使用 Jackson 映射动态 Json 响应（具有变化的属性）

Question

I am trying to map Json response whose attributes changes if there is any error. For example:

valid response:

{
"Header":[{
             //some data 
          }],
"Component":[{
             //data 
                }],
"ServiceParameter":[{
           //data
      }]
}

error response:

{
    "Header":[{
                 //some data 
              }],
    "ErrorMessage":[{
                 //data 
                    }],
    "ServiceParameter":[{
               //data
          }]
    }

How can I map(with Jackson if possible) component data or error message for the given response?

Answer 1

I can only think of having both fields included in your POJO, like this:

class JsonResponse {
    @JsonProperty("Headers")
    private List<Header> headers;

    @JsonProperty("Component")
    private List<Component> components;

    @JsonProperty("ErrorMessage")
    private List<ErrorMessages> errorMessages;

    @JsonProperty("ServiceParameters")
    private List<ServiceParameters> serviceParameters;

    // Getters and setters
}

You can then know whether it's an error or not by checking if the errorMessages list is empty or not.

Jackson is a very flexible JSON (de)serializer, so it's very likely there's a way to do it, but this one is definitely the easiest one!