问题
//main activity in this class two errors shown below within the comments
import android.graphics.Color;
import android.os.Bundle;
import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapActivity;
import com.google.android.maps.MapView;
public class NewroutepathActivity extends MapActivity {
/** Called when the activity is first created. */
MapView mapView;
private String US_API;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
//mapView = (MapView) findViewById(R.id.mapview);
MapView mapView = (MapView) findViewById(R.id.mapview); //or you can declare it directly with the API key
Route route = directions(new GeoPoint((int)(26.2*1E6),(int)(50.6*1E6)), new GeoPoint((int)(26.3*1E6),(int)(50.7*1E6)));
//the obove line also getting error
RouteOverlay routeOverlay = new RouteOverlay(route, Color.BLUE);
mapView.getOverlays().add(routeOverlay);
}
@Override
protected boolean isRouteDisplayed() {
// TODO Auto-generated method stub
return false;
}
private Route directions(final GeoPoint start, final GeoPoint dest) {
Parser parser;
String jsonURL = "maps.google.com/maps/api/directions/json?";
final StringBuffer sBuf = new StringBuffer(jsonURL);
sBuf.append("origin=");
sBuf.append(start.getLatitudeE6()/1E6);
sBuf.append(',');
sBuf.append(start.getLongitudeE6()/1E6);
sBuf.append("&destination=");
sBuf.append(dest.getLatitudeE6()/1E6);
sBuf.append(',');
sBuf.append(dest.getLongitudeE6()/1E6);
sBuf.append("&sensor=true&mode=driving");
parser = new GoogleParser(sBuf.toString());
Route r = parser.parse();// here getting error
return r;
}
}
googleparser classes here one error
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.util.Log;
import com.google.android.maps.GeoPoint;
public class GoogleParser extends XMLParser implements Parser {
/** Distance covered. **/
private int distance;
public GoogleParser(String feedUrl) {
super(feedUrl);
}
/**
* Parses a url pointing to a Google JSON object to a Route object.
* @return a Route object based on the JSON object.
*/
public Route parse() {
// turn the stream into a string
final String result = convertStreamToString(this.getInputStream());
//The above line is getting one error
//Create an empty route
final Route route = new Route();
//Create an empty segment
final Segment segment = new Segment();
try {
//Tranform the string into a json object
final JSONObject json = new JSONObject(result);
//Get the route object
final JSONObject jsonRoute = json.getJSONArray("routes").getJSONObject(0);
//Get the leg, only one leg as we don't support waypoints
final JSONObject leg = jsonRoute.getJSONArray("legs").getJSONObject(0);
//Get the steps for this leg
final JSONArray steps = leg.getJSONArray("steps");
//Number of steps for use in for loop
final int numSteps = steps.length();
//Set the name of this route using the start & end addresses
route.setName(leg.getString("start_address") + " to " + leg.getString("end_address"));
//Get google's copyright notice (tos requirement)
route.setCopyright(jsonRoute.getString("copyrights"));
//Get the total length of the route.
route.setLength(leg.getJSONObject("distance").getInt("value"));
//Get any warnings provided (tos requirement)
if (!jsonRoute.getJSONArray("warnings").isNull(0)) {
route.setWarning(jsonRoute.getJSONArray("warnings").getString(0));
}
/* Loop through the steps, creating a segment for each one and
* decoding any polylines found as we go to add to the route object's
* map array. Using an explicit for loop because it is faster!
*/
for (int i = 0; i < numSteps; i++) {
//Get the individual step
final JSONObject step = steps.getJSONObject(i);
//Get the start position for this step and set it on the segment
final JSONObject start = step.getJSONObject("start_location");
final GeoPoint position = new GeoPoint((int) (start.getDouble("lat")*1E6),
(int) (start.getDouble("lng")*1E6));
segment.setPoint(position);
//Set the length of this segment in metres
final int length = step.getJSONObject("distance").getInt("value");
distance += length;
segment.setLength(length);
segment.setDistance(distance/1000);
//Strip html from google directions and set as turn instruction
segment.setInstruction(step.getString("html_instructions").replaceAll("<(.*?)*>", ""));
//Retrieve & decode this segment's polyline and add it to the route.
route.addPoints(decodePolyLine(step.getJSONObject("polyline").getString("points")));
//Push a copy of the segment to the route
route.addSegment(segment.copy());
}
} catch (JSONException e) {
Log.e(e.getMessage(), "Google JSON Parser - " + feedUrl);
}
return route;
}
/**
* Convert an inputstream to a string.
* @param input inputstream to convert.
* @return a String of the inputstream.
*/
private static String convertStreamToString(final InputStream input) {
final BufferedReader reader = new BufferedReader(new InputStreamReader(input));
final StringBuilder sBuf = new StringBuilder();
String line = null;
try {
while ((line = reader.readLine()) != null) {
sBuf.append(line);
}
} catch (IOException e) {
Log.e(e.getMessage(), "Google parser, stream2string");
} finally {
try {
input.close();
} catch (IOException e) {
Log.e(e.getMessage(), "Google parser, stream2string");
}
}
return sBuf.toString();
}
/**
* Decode a polyline string into a list of GeoPoints.
* @param poly polyline encoded string to decode.
* @return the list of GeoPoints represented by this polystring.
*/
private List<GeoPoint> decodePolyLine(final String poly) {
int len = poly.length();
int index = 0;
List<GeoPoint> decoded = new ArrayList<GeoPoint>();
int lat = 0;
int lng = 0;
while (index < len) {
int b;
int shift = 0;
int result = 0;
do {
b = poly.charAt(index++) - 63;
result |= (b & 0x1f) << shift;
shift += 5;
} while (b >= 0x20);
int dlat = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));
lat += dlat;
shift = 0;
result = 0;
do {
b = poly.charAt(index++) - 63;
result |= (b & 0x1f) << shift;
shift += 5;
} while (b >= 0x20);
int dlng = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));
lng += dlng;
decoded.add(new GeoPoint(
(int) (lat*1E6 / 1E5), (int) (lng*1E6 / 1E5)));
}
return decoded;
}
}
回答1:
That happened to me too. To solve it - in function 'direction', when you start to build the jsonURL string, add 'http://' at the beginning, just before 'map.google.com...'.
回答2:
I think the problem here is that you are targeting newer APIs , that requires accessing the network not in the main thread. Change the definition of getInputStream() (At XMLParser?) to support networking in a seperate thread.
来源：https://stackoverflow.com/questions/11945681/displaying-route-path-names