1
我想向用户显示使用经度和纬度的两个位置之间的持续时间。我遇到了许多问题，我不知道如何处理它。如何使用Google地图显示持续时间？
这里是我的doInBackground代码：
protected String[] doInBackground(String... params) {
try {
LocationManager locationManager = (LocationManager) MyCustomHomeActivity.this
.getSystemService(LOCATION_SERVICE);
// getting GPS status
boolean isGPSEnabled = locationManager
.isProviderEnabled(LocationManager.GPS_PROVIDER);
// getting network status
boolean isNetworkEnabled = locationManager
.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
if (!isGPSEnabled && !isNetworkEnabled) {
// no network provider is enabled
} else {
// if GPS Enabled get lat/long using GPS Services
if (isGPSEnabled) {
if (locationManager != null) {
location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
String shuLat = "41.2207188";
String shuLong = "-73.24168179999999";
String forecastJsonStr = null;
String myUrlSetup = "https://maps.googleapis.com/maps/api/directions/json?origin="+latitude + "," + longitude +"&destination="+shuLat +"," + shuLong + "&departure_time=now&traffic_model=best_guess&key=AIzaSyB6l8vrnspw2-1Q_cnzO03JlAsIOMl-7bs";
HttpURLConnection urlConnection = null;
BufferedReader reader = null;
try {
URL url;
url = new URL(myUrlSetup);
// Create the request to GoogleMapAPI, and open the connection
urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setRequestMethod("GET");
urlConnection.connect();
// Read the input stream into a String
InputStream inputStream = urlConnection.getInputStream();
StringBuffer buffer = new StringBuffer();
if (inputStream == null) {
// Nothing to do.
return null;
}
System.out.println("I am in doInBackground step3");
reader = new BufferedReader(new InputStreamReader(inputStream));
String line;
while ((line = reader.readLine()) != null) {
// Since it's JSON, adding a newline isn't necessary (it won't affect parsing)
// But it does make debugging a *lot* easier if you print out the completed
// buffer for debugging.
buffer.append(line + "\n");
}
if (buffer.length() == 0) {
// Stream was empty. No point in parsing.
return null;
}
forecastJsonStr = buffer.toString();
Log.v(LOG_TAG, "Forecast string: " + forecastJsonStr);
} catch (IOException e) {
Log.e(LOG_TAG, "Error ", e);
// If the code didn't successfully get the weather data, there's no point in attemping
// to parse it.
return null;
} finally {
if (urlConnection != null) {
urlConnection.disconnect();
}
if (reader != null) {
try {
reader.close();
} catch (final IOException e) {
Log.e(LOG_TAG, "Error closing stream", e);
}
}
}
try {
System.out.println("I am just in front of calling getDurationDataFromJson");
return getDurationDataFromJson(forecastJsonStr);
} catch (JSONException e) {
Log.e(LOG_TAG, e.getMessage(), e);
e.printStackTrace();
}
return new String[0];
}//end doInBackground
这里是我的getDurationDataFromJSON代码：我现在面临
private String[] getDurationDataFromJson(String forecastJsonStr)
throws JSONException {
// These are the names of the JSON objects that need to be extracted.
final String OWM_ROUTES = "routes";
final String OWM_LEGS = "legs";
final String OWM_DURATION = "duration";
final String OWM_TEXT = "text";
String[] resultStrs = new String[0];
String duration;
JSONObject durationJson = new JSONObject(forecastJsonStr);
JSONArray routeArray = durationJson.getJSONArray(OWM_ROUTES);
JSONArray legArray = routeArray.getJSONObject(0).getJSONArray(OWM_LEGS);
//Duration
JSONObject durationObj = legArray.getJSONObject(0).getJSONObject(OWM_DURATION);
duration = durationObj.getString(OWM_TEXT);
resultStrs[0] = duration;
System.out.println("Duration is: " + duration);
for (String s : resultStrs) {
System.out.println("Duration entry: " + s);
Log.v(LOG_TAG, "Duration entry: " + s);
}
return resultStrs;
}
麻烦是在doInBackGround代码以下部分：
location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
错误是：
Call requires permission which may be rejected by user: code should explicitly check to see if permission is available(with `check permission`) or explicitly handle a potential `SecurityException`.
我不知道我是否正朝着正确的方向前进。请通过这个指导我。
你能从清单显示你的权限吗？你正在尝试哪个操作系统版本？你是否熟悉API23以来的新的permision API？ – snachmsm
检查出[https：/ /developer.android.com/training/permissions/requesting.html](https://developer.android.com/training/permissions/requesting.html） – snachmsm