具有可变维数组的Java对象

我正在尝试使用解析一个JSON，我有一个JSON，看起来像这样（简化）：

• 当我尝试使用

  double[][][]

  而不是

  ？

  时，我得到了一个

  com.google.gson.JsonSyntaxException:java.lang.IllegalStateException:应为double，但在第6行第146列的BEGIN\u数组中

• 当我尝试将

  Shape

  作为一个抽象类，并为

  MultiPolygon

  和

  Polygon

  使用子类时，

  Gson

  尝试实例化

  Shape

  和错误

---

我可以使用泛型或其他狡猾的方法来解决这个问题吗？

您需要有自己的自定义，因为

坐标变量没有一组定义的数组维度。我建议对形状使用接口，然后为其编写反序列化程序，如下所示：

public interface Shape {

    ShapeType getType();

    enum ShapeType { Polygon, MultiPolygon }
}

然后是每种类型的实现<代码>形状类型.多边形

：

public class PolygonShape implements Shape {

    private final ShapeType type = ShapeType.Polygon;
    private double[][][] coordinates;

    public ShapeType getType() {
        return type;
    }

    public double[][][] getCoordinates() {
        return coordinates;
    }

    public void setCoordinates(double[][][] coordinates) {
        this.coordinates = coordinates;
    }
}

public class MultiPolygonShape implements Shape {

    private final ShapeType type = ShapeType.MultiPolygon;
    private double[][][][] coordinates;

    public ShapeType getType() {
        return type;
    }

    public double[][][][] getCoordinates() {
        return coordinates;
    }

    public void setCoordinates(double[][][][] coordinates) {
        this.coordinates = coordinates;
    }
}

和

ShapeType.MultiPolygon

：

public class PolygonShape implements Shape {

    private final ShapeType type = ShapeType.Polygon;
    private double[][][] coordinates;

    public ShapeType getType() {
        return type;
    }

    public double[][][] getCoordinates() {
        return coordinates;
    }

    public void setCoordinates(double[][][] coordinates) {
        this.coordinates = coordinates;
    }
}

public class MultiPolygonShape implements Shape {

    private final ShapeType type = ShapeType.MultiPolygon;
    private double[][][][] coordinates;

    public ShapeType getType() {
        return type;
    }

    public double[][][][] getCoordinates() {
        return coordinates;
    }

    public void setCoordinates(double[][][][] coordinates) {
        this.coordinates = coordinates;
    }
}

最后，反序列化程序将依赖于每个实现的

类型

：

public class ShapeDeserializer implements JsonDeserializer<Shape> {

    @Override
    public Shape deserialize(JsonElement json, Type typeOfT,
            JsonDeserializationContext context) throws JsonParseException {
        JsonObject jsonObject = json.getAsJsonObject();
        ShapeType type = context.deserialize(jsonObject.get("type"), ShapeType.class);
        switch (type) {
            case Polygon:
                return context.deserialize(json, PolygonShape.class);
            case MultiPolygon:
                return context.deserialize(json, MultiPolygonShape.class);
            default:
                throw new JsonParseException("Unrecognized shape type: " + type);
        }
    }
}

不要忘记使用以下方法注册：

case Line:
    return context.deserialize(json, LineShape.class);

GsonBuilder builder;
// ...
builder.registerTypeAdapter(Shape.class, new ShapeDeserializer());