com.fasterxml.jackson.databind.deser.std

Class MapDeserializer

    • Field Detail

      • _mapType

        protected final JavaType _mapType

      • _standardStringKey

        protected boolean _standardStringKey
        Flag set to indicate that the key type is String (or Object, for which String is acceptable), and that the default Jackson key deserializer would be used. If both are true, can optimize handling.

      • _valueTypeDeserializer

        protected final TypeDeserializer _valueTypeDeserializer
        If value instances have polymorphic type information, this is the type deserializer that can handle it

      • _hasDefaultCreator

        protected final boolean _hasDefaultCreator

      • _delegateDeserializer

        protected JsonDeserializer<Object> _delegateDeserializer
        Deserializer that is used iff delegate-based creator is to be used for deserializing from JSON Object.

      • _propertyBasedCreator

        protected PropertyBasedCreator _propertyBasedCreator
        If the Map is to be instantiated using non-default constructor or factory method that takes one or more named properties as argument(s), this creator is used for instantiation.

      • _ignorableProperties

        protected HashSet<String> _ignorableProperties

    • Method Detail

      • _isStdKeyDeser

        protected final boolean _isStdKeyDeser(JavaType mapType,
                     KeyDeserializer keyDeser)
        Helper method used to check whether we can just use the default key deserialization, where JSON String becomes Java String.

      • setIgnorableProperties

        public void setIgnorableProperties(String[] ignorable)

      • resolve

        public void resolve(DeserializationContext ctxt)
             throws JsonMappingException
        Description copied from interface: ResolvableDeserializer
        Method called after deserializer instance has been constructed (and registered as necessary by provider objects), but before it has returned it to the caller. Called object can then resolve its dependencies to other types, including self-references (direct or indirect).
        Specified by:
        resolve in interface ResolvableDeserializer
        Parameters:
        ctxt - Context to use for accessing configuration, resolving secondary deserializers
        Throws:
        JsonMappingException

      • createContextual

        public JsonDeserializer<?> createContextual(DeserializationContext ctxt,
                                   BeanProperty property)
                                     throws JsonMappingException
        Method called to finalize setup of this deserializer, when it is known for which property deserializer is needed for.
        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

      • isCachable

        public boolean isCachable()
        Turns out that these are expensive enough to create so that caching does make sense.

        IMPORTANT: but, note, that instances CAN NOT BE CACHED if there is a value type deserializer; this caused an issue with 2.4.4 of JAXB Annotations (failing a test). It is also possible that some other settings could make deserializers un-cacheable; but on the other hand, caching can make a big positive difference with performance... so it's a hard choice.

        Overrides:
        isCachable in class JsonDeserializer<Map<Object,Object>>
        Since:
        2.4.4

      • deserialize

        public Map<Object,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 (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<Map<Object,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:
        IOException

      • getMapClass

        public final Class<?> getMapClass()

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