Initial Question
Is it possible to have multiple #JsonCreator methods, and for jackson to detect which one it should use depending on the method definiton?
#JsonCreator
public static StateOfComm factory(String id) {
return StateOfComm.valueOf(id);
}
#JsonCreator
public static StateOfComm factory(CustomType value) {
return StateOfComm.valueOf(value.getId());
}
Update
The JSON that fails (because id=null), is the following:
{"comment":null, "processes":[{"stateOfComm":{"id":"CA"}}]}
The following works:
{"comment":null, "processes":[{"stateOfComm":"CA"}]}
I was able to parse both JSON examples in your question by:
using jackson-modules-java8 version 2.9.1 dependency
invoking the java 8 compiler with -parameters argument
introducing all argument constructors for all classes involved
avoiding #JsonProperty on static creation methods and constructors
defining a class:
class CustomType {
private final String id;
}
My understanding is that Jackson couldn't discern between multiple creators in older version. E.g. see answer here and github issue here. It seems that the option to have parameter names in compiled code in java 8 helps in this case.
I solved this problem by getting rid of the #JsonCreator annotations, and using a custom StdDeserializer that did the trick.
Here is an example:
#JsonIgnoreProperties(
ignoreUnknown = true
)
#JsonDeserialize(
using = IdTextEntry.Deserializer.class
)
#Data
public class IdTextEntry implements IdAndText {
String id;
String text;
public IdTextEntry(Enum<?> val) {
if (val != null) {
this.id = val.name();
this.text = val.toString();
}
}
public static class Deserializer extends StdDeserializer<IdTextEntry> {
public Deserializer() {
this((Class)null);
}
Deserializer(Class<?> vc) {
super(vc);
}
public IdTextEntry deserialize(JsonParser jp, DeserializationContext ctxt) throws IOException {
JsonNode node = (JsonNode)jp.getCodec().readTree(jp);
String id;
if (node.has("id") && node.has("text")) {
id = node.get("id").asText();
String text = node.get("text").asText();
return new IdTextEntry(id, text);
} else if (node.has("id")) {
id = node.get("id").asText();
return new IdTextEntry(id, id);
} else {
id = node.asText();
return new IdTextEntry(id, id);
}
}
}
}
You can have multiple #JsonCreator methods but it requires to use #JsonProperty for specifying which property you are initializing.
#JsonCreator
public static StateOfComm factory(#JsonProperty("id") String id) {
return StateOfComm.valueOf(id);
}
#JsonCreator
public static StateOfComm factory(#JsonProperty("value") CustomType value) {
return StateOfComm.valueOf(value.getId());
}
I have problems deserializing Enums that have multiple names for a value. Here is an example: Info is a Java class that inside has an enum with multiple names:
public class Info {
//...
private ContainerFormat format;
}
// ContainerFormat.java:
public enum ContainerFormat {
// ....
MP4("mp4", "mpeg4"),
UNKNOWN("null");
private String name;
private List<String> others;
ContainerFormat(String name) {
this.name = name;
}
/** The service does not always return the same String for output formats.
* This 'other' string fixes the deserialization issues caused by that.
*/
ContainerFormat(String name, String... others) {
this.name = name;
this.others = new ArrayList<String>();
for (String other : others) {
this.others.add(other);
}
}
#JsonValue
#Override
public String toString() {
return name;
}
public List<String> otherNames() {
return others;
}
#JsonCreator
public static ContainerFormat fromValue(String other) throws JsonMappingException {
for (ContainerFormat format : ContainerFormat.values()) {
if (format.toString().equalsIgnoreCase(other)) {
return format;
}
if (format.otherNames() != null && format.otherNames().contains(other)) {
return format;
}
}
return UNKNOWN;
}
}
The problem is when I deserialize something that contains "mpeg4" instead of mp4 I get this error:
com.fasterxml.jackson.databind.exc.InvalidFormatException: Can not construct instance of com.foo.ContainerFormat from String value 'mpeg4': value not one of declared Enum instance names
at [Source: N/A; line: -1, column: -1] (through reference chain: com.foo.Info["format"])
at com.fasterxml.jackson.databind.exc.InvalidFormatException.from(InvalidFormatException.java:55)
at com.fasterxml.jackson.databind.DeserializationContext.weirdStringException(DeserializationContext.java:650)
at com.fasterxml.jackson.databind.deser.std.EnumDeserializer.deserialize(EnumDeserializer.java:85)
at com.fasterxml.jackson.databind.deser.std.EnumDeserializer.deserialize(EnumDeserializer.java:20)
at com.fasterxml.jackson.databind.deser.SettableBeanProperty.deserialize(SettableBeanProperty.java:375)
at com.fasterxml.jackson.databind.deser.impl.MethodProperty.deserializeAndSet(MethodProperty.java:98)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserializeFromObject(BeanDeserializer.java:308)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:121)
at com.fasterxml.jackson.databind.ObjectMapper._readValue(ObjectMapper.java:2769)
at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:1478)
at com.fasterxml.jackson.databind.ObjectMapper.treeToValue(ObjectMapper.java:1811)
Any pointers on how to fix this?
TIA
I found a good solution based on Florin's answer:
the correct configuration with jackson 2.7.0-rc2 (and probably also before)
private ObjectMapper createObjectMapper() {
final ObjectMapper mapper = new ObjectMapper();
// enable toString method of enums to return the value to be mapped
mapper.enable(SerializationFeature.WRITE_ENUMS_USING_TO_STRING);
mapper.enable(DeserializationFeature.READ_ENUMS_USING_TO_STRING);
return mapper;
}
In your enum you just have to override the toString() method:
public enum EXAMPLE_TYPE {
START("start"),
MORE("more");
// the value which is used for matching
// the json node value with this enum
private final String value;
SectionType(final String type) {
value = type;
}
#Override
public String toString() {
return value;
}
}
You don't need any annotations or custom deserializers.
Get rid of String name and List<String> other and instead have just one field - List<String> names and serialize the single getter with #JsonValue
public enum ContainerFormat {
// ....
MP4("mp4", "mpeg4"),
UNKNOWN("null");
private List<String> names;
ContainerFormat(List<String> names) {
this.names = new ArrayList<String>(names);
}
#JsonValue
public List<String> getNames()
{
return this.names;
}
#JsonCreator
public static ContainerFormat getContainerFromValue(String value) throws JsonMappingException {
for (ContainerFormat format : ContainerFormat.values()) {
if(format.getValues().contains(value))
return format;
}
return UNKNOWN;
}
Alternatively, if you choose to keep your existing code, you could try annotating otherValues() with #JsonValue
Well, I found a workaround: one of these flags does the right thing and allows me to read that mpeg4 back in:
mapper.configure(org.codehaus.jackson.map.SerializationConfig.Feature.WRITE_NULL_PROPERTIES, false);
mapper.configure(org.codehaus.jackson.map.SerializationConfig.Feature.WRITE_ENUMS_USING_TO_STRING, true);
mapper.configure(org.codehaus.jackson.map.DeserializationConfig.Feature.READ_ENUMS_USING_TO_STRING, true);
mapper.setPropertyNamingStrategy(org.codehaus.jackson.map.PropertyNamingStrategy.CAMEL_CASE_TO_LOWER_CASE_WITH_UNDERSCORES);
mapper.setSerializationInclusion(org.codehaus.jackson.map.annotate.JsonSerialize.Inclusion.NON_EMPTY);
mapper.configure(org.codehaus.jackson.map.DeserializationConfig.Feature.FAIL_ON_UNKNOWN_PROPERTIES, false);
I am trying to convert JSON to Java object. When a certain value of a pair is null, it should be set with some default value.
Here is my POJO:
public class Student {
String rollNo;
String name;
String contact;
String school;
public String getRollNo() {
return rollNo;
}
public void setRollNo(String rollNo) {
this.rollNo = rollNo;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getSchool() {
return school;
}
public void setSchool(String school) {
this.school = school;
}
}
Example JSON object:
{
"rollNo":"123", "name":"Tony", "school":null
}
So if school is null, I should make this into a default value, such as "school":"XXX". How can I configure this with Gson while deserializing the objects?
If the null is in the JSON, Gson is going to override any defaults you might set in the POJO. You could go to the trouble of creating a custom deserializer, but that might be overkill in this case.
I think the easiest (and, arguably best given your use case) thing to do is the equivalent of Lazy Loading. For example:
private static final String DEFAULT_SCHOOL = "ABC Elementary";
public String getSchool() {
if (school == null) school == DEFAULT_SCHOOL;
return school;
}
public void setSchool(String school) {
if (school == null) this.school = DEFAULT_SCHOOL;
else this.school = school;
}
Note: The big problem with this solution is that in order to change the Defaults, you have to change the code. If you want the default value to be customizable, you should go with the custom deserializer as linked above.
I think that the way to do this is to either write your no-args constructor to fill in default values, or use a custom instance creator. The deserializer should then replace the default values for all attributes in the JSON object being deserialized.
I was having the same issue, until I found this great solution.
For reference, you can create a post-processing class:
interface PostProcessable {
fun gsonPostProcess()
}
class PostProcessingEnabler : TypeAdapterFactory {
fun <T> create(gson: Gson, type: TypeToken<T>): TypeAdapter<T> {
val delegate = gson.getDelegateAdapter(this, type)
return object : TypeAdapter<T>() {
#Throws(IOException::class)
fun write(out: JsonWriter, value: T) {
delegate.write(out, value)
}
#Throws(IOException::class)
fun read(`in`: JsonReader): T {
val obj = delegate.read(`in`)
if (obj is PostProcessable) {
(obj as PostProcessable).gsonPostProcess()
}
return obj
}
}
}
}
Register it like this:
GsonBuilder().registerTypeAdapterFactory(PostProcessingEnabler())
Implement it on your model:
class MyClass : Serializable, PostProcessable {
// All your variable data
override fun gsonPostProcess() {
// All your post processing logic you like on your object
// set default value for example
}
}
And finally use it when converting json string:
var myObject = myGson.fromJson(myObjectJson, MyClass::class)
Or using retrofit2:
val api = Retrofit.Builder()
.baseUrl(BASE_URL)
.addConverterFactory(
GsonConverterFactory.create(
GsonBuilder().registerTypeAdapterFactory(
GsonPostProcessingEnabler()
).create()
)
)
.client(OkHttpClient.Builder().build())
.build()
.create(AccountApi::class.java)
You can simply make a universal function that checks for null
model.SchoolName= stringNullChecker(model.SchoolName);
public static String stringNullChecker(String val) {
if (null == val) val = "";
return val;
}
I'm using JAVA 1.6 and Jackson 1.9.9 I've got an enum
public enum Event {
FORGOT_PASSWORD("forgot password");
private final String value;
private Event(final String description) {
this.value = description;
}
#JsonValue
final String value() {
return this.value;
}
}
I've added a #JsonValue, this seems to do the job it serializes the object into:
{"event":"forgot password"}
but when I try to deserialize I get a
Caused by: org.codehaus.jackson.map.JsonMappingException: Can not construct instance of com.globalrelay.gas.appsjson.authportal.Event from String value 'forgot password': value not one of declared Enum instance names
What am I missing here?
The serializer / deserializer solution pointed out by #xbakesx is an excellent one if you wish to completely decouple your enum class from its JSON representation.
Alternatively, if you prefer a self-contained solution, an implementation based on #JsonCreator and #JsonValue annotations would be more convenient.
So leveraging on the example by #Stanley the following is a complete self-contained solution (Java 6, Jackson 1.9):
public enum DeviceScheduleFormat {
Weekday,
EvenOdd,
Interval;
private static Map<String, DeviceScheduleFormat> namesMap = new HashMap<String, DeviceScheduleFormat>(3);
static {
namesMap.put("weekday", Weekday);
namesMap.put("even-odd", EvenOdd);
namesMap.put("interval", Interval);
}
#JsonCreator
public static DeviceScheduleFormat forValue(String value) {
return namesMap.get(StringUtils.lowerCase(value));
}
#JsonValue
public String toValue() {
for (Entry<String, DeviceScheduleFormat> entry : namesMap.entrySet()) {
if (entry.getValue() == this)
return entry.getKey();
}
return null; // or fail
}
}
Note that as of this commit in June 2015 (Jackson 2.6.2 and above) you can now simply write:
public enum Event {
#JsonProperty("forgot password")
FORGOT_PASSWORD;
}
The behavior is documented here: https://fasterxml.github.io/jackson-annotations/javadoc/2.11/com/fasterxml/jackson/annotation/JsonProperty.html
Starting with Jackson 2.6 this annotation may also be used to change serialization of Enum like so:
public enum MyEnum {
#JsonProperty("theFirstValue") THE_FIRST_VALUE,
#JsonProperty("another_value") ANOTHER_VALUE;
}
as an alternative to using JsonValue annotation.
You should create a static factory method which takes single argument and annotate it with #JsonCreator (available since Jackson 1.2)
#JsonCreator
public static Event forValue(String value) { ... }
Read more about JsonCreator annotation here.
Actual Answer:
The default deserializer for enums uses .name() to deserialize, so it's not using the #JsonValue. So as #OldCurmudgeon pointed out, you'd need to pass in {"event": "FORGOT_PASSWORD"} to match the .name() value.
An other option (assuming you want the write and read json values to be the same)...
More Info:
There is (yet) another way to manage the serialization and deserialization process with Jackson. You can specify these annotations to use your own custom serializer and deserializer:
#JsonSerialize(using = MySerializer.class)
#JsonDeserialize(using = MyDeserializer.class)
public final class MyClass {
...
}
Then you have to write MySerializer and MyDeserializer which look like this:
MySerializer
public final class MySerializer extends JsonSerializer<MyClass>
{
#Override
public void serialize(final MyClass yourClassHere, final JsonGenerator gen, final SerializerProvider serializer) throws IOException, JsonProcessingException
{
// here you'd write data to the stream with gen.write...() methods
}
}
MyDeserializer
public final class MyDeserializer extends org.codehaus.jackson.map.JsonDeserializer<MyClass>
{
#Override
public MyClass deserialize(final JsonParser parser, final DeserializationContext context) throws IOException, JsonProcessingException
{
// then you'd do something like parser.getInt() or whatever to pull data off the parser
return null;
}
}
Last little bit, particularly for doing this to an enum JsonEnum that serializes with the method getYourValue(), your serializer and deserializer might look like this:
public void serialize(final JsonEnum enumValue, final JsonGenerator gen, final SerializerProvider serializer) throws IOException, JsonProcessingException
{
gen.writeString(enumValue.getYourValue());
}
public JsonEnum deserialize(final JsonParser parser, final DeserializationContext context) throws IOException, JsonProcessingException
{
final String jsonValue = parser.getText();
for (final JsonEnum enumValue : JsonEnum.values())
{
if (enumValue.getYourValue().equals(jsonValue))
{
return enumValue;
}
}
return null;
}
I've found a very nice and concise solution, especially useful when you cannot modify enum classes as it was in my case. Then you should provide a custom ObjectMapper with a certain feature enabled. Those features are available since Jackson 1.6. So you only need to write toString() method in your enum.
public class CustomObjectMapper extends ObjectMapper {
#PostConstruct
public void customConfiguration() {
// Uses Enum.toString() for serialization of an Enum
this.enable(WRITE_ENUMS_USING_TO_STRING);
// Uses Enum.toString() for deserialization of an Enum
this.enable(READ_ENUMS_USING_TO_STRING);
}
}
There are more enum-related features available, see here:
https://github.com/FasterXML/jackson-databind/wiki/Serialization-Features
https://github.com/FasterXML/jackson-databind/wiki/Deserialization-Features
Try this.
public enum Event {
FORGOT_PASSWORD("forgot password");
private final String value;
private Event(final String description) {
this.value = description;
}
private Event() {
this.value = this.name();
}
#JsonValue
final String value() {
return this.value;
}
}
I like the accepted answer. However, I would improve it a little (considering that there is now Java higher than version 6 available).
Example:
public enum Operation {
EQUAL("eq"),
NOT_EQUAL("ne"),
LESS_THAN("lt"),
GREATER_THAN("gt");
private final String value;
Operation(String value) {
this.value = value;
}
#JsonValue
public String getValue() {
return value;
}
#JsonCreator
public static Operation forValue(String value) {
return Arrays.stream(Operation.values())
.filter(op -> op.getValue().equals(value))
.findFirst()
.orElseThrow(); // depending on requirements: can be .orElse(null);
}
}
You can customize the deserialization for any attribute.
Declare your deserialize class using the annotationJsonDeserialize (import com.fasterxml.jackson.databind.annotation.JsonDeserialize) for the attribute that will be processed. If this is an Enum:
#JsonDeserialize(using = MyEnumDeserialize.class)
private MyEnum myEnum;
This way your class will be used to deserialize the attribute. This is a full example:
public class MyEnumDeserialize extends JsonDeserializer<MyEnum> {
#Override
public MyEnum deserialize(JsonParser jsonParser, DeserializationContext deserializationContext) throws IOException {
JsonNode node = jsonParser.getCodec().readTree(jsonParser);
MyEnum type = null;
try{
if(node.get("attr") != null){
type = MyEnum.get(Long.parseLong(node.get("attr").asText()));
if (type != null) {
return type;
}
}
}catch(Exception e){
type = null;
}
return type;
}
}
Here is another example that uses string values instead of a map.
public enum Operator {
EQUAL(new String[]{"=","==","==="}),
NOT_EQUAL(new String[]{"!=","<>"}),
LESS_THAN(new String[]{"<"}),
LESS_THAN_EQUAL(new String[]{"<="}),
GREATER_THAN(new String[]{">"}),
GREATER_THAN_EQUAL(new String[]{">="}),
EXISTS(new String[]{"not null", "exists"}),
NOT_EXISTS(new String[]{"is null", "not exists"}),
MATCH(new String[]{"match"});
private String[] value;
Operator(String[] value) {
this.value = value;
}
#JsonValue
public String toStringOperator(){
return value[0];
}
#JsonCreator
public static Operator fromStringOperator(String stringOperator) {
if(stringOperator != null) {
for(Operator operator : Operator.values()) {
for(String operatorString : operator.value) {
if (stringOperator.equalsIgnoreCase(operatorString)) {
return operator;
}
}
}
}
return null;
}
}
There are various approaches that you can take to accomplish deserialization of a JSON object to an enum. My favorite style is to make an inner class:
import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonFormat;
import com.fasterxml.jackson.annotation.JsonProperty;
import org.hibernate.validator.constraints.NotEmpty;
import java.util.Arrays;
import java.util.Map;
import java.util.function.Function;
import java.util.stream.Collectors;
import static com.fasterxml.jackson.annotation.JsonFormat.Shape.OBJECT;
#JsonFormat(shape = OBJECT)
public enum FinancialAccountSubAccountType {
MAIN("Main"),
MAIN_DISCOUNT("Main Discount");
private final static Map<String, FinancialAccountSubAccountType> ENUM_NAME_MAP;
static {
ENUM_NAME_MAP = Arrays.stream(FinancialAccountSubAccountType.values())
.collect(Collectors.toMap(
Enum::name,
Function.identity()));
}
private final String displayName;
FinancialAccountSubAccountType(String displayName) {
this.displayName = displayName;
}
#JsonCreator
public static FinancialAccountSubAccountType fromJson(Request request) {
return ENUM_NAME_MAP.get(request.getCode());
}
#JsonProperty("name")
public String getDisplayName() {
return displayName;
}
private static class Request {
#NotEmpty(message = "Financial account sub-account type code is required")
private final String code;
private final String displayName;
#JsonCreator
private Request(#JsonProperty("code") String code,
#JsonProperty("name") String displayName) {
this.code = code;
this.displayName = displayName;
}
public String getCode() {
return code;
}
#JsonProperty("name")
public String getDisplayName() {
return displayName;
}
}
}
In the context of an enum, using #JsonValue now (since 2.0) works for serialization and deserialization.
According to the jackson-annotations javadoc for #JsonValue:
NOTE: when use for Java enums, one additional feature is that value returned by annotated method is also considered to be the value to deserialize from, not just JSON String to serialize as. This is possible since set of Enum values is constant and it is possible to define mapping, but can not be done in general for POJO types; as such, this is not used for POJO deserialization.
So having the Event enum annotated just as above works (for both serialization and deserialization) with jackson 2.0+.
Besides using #JsonSerialize #JsonDeserialize, you can also use SerializationFeature and DeserializationFeature (jackson binding) in the object mapper.
Such as DeserializationFeature.READ_UNKNOWN_ENUM_VALUES_USING_DEFAULT_VALUE, which give default enum type if the one provided is not defined in the enum class.
In my case, this is what resolved:
import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonFormat;
import com.fasterxml.jackson.annotation.JsonProperty;
#JsonFormat(shape = JsonFormat.Shape.OBJECT)
public enum PeriodEnum {
DAILY(1),
WEEKLY(2),
;
private final int id;
PeriodEnum(int id) {
this.id = id;
}
public int getId() {
return id;
}
public String getName() {
return this.name();
}
#JsonCreator
public static PeriodEnum fromJson(#JsonProperty("name") String name) {
return valueOf(name);
}
}
Serializes and deserializes the following json:
{
"id": 2,
"name": "WEEKLY"
}
I hope it helps!
#JsonFormat(shape = JsonFormat.Shape.OBJECT)
public enum LoginOptionType {
PHONE(1, "Phone"), MAIL(2, "mail"), PERSONAL_EMAIL(3, "Personal email");
private static List<LoginOptionType> all;
static {
all = new ArrayList<LoginOptionType>() {
{
add(LoginOptionType.PHONE);
add(LoginOptionType.MAIL);
add(LoginOptionType.PERSONAL_EMAIL);
}
};
}
private final Integer viewValue;
private final String name;
LoginOptionType(Integer viewValue, String name) {
this.viewValue = viewValue;
this.name = name;
}
public Integer getViewValue() {
return viewValue;
}
public String getName() {
return name;
}
public static List<LoginOptionType> getAll() {
return all;
}
}
Response
[
{
"viewValue": 1,
"name": "Phone"
},
{
"viewValue": 2,
"name": "mail"
},
{
"viewValue": 3,
"name": "Personal email"
}
]
Here, 'value' acts as a deserialiser and 'namespace' acts as a serialiser. Hence, you can pass in value "Student Absent" to API while saving, and in DB it will be saved as "STUDENT_ABSENT". On the other hand, while retrieving data in your class, your API will return "Student Absent"
import com.fasterxml.jackson.annotation.JsonProperty;
public enum AttendanceEnums {
STUDENT_PRESENT,
#JsonProperty(value = "Student Absent", namespace = "Student Absent")
STUDENT_ABSENT;
}
I had been looking for a solution to enum serialization and I finally made a solution.
https://github.com/sirgilligan/EnumerationSerialization
https://digerati-illuminatus.blogspot.com/2022/10/java-enum-generic-serializer-and.html
It uses a new annotation and two new classes, EnumerationSerializer and EnumerationDeserializer. You can subclass the EnumerationDeserializer and make a class that sets the enum Class (typical approach) or you can annotate the enum and you don't have to have a subclass of EnumerationDeserializer.
#JsonSerialize(using = EnumerationSerializer.class)
#JsonDeserialize(using = EnumerationDeserializer.class)
#EnumJson(serializeProjection = Projection.NAME, deserializationClass = RGB.class)
enum RGB {
RED,
GREEN,
BLUE
}
Notice how the implementation of ContextualDeserializer pulls the class from the annotation.
https://github.com/sirgilligan/EnumerationSerialization/blob/main/src/main/java/org/example/EnumerationDeserializer.java
There is a lot of good code in this that might give insights.
For your specific question you could do this:
#JsonSerialize(using = EnumerationSerializer.class)
#JsonDeserialize(using = EnumerationDeserializer.class)
#EnumJson(serializeProjection = Projection.NAME, deserializationClass = Event.class)
public enum Event {
FORGOT_PASSWORD("forgot password");
//This annotation is optional because the code looks for value or alias.
#EnumJson(serializeProjection = Projection.VALUE)
private final String value;
private Event(final String description) {
this.value = description;
}
}
Or you could do this:
#JsonSerialize(using = EnumerationSerializer.class)
#JsonDeserialize(using = EnumerationDeserializer.class)
#EnumJson(serializeProjection = Projection.NAME, deserializationClass = Event.class)
public enum Event {
FORGOT_PASSWORD("forgot password");
private final String value;
private Event(final String description) {
this.value = description;
}
}
That's all you have to do.
Then if you have a class that "has a" event you can annotate each occurance to serialize the way you want.
class EventHolder {
#EnumJson(serializeProjection = Projection.NAME)
Event someEvent;
#EnumJson(serializeProjection = Projection.ORDINAL)
Event someOtherEvent;
#EnumJson(serializeProjection = Projection.VALUE)
Event yetAnotherEvent;
}
The simplest way I found is using #JsonFormat.Shape.OBJECT annotation for the enum.
#JsonFormat(shape = JsonFormat.Shape.OBJECT)
public enum MyEnum{
....
}
I did it like this :
// Your JSON
{"event":"forgot password"}
// Your class to map
public class LoggingDto {
#JsonProperty(value = "event")
private FooEnum logType;
}
//Your enum
public enum FooEnum {
DATA_LOG ("Dummy 1"),
DATA2_LOG ("Dummy 2"),
DATA3_LOG ("forgot password"),
DATA4_LOG ("Dummy 4"),
DATA5_LOG ("Dummy 5"),
UNKNOWN ("");
private String fullName;
FooEnum(String fullName) {
this.fullName = fullName;
}
public String getFullName() {
return fullName;
}
#JsonCreator
public static FooEnum getLogTypeFromFullName(String fullName) {
for (FooEnum logType : FooEnum.values()) {
if (logType.fullName.equals(fullName)) {
return logType;
}
}
return UNKNOWN;
}
}
So the value of the property "logType" for class LoggingDto will be DATA3_LOG
This post is old, but if it can help someone, use JsonFormat.Shape.STRING
#JsonFormat(shape = JsonFormat.Shape.STRING)
public enum SomeEnum{
#JsonProperty("SOME_PROPERTY")
someProperty,
...
}
Code results is like this
{"someenum":"SOME_PROPERTY"}