so it will get JSON like this       userId   2     userName     john      emailId     john gmail com      encryptedPwd     Co7Fwd1fXYk       createdBy    null     updatedBy    null     If I don t want to set encrypted Password  I will set that field also as null   But I don t want like this  I dont want to send all fields to client side  If I dont want password  updatedby  createdby fields to send  My result JSON should be like       userId   2     userName     john      emailId     john gmail com      The list of fields which I don t want to send to client coming from other database table  So it will change based on the user who is logged in   How can I do that   I hope You got my question

User · Answer

I know I m a bit late to the party  but I actually ran into this as well a few months back  All of the available solutions weren t very appealing to me  mixins  ugh    so I ended up creating a new library to make this process cleaner  It s available here if anyone would like to try it out  https   github com monitorjbl spring-json-view   The basic usage is pretty simple  you use the JsonView object in your controller methods like so   import com monitorjbl json JsonView  import static com monitorjbl json Match match    RequestMapping method   RequestMethod GET  value     myObject    ResponseBody public void getMyObjects           get a list of the objects     List lt MyObject gt  list   myObjectService list           exclude expensive field     JsonView with list  onClass MyObject class  match   exclude  contains         You can also use it outside of Spring    import com fasterxml jackson databind ObjectMapper  import com fasterxml jackson databind module SimpleModule  import static com monitorjbl json Match match   ObjectMapper mapper   new ObjectMapper    SimpleModule module   new SimpleModule    module addSerializer JsonView class  new JsonViewSerializer     mapper registerModule module    mapper writeValueAsString JsonView with list         onClass MyObject class  match            exclude  contains           onClass MySmallObject class  match            exclude  id

User · Answer

If I were you and wanted to do so  I wouldn t use my User entity in Controller layer Instead I create and use UserDto  Data transfer object  to communicate with business Service  layer and Controller  You can use Apache BeanUtils copyProperties method  to copy data from User entity to UserDto

User · Answer

Yes  you can specify which fields are serialized as JSON response and which to ignore  This is what you need to do to implement Dynamically ignore properties   1  First  you need to add  JsonFilter from com fasterxml jackson annotation JsonFilter on your entity class as   import com fasterxml jackson annotation JsonFilter    JsonFilter  SomeBeanFilter   public class SomeBean      private String field1     private String field2     private String field3        getters setters     2  Then in your controller  you have to add create the MappingJacksonValue object and set filters on it and in the end  you have to return this object   import java util Arrays  import java util List   import org springframework http converter json MappingJacksonValue  import org springframework web bind annotation GetMapping  import org springframework web bind annotation RestController   import com fasterxml jackson databind ser FilterProvider  import com fasterxml jackson databind ser impl SimpleBeanPropertyFilter  import com fasterxml jackson databind ser impl SimpleFilterProvider    RestController public class FilteringController         Here i want to ignore all properties except field1 field2     GetMapping   ignoreProperties     public MappingJacksonValue retrieveSomeBean         SomeBean someBean   new SomeBean  value1    value2    value3         SimpleBeanPropertyFilter filter   SimpleBeanPropertyFilter filterOutAllExcept  field1    field2         FilterProvider filters   new SimpleFilterProvider   addFilter  SomeBeanFilter   filter        MappingJacksonValue mapping   new MappingJacksonValue someBean        mapping setFilters filters        return mapping          This is what you will get in response       field1  value1     field2  value2      instead of this       field1  value1     field2  value2     field3  value3      Here you can see it ignores other properties field3 in this case  in response except for property field1 and field2   Hope this helps

User · Answer

I ve found a solution for me with Spring and jackson  First specify the filter name in the entity   Entity  Table name    SECTEUR    JsonFilter ModelJsonFilters SECTEUR FILTER  public class Secteur implements Serializable        Serial UID    private static final long serialVersionUID   5697181222899184767L          Unique ID      Id  JsonView View SecteurWithoutChildrens class   Column name    id    GeneratedValue strategy   GenerationType IDENTITY  private long id    JsonView View SecteurWithoutChildrens class   Column name    code   nullable   false  length   35  private String code          Identifiant du secteur parent      JsonView View SecteurWithoutChildrens class   Column name    id parent   private Long idParent    OneToMany fetch   FetchType LAZY   JoinColumn name    id parent   private List lt Secteur gt  secteursEnfants   new ArrayList lt  gt  0        Then you can see the constants filters names class with the default FilterProvider used in spring configuration  public class ModelJsonFilters    public final static String SECTEUR FILTER    SecteurFilter   public final static String APPLICATION FILTER    ApplicationFilter   public final static String SERVICE FILTER    ServiceFilter   public final static String UTILISATEUR FILTER    UtilisateurFilter    public static SimpleFilterProvider getDefaultFilters         SimpleBeanPropertyFilter theFilter   SimpleBeanPropertyFilter serializeAll        return new SimpleFilterProvider   setDefaultFilter theFilter          Spring configuration     EnableWebMvc  Configuration  ComponentScan basePackages    fr sodebo    public class ApiRootConfiguration extends WebMvcConfigurerAdapter     Autowired private EntityManagerFactory entityManagerFactory           config qui permet d   viter les  Lazy loading Error  au moment de la    conversion json par jackson pour les retours des services REST lt br gt     on permet    jackson d acceder    sessionFactory pour charger ce dont il a    besoin      Override public void configureMessageConverters List lt HttpMessageConverter lt   gt  gt  converters         super configureMessageConverters converters       MappingJackson2HttpMessageConverter converter   new MappingJackson2HttpMessageConverter        ObjectMapper mapper   new ObjectMapper            config d hibernate pour la conversion json     mapper registerModule getConfiguredHibernateModule               inscrit les filtres json     subscribeFiltersInMapper mapper           config du comportement de json views     mapper configure MapperFeature DEFAULT VIEW INCLUSION  false        converter setObjectMapper mapper       converters add converter             config d hibernate pour la conversion json         return Hibernate5Module     private Hibernate5Module getConfiguredHibernateModule         SessionFactory sessionFactory   entityManagerFactory unwrap SessionFactory class       Hibernate5Module module   new Hibernate5Module sessionFactory       module configure Hibernate5Module Feature FORCE LAZY LOADING  true        return module             inscrit les filtres json         param mapper     private void subscribeFiltersInMapper ObjectMapper mapper         mapper setFilterProvider ModelJsonFilters getDefaultFilters             Endly I can specify a specific filter in restConstoller when i need       RequestMapping value      id  droits    method   RequestMethod GET  public MappingJacksonValue getListDroits  PathVariable long id         LOGGER debug  Get all droits of user with id      id        List lt Droit gt  droits   utilisateurService findDroitsDeUtilisateur id        MappingJacksonValue value       UtilisateurWithSecteurs utilisateurWithSecteurs   droitsUtilisateur fillLists droits  get id        value   new MappingJacksonValue utilisateurWithSecteurs        FilterProvider filters   ModelJsonFilters getDefaultFilters   addFilter ModelJsonFilters SECTEUR FILTER  SimpleBeanPropertyFilter serializeAllExcept  secteursEnfants    addFilter ModelJsonFilters APPLICATION FILTER              SimpleBeanPropertyFilter serializeAllExcept  services          value setFilters filters       return value

User · Answer

Add the  JsonIgnoreProperties  fieldname   annotation  to your POJO   Or you can use  JsonIgnore before the name of the field you want to ignore while deserializing JSON  Example    JsonIgnore  JsonProperty value    user password   public String getUserPassword         return userPassword      GitHub example

User · Answer

We can do this by setting access to JsonProperty Access WRITE ONLY while declaring the property    JsonProperty  value    password   access   JsonProperty Access WRITE ONLY   SerializedName  password   private String password

User · Answer

Can I do it dynamically    Create view class   public class View       static class Public         static class ExtendedPublic extends Public         static class Internal extends ExtendedPublic         Annotate you model   Document public class User         Id      JsonView View Public class      private String id        JsonView View Internal class      private String email        JsonView View Public class      private String name        JsonView View Public class      private Instant createdAt   Instant now           getters setters     Specify the view class in your controller   RequestMapping   user  email    public class UserController        private final UserRepository userRepository        Autowired     UserController UserRepository userRepository            this userRepository   userRepository              RequestMapping method   RequestMethod GET       JsonView View Internal class      public  ResponseBody Optional lt User gt  get  PathVariable String email            return userRepository findByEmail email              Data example     id   5aa2496df863482dc4da2067   name   test   createdAt   2018-03-10T09 35 31 050353800Z

User · Answer

This is a clean utility tool for the above answer     GetMapping value     my-url   public  ResponseBody MappingJacksonValue getMyBean         List lt MyBean gt  myBeans   Service findAll        MappingJacksonValue mappingValue   MappingFilterUtils applyFilter myBeans  MappingFilterUtils JsonFilterMode EXCLUDE FIELD MODE   MyFilterName    myBiggerObject mySmallerObject mySmallestObject        return mappingValue       AND THE UTILITY CLASS public class MappingFilterUtils        public enum JsonFilterMode           INCLUDE FIELD MODE  EXCLUDE FIELD MODE           public static MappingJacksonValue applyFilter Object object  final JsonFilterMode mode  final String filterName  final String    fields            if  fields    null    fields length    0                throw new IllegalArgumentException  You should pass at least one field                      return applyFilter object  mode  filterName  new HashSet lt  gt  Arrays asList fields                public static MappingJacksonValue applyFilter Object object  final JsonFilterMode mode  final String filterName  final Set lt String gt  fields            if  fields    null    fields isEmpty                  throw new IllegalArgumentException  You should pass at least one field                       SimpleBeanPropertyFilter filter   null          switch  mode                case EXCLUDE FIELD MODE                  filter   SimpleBeanPropertyFilter serializeAllExcept fields                   break              case INCLUDE FIELD MODE                  filter   SimpleBeanPropertyFilter filterOutAllExcept fields                   break                     FilterProvider filters   new SimpleFilterProvider   addFilter filterName  filter           MappingJacksonValue mapping   new MappingJacksonValue object           mapping setFilters filters           return mapping

User · Answer

Add  JsonInclude JsonInclude Include NON NULL   forces Jackson to serialize null values  to the class as well as  JsonIgnore to the password field   You could of course set  JsonIgnore on createdBy and updatedBy as well if you always want to ignore then and not just in this specific case   UPDATE  In the event that you do not want to add the annotation to the POJO itself  a great option is Jackson s Mixin Annotations  Check out the documentation

User · Answer

To acheive dynamic filtering follow the link - https   iamvickyav medium com spring-boot-dynamically-ignore-fields-while-converting-java-object-to-json-e8d642088f55  Add the  JsonFilter  quot Filter name quot   annotation to the model class   Inside the controller function add the code - SimpleBeanPropertyFilter simpleBeanPropertyFilter           SimpleBeanPropertyFilter serializeAllExcept  quot id quot    quot dob quot      FilterProvider filterProvider   new SimpleFilterProvider            addFilter  quot Filter name quot   simpleBeanPropertyFilter    List lt User gt  userList   userService getAllUsers    MappingJacksonValue mappingJacksonValue   new MappingJacksonValue userList   mappingJacksonValue setFilters filterProvider    return mappingJacksonValue    make sure the return type is MappingJacksonValue

User · Answer

I have created a JsonUtil which can be used to ignore fields at runtime while giving a response    Example Usage        First argument should be any POJO class  Student  and ignoreFields is comma seperated fields you want to ignore in response     Student st   new Student     createJsonIgnoreFields st  firstname age     import java util logging Logger   import org codehaus jackson map ObjectMapper  import org codehaus jackson map ObjectWriter  import org codehaus jackson map ser FilterProvider  import org codehaus jackson map ser impl SimpleBeanPropertyFilter  import org codehaus jackson map ser impl SimpleFilterProvider   public class JsonUtil      public static String createJsonIgnoreFields Object object  String ignoreFields         try            ObjectMapper mapper   new ObjectMapper             mapper getSerializationConfig   addMixInAnnotations Object class  JsonPropertyFilterMixIn class            String   ignoreFieldsArray   ignoreFields split                FilterProvider filters   new SimpleFilterProvider                 addFilter  filter properties by field names                    SimpleBeanPropertyFilter serializeAllExcept ignoreFieldsArray             ObjectWriter writer   mapper writer   withFilters filters            return writer writeValueAsString object          catch  Exception e               handle exception here             return              public static String createJson Object object            try            ObjectMapper mapper   new ObjectMapper             ObjectWriter writer   mapper writer   withDefaultPrettyPrinter             return writer writeValueAsString object            catch  Exception e               handle exception here                   return

User · Answer

Would not creating a UserJsonResponse class and populating with the wanted fields be a cleaner solution   Returning directly a JSON seems a great solution when you want to give all the model back  Otherwise it just gets messy   In the future  for example you might want to have a JSON field that does not match any Model field and then you re in a bigger trouble

User · Answer

In your entity class add  JsonInclude JsonInclude Include NON NULL  annotation to resolve the problem  it will look like   Entity  JsonInclude JsonInclude Include NON NULL

User · Answer

I ve solved using only  JsonIgnore like  kryger has suggested  So your getter will become    JsonIgnore public String getEncryptedPwd         return this encryptedPwd      You can set  JsonIgnore of course on field  setter or getter like described here   And  if you want to protect encrypted password only on serialization side  e g  when you need to login your users   add this  JsonProperty annotation to your field    JsonProperty access   Access WRITE ONLY  private String encryptedPwd    More info here

User · Answer

Place  JsonIgnore on the field or its getter  or create a custom dto   JsonIgnore private String encryptedPwd    or as mentioned above by ceekay annotate it with  JsonProperty where access attribute is set to write only   JsonProperty  value    password   access   JsonProperty Access WRITE ONLY  private String encryptedPwd

[java] Ignore fields from Java object dynamically while sending as JSON from Spring MVC

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