@JsonFormat Support for locale specific number format

Describe the bug @JsonFormat does not work as expected when converting string to double and vice versa.

Version information 2.11.3

To Reproduce I have an entity with a double property. Challenge is to read an external API that sends the capacity value as string in German Format.

@JsonIgnoreProperties(ignoreUnknown = true)
data class Event(
		@JsonProperty("NUMCapacity")
		@JsonFormat(shape = Shape.STRING, locale = "de_DE", pattern = "#.#")
		var capacity: Double,

Caused by: org.springframework.http.converter.HttpMessageNotReadableException: JSON parse error: Cannot deserialize value of type `double` from String "158,1": not a valid Double value; nested exception is com.fasterxml.jackson.databind.exc.InvalidFormatException: Cannot deserialize value of type `double` from String "158,1": not a valid Double value

Expected behavior Expected behaviour is, when given the German locale, the comma is understood as the decimal separator.

[cowtowncoder]

@emiatej9 Typically all handling of format annotations should be done during construction or contextualization phases and specifically should never be passed (and rarely if ever used) accessed during actual deserialization calls.

Contextualization refers to handling in method createContextual(), which is called after construction but before any actual use for deserialization. It will be passed BeanProperty through which annotations (property and class annotations) are accessible.

You don’t need to check FieldProperty methods: this is not the place handling should occur (since these are deserializer-independent entities).

Instead, createContextual() method – you may want to see how other standard deserializers use it – usually checks for various configuration settings, annotations, and so on, and then creates (and returns) a differently configured instance as necessary.

[emiatej9]

Searching code related to this issue, I found below lines in deserializeAndSet method:

https://github.com/FasterXML/jackson-databind/blob/ada34dcf6676aa5c5869791c23143a65a7bf56c2/src/main/java/com/fasterxml/jackson/databind/deser/impl/FieldProperty.java#L135-L140

In line 138 _valueDeserializer have reference of static class DoubleDeserializer in NumberDeserializers. I think the annotations the _field property is holding should be passed to DoubleDeserializer#deserialize(p, ctxt) at this point so as to exploit locale and pattern before parsing the given text.

https://github.com/FasterXML/jackson-databind/blob/ada34dcf6676aa5c5869791c23143a65a7bf56c2/src/main/java/com/fasterxml/jackson/databind/deser/impl/FieldProperty.java#L31-L36

However, It seems very difficult to modify parameters of deserialize(Jsonparser p, DeserializationContext ctxt) method which is inherited from JsonDeserialize class.

Could you give me some hints or guides to fix this issue?