Google 当您无法驾车前往某个位置时，地图会崩溃

Question

我有一个 google 地图项目，您可以在其中输入地址，然后会显示一个标记、地址、持续时间（驾车旅行）以及从用户位置到点的距离B. 效果很好！

但我的问题是，每当我放置一个汽车无法进入的位置时，应用程序就会崩溃。我不是在寻找任何重要的东西，除了行驶距离之外我不需要任何其他东西，所以让用户被告知你不能在这里开车，对我来说就很好。

我在 Url请求后使用 JSONParsing 解析地址。 legs, distance, duration, end_address, end-lat, end-lng, 是我从这个文件中获取的值：

legs: [
{
    distance: {
        text: "547 km",
                value: 547015
    },
    duration: {
        text: "5 h 23 min",
                value: 19361
    },
    end_address: "Montreal, Quebec, Kanada",
            end_location: {
    lat: 45.5017123,
            lng: -73.5672184
},
    start_address: "Toronto, Ontario, Kanada",
            start_location: {
    lat: 43.6533096,
            lng: -79.3827656
},
    steps: [
    {
        distance: {
            text: "0,3 km",
                    value: 280
        },
        duration: {
            text: "1 min",
                    value: 66
        },
        end_location: {
            lat: 43.6557259,
                    lng: -79.3837337
        },
        html_instructions: "",
                polyline: {
        points: "e`miGhmocNs@Rm@N]JmA^KBcAZSFWHe@Nk@Pa@Le@L"
    },
        start_location: {
            lat: 43.6533096,
                    lng: -79.3827656
        },
        travel_mode: "DRIVING"
    },

所以我的问题是，有没有人有什么建议，对于这种方法我应该具备什么样的条件运行。

if(!=travel_mode: "DRIVING")
{
 Toast.makeText(MapsActivity.this, "You cannot drive there", 
    Toast.LENGTH:SHORT).show();
}
else
{
   execute code;
}

获取 travel_mode 并以某种方式将其作为条件？提前致谢！

我的全部代码，

主要class，当你按下一个按钮时，地址将被转换

private void init() {
    searchText.setOnEditorActionListener(new TextView.OnEditorActionListener() {
        @Override
        public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
            dataTransfer = new Object[2];
            url = getDirectionsUrl();
            GetDistances getDistances = new GetDistances();
            dataTransfer[0] = mMap;
            dataTransfer[1] = url;
            getDistances.execute(dataTransfer);
            return false;
        }
    });

建设 URL...

private String getDirectionsUrl()
{
    //WORKS
    //https://maps.googleapis.com/maps/api/directions/json?origin=Toronto&destination=Montreal&key=API_KEY"
    StringBuilder googleDirectionsUrl = new StringBuilder("https://maps.googleapis.com/maps/api/directions/json?");
    //Possible two textfields with origin being another textfield
    googleDirectionsUrl.append("origin="+myLat+","+myLng);
    googleDirectionsUrl.append("&destination="+searchText.getText().toString());
    googleDirectionsUrl.append("&key="+"API_KEY");

    return googleDirectionsUrl.toString();
}

正在发送 Url 进行解析...

public class DataParser {

private HashMap<String, String> getDuration(JSONArray googleDirectionsJson) {
    HashMap<String, String> googleDirectionsMap = new HashMap<>();
    String duration = "";
    String distance = "";
    String title = "";

    Log.d("json response", googleDirectionsJson.toString());
    try {
        duration = googleDirectionsJson.getJSONObject(0).getJSONObject("duration").getString("text");
        distance = googleDirectionsJson.getJSONObject(0).getJSONObject("distance").getString("text");
        title = googleDirectionsJson.getJSONObject(0).getString("end_address");

        googleDirectionsMap.put("duration", duration);
        googleDirectionsMap.put("distance", distance);
        googleDirectionsMap.put("end_address", title);

    } catch (JSONException e) {
        e.printStackTrace();
    }
    return googleDirectionsMap;
}

public HashMap<String, String> parseDirections(String jsonData) {
    JSONArray jsonArray = null;
    JSONObject jsonObject;

    try {
        jsonObject = new JSONObject(jsonData);
        jsonArray = jsonObject.getJSONArray("routes").getJSONObject(0).getJSONArray("legs");
    } catch (JSONException e) {
        e.printStackTrace();
    }

    return getDuration(jsonArray);
}

private HashMap<String, Double> getLatLng(JSONArray googleLatLngJson) {
    HashMap<String, Double> googleLatLngMap = new HashMap<>();
    Double latitude = 0.0;
    Double longitude = 0.0;

    try {
        latitude = googleLatLngJson.getJSONObject(0).getJSONObject("end_location").getDouble("lat");
        longitude = googleLatLngJson.getJSONObject(0).getJSONObject("end_location").getDouble("lng");

        googleLatLngMap.put("lat", latitude);
        googleLatLngMap.put("lng", longitude);
        Log.d("json response", googleLatLngMap.toString());

    } catch (JSONException e) {
        e.printStackTrace();
    }
    return googleLatLngMap;
}

public HashMap<String, Double> parseLatLng(String jsonData) {
    JSONArray jsonArray = null;
    JSONObject jsonObject;

    try {
        jsonObject = new JSONObject(jsonData);
        jsonArray = jsonObject.getJSONArray("routes").getJSONObject(0).getJSONArray("legs");
    } catch (JSONException e) {
        e.printStackTrace();
    }

    return getLatLng(jsonArray);
}

}

从 JSONparsed 哈希图中获取值并将它们放入新的哈希图中以添加带有它们值的标记

public class GetDistances extends AsyncTask<Object, String, String>{

GoogleMap mMap;
String url;
String googleDirectionsData;
String duration, distance;
Double latitude, longitude;
LatLng latLng;
String title;

@Override
protected String doInBackground(Object... objects) {
   mMap = (GoogleMap)objects[0];
   url = (String)objects[1];

   HttpHandler httpHandler = new HttpHandler();
   try
   {
       googleDirectionsData = httpHandler.readUrl(url);
   }
   catch(IOException e)
   {
       e.printStackTrace();
   }
   return googleDirectionsData;
}

@Override
protected void onPostExecute(String s)
{
    DataParser parser = new DataParser();

    HashMap<String, String> directionsList = null;
    directionsList = parser.parseDirections(s);
    duration = directionsList.get("duration");
    distance = directionsList.get("distance");
    title = directionsList.get("end_address");


    HashMap<String, Double> positionList = null;
    positionList = parser.parseLatLng(s);
    latitude = positionList.get("lat");
    longitude = positionList.get("lng");
    latLng = (new LatLng(latitude, longitude));

    mMap.animateCamera(CameraUpdateFactory.newLatLngZoom(latLng, 13));
    MarkerOptions markerOptions = new MarkerOptions()
            .position(latLng)
            .draggable(true)
            .title(title);
    markerOptions.snippet("Distance: " + distance + ", " + "Duration: " + duration);

    mMap.addMarker(markerOptions);
}
}

"API_KEY" - 是我的实际密钥，只是想保密。

已解决 我刚刚在onPostExecute方法中尝试了一个try catch，它解决了崩溃问题。

public class GetDestination extends AsyncTask<Object, String, String>{

GoogleMap mMap;
String url;
String googleDirectionsData;
String duration, distance;
Double latitude, longitude;
LatLng latLng;
String title;

private static Context context;
public GetDestination(Context c){
    context = c;
}

public static void showToast(){
    Toast.makeText(context, "You can't drive through the oceans!", Toast.LENGTH_LONG).show();
}

@Override
protected String doInBackground(Object... objects) {
   mMap = (GoogleMap)objects[0];
   url = (String)objects[1];

   HttpHandler httpHandler = new HttpHandler();
   try
   {
       googleDirectionsData = httpHandler.readUrl(url);
   }
   catch(IOException e)
   {
       e.printStackTrace();
   }
   return googleDirectionsData;
}

@Override
protected void onPostExecute(String s)
{
    try {
        DataParser parser = new DataParser();

        HashMap<String, String> directionsList = null;
        directionsList = parser.parseDirections(s);
        duration = directionsList.get("duration");
        distance = directionsList.get("distance");
        title = directionsList.get("start_address");


        HashMap<String, Double> positionList = null;
        positionList = parser.parseLatLng(s);
        latitude = positionList.get("lat");
        longitude = positionList.get("lng");

        latLng = (new LatLng(latitude, longitude));

        mMap.animateCamera(CameraUpdateFactory.newLatLngZoom(latLng, 13));
        MarkerOptions markerOptions = new MarkerOptions()
                .position(latLng)
                .draggable(true)
                .title(title);
        markerOptions.snippet("Distance: " + distance + ", " + "Duration: " + duration);

        mMap.addMarker(markerOptions);
    }
    catch (Exception e)
    {
        showToast();
        e.printStackTrace();
    }
}
}

一定要在Mainactivity中传入context class,

searchText1.setOnEditorActionListener(new TextView.OnEditorActionListener() {
        @Override
        public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
                dataTransfer = new Object[2];
                url = getDirectionsUrl();
                GetDestination getDestination = new GetDestination(MapsActivity.this);
                dataTransfer[0] = mMap;
                dataTransfer[1] = url;
                getDestination.execute(dataTransfer);
                return false;
        }
    });

Answer 1

很高兴你自己解决了这个问题。恭喜。

但更好的方法是在响应中放入 log 并检查两者之间的差异 responses 即 drivable and not drivable。

通过这种方式，您可以读取准确的响应，并根据响应向用户显示不同的消息。

当然，try, catch 可以处理任何类型的异常。

希望对您有所帮助。

Google 当您无法驾车前往某个位置时，地图会崩溃

Google Maps crashes when you cannot drive to a location

android

google-maps

directions