Gson Json parser Array of Arrays

问题

Looking to parse some Json and parse out array of arrays. Unfortunately I cannot figure out how to handle nested arrays within the json.

json

{
    "type": "MultiPolygon",
    "coordinates": [
        [
            [
                [
                    -71.25,
                    42.33
                ],
                [
                    -71.25,
                    42.33
                ]
            ]
        ],
        [
            [
                [
                    -71.23,
                    42.33
                ],
                [
                    -71.23,
                    42.33
                ]
            ]
        ]
    ]
}

What I have implemented when I just an a single array.

public class JsonObjectBreakDown {
    public String type; 
    public List<List<String[]>> coordinates = new ArrayList<>();
    public void setCoordinates(List<List<String[]>> coordinates) {
        this.coordinates = coordinates;
    }




}

parsing call

JsonObjectBreakDown p = gson.fromJson(withDup, JsonObjectBreakDown.class);

回答1:

You've got an array of arrays of arrays of arrays of Strings. You need

public List<List<List<String[]>>> coordinates = new ArrayList<>();

The following

public static void main(String args[]) {
    Gson gson = new Gson();
    String jsonstr ="{  \"type\": \"MultiPolygon\",\"coordinates\": [        [            [                [                    -71.25,                    42.33                ],                [                    -71.25,                    42.33                ]            ]        ],        [            [                [                    -71.23,                    42.33                ],                [                    -71.23,                    42.33                ]            ]        ]    ]}";
    JsonObjectBreakDown obj = gson.fromJson(jsonstr, JsonObjectBreakDown.class);

    System.out.println(Arrays.toString(obj.coordinates.get(0).get(0).get(0)));
}

public static class JsonObjectBreakDown {
    public String type; 
    public List<List<List<String[]>>> coordinates = new ArrayList<>();
    public void setCoordinates(List<List<List<String[]>>> coordinates) {
        this.coordinates = coordinates;
    }
}

prints

[-71.25, 42.33]

来源：https://stackoverflow.com/questions/18906140/gson-json-parser-array-of-arrays