Android中的Http GET Request错误

Question

我试图从android上的http get请求获取响应，而不使用map活动，仅发送url请求以获取对字符串的响应。

从以下网址获取响应的网址： https : //maps.googleapis.com/maps/api/distancematrix/json?origins=ashdod&destinations=yavne&key

我正在尝试的代码是：

HttpURLConnection urlConnection= null;
    URL url = null;
    String response = "";
    try {
        url  = new URL(urlString.toString());
        urlConnection=(HttpURLConnection)url.openConnection();
        urlConnection.setRequestMethod("GET");
        urlConnection.setDoOutput(true);
        urlConnection.setDoInput(true);
        urlConnection.connect();
        InputStream inStream = null;
        inStream = urlConnection.getInputStream();
        BufferedReader bReader = new BufferedReader(new InputStreamReader(inStream));
        String temp = "";
        while((temp = bReader.readLine()) != null){
            //Parse data
            response += temp;
        }
        bReader.close();
        inStream.close();
        urlConnection.disconnect();

    } catch (Exception e) {
        e.printStackTrace();
    }

    try {
        JSONObject Jresponse = new JSONObject(response.toString());
        JSONArray rows = Jresponse.getJSONArray("rows");
        JSONObject rows_obj = (JSONObject) rows.get(0);
        JSONArray elems = rows_obj.getJSONArray("elements");
        JSONObject elems_obj = (JSONObject) elems.get(0);
        JSONObject dist = (JSONObject) elems_obj.get("distance");
        JSONObject dur = (JSONObject) elems_obj.get("duration");
        finalDistance = dist.getInt("value");
        finalDuration = dist.getInt("value");
    } catch (JSONException e) {
        e.printStackTrace();
    }
}

问题是它在到达连接时抛出异常。

PS这是我第一次使用android，所以请对我好一点。

Answer 1

在执行GET请求时，您不需要执行输出。

只需删除此行：

urlConnection.setDoOutput(true);

或者您可以简单地将urlConnection.setDoOutput(true)更改为urlConnection.setDoOutput(false)

除此之外，您还应该更改代码的这一部分以防止代码乱码：

BufferedReader bufferedReader = 
            new BufferedReader(new InputStreamReader(inStream, StandardCharsets.UTF_8));