java - 如何使用 GSON 获取 JSON 数组中的值

Question

我想知道 JSON 数组中的选择值。

我的 JSON 是

{
  "meta": {
    "is_end": true,
    "total_count": 1,
    "pageable_count": 1
  },
  "documents": [
    {
      "road_address": {
        "undergroun_yn": "N",
        "road_name": "충대로",
        "underground_yn": "N",
        "region_2depth_name": "청주시 서원구",
        "zone_no": "28644",
        "sub_building_no": "",
        "region_3depth_name": "개신동",
        "main_building_no": "1",
        "address_name": "충북 청주시 서원구 충대로 1",
        "y": "36.63003935314667",
        "x": "127.45479196889647",
        "region_1depth_name": "충북",
        "building_name": "충북대학교"
      },
      "address_name": "충북 청주시 서원구 충대로 1",
      "address": {
        "b_code": "4311210900",
        "region_3depth_h_name": "성화.개신.죽림동",
        "main_address_no": "12",
        "h_code": "4311259000",
        "region_2depth_name": "청주시 서원구",
        "main_adderss_no": "12",
        "sub_address_no": "",
        "region_3depth_name": "개신동",
        "address_name": "충북 청주시 서원구 개신동 12",
        "y": "36.6284039605616",
        "x": "127.45921419389084",
        "mountain_yn": "N",
        "zip_code": "361763",
        "region_1depth_name": "충북",
        "sub_adderss_no": ""
      },
      "y": "36.63003935314667",
      "x": "127.45479196889647",
      "address_type": "ROAD_ADDR"
    }
  ]
}

但是，出现此代码错误，显示“java.lang.IllegalStateException:不是 JSON 对象”所以，我尝试解决它们并寻找多种方法。我不使用“元”的一部分，只使用 JSON 中的“文档”。然后，我编写java代码。我原来的代码是

JsonElement jsonElement = parser.parse(html.toString()).getAsJsonObject();
JsonObject rootObj = jsonElement.getAsJsonObject();


        JsonObject element = rootObj.get("documents").getAsJsonObject();
        String y = element.getAsJsonObject().get("x").toString();
        String x = element.getAsJsonObject().get("y").toString();

        System.out.println(y);
        System.out.println(x);
        System.out.println(html.toString());
        return html.toString();

我知道“文档”是 JSON 数组，所以我修改了我的代码。我修改后的java代码是

    JsonElement jsonElement = parser.parse(html.toString()).getAsJsonObject();
    JsonObject rootObj = jsonElement.getAsJsonObject();
    String y = rootObj.getAsJsonArray().get(Integer.parseInt("x")).toString();
    String x = rootObj.getAsJsonArray().get(Integer.parseInt("y")).toString();

        System.out.println(y);
        System.out.println(x);
        System.out.println(html.toString());
        return html.toString();

但也发生错误，显示“java.lang.IllegalStateException:不是 JSON 数组”我想要得到像这样的结果

{
"documents": [
        {
          "road_address": {
            "undergroun_yn": "N",
            "road_name": "충대로",
            "underground_yn": "N",
            "region_2depth_name": "청주시 서원구",
            "zone_no": "28644",
            "sub_building_no": "",
            "region_3depth_name": "개신동",
            "main_building_no": "1",
            "address_name": "충북 청주시 서원구 충대로 1",
            "y": "36.63003935314667",
            "x": "127.45479196889647",
            "region_1depth_name": "충북",
            "building_name": "충북대학교"
          },
          "address_name": "충북 청주시 서원구 충대로 1",
          "address": {
            "b_code": "4311210900",
            "region_3depth_h_name": "성화.개신.죽림동",
            "main_address_no": "12",
            "h_code": "4311259000",
            "region_2depth_name": "청주시 서원구",
            "main_adderss_no": "12",
            "sub_address_no": "",
            "region_3depth_name": "개신동",
            "address_name": "충북 청주시 서원구 개신동 12",
            "y": "36.6284039605616",
            "x": "127.45921419389084",
            "mountain_yn": "N",
            "zip_code": "361763",
            "region_1depth_name": "충북",
            "sub_adderss_no": ""
          },
          "y": "36.63003935314667",
          "x": "127.45479196889647",
          "address_type": "ROAD_ADDR"
        }
      ]
    }
}

并获取键“x”、“y”和这些值但是，错误不断发生。如何解决？

Answer 1

您应该迭代 JSONArray 以查找 JSONObject，然后读取 x 和 y 值。

JsonElement jsonElement = parser.parse(html.toString()).getAsJsonObject();
JsonObject rootObj = jsonElement.getAsJsonObject();
JsonArray documents = (JsonArray) rootObj.get("documents");
Iterator < JsonElement > itr = documents.iterator();
while (itr.hasNext()) {
 JsonObject jsonObject = (JsonObject) itr.next();
 double x = jsonObject.getDouble("x");
 double y = jsonObject.getDouble("y");
}