Java 用 Jackson 解析 JSON

Question

I try to parse JSON below with java Jackson library but I not able to get the value at level "ChannelType", "Address" and etc. It is because of value "endpoint123" & "endppoint456", which cause some problem for me. 我尝试用谷歌搜索，但在其他地方找不到。 希望有 1 位专家在这里提供帮助。 提前致谢。

    {
    "Message": {},
    "ApplicationId": "aaa",
    "CampaignId": "bbb",
    "TreatmentId": "0",
    "ActivityId": "ccc",
    "ScheduledTime": "2021-04-07T08:43:16.406Z",
    "Endpoints": {
        "endpointa123": {
            "ChannelType": "CUSTOM",
            "Address": "bobby@abc.com.my",
            "EndpointStatus": "ACTIVE",
            "OptOut": "NONE",
            "EffectiveDate": "2021-04-07T08:35:48.796Z",
            "User": {
                "UserAttributes": {
                    "Custom4": [
                        "data4"
                    ],
                    "Custom3": [
                        "data3"
                    ],
                    "Custom2": [
                        "data2"
                    ],
                    "Custom1": [
                        "data1"
                    ],
                    "Custom5": [
                        "data5"
                    ]
                }
            },
            "CreationDate": "2021-04-07T08:35:48.796Z"
        },
        "endpoint456": {
            "ChannelType": "CUSTOM",
            "Address": "fifis@abc.com.my",
            "EndpointStatus": "ACTIVE",
            "OptOut": "NONE",
            "EffectiveDate": "2021-04-07T08:35:48.792Z",
            "User": {
                "UserAttributes": {
                    "Custom4": [
                        "data4"
                    ],
                    "Custom3": [
                        "data3"
                    ],
                    "Custom2": [
                        "data2"
                    ],
                    "Custom1": [
                        "data1"
                    ],
                    "Custom5": [
                        "data5"
                    ]
                }
            },
            "CreationDate": "2021-04-07T08:35:48.792Z"
        }
    }
}

我的代码如下所示，Campaign 是我自己定义的 class。

            Campaign campaign = mapper.readValue(json, Campaign.class);
            String valueOut =  mapper.writerWithDefaultPrettyPrinter().writeValueAsString(campaign);
            System.out.println(valueOut);

我的 Java Object Model 如下所示。

Campaign 
   |--EndPoints
       |-- EndPointsContainer (Array) 
            |--User 
                 |--UserAttributes

以下是我得到的结果。

"Message" : { },
"ApplicationId" : "aaa",
"CampaignId" : "bbb",
"TreatmentId" : "0",
"ActivityId" : "ccc",
"ScheduledTime" : "2021-04-07T10:44:27.598Z",
"EndPoints" : {
"endPointsContainer" : [ ],
"creationDate" : null,
"CreationDate" : null

感谢@罗伯特。 它至少与原始 JSON 非常相似。 POJO 是按如下方式重构的。

Campaign 
   |--EndPoints
        |--User 
             |--UserAttributes

但是，CreationDate 位于 object“endpoint123”和“endpoint456”内部，而不是外部。 因为它很长。 我贴了一部分。

"ScheduledTime": "2021-04-07T08:43:16.406Z",
"Endpoints": {
    "endpointa123": {
        "CreationDate": "2021-04-07T08:35:48.796Z"
        "ChannelType": "CUSTOM",

Answer 1

这里有两个问题，

1. JSON 的格式不正确。 如果您希望enpoints是一个数组并且具有变量名称endPointsContainer ，则您需要具有相同的名称。 endpointa123和endpoint456将被视为不同的对象，不会成为单个列表的一部分
2. 变量CreationDate是端点的一部分，因此它将在endPointsContainer中可用

因此，按照您的期望，正确的 JSON 将是，

{
  "Message": {},
  "ApplicationId": "aaa",
  "CampaignId": "bbb",
  "TreatmentId": "0",
  "ActivityId": "ccc",
  "ScheduledTime": "2021-04-07T08:43:16.406Z",
  "Endpoints": {
    "endPointsContainer": [
      {
        "endpoint": {
          "ChannelType": "CUSTOM",
          "Address": "bobby@abc.com.my",
          "EndpointStatus": "ACTIVE",
          "OptOut": "NONE",
          "EffectiveDate": "2021-04-07T08:35:48.796Z",
          "User": {
            "UserAttributes": {
              "Custom4": [
                "data4"
              ],
              "Custom3": [
                "data3"
              ],
              "Custom2": [
                "data2"
              ],
              "Custom1": [
                "data1"
              ],
              "Custom5": [
                "data5"
              ]
            }
          },
          "CreationDate": "2021-04-07T08:35:48.796Z"
        }
      },
      {
        "endpoint": {
          "ChannelType": "CUSTOM",
          "Address": "fifis@abc.com.my",
          "EndpointStatus": "ACTIVE",
          "OptOut": "NONE",
          "EffectiveDate": "2021-04-07T08:35:48.792Z",
          "User": {
            "UserAttributes": {
              "Custom4": [
                "data4"
              ],
              "Custom3": [
                "data3"
              ],
              "Custom2": [
                "data2"
              ],
              "Custom1": [
                "data1"
              ],
              "Custom5": [
                "data5"
              ]
            }
          },
          "CreationDate": "2021-04-07T08:35:48.792Z"
        }
      }
    ]
  }
}

当我将其反序列化为 MAP class 时，

ObjectMapper jsonMapper = new ObjectMapper();
Map<String,Object> compaign = jsonMapper.readValue(json, Map.class);

这就是它的样子，