Java json路径库的问题

Question

全部的我和你有一个很奇怪的问题https://github.com/json-path/JsonPath

其中一个问题似乎是实现中存在的重入问题：当执行路径时，每个片段返回一个字符串：

Expected to find an object with property ['ModuleListResponse'] in path $[0]['response'] but found 'java.lang.String'. This is not a json object according to the JsonProvider: 'com.jayway.jsonpath.spi.json.JsonSmartJsonProvider'.

我通过将JSONObject/JSONArray传递给JsonPath.read（）而不是JSON字符串来“黑客”。做完后，现在我得到了：

Filter: [0]['name'] can only be applied to arrays. Current context is: [{"startLocation":{"types":["city"],"address":"Argentina","latitude":-34.6075682,"name":"Buenos Aires","description":"Buenos Aires is the capital and largest city of Argentina. The city is located on the western shore of the estuary of the Río de la Plata, o...449a049a781"}}]

如您所见，这已经是一个数组。我在谷歌上搜索了很多次，但都找不到问题所在。

关于解析它的代码，这里有：

    jsonString = StringUtils.trim(jsonString);
    if (jsonString.startsWith("[")) {
        jsonObject = new org.json.JSONArray(jsonString);
    } else {
        jsonObject = new JSONObject(jsonString);
    }
    String jsonPath = "$[0].name";
    Object jsonResult = JsonPath.using(conf)
                             .parse(jsonObject)
                             .read(jsonPath);

所以，问题是：为什么JsonPath将json读取为字符串，而不是json？对于第二个问题，当它显然是一个数组时，为什么不把它作为数组。

Answer 1

如果将JSON格式化为易于阅读的格式，您将看到您的属性路径不正确。下面是实际的JSON：

[
  {
  "startLocation": 
    {
      "types": ["city"],
      "address": "Argentina",
      "latitude": -34.6075682,
      "name": "Buenos Aires",
      "description": "Buenos Aires is the capital and largest city of Argentina. The city is located on the western shore of the estuary of the Río de la Plata, o...449a049a781"
    }
  }
]

您正在尝试访问$。[0].名称，但该值不存在。

$。[0]

{
    "startLocation": {
      "types": ["city"],
      "address": "Argentina",
      "latitude": -34.6075682,
      "name": "Buenos Aires",
      "description": "Buenos Aires is the capital and largest city of Argentina. The city is located on the western shore of the estuary of the Río de la Plata, o...449a049a781"
}

$的唯一顶级键。[0]是startLocation，所以您实际上要查找的是

$。[0].令人震惊。名称

我建议撤消您添加的JSONArray和JSONObject fluff，因为这可能掩盖了真正的问题，这只是一个无效的属性路径。