Android-筆記 GoogleMap 路徑規劃

 

	
        //markerClick事件
        @Override
	public boolean onMarkerClick(Marker marker) {
		
		if(marker.equals(myMaker)) return true;
		
		final String url = getDirectionsUrl(mMyLatLng, marker.getPosition());
		new Thread(new Runnable() {
			
			@Override
			public void run() {
				String data = getRouteJsonData(url);
				ParserTask parserTask = new ParserTask();
				parserTask.execute(data);
			}
		}).start();
		
		return true;
	}


        private class ParserTask extends AsyncTask>>> {
		@Override
		protected List>> doInBackground(String... jsonData){
			JSONObject jObject;
			List>> routes = null;
			try {
				jObject = new JSONObject(jsonData[0]);
				DirectionsJSONParser parser = new DirectionsJSONParser();

				// Starts parsing data
				routes = parser.parse(jObject);
		 	} catch (Exception e) {
		 		e.printStackTrace();
		 	}
			return routes;
		}
		 
		@Override
		protected void onPostExecute(List>> result) {
			ArrayList points = null;
			MarkerOptions markerOptions = new MarkerOptions();
			PolylineOptions lineOptions = null;
			
			// Traversing through all the routes
			for (int i = 0; i < result.size(); i++) {
				points = new ArrayList();
				lineOptions = new PolylineOptions();

				// Fetching i-th route
				List> path = result.get(i);

				// Fetching all the points in i-th route
				for (int j = 0; j < path.size(); j++) {
					HashMap point = path.get(j);

					double lat = Double.parseDouble(point.get("lat"));
					double lng = Double.parseDouble(point.get("lng"));
					LatLng position = new LatLng(lat, lng);

					points.add(position);
				 }
				 
				 // Adding all the points in the route to LineOptions
				 lineOptions.addAll(points);
				 lineOptions.width(10);  //導航路徑寬度
				 lineOptions.color(0xfff42046); //導航路徑顏色
		    }
			if(mPolyline != null) mPolyline.remove();
			mPolyline = mGoogleMap.addPolyline(lineOptions);
		}
	}



        public static String getDirectionsUrl(LatLng origin, LatLng dest) {
		String url="";
		String str_origin = "origin=" + origin.latitude + "," + origin.longitude;
		String str_dest = "destination=" + dest.latitude + "," + dest.longitude;
		String sensor = "sensor=false";
		String mode = "mode=walking";
		url = "https://maps.googleapis.com/maps/api/directions/json?" + str_origin + "&"
				+ str_dest + "&" + sensor + "&" + mode;
		
		return url;
	}
	
	public static String getRouteJsonData(String strUrl) {
		String data = "";
		InputStream iStream = null;
		HttpURLConnection urlConnection = null;
		try {
			URL url = new URL(strUrl);

			// Creating an http connection to communicate with url
			urlConnection = (HttpURLConnection) url.openConnection();

			// Connecting to url
			urlConnection.connect();

			// Reading data from url
			iStream = urlConnection.getInputStream();

			BufferedReader br = new BufferedReader(new InputStreamReader(iStream));

			StringBuffer sb = new StringBuffer();

			String line = "";
			while ((line = br.readLine()) != null) {
				sb.append(line);
			}

			data = sb.toString();

			br.close();

		} catch (Exception e) {
			Log.d("Exception while downloading url", e.toString());
		} finally {
			
			try {
				iStream.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
			
			urlConnection.disconnect();
		}
		return data;
	}