StringCollectionDeserializer
Date: 2016-12-04

com.fasterxml.jackson.databind.deser.std

## Class StringCollectionDeserializer

- java.lang.Object
- - com.fasterxml.jackson.databind.JsonDeserializer<T>
  - - com.fasterxml.jackson.databind.deser.std.StdDeserializer<T>
    - - com.fasterxml.jackson.databind.deser.std.ContainerDeserializerBase<java.util.Collection<java.lang.String>>
      - - com.fasterxml.jackson.databind.deser.std.StringCollectionDeserializer

- All Implemented Interfaces:
    ContextualDeserializer, java.io.Serializable

      public final class StringCollectionDeserializer
      extends ContainerDeserializerBase<java.util.Collection<java.lang.String>>
      implements ContextualDeserializer

  Specifically optimized version for `Collection`s that contain String values; reason is that this is a very common type and we can make use of the fact that Strings are final.
  See Also:
    Serialized Form

- - ### Nested Class Summary

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

      `JsonDeserializer.None`

  - ### Field Summary

    Fields
    Modifier and Type | Field and Description
    --- | ---
    `protected JavaType` | `_collectionType`
    `protected JsonDeserializer<java.lang.Object>` | `_delegateDeserializer` Deserializer that is used iff delegate-based creator is to be used for deserializing from JSON Object.
    `protected java.lang.Boolean` | `_unwrapSingle` Specific override for this instance (from proper, or global per-type overrides) to indicate whether single value may be taken to mean an unwrapped one-element array or not.
    `protected JsonDeserializer<java.lang.String>` | `_valueDeserializer` Value deserializer to use, if NOT the standard one (if it is, will be null).
    `protected ValueInstantiator` | `_valueInstantiator` Instantiator used in case custom handling is needed for creation.

    - ### Fields inherited from class com.fasterxml.jackson.databind.deser.std.StdDeserializer

      `_valueClass, F_MASK_INT_COERCIONS`

  - ### Constructor Summary

    Constructors
    Modifier | Constructor and Description
    --- | ---
    `` | `StringCollectionDeserializer(JavaType collectionType, JsonDeserializer<?> valueDeser, ValueInstantiator valueInstantiator)`
    `protected` | `StringCollectionDeserializer(JavaType collectionType, ValueInstantiator valueInstantiator, JsonDeserializer<?> delegateDeser, JsonDeserializer<?> valueDeser, java.lang.Boolean unwrapSingle)`

  - ### Method Summary

    Methods
    Modifier and Type | Method and 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.util.Collection<java.lang.String>` | `deserialize(com.fasterxml.jackson.core.JsonParser p, DeserializationContext ctxt)` Method that can be called to ask implementation to deserialize JSON content into the value type this serializer handles.
    `java.util.Collection<java.lang.String>` | `deserialize(com.fasterxml.jackson.core.JsonParser p, DeserializationContext ctxt, java.util.Collection<java.lang.String> result)` Alternate deserialization method (compared to the most commonly used, `JsonDeserializer.deserialize(JsonParser, DeserializationContext)`), which takes in initialized value instance, to be configured and/or populated by deserializer.
    `java.lang.Object` | `deserializeWithType(com.fasterxml.jackson.core.JsonParser p, DeserializationContext ctxt, TypeDeserializer typeDeserializer)` Base implementation that does not assume specific type inclusion mechanism.
    `JsonDeserializer<java.lang.Object>` | `getContentDeserializer()` Accesor for deserializer use for deserializing content values.
    `JavaType` | `getContentType()` Accessor for declared type of contained value elements; either exact type, or one of its supertypes.
    `boolean` | `isCachable()` Method called to see if deserializer instance is cachable and usable for other properties of same type (type for which instance was created).
    `protected StringCollectionDeserializer` | `withResolved(JsonDeserializer<?> delegateDeser, JsonDeserializer<?> valueDeser, java.lang.Boolean unwrapSingle)`

    - ### Methods inherited from class com.fasterxml.jackson.databind.deser.std.ContainerDeserializerBase

      `findBackReference, wrapAndThrow`

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

      `_coerceIntegral, _deserializeFromEmpty, _failDoubleToIntCoercion, _hasTextualNull, _isIntNumber, _isNaN, _isNegInf, _isPosInf, _parseBoolean, _parseBooleanFromInt, _parseBooleanFromOther, _parseBooleanPrimitive, _parseByte, _parseDate, _parseDate, _parseDouble, _parseDoublePrimitive, _parseFloat, _parseFloatPrimitive, _parseInteger, _parseIntPrimitive, _parseLong, _parseLongPrimitive, _parseShort, _parseShortPrimitive, _parseString, findConvertingContentDeserializer, findDeserializer, findFormatFeature, findFormatOverrides, getValueClass, getValueType, handledType, handleMissingEndArrayForSingle, handleUnknownProperty, isDefaultDeserializer, isDefaultKeyDeserializer, parseDouble`

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

      `getDelegatee, getEmptyValue, getEmptyValue, getKnownPropertyNames, getNullValue, getNullValue, getObjectIdReader, replaceDelegatee, unwrappingDeserializer`

    - ### Methods inherited from class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- - ### Field Detail

    - #### _collectionType

          protected final JavaType _collectionType

    - #### _valueDeserializer

          protected final JsonDeserializer<java.lang.String> _valueDeserializer

      Value deserializer to use, if NOT the standard one (if it is, will be null).

    - #### _valueInstantiator

          protected final ValueInstantiator _valueInstantiator

      Instantiator used in case custom handling is needed for creation.

    - #### _delegateDeserializer

          protected final JsonDeserializer<java.lang.Object> _delegateDeserializer

      Deserializer that is used iff delegate-based creator is to be used for deserializing from JSON Object.

    - #### _unwrapSingle

          protected final java.lang.Boolean _unwrapSingle

      Specific override for this instance (from proper, or global per-type overrides) to indicate whether single value may be taken to mean an unwrapped one-element array or not. If null, left to global defaults.
      Since:
        2.7

  - ### Constructor Detail

    - #### StringCollectionDeserializer

          public StringCollectionDeserializer(JavaType collectionType,
                                      JsonDeserializer<?> valueDeser,
                                      ValueInstantiator valueInstantiator)

    - #### StringCollectionDeserializer

          protected StringCollectionDeserializer(JavaType collectionType,
                                      ValueInstantiator valueInstantiator,
                                      JsonDeserializer<?> delegateDeser,
                                      JsonDeserializer<?> valueDeser,
                                      java.lang.Boolean unwrapSingle)

  - ### Method Detail

    - #### withResolved

          protected StringCollectionDeserializer withResolved(JsonDeserializer<?> delegateDeser,
                                                  JsonDeserializer<?> valueDeser,
                                                  java.lang.Boolean unwrapSingle)

    - #### isCachable

          public boolean isCachable()

      Description copied from class: `JsonDeserializer`
      Method called to see if deserializer instance is cachable and usable for other properties of same type (type for which instance was created).

      Note that cached instances are still resolved on per-property basis, if instance implements `ResolvableDeserializer`: cached instance is just as the base. This means that in most cases it is safe to cache instances; however, it only makes sense to cache instances if instantiation is expensive, or if instances are heavy-weight.

      Default implementation returns false, to indicate that no caching is done.

      Overrides:
        `isCachable` in class `JsonDeserializer<java.util.Collection<java.lang.String>>`

    - #### 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 can not 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`

    - #### getContentType

          public JavaType getContentType()

      Description copied from class: `ContainerDeserializerBase`
      Accessor for declared type of contained value elements; either exact type, or one of its supertypes.
      Specified by:
        `getContentType` in class `ContainerDeserializerBase<java.util.Collection<java.lang.String>>`

    - #### getContentDeserializer

          public JsonDeserializer<java.lang.Object> getContentDeserializer()

      Description copied from class: `ContainerDeserializerBase`
      Accesor for deserializer use for deserializing content values.
      Specified by:
        `getContentDeserializer` in class `ContainerDeserializerBase<java.util.Collection<java.lang.String>>`

    - #### deserialize

          public java.util.Collection<java.lang.String> deserialize(com.fasterxml.jackson.core.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 (jp.getCurrentToken() == JsonToken.START_OBJECT) {
                   jp.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.util.Collection<java.lang.String>>`
      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`

    - #### deserialize

          public java.util.Collection<java.lang.String> deserialize(com.fasterxml.jackson.core.JsonParser p,
                                                           DeserializationContext ctxt,
                                                           java.util.Collection<java.lang.String> result)
                                                             throws java.io.IOException

      Description copied from class: `JsonDeserializer`
      Alternate deserialization method (compared to the most commonly used, `JsonDeserializer.deserialize(JsonParser, DeserializationContext)`), which takes in initialized value instance, to be configured and/or populated by deserializer. Method is not necessarily used (or supported) by all types (it will not work for immutable types, for obvious reasons): most commonly it is used for Collections and Maps. It may be used both with "updating readers" (for POJOs) and when Collections and Maps use "getter as setter".

      Default implementation just throws `UnsupportedOperationException`, to indicate that types that do not explicitly add support do not necessarily support update-existing-value operation (esp. immutable types)

      Overrides:
        `deserialize` in class `JsonDeserializer<java.util.Collection<java.lang.String>>`
      Throws:
        `java.io.IOException`

    - #### deserializeWithType

          public java.lang.Object deserializeWithType(com.fasterxml.jackson.core.JsonParser p,
                                             DeserializationContext ctxt,
                                             TypeDeserializer typeDeserializer)
                                               throws java.io.IOException

      Description copied from class: `StdDeserializer`
      Base implementation that does not assume specific type inclusion mechanism. Sub-classes are expected to override this method if they are to handle type information.
      Overrides:
        `deserializeWithType` in class `StdDeserializer<java.util.Collection<java.lang.String>>`
        `typeDeserializer` - Deserializer to use for handling type information
      Throws:
        `java.io.IOException`