Question

我有来自shipcloud.io的以下JSON响应：

[
  {
    "name": "dhl",
    "display_name": "Deutsche Post DHL",
    "services": [
      "standard",
      "returns",
      "one_day",
      "one_day_early"
    ],
    "package_types": [
      "parcel",
      "bulk"
    ]
  },
  {
    "name": "dpag",
    "display_name": "Deutsche Post",
    "services": [
      "standard"
    ],
    "package_types": [
      "letter",
      "parcel_letter",
      "books"
    ]
  },
  {
    "name": "dpd",
    "display_name": "DPD - Dynamic Parcel Distribution",
    "services": [
      "standard",
      "returns",
      "one_day",
      "one_day_early"
    ],
    "package_types": [
      "parcel",
      "parcel_letter"
    ]
  }
]

如何用Jackson反序列化这个JSON数组？通常我使用简单的POJO并定义列表/数组的属性名称（例如@JsonProperty（“blub”））。问题是，这里没有使用属性名称...... 我尝试使用空属性名称，但它没有用。我刚刚收到此错误消息：

Can not deserialize instance of Response.CarriersResponse out of 
START_ARRAY token

Answer 1

如果您想使用jackson，这是适合我的解决方案：

ObjectMapper mapper = new ObjectMapper();
mapper.configure(DeserializationFeature.UNWRAP_ROOT_VALUE, false);

Answer 2

您正在反序列化该类型的多个对象，因此您需要将其作为列表进行，例如

// somewhere in an example TypeReferences class
public static final TypeReference<List<Response.CarriersResponse>> CARRIER_RESPONSES = new TypeReference<List<Response.CarriersResponse>>() {
};

// elsewhere where you're calling the mapper
List<Response.CarriersResponse> responses = mapper.readValue(text, TypeReferences.CARRIER_RESPONSES);

您可以就地实例化它，但这是性能与总内存消耗之间的设计决策。

Answer 3

尝试反序列化为Response.CarriersResponse[]类。

Response.CarriersResponse[] responses = mapper.readValue(text, Response.CarriersResponse[].class);

杰克逊 - 反序列化没有属性名称的数组

3 个答案: