Package com.fasterxml.jackson.databind.deser.std

Class EnumDeserializer

java.lang.Object

com.fasterxml.jackson.databind.JsonDeserializer<T>

com.fasterxml.jackson.databind.deser.std.StdDeserializer<T>

com.fasterxml.jackson.databind.deser.std.StdScalarDeserializer<java.lang.Object>

com.fasterxml.jackson.databind.deser.std.EnumDeserializer

All Implemented Interfaces:

ContextualDeserializer, NullValueProvider, ValueInstantiator.Gettable, java.io.Serializable

public class EnumDeserializer
extends StdScalarDeserializer<java.lang.Object>
implements ContextualDeserializer

Deserializer class that can deserialize instances of specified Enum class from Strings and Integers.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class com.fasterxml.jackson.databind.JsonDeserializer

JsonDeserializer.None

Constructor Summary

Constructors

Constructor	Description
EnumDeserializer(EnumResolver byNameResolver)	Deprecated. Since 2.9
EnumDeserializer(EnumResolver byNameResolver, java.lang.Boolean caseInsensitive)

Method Summary

Modifier and Type	Method	Description
JsonDeserializer<?>	createContextual(DeserializationContext ctxt, BeanProperty property)	Method called to see if a different (or differently configured) deserializer is needed to deserialize values of specified property.
java.lang.Object	deserialize(JsonParser p, DeserializationContext ctxt)	Method that can be called to ask implementation to deserialize JSON content into the value type this serializer handles.
static JsonDeserializer<?>	deserializerForCreator(DeserializationConfig config, java.lang.Class<?> enumClass, AnnotatedMethod factory)	Deprecated. Since 2.8
static JsonDeserializer<?>	deserializerForCreator(DeserializationConfig config, java.lang.Class<?> enumClass, AnnotatedMethod factory, ValueInstantiator valueInstantiator, SettableBeanProperty[] creatorProps)	Factory method used when Enum instances are to be deserialized using a creator (static factory method)
static JsonDeserializer<?>	deserializerForNoArgsCreator(DeserializationConfig config, java.lang.Class<?> enumClass, AnnotatedMethod factory)	Factory method used when Enum instances are to be deserialized using a zero-/no-args factory method
java.lang.Object	getEmptyValue(DeserializationContext ctxt)	Method called to determine value to be used for "empty" values (most commonly when deserializing from empty JSON Strings).
boolean	isCachable()	Because of costs associated with constructing Enum resolvers, let's cache instances by default.
LogicalType	logicalType()	Method for accessing logical type of values this deserializer produces.
EnumDeserializer	withResolved(java.lang.Boolean caseInsensitive)

Methods inherited from class com.fasterxml.jackson.databind.deser.std.StdScalarDeserializer

deserialize, deserializeWithType, getEmptyAccessPattern, getNullAccessPattern, supportsUpdate

Methods inherited from class com.fasterxml.jackson.databind.deser.std.StdDeserializer

getValueClass, getValueInstantiator, getValueType, getValueType, handledType

Methods inherited from class com.fasterxml.jackson.databind.JsonDeserializer

deserializeWithType, findBackReference, getAbsentValue, getDelegatee, getEmptyValue, getKnownPropertyNames, getNullValue, getNullValue, getObjectIdReader, replaceDelegatee, unwrappingDeserializer

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

EnumDeserializer

public EnumDeserializer(EnumResolver byNameResolver,
                        java.lang.Boolean caseInsensitive)

Since:

2.9

EnumDeserializer

@Deprecated
public EnumDeserializer(EnumResolver byNameResolver)

Deprecated.

Since 2.9

Method Detail

deserializerForCreator

@Deprecated
public static JsonDeserializer<?> deserializerForCreator(DeserializationConfig config,
                                                         java.lang.Class<?> enumClass,
                                                         AnnotatedMethod factory)

Deprecated.

Since 2.8

deserializerForCreator

public static JsonDeserializer<?> deserializerForCreator(DeserializationConfig config,
                                                         java.lang.Class<?> enumClass,
                                                         AnnotatedMethod factory,
                                                         ValueInstantiator valueInstantiator,
                                                         SettableBeanProperty[] creatorProps)

Factory method used when Enum instances are to be deserialized using a creator (static factory method)

Returns:

Deserializer based on given factory method

Since:

2.8

deserializerForNoArgsCreator

public static JsonDeserializer<?> deserializerForNoArgsCreator(DeserializationConfig config,
                                                               java.lang.Class<?> enumClass,
                                                               AnnotatedMethod factory)

Factory method used when Enum instances are to be deserialized using a zero-/no-args factory method

Returns:

Deserializer based on given no-args factory method

Since:

2.8

withResolved

public EnumDeserializer withResolved(java.lang.Boolean caseInsensitive)

Since:

2.9

createContextual

public JsonDeserializer<?> createContextual(DeserializationContext ctxt,
                                            BeanProperty property)
                                     throws JsonMappingException

Description copied from interface: ContextualDeserializer

Method called to see if a different (or differently configured) deserializer is needed to deserialize values of specified property. Note that instance that this method is called on is typically shared one and as a result method should NOT modify this instance but rather construct and return a new instance. This instance should only be returned as-is, in case it is already suitable for use.

Specified by:

createContextual in interface ContextualDeserializer

Parameters:

ctxt - Deserialization context to access configuration, additional deserializers that may be needed by this deserializer

property - Method, field or constructor parameter that represents the property (and is used to assign deserialized value). Should be available; but there may be cases where caller cannot provide it and null is passed instead (in which case impls usually pass 'this' deserializer as is)

Returns:

Deserializer to use for deserializing values of specified property; may be this instance or a new instance.

Throws:

JsonMappingException

isCachable

public boolean isCachable()

Because of costs associated with constructing Enum resolvers, let's cache instances by default.

Overrides:

isCachable in class JsonDeserializer<java.lang.Object>

logicalType

public LogicalType logicalType()

Description copied from class: JsonDeserializer

Method for accessing logical type of values this deserializer produces. Typically used for further configuring handling of values, for example, to find which coercions are legal.

Overrides:

logicalType in class StdScalarDeserializer<java.lang.Object>

Returns:

Logical type of values this deserializer produces, if known; null if not

getEmptyValue

public java.lang.Object getEmptyValue(DeserializationContext ctxt)
                               throws JsonMappingException

Description copied from class: JsonDeserializer

Method called to determine value to be used for "empty" values (most commonly when deserializing from empty JSON Strings). Usually this is same as JsonDeserializer.getNullValue(com.fasterxml.jackson.databind.DeserializationContext) (which in turn is usually simply Java null), but it can be overridden for specific types. Or, if type should never be converted from empty String, method can also throw an exception.

This method may be called once, or multiple times, depending on what JsonDeserializer.getEmptyAccessPattern() returns.

Default implementation simply calls JsonDeserializer.getNullValue(com.fasterxml.jackson.databind.DeserializationContext) and returns value.

Overrides:

getEmptyValue in class JsonDeserializer<java.lang.Object>

Throws:

JsonMappingException

deserialize

public java.lang.Object deserialize(JsonParser p,
                                    DeserializationContext ctxt)
                             throws java.io.IOException

Description copied from class: JsonDeserializer

Method that can be called to ask implementation to deserialize JSON content into the value type this serializer handles. Returned instance is to be constructed by method itself.

Pre-condition for this method is that the parser points to the first event that is part of value to deserializer (and which is never JSON 'null' literal, more on this below): for simple types it may be the only value; and for structured types the Object start marker or a FIELD_NAME.

The two possible input conditions for structured types result from polymorphism via fields. In the ordinary case, Jackson calls this method when it has encountered an OBJECT_START, and the method implementation must advance to the next token to see the first field name. If the application configures polymorphism via a field, then the object looks like the following.

      {
          "@class": "class name",
          ...
      }
  

Jackson consumes the two tokens (the @class field name and its value) in order to learn the class and select the deserializer. Thus, the stream is pointing to the FIELD_NAME for the first field after the @class. Thus, if you want your method to work correctly both with and without polymorphism, you must begin your method with:

       if (p.currentToken() == JsonToken.START_OBJECT) {
         p.nextToken();
       }
  

This results in the stream pointing to the field name, so that the two conditions align.

Post-condition is that the parser will point to the last event that is part of deserialized value (or in case deserialization fails, event that was not recognized or usable, which may be the same event as the one it pointed to upon call).

Note that this method is never called for JSON null literal, and thus deserializers need (and should) not check for it.

Specified by:

deserialize in class JsonDeserializer<java.lang.Object>

Parameters:

p - Parsed used for reading JSON content

ctxt - Context that can be used to access information about this deserialization activity.

Returns:

Deserialized value

Throws:

java.io.IOException