I've defined the following set of data
Response response = new Response();
List<ObjectTest> objList = new ArrayList<ObjectTest>();
objList.add(new ObjectTest(new Attributes(new FirstName("ab","1"),new LastName("hernandez","2"))));
objList.add(new ObjectTest(new Attributes(new FirstName("jose","1"),new LastName("perez","2"))));
objList.add(new ObjectTest(new Attributes(new FirstName("paco","2"),new LastName("jackson","2"))));
objList.add(new ObjectTest(new Attributes(new FirstName("pedro","1"),new LastName("herrera","2"))));
objList.add(new ObjectTest(new Attributes(new FirstName("juan","2"),new LastName("flores","2"))));
response.setObjectList(objList);
So based on what the user selects I need to be able to get the specific class and the attribute, for example:
if the user selects [Attributes - FirstName - value] the output would be :
ab
jose
paco
pedro
juan
if the user selects [Attributes - LastName- status] the output would be:
2
2
2
2
2
The problem here is that I dont know how to get the specific class in runtime. Also the main object could have any number of classes inside of it like MainClass.ClassA.ClasstB.ClassX.classAttributeValue. The only thing that I know is that the last value is going to be the one that I have to take in that case I have to print classAttributeValue . Any ideas how to solve this using java 8 ?
Assuming your class structure looks something like this:
public static abstract class Attribute {
public final String value;
public final String status;
public Attribute(String value, String status) {
this.value = value;
this.status = status;
}
}
public static class FirstName extends Attribute {
public FirstName(String value, String status) {
super(value, status);
}
}
public static class LastName extends Attribute {
public LastName(String value, String status) {
super(value, status);
}
}
public static class Attributes {
public final FirstName firstName;
public final LastName lastName;
public Attributes(FirstName firstName, LastName lastName) {
this.firstName = firstName;
this.lastName = lastName;
}
}
public static class ObjectTest {
public final Attributes attributes;
public ObjectTest(Attributes attributes) {
this.attributes = attributes;
}
}
You can define java.util.function.Function accessors for each stage:
Function<ObjectTest, Attributes> attributes = t -> t.attributes;
Function<Attributes, FirstName> firstName = t -> t.firstName;
Function<Attributes, LastName> lastName = t -> t.lastName;
Function<Attribute, String> value = t -> t.value;
Function<Attribute, String> status = t -> t.status;
And combine them like so:
Function<ObjectTest, String> attributeFirstNameValue =
attributes.andThen(firstName).andThen(value);
Function<ObjectTest, String> attributeLastNameStatus =
attributes.andThen(lastName).andThen(status);
Then apply the combined accessor to the list:
objList.stream().map(attributeFirstNameValue).forEach(System.out::println);
objList.stream().map(attributeLastNameStatus).forEach(System.out::println);
Is it critical to use this class structure?
In your example using a associative container is more suitable.
For example you can create class with structure like this:
Firstly you shoud something for itterate by Tree:
class DynamicObjectNode {
private HashMap<String, DynamicObjectNode> childs = new HashMap<>();
public HashMap<String, DynamicObjectNode> getChilds() {
return childs;
}
}
All values should be in leafs:
class DynamicObjectNodeValue<T> extends DynamicObjectNode {
public DynamicObjectNodeValue(T value) {
this.value = value;
}
private T value;
public T getValue() {
return value;
}
public void setValue(T value) {
this.value = value;
}
#Override
public HashMap<String, DynamicObjectNode> getChilds() {
return null; //Tree leafs should not has childs
}
}
If you need to work with this as objects. You can use wrapped class like this:
class FirstNameAttribute extends DynamicObjectNode{
private static final String NameValueProperty = "NameValue";
private static final String StatusProperty = "Status";
private DynamicObjectNodeValue<String> nameValue = new DynamicObjectNodeValue<String>("Default name");
private DynamicObjectNodeValue<Integer> status = new DynamicObjectNodeValue<Integer>(1);
public FirstNameAttribute() {
getChilds().put(NameValueProperty, nameValue);
getChilds().put(StatusProperty, status);
}
public String getName() {
return nameValue.getValue();
}
public Integer getStatus() {
return status.getValue();
}
public void setName(String val) {
nameValue.setValue(val);
}
public void setStatus(Integer val) {
status.setValue(val);
}
}
So, with this code you can iterate it as a Tree and get values Dynamic.
And you can use this as objects to call some methods.
Thank you for your responses, what I finally did was to use JsonNode and based on the attribute I wanted to get I was iterating the same object and assign the result to se same object for example:
Json Response:
Object.Person1.firstName.value
I created an array of that and split it by "." then I created a for and I used this
jsonNode = jsonNode.get(inputArray[x]);
at the end the last element of the array is the one that I need so I added some logic to get it.
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!
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"}
#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"
}
]
I have a problem which seems to have a simple solution but I haven't been able to solve for months:
I'm trying to POST/PUT JSONs, and having the server recognize and deserialize them as their corresponding classes. But the server is not able to parse the entity, and returns a 500 error code.
This has to do with the fact that the generated code expects an interface (Apple) instead of a 'normal' Java class (AppleImpl).
I know this because the methods work if I change the interface (Apple) with the implementation (AppleImpl) in the endpoint, since the server detects the type and deserializes it correctly, but it is tedious and error-prone to manually change the interfaces to implementations every time that a change is made in the RAML.
In the Java backend, I'm using an entity, interface and endpoint, all of which were generated using raml-to-jax-rs v3.0.2. I'm using Maven with Jersey (jersey-bom) v2.27.
To summarize, I would like to know how to successfully deserialize an interface in Jersey/JAX-RS. Am I missing an annotation, are my Maven package versions wrong, or is it something else?
I would very much appreciate if someone could help me with this, and I will provide more information if necessary. Below is some sample generated code so that the problem is clearer.
Sample generated code:
(1/3) Sample generated interface Apple:
#JsonDeserialize(
as = AppleImpl.class
)
public interface Apple {
#JsonAnyGetter
Map<String, Object> getAdditionalProperties();
#JsonAnySetter
void setAdditionalProperties(String key, Object value);
#JsonProperty("name")
String getName();
#JsonProperty("name")
void setName(String name);
#JsonProperty("values")
List<String> getValues();
#JsonProperty("values")
void setValues(List<String> values);
#JsonProperty("defaultValue")
String getDefaultValue();
#JsonProperty("defaultValue")
void setDefaultValue(String defaultValue);
}
(2/3) Sample generated class AppleImpl:
#JsonInclude(JsonInclude.Include.NON_NULL)
#JsonPropertyOrder({
"name",
"values",
"defaultValue"
})
public class AppleImpl implements Apple {
#NotNull
#JsonProperty("name")
private String name;
#JsonProperty("values")
#NotNull
private List<String> values;
#JsonProperty("defaultValue")
#NotNull
private String defaultValue;
#JsonIgnore
private Map<String, Object> additionalProperties = new HashMap<String, Object>();
#JsonProperty("name")
public String getName() {
return this.name;
}
#JsonProperty("name")
public void setName(String name) {
this.name = name;
}
#JsonProperty("values")
public List<String> getValues() {
return this.values;
}
#JsonProperty("values")
public void setValues(List<String> values) {
this.values = values;
}
#JsonProperty("defaultValue")
public String getDefaultValue() {
return this.defaultValue;
}
#JsonProperty("defaultValue")
public void setDefaultValue(String defaultValue) {
this.defaultValue = defaultValue;
}
#JsonAnyGetter
public Map<String, Object> getAdditionalProperties() {
return additionalProperties;
}
#JsonAnySetter
public void setAdditionalProperties(String key, Object value) {
this.additionalProperties.put(key, value);
}
#Override
public boolean equals(Object o) {
if (o == null) return false;
if (this == o) return true;
if (getClass() != o.getClass()) return false;
AppleImpl other = (AppleImpl) o;
return java.util.Objects.equals(this.name, other.name) && java.util.Objects.equals(this.values, other.values) && java.util.Objects.equals(this.defaultValue, other.defaultValue) && java.util.Objects.equals(this.additionalProperties, other.additionalProperties);
}
#Override
public int hashCode() {
return Objects.hash(name,values,defaultValue,additionalProperties);
}
}
(3/3) Sample generated POST endpoint:
#Override
public PostApplesResponse postApples(String xSessionToken, Apple bean) {
try {
MUser user = AuthUtils.authenticates(xSessionToken);
ModelMapperApple.get().validateBean(bean);
MApple entity = ModelMapperApple.get().b2e(bean);
MApple entityOut = AppleService.getInstance().post(user, entity);
AppleResponse beanOut = ModelMapperApple.get().e2b(entityOut);
return PostApplesResponse.respond201WithApplicationJson(beanOut);
} catch (BadRequestException e) {
CRUDUtils.logException(e);
return PostApplesResponse.respond400WithApplicationJson(ErrorMessageUtils.build(e));
} catch (UnauthorizedException e) {
CRUDUtils.logException(e);
return PostApplesResponse.respond401();
} catch (ConflictException e) {
CRUDUtils.logException(e);
return PostApplesResponse.respond409();
} catch (Exception e) {
CRUDUtils.logException(e);
return PostApplesResponse.respond500();
}
}
application.properties file contains properties that have sub properties:
status.available=00, STATUS.ALLOWED
status.forbidden=01, STATUS.FORBIDDEN
status.authdenied=05, STATUS.AUTH_DENIED
The idea was to get those properties into the application like this:
#Configuration
#ConfigurationProperties(prefix = "status")
#JsonAutoDetect(fieldVisibility = JsonAutoDetect.Visibility.NONE)
public class StatusProperties {
private Map <String, List <String>> statusMapping;
public Map <String, List <String>> getStatusMapping () {
return statusMapping;
}
public void setStatusMapping (Map <String, List <String>> statusMapping) {
this.statusMapping = statusMapping;
}
}
The problem is that this Map is returned empty. I must be doing something wrong. Maybe this is not even possible in Spring to do like this?
I'm not sure about your choice regarding the data type and its assignment. I'd suggest you to rethink this design.
To your main question:
Spring can't know, that status.* should be mapped to private Map <String, List <String>> statusMapping;. Also as your class is named *properties, It seems that you don't want it to be a #Configuration class. Consider the following pattern:
First, create a properties class to hold the properties:
#ConfigurationProperties(prefix = "status")
public class StatusProperties {
private Map.Entry<Integer, String> available;
private Map.Entry<Integer, String> forbidden;
private Map.Entry<Integer, String> authdenied;
public Map.Entry<Integer, String> getAvailable() {
return available;
}
public void setAvailable(Map.Entry<Integer, String> available) {
this.available = available;
}
public Map.Entry<Integer, String> getForbidden() {
return forbidden;
}
public void setForbidden(Map.Entry<Integer, String> forbidden) {
this.forbidden = forbidden;
}
public Map.Entry<Integer, String> getAuthdenied() {
return authdenied;
}
public void setAuthdenied(Map.Entry<Integer, String> authdenied) {
this.authdenied = authdenied;
}
}
Now, your IDE should be able to read the docs from the setters while editing application.properties and check the validity. Spring can autowire the fields and automatically create the correct data types for you.
Consider mapping the Entries to a Map (Or, as I already told, change the design)
Now, you can use this properties class in your configuration:
#Configuration
#EnableConfigurationProperties(StatusProperties.class)
public class StatusConfiguration {
#Bean
public MyBean myBean(StatusProperties properties) {
return new MyBean(properties);
}
}
I found the solution:
application.properties:
app.statuses[0].id=00
app.statuses[0].title=STATUS.ALLOWED
app.statuses[1].id=01
app.statuses[1].title=STATUS.FORBIDDEN
app.statuses[2].id=02
app.statuses[2].title=STATUS.CONTRACT_ENDED
Properties.java
#Component
#ConfigurationProperties(prefix = "app")
#JsonAutoDetect(fieldVisibility = JsonAutoDetect.Visibility.NONE)
public class StatusProperties {
private List<Status> statuses = new ArrayList<>();
public List <Status> getStatuses () {
return statuses;
}
public void setStatuses (List <Status> statuses) {
this.statuses = statuses;
}
public static class Status {
private String id;
private String title;
public String getId () {
return id;
}
public void setId (String id) {
this.id = id;
}
public String getTitle () {
return title;
}
public void setTitle (String title) {
this.title = title;
}
}
}
I have a class DocumentBO which has the following attributes -
public class DocumentBO implements IStorageBO {
private String aId;
private String studyId;
private Map<AlgorithmsEnum, JobIOStatus> status;
private String text;
private Collection<Sentence> sentences;
public String getaId() {
return aId;
}
public void setaId(String aId) {
this.aId = aId;
}
public String getStudyId() {
return studyId;
}
public void setStudyId(String studyId) {
this.studyId = studyId;
}
public Map<AlgorithmsEnum, JobIOStatus> getStatus() {
return status;
}
public void setStatus(Map<AlgorithmsEnum, JobIOStatus> status) {
this.status = status;
}
public String getText() {
return text;
}
public void setText(String text) {
this.text = text;
}
public Collection<Sentence> getSentences() {
return sentences;
}
public void setSentences(Collection<Sentence> sentences) {
this.sentences = sentences;
}
}
The AlgorithmsEnum is as follows -
public enum AlgorithmsEnum {
SENTIMENT("sentiment"),
INTENTION("intention"),
TOPIC("topic"),
NER("ner"),
UIMA("uima");
private final String value;
private AlgorithmsEnum(String value) {
this.value = value;
}
public String value() {
return value;
}
#Override
public String toString() {
return value;
}
public static AlgorithmsEnum fromValue(String value) {
if (value != null) {
for (AlgorithmsEnum aEnum : AlgorithmsEnum.values()) {
if (aEnum.value().equals(value)) {
return aEnum;
}
}
}
return null;
}
}
The JobIOStatus is also similar.
I am successfully able to create a JSON string of Collection using GSON using the following TypeToken
Type type = new TypeToken<Collection<DocumentBO>>() {}.getType();
But, when I try to recreate the Collection object using the JSON string returned by Gson and the same TypeToken, the key of the status hashmap is always returned as NULL whereas the value is successfully created. What do you think can be the issue?
The problem is that you have overridden toString() in your enum.
If you look at the JSON being produced, the keys to your Map<AlgorithmsEnum, JobIOStatus> are the lowercase names you're creating. That won't work. Gson has no idea how to recreate the enum from those when you attempt to deserialize the JSON.
If you remove your toString() method it will work just fine.
Alternatively you can use the .enableComplexMapKeySerialization() method in GsonBuilder when serializing which will ignore your toString() method and produce JSON using the default representations of your enum values which is what is required.
There are "well" known :) issues of Gson to serialize Map when the key is derived from object and its not a "native" data type.
Please use this
GsonBuilder builder = new GsonBuilder();
Gson gson = builder.enableComplexMapKeySerialization().create();
Collection<DocumentBO> obj = gson.fromJson(str, type);