J2ME / Android / BlackBerry - 行车路线,两个地点之间的路线

时间:2010-01-07 21:05:39

标签: android blackberry java-me geolocation driving-directions

在Android 1.0上,有一个com.google.googlenav命名空间用于行车路线:
Route - Improved Google Driving Directions
但是在较新的SDK中,它被某种原因删除了......
Android: DrivingDirections removed since API 1.0 - how to do it in 1.5/1.6? 在黑莓手机上也缺少这些东西的API:
how to find the route between two places in Blackberry?

csie-tw提供了一种解决方法(查询kml文件的gmaps并解析它):
Android - Driving Direction (Route Path)
此外,Andrea为Android制作了DrivingDirections helper classes 我在j2me中为这个功能写了一个小助手,所以我想在Android和BlackBerry上分享我的样本。

更新
正如评论中所述,它不是正式允许的Google Maps APIs Terms of Service

  

Google地图/ Google地球API服务条款
  最后更新时间:2009年5月27日
  ...
  10.许可限制。除非条款明确允许,或者除非您事先获得Google(或适用的特定内容提供商)的书面授权,否则Google的上述许可均受您遵守以下所有限制的约束。除非在第7节或Maps API文档中明确允许,否则您不得(也不允许任何其他人):
  ...
  10.9将服务或内容与任何产品,系统或应用程序一起使用或与之相关:
  (a)实时导航或路线引导,包括但不限于与用户的传感器设备位置同步的转弯路线引导;

可能会针对某些应用停用(不知何故,至少在Android上)...来自Geocode scraping in .NET conversation

  

API使用条款不允许这样做。你不应该刮   谷歌地图生成地理编码。我们将阻止这样做的服务   自动查询我们的服务器。

     布雷特泰勒   产品经理,谷歌地图

对任何替代方案和/或建议表示感谢! 谢谢!

1 个答案:

答案 0 :(得分:116)

J2ME Map Route Provider

maps.google.com有一个导航服务,可以KML格式为您提供路线信息。

要获取kml文件,我们需要形成包含起始位置和目标位置的网址:

public static String getUrl(double fromLat, double fromLon,
                            double toLat, double toLon) {// connect to map web service
    StringBuffer urlString = new StringBuffer();
    urlString.append("http://maps.google.com/maps?f=d&hl=en");
    urlString.append("&saddr=");// from
    urlString.append(Double.toString(fromLat));
    urlString.append(",");
    urlString.append(Double.toString(fromLon));
    urlString.append("&daddr=");// to
    urlString.append(Double.toString(toLat));
    urlString.append(",");
    urlString.append(Double.toString(toLon));
    urlString.append("&ie=UTF8&0&om=0&output=kml");
    return urlString.toString();
}

接下来,您将需要解析xml(使用SAXParser实现)并填充数据结构:

public class Point {
    String mName;
    String mDescription;
    String mIconUrl;
    double mLatitude;
    double mLongitude;
}

public class Road {
    public String mName;
    public String mDescription;
    public int mColor;
    public int mWidth;
    public double[][] mRoute = new double[][] {};
    public Point[] mPoints = new Point[] {};
}

网络连接在Android和Blackberry上以不同方式实现,因此您必须首先形成网址:

 public static String getUrl(double fromLat, double fromLon,
     double toLat, double toLon)

然后创建与此url的连接并获取InputStream 然后传递此InputStream并获得解析的数据结构:

 public static Road getRoute(InputStream is) 

完整源代码RoadProvider.java

黑莓

class MapPathScreen extends MainScreen {
    MapControl map;
    Road mRoad = new Road();
    public MapPathScreen() {
        double fromLat = 49.85, fromLon = 24.016667;
        double toLat = 50.45, toLon = 30.523333;
        String url = RoadProvider.getUrl(fromLat, fromLon, toLat, toLon);
        InputStream is = getConnection(url);
        mRoad = RoadProvider.getRoute(is);
        map = new MapControl();
        add(new LabelField(mRoad.mName));
        add(new LabelField(mRoad.mDescription));
        add(map);
    }
    protected void onUiEngineAttached(boolean attached) {
        super.onUiEngineAttached(attached);
        if (attached) {
            map.drawPath(mRoad);
        }
    }
    private InputStream getConnection(String url) {
        HttpConnection urlConnection = null;
        InputStream is = null;
        try {
            urlConnection = (HttpConnection) Connector.open(url);
            urlConnection.setRequestMethod("GET");
            is = urlConnection.openInputStream();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return is;
    }
}

查看Google代码{/ 3}上的完整代码

的Android

Android G1 screenshot

public class MapRouteActivity extends MapActivity {
    LinearLayout linearLayout;
    MapView mapView;
    private Road mRoad;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        mapView = (MapView) findViewById(R.id.mapview);
        mapView.setBuiltInZoomControls(true);
        new Thread() {
            @Override
            public void run() {
                double fromLat = 49.85, fromLon = 24.016667;
                double toLat = 50.45, toLon = 30.523333;
                String url = RoadProvider
                        .getUrl(fromLat, fromLon, toLat, toLon);
                InputStream is = getConnection(url);
                mRoad = RoadProvider.getRoute(is);
                mHandler.sendEmptyMessage(0);
            }
        }.start();
    }

    Handler mHandler = new Handler() {
        public void handleMessage(android.os.Message msg) {
            TextView textView = (TextView) findViewById(R.id.description);
            textView.setText(mRoad.mName + " " + mRoad.mDescription);
            MapOverlay mapOverlay = new MapOverlay(mRoad, mapView);
            List<Overlay> listOfOverlays = mapView.getOverlays();
            listOfOverlays.clear();
            listOfOverlays.add(mapOverlay);
            mapView.invalidate();
        };
    };

    private InputStream getConnection(String url) {
        InputStream is = null;
        try {
            URLConnection conn = new URL(url).openConnection();
            is = conn.getInputStream();
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return is;
    }
    @Override
    protected boolean isRouteDisplayed() {
        return false;
    }
}

查看Google代码{/ 3}上的完整代码