Java使用GSON处理一段json

Question

我有一个 JSON 响应:

    {
   "results" : [
      {
         "address_components" : [
            {
               "long_name" : "3",
               "short_name" : "3",
               "types" : [ "street_number" ]
            },
            {
               "long_name" : "1033",
               "short_name" : "1033",
               "types" : []
            },
            {
               "long_name" : "K osmidomkům",
               "short_name" : "K osmidomkům",
               "types" : [ "route" ]
            },
            {
               "long_name" : "Praha-Suchdol",
               "short_name" : "Praha-Suchdol",
               "types" : [ "sublocality", "political" ]
            },
            {
               "long_name" : "Praha",
               "short_name" : "Praha",
               "types" : [ "locality", "political" ]
            },
            {
               "long_name" : "Hlavní město Praha",
               "short_name" : "Hlavní město Praha",
               "types" : [ "administrative_area_level_2", "political" ]
            },
            {
               "long_name" : "Hlavní město Praha",
               "short_name" : "Hlavní město Praha",
               "types" : [ "administrative_area_level_1", "political" ]
            },
            {
               "long_name" : "Česká republika",
               "short_name" : "CZ",
               "types" : [ "country", "political" ]
            },
            {
               "long_name" : "165 00",
               "short_name" : "165 00",
               "types" : [ "postal_code" ]
            },
            {
               "long_name" : "Praha 620",
               "short_name" : "Praha 620",
               "types" : [ "postal_town" ]
            }
         ],
         "formatted_address" : "K osmidomkům 1033/3, 165 00 Praha-Praha-Suchdol, Česká republika",
         "geometry" : {
            "location" : {
               "lat" : 50.13670170,
               "lng" : 14.36865280
            },
            "location_type" : "ROOFTOP",
            "viewport" : {
               "northeast" : {
                  "lat" : 50.13805068029150,
                  "lng" : 14.37000178029150
               },
               "southwest" : {
                  "lat" : 50.13535271970850,
                  "lng" : 14.36730381970850
               }
            }
         },
         "types" : [ "street_address" ]
      }
   ],
   "status" : "OK"
}

现在我需要通过 GSON 处理 JSON，但我只需要“几何”部分。我需要位置(经纬度)。如何将这段json绑定(bind)到POJO上呢？我的意思是类似的事情

public class GoogleMapLocation
{
    @SerializedName("lat")
    private double latitude;

    @SerializedName("lng")
    private double longitude;

    public double getLatitude()
    {
        return latitude;
    }

    public void setLatitude(final double latitude)
    {
        this.latitude = latitude;
    }

    public double getLongitude()
    {
        return longitude;
    }

    public void setLongitude(final double longitude)
    {
        this.longitude = longitude;
    }
}

然后

GoogleMapLocation gml = gson.fromJson(jsonReader, GoogleMapLocation.class);

Answer 1

这应该可以工作(为了清楚起见省略了 getter、setter，...不防错):

public class GoogleMapLocation {
    List<Result> results;

    String status;
}

public class Result {
    @SerializedName("address_components")
    private List<AddressComponent> addressComponents;

    @SerializedName("formatted_address")
    private String formattedAddress;

    private Geometry geometry;

    @SerializedName("partial_match")
    private String partialMatch; // not sure of the type

    private List<String> types;
}

public class AddressComponents {
    @SerializedName("long_name")
    private String longName;

    @SerializedName("short_name")
    private String shortName;

    private List<String> types;
}

public class Geometry {
    LatLng location;

    Viewport viewport;

    Viewport bounds;

    @SerializedName("location_type")
    String locationType;
}

public class LatLng {
    @SerializedName("lat");
    private double latitude;

    @SerializedName("lng");
    private double longitude;
}

public class Viewport {
    private LatLng northeast;

    private LatLng southwest;
}

参见official documentation .

编辑:请注意，某些字段也可以声明为枚举(status，...)