Class TypeWrappedDeserializer

  • All Implemented Interfaces:
    NullValueProvider, Serializable

    public final class TypeWrappedDeserializer
    extends JsonDeserializer<Object>
    implements Serializable
    Simple deserializer that will call configured type deserializer, passing in configured data deserializer, and exposing it all as a simple deserializer. This is necessary when there is no "parent" deserializer which could handle details of calling a TypeDeserializer, most commonly used with root values.
    See Also:
    Serialized Form
    • Method Detail

      • 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.
        logicalType in class JsonDeserializer<Object>
        Logical type of values this deserializer produces, if known; null if not
      • handledType

        public Class<?> handledType()
        Description copied from class: JsonDeserializer
        Method for accessing concrete physical type of values this deserializer produces. Note that this information is not guaranteed to be exact -- it may be a more generic (super-type) -- but it should not be incorrect (return a non-related type).

        Default implementation will return null, which means almost same same as returning Object.class would; that is, that nothing is known about handled type.

        handledType in class JsonDeserializer<Object>
        Physical type of values this deserializer produces, if known; null if not
      • supportsUpdate

        public Boolean supportsUpdate​(DeserializationConfig config)
        Description copied from class: JsonDeserializer
        Introspection method that may be called to see whether deserializer supports update of an existing value (aka "merging") or not. Return value should either be Boolean.FALSE if update is not supported at all (immutable values); Boolean.TRUE if update should usually work (regular POJOs, for example), or null if this is either not known, or may sometimes work.

        Information gathered is typically used to either prevent merging update for property (either by skipping, if based on global defaults; or by exception during deserialization construction if explicit attempt made) if Boolean.FALSE returned, or inclusion if Boolean.TRUE is specified. If "unknown" case (null returned) behavior is to exclude property if global defaults used; or to allow if explicit per-type or property merging is defined.

        Default implementation returns null to allow explicit per-type or per-property attempts.

        supportsUpdate in class JsonDeserializer<Object>
      • getDelegatee

        public JsonDeserializer<?> getDelegatee()
        Description copied from class: JsonDeserializer
        Accessor that can be used to determine if this deserializer uses another deserializer for actual deserialization, by delegating calls. If so, will return immediate delegate (which itself may delegate to further deserializers); otherwise will return null.
        getDelegatee in class JsonDeserializer<Object>
        Deserializer this deserializer delegates calls to, if null; null otherwise.
      • getKnownPropertyNames

        public Collection<Object> getKnownPropertyNames()
        Description copied from class: JsonDeserializer
        Method that will either return null to indicate that type being deserializers has no concept of properties; or a collection of identifiers for which toString will give external property name. This is only to be used for error reporting and diagnostics purposes (most commonly, to accompany "unknown property" exception).
        getKnownPropertyNames in class JsonDeserializer<Object>
      • deserialize

        public Object deserialize​(JsonParser p,
                                  DeserializationContext ctxt)
                           throws 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) {
        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<Object>
        p - Parsed used for reading JSON content
        ctxt - Context that can be used to access information about this deserialization activity.
        Deserialized value
      • deserializeWithType

        public Object deserializeWithType​(JsonParser p,
                                          DeserializationContext ctxt,
                                          TypeDeserializer typeDeserializer)
                                   throws IOException
        Description copied from class: JsonDeserializer
        Deserialization called when type being deserialized is defined to contain additional type identifier, to allow for correctly instantiating correct subtype. This can be due to annotation on type (or its supertype), or due to global settings without annotations.

        Default implementation may work for some types, but ideally subclasses should not rely on current default implementation. Implementation is mostly provided to avoid compilation errors with older code.

        deserializeWithType in class JsonDeserializer<Object>
        typeDeserializer - Deserializer to use for handling type information