java - 如何使用 GSON 解析 JSON 响应 (Java/Android)

Question

我只需要一个快速建议，因为我是 JSON 的初学者。

我从网络服务器收到以下响应，我将其存储在字符串中:

{  
   "station62":[  
      {  
         "departureTime":1982,
         "delay":"-1.0",
         "line":"6",
         "stationName":"randomname",
         "direction":2
      }
   ],
   "station63":[  
      {  
         "departureTime":1234,
         "delay":"-1.0",
         "line":"87",
         "stationName":"anotherrandomname",
         "direction":2
      }
   ],
   "station64":[  
      {  
         "departureTime":4542,
         "delay":"-1.0",
         "line":"4",
         "stationName":"yetanotherrandomname",
         "direction":2
      }
   ],
   "station65":[  
      {  
         "departureTime":1232,
         "delay":"-1.0",
         "line":"23",
         "stationName":"onemorerandomname",
         "direction":2
      }
   ]
}

(抱歉，我不知道缩进是如何工作的。)

响应较长，但在本例中已缩短。所以我需要的是解析每个“站”对象的信息。我不需要“station62”字符串，我只需要 java 对象中的“departureTime”、“delay”、“line”、“stationName”和“direction”。

我已经读过这篇文章，但我无法让它工作:https://stackoverflow.com/a/16378782

我是一个完全的初学者，所以任何帮助将非常感激。

编辑:这是我的代码:

我创建了一个包装类，就像上面的示例链接中一样。我对 map 类型进行了一些尝试，但到目前为止还没有运气。

public class ServerResponse
{

private Map<String, ArrayList<Station>> stationsInResponse = new HashMap<String, ArrayList<Station>>();

public Map<String, ArrayList<Station>> getStationsInResponse()
{
    return stationsInResponse;
}

public void setStationsInResponse(Map<String, ArrayList<Station>> stationsInResponse)
{
    this.stationsInResponse = stationsInResponse;
}
}

问题是，这张 map 没有被我下面显示的 gson.fromJSON(...) 调用填充。 map 大小始终为零。

站点类如下所示:

public class Station
{
String line;
String stationName;
String departureTime;
String direction;
String delay;

// getters and setters are there aswell
}

我想做的是

Gson gson = new Gson();
ServerResponse response = gson.fromJson(jsonString, ServerResponse.class);

其中“jsonString”包含字符串形式的 JSON 响应。

我希望代码显示了我需要做什么，它应该非常简单，但我在 JSON 方面还不够好。

编辑2

我需要我的 JSON 是这样的吗？

{"stationsInResponse": {
"station62": [{
    "departureTime": 1922,
    "delay": "-1.0",
    "line": "8",
    "stationName": "whateverrandomname",
    "direction": 2
  }],
"station67": [{
    "departureTime": 1573,
    "delay": "-1.0",
    "line": "8",
    "stationName": "rndmname",
    "direction": 2
  }],
"station157": [{
    "departureTime": 1842,
    "delay": "-2.0",
    "line": "8",
    "stationName": "randomname",
    "direction": 2
  }]
}}

Answer 1

这是工作代码:

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import com.google.gson.Gson;

public class GSONTest {

    public static void main(String[] args){

        String gsonStr = "{\"stationsInResponse\": { \"station62\":[  {  \"departureTime\":1982,\"delay\":\"-1.0\",\"line\":\"6\",\"stationName\":\"randomname\",\"direction\":2} ],\"station63\":[  {  \"departureTime\":1981,\"delay\":\"-1.1\",\"line\":\"7\",\"stationName\":\"randomname2\",\"direction\":3} ]}}";

        Gson gson = new Gson();
        Response response = gson.fromJson(gsonStr, Response.class);

        System.out.println("Map size:"+response.getStationsInResponse().size());

        for (Iterator iterator = response.getStationsInResponse().keySet().iterator(); iterator.hasNext();) {

            String key = (String) iterator.next();

            ArrayList<Station> stationList = (ArrayList<Station>) response.getStationsInResponse().get(key);

            for (Iterator iterator2 = stationList.iterator(); iterator2.hasNext();) {

                Station station = (Station) iterator2.next();

                System.out.println("Delay: "+station.getDelay());
                System.out.println("DepartureTime: "+station.getDepartureTime());
                System.out.println("Line: "+station.getLine());
                System.out.println("StationName: "+station.getStationName());
            }


        }


    }


}

class Response {
      private Map<String, List<Station>> stationsInResponse;
      //getters and setters

    public Map<String, List<Station>> getStationsInResponse() {
        return stationsInResponse;
    }

    public void setStationsInResponse(Map<String, List<Station>> stationsInResponse) {
        this.stationsInResponse = stationsInResponse;
    }
    }

class Station {
      private String departureTime;
      public String getDepartureTime() {
        return departureTime;
    }
    public void setDepartureTime(String departureTime) {
        this.departureTime = departureTime;
    }
    public String getDelay() {
        return delay;
    }
    public void setDelay(String delay) {
        this.delay = delay;
    }
    public String getLine() {
        return line;
    }
    public void setLine(String line) {
        this.line = line;
    }
    public String getStationName() {
        return stationName;
    }
    public void setStationName(String stationName) {
        this.stationName = stationName;
    }
    public String getDirection() {
        return direction;
    }
    public void setDirection(String direction) {
        this.direction = direction;
    }
      private String delay;
      private String line;
      private String stationName;
      private String direction;

}

控制台中的输出是这样的(因为我缩短了你的 json 字符串):

Map size:2
Delay: -1.0
DepartureTime: 1982
Line: 6
StationName: randomname
Delay: -1.1
DepartureTime: 1981
Line: 7
StationName: randomname2