如何基于Java中的给定深度来深度选择节点？

Question

我有如下所示的json表示形式：

{
  "total": "555",
  "offset": "555",
  "hasMore": "false",
  "results": [
    {
      "associations": {
        "workflowIds": [],
        "companyIds": [],
        "ownerIds": [],
        "child": {
         "name" : "association1",
          "key" : "a1"
        }, 
        "quoteIds": [],
        "contentIds": [],
        "dealIds": [],
        "contactIds": [
          4646915
        ],
        "ticketIds": []
      },
      "scheduledTasks": [
        {
          "taskType": "REMINDER",
          "portalId": 214129,
          "engagementType": "TASK",
          "engagementId": 6604524566,     
          "timestamp": 1586815200000
        }
      ]
    },
    {
      "associations": {
        "workflowIds": [],
        "companyIds": [],
        "ownerIds": [],
        "quoteIds": [],
        "contentIds": [],
        "child": {
         "name" : "association2",
          "key" : "a2"
        }, 
        "dealIds": [],
        "contactIds": [
          4646915
        ],
        "ticketIds": []
      }
    },
    {
      "associations": {
        "workflowIds": [],
        "companyIds": [],
        "ownerIds": [],
        "quoteIds": [],
        "contentIds": [],
        "dealIds": [],
        "child": {
         "name" : "association3",
          "key" : "a3"
        }, 
        "contactIds": [
          3995065
        ],
        "ticketIds": []
      }
    },
    {
      "associations": {
        "workflowIds": [],
        "companyIds": [],
        "ownerIds": [],
        "quoteIds": [],
        "contentIds": [],
        "dealIds": [],
        "contactIds": [
          4648365
        ],
        "ticketIds": []
      }
    }
]
}

我想通过传递节点选择器字符串来获取给定节点的过滤信息（类似于sql），要实现这一点，我正在执行以下操作：

ObjectMapper objectMapper = new ObjectMapper();
        JsonNode root = objectMapper.readTree(new File("/Users/pra/automation/foo.json"));
       String result = root.at("/results/0/associations/0/child").toString();
       Assert.assertNotNull(result);

并且此代码也正常工作，因为传递了0级索引，所以它从数组中筛选出了第一个节点，但是我需要输出所有匹配的元素，以实现我传递了*而不是0，但它不起作用。

意味着我正在尝试类似以下操作（失败）：

String result = root.at("/results/*/associations/*/child").toString();

所需的所需输出：

[
{
   "name" : "association1",
   "key" : "a1"
},
{
   "name" : "association2",
   "key" : "a2"
},
{
   "name" : "association3",
   "key" : "a3"
}
]

我愿意接受其他基于Java的替代方案来实现这一目标。谢谢。

Answer 1

如果您可以切换到Gson库，则可以使用im.wilk.vor：Voritem库gitHub或在Maven存储库中。

VorItem vorItemFactory = VorItemFactoryBuilder.standard.build();
JsonElement je = JsonParser.parse(...)

VorItem vi = vorItemFactory.from(je);
VorItem result = vorItemFactory.empty();

for (int idx = 0; idx < vi.get("result").list().size(); idx++) {
    result.get(idx).set("name", vi.get("result").get(idx).get("associations/child/name");
    result.get(idx).set("key", vi.get("result").get(idx).get("associations/child/key");

}

return result.asJsonElement().toString();