android get duration from maps.google.com directions

问题

At the moment I am using this code to inquire google maps for directions from an address to another one, then I simply draw it on a mapview from its GeometryCollection. But yet this isn't enough I need also to extract the total expected duration from the kml. can someone give a little sample code to help me? thanks

StringBuilder urlString = new StringBuilder();
urlString.append("http://maps.google.com/maps?f=d&hl=en");
urlString.append("&saddr=");//from
urlString.append( Double.toString((double)src.getLatitudeE6()/1.0E6 ));
urlString.append(",");
urlString.append( Double.toString((double)src.getLongitudeE6()/1.0E6 ));
urlString.append("&daddr=");//to
urlString.append( Double.toString((double)dest.getLatitudeE6()/1.0E6 ));
urlString.append(",");
urlString.append( Double.toString((double)dest.getLongitudeE6()/1.0E6 ));
urlString.append("&ie=UTF8&0&om=0&output=kml");
//Log.d("xxx","URL="+urlString.toString());
// get the kml (XML) doc. And parse it to get the coordinates(direction route).
Document doc = null;
HttpURLConnection urlConnection= null;
URL url = null;
try
{
    url = new URL(urlString.toString());
    urlConnection=(HttpURLConnection)url.openConnection();
    urlConnection.setRequestMethod("GET");
    urlConnection.setDoOutput(true);
    urlConnection.setDoInput(true);
    urlConnection.connect();
    dbf = DocumentBuilderFactory.newInstance();
    db = dbf.newDocumentBuilder();
    doc = db.parse(urlConnection.getInputStream());
    if(doc.getElementsByTagName("GeometryCollection").getLength()>0)
    {
        //String path = doc.getElementsByTagName("GeometryCollection").item(0).getFirstChild().getFirstChild().getNodeName();
        String path = doc.getElementsByTagName("GeometryCollection").item(0).getFirstChild().getFirstChild().getFirstChild().getNodeValue() ;
        //Log.d("xxx","path="+ path);
        String[] pairs = path.split(" ");
        String[] lngLat = pairs[0].split(","); // lngLat[0]=longitude lngLat[1]=latitude lngLat[2]=height
        // src
        GeoPoint startGP = new GeoPoint((int)(Double.parseDouble(lngLat[1])*1E6),(int)(Double.parseDouble(lngLat[0])*1E6));
        mMapView01.getOverlays().add(new MyOverLay(startGP,startGP,1));
        GeoPoint gp1;
        GeoPoint gp2 = startGP;
        for(int i=1;i<pairs.length;i++) // the last one would be crash
        {
            lngLat = pairs[i].split(",");
            gp1 = gp2;
            // watch out! For GeoPoint, first:latitude, second:longitude
            gp2 = new GeoPoint((int)(Double.parseDouble(lngLat[1])*1E6),(int)(Double.parseDouble(lngLat[0])*1E6));
            mMapView01.getOverlays().add(new MyOverLay(gp1,gp2,2,color));
            //Log.d("xxx","pair:" + pairs[i]);
        }
        mMapView01.getOverlays().add(new MyOverLay(dest,dest, 3)); // use the default color
        }
    }catch (MalformedURLException e){
        e.printStackTrace();
    }catch (IOException e){
        e.printStackTrace();
    }catch (SAXException e){
        e.printStackTrace();
    } catch (ParserConfigurationException e) {
        e.printStackTrace();
    }
}

回答1:

Use the new Directions api. The duration is returned in the response and no more parsing of KML, which I think breaks the Google maps license terms anyways.

Update. Ok use the JSON output, with it parsing is built into Android.

Ex url

Response is

{
  "status": "OK",
  "routes": [ {
    "summary": "I-40 W",
    "legs": [ {
      "steps": [ {
        "travel_mode": "DRIVING",
        "start_location": {
          "lat": 41.8507300,
          "lng": -87.6512600
        },
        "end_location": {
          "lat": 41.8525800,
          "lng": -87.6514100
        },
        "polyline": {
          "points": "a~l~Fjk~uOwHJy@P",
          "levels": "B?B"
        },
        "duration": {
          "value": 19,
          "text": "1 min"
        },
        "html_instructions": "Head \u003cb\u003enorth\u003c/b\u003e on \u003cb\u003eS Morgan St\u003c/b\u003e toward \u003cb\u003eW Cermak Rd\u003c/b\u003e",
        "distance": {
          "value": 207,
          "text": "0.1 mi"
        }
      },
      ...
      ... additional steps of this leg
    ...
    ... additional legs of this route
      "duration": {
        "value": 74384,
        "text": "20 hours 40 mins"
      },
      "distance": {
        "value": 2137146,
        "text": "1,328 mi"
      },
      "start_location": {
        "lat": 35.4675602,
        "lng": -97.5164276
      },
      "end_location": {
        "lat": 34.0522342,
        "lng": -118.2436849
      },
      "start_address": "Oklahoma City, OK, USA",
      "end_address": "Los Angeles, CA, USA"
    } ],
    "copyrights": "Map data ©2010 Google, Sanborn",
    "overview_polyline": {
      "points": "a~l~Fjk~uOnzh@vlbBtc~@tsE`vnApw{A`dw@~w\\|tNtqf@l{Yd_Fblh@rxo@b}@xxSfytAblk@xxaBeJxlcBb~t@zbh@jc|Bx}C`rv@rw|@rlhA~dVzeo@vrSnc}Axf]fjz@xfFbw~@dz{A~d{A|zOxbrBbdUvpo@`cFp~xBc`Hk@nurDznmFfwMbwz@bbl@lq~@loPpxq@bw_@v|{CbtY~jGqeMb{iF|n\\~mbDzeVh_Wr|Efc\\x`Ij{kE}mAb~uF{cNd}xBjp]fulBiwJpgg@|kHntyArpb@bijCk_Kv~eGyqTj_|@`uV`k|DcsNdwxAott@r}q@_gc@nu`CnvHx`k@dse@j|p@zpiAp|gEicy@`omFvaErfo@igQxnlApqGze~AsyRzrjAb__@ftyB}pIlo_BflmA~yQftNboWzoAlzp@mz`@|}_@fda@jakEitAn{fB_a]lexClshBtmqAdmY_hLxiZd~XtaBndgC",
      "levels": "BBBAAAAABAABAAAAAABBAAABBAAAABBAAABABAAABABBAABAABAAAABABABABBABAABB"
    },
    "warnings": [ ],
    "waypoint_order": [ 0, 1 ]
  } ]
} 

Let's say you used the standard http client libraries and now have the response in a String.

JSONObject jsonObject = new JSONObject(response); // parse response into json object
JSONObject routeObject = jsonObject.getJSONObject("route"); // pull out the "route" object
JSONObject durationObject = jsonObject.getJSONObject("duration"); // pull out the "duration" object
String duration = durationObject.getString("text"); //this should be the duration text value (20 hours 40 mins)

You will have to wrap all that in a try-catch block to catch the JSONExceptions.

来源：https://stackoverflow.com/questions/2951007/android-get-duration-from-maps-google-com-directions