Java json-path库问题

Question

全。我和https://github.com/json-path/JsonPath有一个非常奇怪的问题

其中一个问题似乎是实现所具有的可重入问题:当执行路径时，每个片段都返回一个字符串：

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JSON对象/JSON数组传递给JsonPath.read()而不是JSON字符串来实现了这一点。在这样做之后，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，这已经是一个数组了。我已经用谷歌搜索了很多次，但找不到问题出在哪里。

关于解析它的代码，你已经知道了：

    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);

因此，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，为什么它不将其作为数组，而它显然是一个数组。

Answer 1

如果将JSON格式化为易于阅读的格式，您将看到属性路径是不正确的。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].name，但该值不存在。

$.[0]是

{
    "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"
}

$.[0]的惟一顶级密钥是startLocation，所以您实际要找的是

$.[0].startLocation.name

我建议撤销你添加的JSONArray和JSONObject毛发，因为它可能掩盖了真正的问题，那只是一个无效的属性路径。