Class NumberDeserializers.NumberDeserializer

All Implemented Interfaces:
NullValueProvider, ValueInstantiator.Gettable, Serializable
Enclosing class:
NumberDeserializers

public static class NumberDeserializers.NumberDeserializer extends StdScalarDeserializer<Object>
For type Number.class, we can just rely on type mappings that plain JsonParser.getNumberValue() returns.

There is one additional complication: some numeric types (specifically, int/Integer and double/Double) are "non-typed"; meaning that they will NEVER be output with type information. But other numeric types may need such type information. This is why deserializeWithType(edu.internet2.middleware.grouperClientExt.com.fasterxml.jackson.core.JsonParser, edu.internet2.middleware.grouperClientExt.com.fasterxml.jackson.databind.DeserializationContext, edu.internet2.middleware.grouperClientExt.com.fasterxml.jackson.databind.jsontype.TypeDeserializer) must be overridden.

See Also:
  • Field Details

  • Constructor Details

    • NumberDeserializer

      public NumberDeserializer()
  • Method Details

    • logicalType

      public final 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<Object>
      Returns:
      Logical type of values this deserializer produces, if known; null if not
    • 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) {
               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<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
    • deserializeWithType

      public Object deserializeWithType(JsonParser p, DeserializationContext ctxt, TypeDeserializer typeDeserializer) throws IOException
      As mentioned in class Javadoc, there is additional complexity in handling potentially mixed type information here. Because of this, we must actually check for "raw" integers and doubles first, before calling type deserializer.
      Overrides:
      deserializeWithType in class StdScalarDeserializer<Object>
      typeDeserializer - Deserializer to use for handling type information
      Throws:
      IOException