如何使用改进的android向服务器发送多维数组

int[][] arr = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}};

JSONArray jsonArray = new JSONArray();
for (int i = 0; i < arr.length; i++) {
    JSONArray innerArray = new JSONArray();
    for (int j = 0; j < arr[i].length; j++) {
        innerArray.put(arr[i][j]);
    }
    jsonArray.put(innerArray);
}
String jsonStr = jsonArray.toString();

URL url = new URL("http://your-server-url");
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("POST");
conn.setDoOutput(true);
conn.setRequestProperty("Content-Type", "application/json");
OutputStreamWriter writer = new OutputStreamWriter(conn.getOutputStream());
writer.write(jsonStr);
writer.flush();
writer.close();