杰克逊多态反序列化场错误

Question

I am getting error when trying to deserialize json into an abstract type.

Code:

@JsonTypeInfo(use=JsonTypeInfo.Id.CLASS, include=JsonTypeInfo.As.PROPERTY, property="@class")
public abstract class Animal
{
}

public class Dog extends Animal
{
}

public class Zoo
{
    Animal a;
}

@RequestMapping(value = "/zoos", method = RequestMethod.POST)
public void create(@RequestBody Zoo zoo)
{
  ...
}

When I post the following json to zoos:

{
    "@class": "com.example.Dog",
    "a": {}
}

I get the error: org.codehaus.jackson.map.exc.UnrecognizedPropertyException: Unrecognized field "@class" (Class com.example.Zoo), not marked as ignorable

What am I doing wrong?

Answer 1

Ok, I'm an idiot:

The json should be:

{   
    "a": {
        "@class": "com.example.Dog"
     }
}

because the @class belongs to the type animal.