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How to remove a field from POJO

public class user {
private String planId;
private String eid;
#JsonProperty(access = JsonProperty.Access.WRITE_ONLY)
private Collection<String> userIds;
}
I have a pojo like above
and the code which is use for creating the json request object is this :
public UserCollection getUserCollection(final user args) {
Map<String, String> headersMap = new HashMap<>();
ObjectMapper jacksonMapper = new ObjectMapper();
jacksonMapper.disable(MapperFeature.USE_ANNOTATIONS); // this line is creating the userIds field to reflect
//By any code we can remove the userId field from the args object
String responseBody = null;
String responseStatus = null;
String jsonRequestBody = jacksonMapper.writeValueAsString(args);
}
I just want to remove userIds from the args by not removing any of the above code.
Thanks in advance.

I don't know how you should solve this without removing the annotation processing code, you should maybe add a custom serializer. You can read further about the topic at here.
public class HelloWorld {
public static void main(String[] args) throws JsonProcessingException {
User myItem = new User("planId", "eId", List.of("1", "2"));
ObjectMapper mapper = new ObjectMapper();
SimpleModule module = new SimpleModule();
module.addSerializer(User.class, new UserSerializer());
mapper.registerModule(module);
String serialized = mapper.writeValueAsString(myItem);
}
#Data
#AllArgsConstructor
public static class User {
private String planId;
private String eId;
private Collection<String> userIds;
}
public static class UserSerializer extends StdSerializer<User> {
public UserSerializer() {
this(null);
}
public UserSerializer(Class<User> t) {
super(t);
}
#Override
public void serialize(User value, JsonGenerator gen, SerializerProvider provider) throws IOException{
gen.writeStartObject();
gen.writeStringField("planId", value.planId);
gen.writeStringField("eId", value.eId);
gen.writeEndObject();
}
}
}
If you had to use it without annotations, and cannot add a custom serializer you should map the User class into a more specific class without the field in question and then serialize that one.

Java Jackson: why do I get JsonMappingException although I used #JsonDeserialize

I need some help with Jackson library in Java. I have the following class:
#JsonIgnoreProperties(ignoreUnknown = true)
public class MarketHistoryData {
private String countryCode;
#JsonDeserialize(keyUsing = BpTimeDeserializer.class)
private Map<BpTime, Double> hourToExpectedEngagePaidListings;
#JsonDeserialize(keyUsing = BpTimeDeserializer.class)
private Map<BpTime, Double> hourMinuteToExpectedEngagePaidListings;
public MarketHistoryData() {}
...
// getters and setters
}
I understood that Jackson has difficulties with deserializing a map which its keys are an object. Therefore, I added the annotations:
#JsonDeserialize(keyUsing = BpTimeDeserializer.class)
The class BpTimeDeserializer is:
public class BpTimeDeserializer extends KeyDeserializer {
private ObjectMapper mapper = new ObjectMapper();
#Override
public BpTime deserializeKey(String key, DeserializationContext ctxt) throws IOException {
return mapper.readValue(key, BpTime.class);
}
}
Still, I get an error during the deserialization process:
*****.UncheckedExecutionException:
com.fasterxml.jackson.databind.JsonMappingException: Unrecognized
token 'com': was expecting (JSON String, Number, Array, Object or
token 'null', 'true' or 'false') at [Source:
(String)"****BpTime#5922062e[hour=1,minute=0]";
line: 1, column: 1] (through reference chain:
***PacerCycleOutput["campaignIdToFactorComputationData"]->java.util.LinkedHashMap["1011620661"]->****FactorComputationData["selectedMarketHistoryDataForCampaign"]->***MarketHistoryData["hourToExpectedEngagePaidListings"])
Do you know what I can do to overcome this error?

I finally found a way how to resolve this error.
#JsonIgnoreProperties(ignoreUnknown = true)
public class MarketHistoryData {
private String countryCode;
#JsonDeserialize(keyUsing = BpTimeDeserializer.class)
#JsonSerialize(keyUsing = BpTimeSerializer.class)
private Map<BpTime, Double> hourToExpectedEngagePaidListings;
#JsonDeserialize(keyUsing = BpTimeDeserializer.class)
#JsonSerialize(keyUsing = BpTimeSerializer.class)
private Map<BpTime, Double> hourMinuteToExpectedEngagePaidListings;
...
}
public class BpTimeDeserializer extends KeyDeserializer {
private ObjectMapper mapper = new ObjectMapper();
#Override
public BpTime deserializeKey(String key, DeserializationContext ctxt) throws IOException {
String[] keySplit = key.split(" ");
BpTime bpTime = new BpTime();
if (!keySplit[0].equals("-1")) {
bpTime.setHour(Integer.parseInt(keySplit[0]));
}
if (!keySplit[1].equals("-1")) {
bpTime.setMinute(Integer.parseInt(keySplit[1]));
}
return bpTime;
}
}
public class BpTimeSerializer extends StdSerializer<BpTime> {
public BpTimeSerializer() {
this(null);
}
public BpTimeSerializer(Class<BpTime> t) {
super(t);
}
#Override
public void serialize(BpTime value, JsonGenerator generator, SerializerProvider arg2) throws IOException {
generator.writeFieldName(String.format("%s %s", ofNullable(value.getHour()).orElse(-1),
ofNullable(value.getMinute()).orElse(-1)));
}
}

Jackson Module Deserializer not called

I am trying to write Jackson deserializer module in Spring Boot app.
The main reason is to encrypt pin number from incoming request by using custom Jackson deserializer.
Encryption properties are provided by spring component CipherInterface
I was trying solution from this but my custom deserializer still was not called.
Instead of this based StringDeserializer is always called and no encryption is performed
Thanks in advance
Annotation:
#Retention(RetentionPolicy.RUNTIME)
#Target(ElementType.FIELD)
#JacksonAnnotation
public #interface Encrypted {
}
Request body with field to be encrypted
#Value
public class CardCounterDecreaseRequest {
#Encrypted
private final String pinValue;
}
Jackson configuration
#Bean
ObjectMapper unrestrictObjectMapper(final CipherInterface cipherInterface) {
return JsonMapper.builder()
.enable(MapperFeature.ACCEPT_CASE_INSENSITIVE_ENUMS)
.enable(MapperFeature.ACCEPT_CASE_INSENSITIVE_PROPERTIES)
.enable(SerializationFeature.INDENT_OUTPUT)
.enable(DeserializationFeature.FAIL_ON_NULL_FOR_PRIMITIVES)
.enable(DeserializationFeature.FAIL_ON_NUMBERS_FOR_ENUMS)
.disable(DeserializationFeature.FAIL_ON_MISSING_EXTERNAL_TYPE_ID_PROPERTY)
.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS)
.disable(DeserializationFeature.ADJUST_DATES_TO_CONTEXT_TIME_ZONE)
.disable(SerializationFeature.FAIL_ON_EMPTY_BEANS)
.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES)
.disable(DeserializationFeature.ACCEPT_FLOAT_AS_INT)
.visibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.NONE)
.visibility(PropertyAccessor.FIELD, JsonAutoDetect.Visibility.ANY)
.addModules(new EncryptionModule(cipherInterface), new JavaTimeModule(), new VavrModule(), new ParanamerModule())
.build();
}
Module:
public class EncryptionModule extends SimpleModule {
private final CipherInterface cipher;
public EncryptionModule(final CipherInterface cipher) {
super();
this.cipher = cipher;
}
#Override
public void setupModule(final SetupContext context) {
context.addBeanDeserializerModifier(new EncryptedDeserializerModifier(cipher));
}
}
public class EncryptedDeserializerModifier extends BeanDeserializerModifier {
private final CipherInterface cipher;
public EncryptedDeserializerModifier(final CipherInterface cipher) {
super();
this.cipher = cipher;
}
#Override
public BeanDeserializerBuilder updateBuilder(final DeserializationConfig config,
final BeanDescription beanDesc,
final BeanDeserializerBuilder builder) {
final Iterator<SettableBeanProperty> it = builder.getProperties();
while (it.hasNext()) {
final SettableBeanProperty prop = it.next();
if (null != prop.getAnnotation(Encrypted.class)) {
final JsonDeserializer<Object> current = prop.getValueDeserializer(); // always returns null
final EncryptedJsonDeserializer encryptedDeserializer = new EncryptedJsonDeserializer(cipher, current);
final SettableBeanProperty propWithEncryption = prop.withValueDeserializer(encryptedDeserializer);
builder.addOrReplaceProperty(propWithEncryption, true);
}
}
return builder;
}
}
And finally deserializer:
public class EncryptedJsonDeserializer extends JsonDeserializer<Object> implements ContextualDeserializer {
private final CipherInterface service;
private final JsonDeserializer<Object> baseDeserializer;
private final BeanProperty property;
public EncryptedJsonDeserializer(final CipherInterface service, final JsonDeserializer<Object> baseDeserializer) {
this.service = service;
this.baseDeserializer = baseDeserializer;
this.property = null;
}
public EncryptedJsonDeserializer(final CipherInterface service, final JsonDeserializer<Object> wrapped, final BeanProperty property) {
this.service = service;
this.baseDeserializer = wrapped;
this.property = property;
}
#Override
public Object deserialize(final JsonParser p, final DeserializationContext ctxt) throws IOException, JsonProcessingException {
JsonDeserializer<?> deserializer = baseDeserializer;
if (deserializer instanceof ContextualDeserializer) {
deserializer = ((ContextualDeserializer) deserializer).createContextual(ctxt, property);
}
return // encryption logic here
}
#Override
public JsonDeserializer<?> createContextual(final DeserializationContext ctxt, final BeanProperty property) throws JsonMappingException {
JsonDeserializer<Object> wrapped = ctxt.findRootValueDeserializer(property.getType());
return new EncryptedJsonDeserializer(service, wrapped, property);
}

Just try below code, as you had created deserializer correctly but you are not informing spring that while deserialize this entity use below Custom desierializer class.
Add this extra line #JsonDeserialize(using = EncryptedJsonDeserializer.class) and try once.
#Value
#JsonDeserialize(using = EncryptedJsonDeserializer.class)
public class CardCounterDecreaseRequest {
#Encrypted
private final String pinValue;
}
It will help you.

Spring Boot Cannot Deserialize Object That contanis OffsetDateTime

I'm trying to call a rest endpoint which returns a pojo object which looks like this:
public class Process {
#JsonProperty("id")
private String id = null;
#JsonProperty("processDefinitionId")
private String processDefinitionId = null;
#JsonProperty("businessKey")
private String businessKey = null;
#JsonProperty("startedAt")
private OffsetDateTime startedAt = null;
#JsonProperty("endedAt")
private OffsetDateTime endedAt = null;
#JsonProperty("durationInMs")
private Integer durationInMs = null;
#JsonProperty("startActivityDefinitionId")
private String startActivityDefinitionId = null;
#JsonProperty("endActivityDefinitionId")
private String endActivityDefinitionId = null;
#JsonProperty("startUserId")
private String startUserId = null;
#JsonProperty("deleteReason")
private String deleteReason = null;
//constructors and setters+getters
}
Here is the call:
ResponseEntity<Process> responseModel = restTemplate.exchange("http://localhost:8062/processes", HttpMethod.POST, httpEntity, Process.class);
The problem is that i've tried a few methods like ignoring the OffsetDateTime properties or trying to change the format of that date but it will throw this error:
com.fasterxml.jackson.databind.exc.InvalidDefinitionException: Cannot construct instance of `org.threeten.bp.OffsetDateTime` (no Creators, like default construct, exist): no String-argument constructor/factory method to deserialize from String value ('2019-10-04T13:20:29.315Z')
Or it will return null :(
What would be a good solution to solve this?

The error states it cannot construct instance of org.threeten.bp.OffsetDateTime. You need to use
java.time.offsetdatetime
Then in your model you can format it whatever way you like e.g.
#JsonProperty("endedAt") //this line is not needed when it is the same as the instance variable name
#JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd#HH:mm:ss.SSSZ")
private OffsetDateTime endedAt;

I had the same problem with a bean generated by swagger. To solve it I created some serializer and deserializer for date types: org.threeten.bp.LocalDate and org.threeten.bp.OffsetDateTime. And it works well :).
#Bean
#Primary
public ObjectMapper serializingObjectMapper() {
ObjectMapper objectMapper = new ObjectMapper();
JavaTimeModule javaTimeModule = new JavaTimeModule();
javaTimeModule.addSerializer(OffsetDateTime.class, new OffsetDateTimeSerializer());
javaTimeModule.addDeserializer(OffsetDateTime.class, new OffsetDateTimeDeserializer());
javaTimeModule.addSerializer(LocalDate.class, new LocalDateSerializer());
javaTimeModule.addDeserializer(LocalDate.class, new LocalDateDeserializer());
objectMapper.registerModule(javaTimeModule);
return objectMapper;
}
public static class OffsetDateTimeSerializer extends JsonSerializer<OffsetDateTime> {
#Override
public void serialize(OffsetDateTime arg0, JsonGenerator arg1, SerializerProvider arg2) throws IOException {
arg1.writeString(arg0.toString());
}
}
public static class OffsetDateTimeDeserializer extends JsonDeserializer<OffsetDateTime> {
#Override
public OffsetDateTime deserialize(JsonParser arg0, DeserializationContext arg1) throws IOException {
return OffsetDateTime.parse(arg0.getText());
}
}
public static class LocalDateSerializer extends JsonSerializer<LocalDate> {
#Override
public void serialize(LocalDate arg0, JsonGenerator arg1, SerializerProvider arg2) throws IOException {
arg1.writeString(arg0.toString());
}
}
public static class LocalDateDeserializer extends JsonDeserializer<LocalDate> {
#Override
public LocalDate deserialize(JsonParser arg0, DeserializationContext arg1) throws IOException {
return LocalDate.parse(arg0.getText());
}
}

Spring #RestController custom JSON deserializer

I want to use custom JSON deserializer for some classes(Role here) but I can't get it working. The custom deserializer just isn't called.
I use Spring Boot 1.2.
Deserializer:
public class ModelDeserializer extends JsonDeserializer<Role> {
#Override
public Role deserialize(JsonParser jsonParser, DeserializationContext deserializationContext) throws IOException, JsonProcessingException {
return null; // this is what should be called but it isn't
}
}
Controller:
#RestController
public class RoleController {
#RequestMapping(value = "/role", method = RequestMethod.POST)
public Object createRole(Role role) {
// ... this is called
}
}
#JsonDeserialize on Role
#JsonDeserialize(using = ModelDeserializer.class)
public class Role extends Model {
}
Jackson2ObjectMapperBuilder bean in Java Config
#Bean
public Jackson2ObjectMapperBuilder jacksonBuilder() {
Jackson2ObjectMapperBuilder builder = new Jackson2ObjectMapperBuilder();
builder.deserializerByType(Role.class, new ModelDeserializer());
return builder;
}
What am I doing wrong?
EDIT It is probably caused by #RestController because it works with #Controller...

First of all you don't need to override Jackson2ObjectMapperBuilder to add custom deserializer. This approach should be used when you can't add #JsonDeserialize annotation. You should use #JsonDeserialize or override Jackson2ObjectMapperBuilder.
What is missed is the #RequestBody annotation:
#RestController
public class JacksonCustomDesRestEndpoint {
#RequestMapping(value = "/role", method = RequestMethod.POST, consumes = MediaType.APPLICATION_JSON_VALUE, produces = MediaType.APPLICATION_JSON_VALUE)
#ResponseBody
public Object createRole(#RequestBody Role role) {
return role;
}
}
#JsonDeserialize(using = RoleDeserializer.class)
public class Role {
// ......
}
public class RoleDeserializer extends JsonDeserializer<Role> {
#Override
public Role deserialize(JsonParser jp, DeserializationContext ctxt) throws IOException, JsonProcessingException {
// .................
return something;
}
}

There is also another pretty interesting solution which can be helpful in case when you want to modify your JSON body before calling default deserializer. And let's imagine that you need to use some additional bean for that (use #Autowire mechanism)
Let's image situation, that you have the following controller:
#RequestMapping(value = "/order/product", method = POST)
public <T extends OrderProductInterface> RestGenericResponse orderProduct(#RequestBody #Valid T data) {
orderService.orderProduct(data);
return generateResponse();
}
Where OrderProductInterface is:
#JsonIgnoreProperties(ignoreUnknown = true)
#JsonSerialize(include = NON_EMPTY)
#JsonTypeInfo(use = JsonTypeInfo.Id.NAME, visible = true, property = "providerType")
#JsonSubTypes({
#JsonSubTypes.Type(value = OrderProductForARequestData.class, name = "A")
})
public interface OrderProductInterface{}
The code above will provide dynamic deserialization base on filed providerType and validation according to concrete implementation. For better grasp, consider that OrderProductForARequestData can be something like that:
public class OrderProductForARequestData implements OrderProductInterface {
#NotBlank(message = "is mandatory field.")
#Getter #Setter
private String providerId;
#NotBlank(message = "is mandatory field.")
#Getter #Setter
private String providerType;
#NotBlank(message = "is mandatory field.")
#Getter #Setter
private String productToOrder;
}
And let's image now that we want to init somehow providerType (enrich input) before default deserialization will be executed. so the object will be deserialized properly according to the rule in OrderProductInterface.
To do that you can just modify your #Configuration class in the following way:
//here can be any annotation which will enable MVC/Boot
#Configuration
public class YourConfiguration{
#Autowired
private ObjectMapper mapper;
#Autowired
private ProviderService providerService;
#Override
public void setup() {
super.setup();
SimpleModule module = new SimpleModule();
module.setDeserializerModifier(new BeanDeserializerModifier() {
#Override
public JsonDeserializer<?> modifyDeserializer(DeserializationConfig config, BeanDescription beanDesc, JsonDeserializer<?> deserializer) {
if (beanDesc.getBeanClass() == OrderProductInterface.class) {
return new OrderProductInterfaceDeserializer(providerService, beanDesc);
}
return deserializer;
}
});
mapper.registerModule(module);
}
public static class OrderProductInterfaceDeserializer extends AbstractDeserializer {
private static final long serialVersionUID = 7923585097068641765L;
private final ProviderService providerService;
OrderProductInterfaceDeserializer(roviderService providerService, BeanDescription beanDescription) {
super(beanDescription);
this.providerService = providerService;
}
#Override
public Object deserializeWithType(JsonParser p, DeserializationContext context, TypeDeserializer typeDeserializer) throws IOException {
ObjectCodec oc = p.getCodec();
JsonNode node = oc.readTree(p);
//Let's image that we have some identifier for provider type and we want to detect it
JsonNode tmp = node.get("providerId");
Assert.notNull(tmp, "'providerId' is mandatory field");
String providerId = tmp.textValue();
Assert.hasText(providerId, "'providerId' can't be empty");
// Modify node
((ObjectNode) node).put("providerType",providerService.getProvider(providerId));
JsonFactory jsonFactory = new JsonFactory();
JsonParser newParser = jsonFactory.createParser(node.toString());
newParser.nextToken();
return super.deserializeWithType(newParser, context, typeDeserializer);
}
}
}