将 API json 解析为 java servlet

Question

我正在为学校构建一个 java servlet 页面，我想在其中放置一个 API。到目前为止，我在使用 API 时遇到了一些问题。
这是我想链接到我的网页的“Schiphol PublicFlight API”。
但是我无法让 java 使用基于 JSON 的 API。

到目前为止，我已经尝试“隔离”越来越多的 JSON 代码，但我就是无法让它工作。为了让我更容易一些，我现在将 java servlet 代码从项目中分离出来。所以这是我现在的代码：

package nl.hva.ic103.johannes;

import java.io.FileReader;
import java.util.Iterator;
import java.util.Map;

import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;
import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
import org.json.simple.parser.*;

public class Main {

    public static void main(String[] args) throws Exception {
        JSONParser parser = new JSONParser();

        String flightnumber = "HV6672";
        HttpClient httpClient = HttpClients.createDefault();
        HttpGet request = new HttpGet("https://api.schiphol.nl/public-flights/flights?app_id=61439ff8&app_key=b313373fd4122e93704874c69a59233d&flightname=" + flightnumber + "&sort=%2Bscheduletime");
        request.addHeader("ResourceVersion", "v3");

        HttpResponse response = httpClient.execute(request);

        if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
            String responseBody = EntityUtils.toString(response.getEntity(), "UTF-8");

            System.out.println(responseBody);

            JSONObject jsonObject = (JSONObject) parser.parse(responseBody);
            JSONObject jo = (JSONObject) jsonObject;

            String id = (String) jo.get("id");
            String lastName = (String) jo.get("flightName");

            System.out.println(id);
            System.out.println(lastName);

            JSONArray ja = (JSONArray) jo.get("flights");

            System.out.println(ja);
        }
    }
}

这是 API 给我的 JSON 格式：

{
    "flights": [
    {
        "id": 125936439536285950,
        "flightName": "HV6672",
        "scheduleDate": "2018-12-26",
        "flightDirection": "A",
        "flightNumber": 6672,
        "prefixIATA": "HV",
        "prefixICAO": "TRA",
        "scheduleTime": "01:00:00",
        "serviceType": "J",
        "mainFlight": "HV6672",
        "codeshares": {
            "codeshares": [
                "KL2582"
            ]
        },
        "estimatedLandingTime": "2018-12-26T00:30:49.000+01:00",
        "actualLandingTime": "2018-12-26T00:30:55.000+01:00",
        "publicEstimatedOffBlockTime": null,
        "actualOffBlockTime": null,
        "publicFlightState": {
            "flightStates": [
                "LND",
                "EXP"
            ]
        },
        "route": {
            "destinations": [
                "TFS"
            ]
        },
        "terminal": 1,
        "gate": "D74",
        "baggageClaim": {
            "belts": [
                "6"
            ]
        },
        "expectedTimeOnBelt": "2018-12-26T01:16:53.669+01:00",
        "checkinAllocations": null,
        "transferPositions": null,
        "aircraftType": {
            "iatamain": "73H",
            "iatasub": "73H"
        },
        "aircraftRegistration": "PHHZX",
        "airlineCode": 164,
        "expectedTimeGateOpen": null,
        "expectedTimeBoarding": null,
        "expectedTimeGateClosing": null,
        "schemaVersion": "3"
    }
    ],
    "schemaVersion": "3"
}

如何将“门”、“终端”和“飞机类型”等内容解析为我的 java 程序？我觉得我能从这些结果中得到的一切就像一个数据，不可能将数据分开。 有谁知道如何将这三个结果解析到我的 java 项目中？ 有关 API 的更多信息列在他们的网站上： https://www.schiphol.nl/en/developer-center/page/our-flight-api-explored/

Answer 1

JSONArray ja = (JSONArray) jo.get("flights");
JsonObject flightRec = ja.getJsonObject(0);
String gate = (String) flightRec.get("gate");
//...etc

什么问题？