杰克逊：反序列化错误。没有要从字符串值反序列化的字符串参数构造函数/工厂方法

Question

我正在尝试反序列化以下JSON

{
  "deliverLumpSum": 0.0,
  "faxQId": "{\"type\":\"TAKEAWAY\",\"data\":{\"orderId\":\"AWSWD-AWSAW\",\"orderKey\":\"DERS34S32SD\"}}"
}

借助以下自定义反序列化器

public class OrderIdDeserializer extends JsonDeserializer<OrderId> {

  @Override
  public OrderId deserialize(JsonParser jsonParser, DeserializationContext deserializationContext) throws IOException {
      OrderId orderId = jsonParser.readValueAs(OrderId.class);
      return orderId;
  }
}

进入以下对象结构

@Data
public class AddInfo {

  protected double deliverLumpSum;

  @JsonDeserialize( using = OrderIdDeserializer.class)
  public OrderId orderId;

}

@Data
public class OrderId {

  private String type;
  private TakeawayData data;

}

@Data
public class TakeawayData {

  private String orderId;
  private String orderKey;

}

我收到以下错误

com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot construct instance of `OrderId` (although at least one Creator exists): no String-argument constructor/factory method to deserialize from String value ('{"type":"TAKEAWAY","data":{"orderId":"AWSWD-AWSAW","orderKey":"DERS34S32SD"}}')

我怎么办？我该如何解决这个问题？

thx

Answer 1

在deserialize私有字段中，您必须添加getter或/和setter

  

设置器使非公共字段只能反序列化

或者只是将其公开

 public class OrderId {

    public String type;
    public TakeawayData data;

 }

 public class TakeawayData {

   public String orderId;
   public String orderKey;

 }