定制杰克逊解串器获取当前现场类 [英] Custom Jackson Deserializer Getting Access to Current Field Class

问题描述

我正在尝试为杰克逊编写一个自定义反序列化程序，我想让它成为通用的（在任何类型的工作意义上都是通用的，而不是在泛型中）。

I'm trying to write a custom deserializer for Jackson and I want to make it generic (generic in the sense of working on any type, not as in "generics").

但是我似乎无法弄清楚如何处理被反序列化的字段的类型。

However I cannot seem to figure out how to get a handle to the type of the field being deserialized.

例如，我正在寻找一些事情如下所示：

Eg, I'm looking to do something like the following:

@Override
public MyObject deserialize(JsonParser jp, DeserializationContext ctxt) throws IOException, JsonProcessingException {

         Class c = <get type of current field>
         // do something with that type
         return new SubclassOfC(somedata based on c);
}

具体是获取当前字段的类型部分我一直在努力。

It's specifically the get type of current field part that I have struggled with.

编辑：这是我感兴趣的java字段的类型。

It is the type of the java field I am interested in.

推荐答案

我通过向ObjectMapper添加反序列化器的实现解决了我的特殊问题。例如

I have solved my particular problem by adding an implementation of Deserializers to the ObjectMapper. Eg

   Deserializers d = new Deserializers.Base() {

   @Override
   public JsonDeserializer<?> findEnumDeserializer(Class<?> type, DeserializationConfig config, BeanDescription beanDesc, BeanProperty property)
                  throws JsonMappingException {
                if (property.getType().getContentType() != null)
                    return new EnumDeserializer(property.getType().getContentType().getRawClass());
                return new EnumDeserializer(property.getType().getRawClass());
            }

        };
        mapper.setDeserializerProvider(mapper.getDeserializerProvider().withAdditionalDeserializers(d));

这将返回为每个单独的枚举类型实例化的自定义EnumDeserializer。

This will return my custom EnumDeserializer instantiated for each separate Enum type.

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