这是我的main
活动
import java.net.HttpURLConnection;
import java.net.URL;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import android.os.Bundle;
import android.util.Log;
import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapActivity;
import com.google.android.maps.MapController;
import com.google.android.maps.MapView;
public class DrawActivity extends MapActivity {
MapView myMapView = null;
MapController myMC = null;
GeoPoint geoPoint = null;
String pairs[]=null;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
myMapView = (MapView) findViewById(R.id.mapview);
geoPoint = null;
myMapView.setSatellite(false);
System.out.println("before pairs");
String pairs[] = getDirectionData("Hyderabad","hyderguda");
System.out.println("pairs:"+pairs[1]);
String[] lngLat = pairs[0].split(",");
// STARTING POINT
GeoPoint startGP = new GeoPoint(
(int) (Double.parseDouble(lngLat[1]) * 1E6), (int) (Double
.parseDouble(lngLat[0]) * 1E6));
myMC = myMapView.getController();
geoPoint = startGP;
myMC.setCenter(geoPoint);
myMC.setZoom(15);
myMapView.getOverlays().add(new DirectionPathOverlay(startGP, startGP));
// NAVIGATE THE PATH
GeoPoint gp1;
GeoPoint gp2 = startGP;
for (int i = 1; i < pairs.length; i++) {
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));
myMapView.getOverlays().add(new DirectionPathOverlay(gp1, gp2));
Log.d("xxx", "pair:" + pairs[i]);
}
// END POINT
myMapView.getOverlays().add(new DirectionPathOverlay(gp2, gp2));
myMapView.getController().animateTo(startGP);
myMapView.setBuiltInZoomControls(true);
myMapView.displayZoomControls(true);
}
@Override
protected boolean isRouteDisplayed() {
// TODO Auto-generated method stub
return false;
}
private String[] getDirectionData(String srcPlace, String destPlace) {
String urlString = "http://maps.google.com/maps?f=d&hl=en&saddr="
+ srcPlace + "&daddr=" + destPlace
+ "&ie=UTF8&0&om=0&output=kml";
Log.d("URL", urlString);
Document doc = null;
HttpURLConnection urlConnection = null;
URL url = null;
String pathConent = "";
try {
url = new URL(urlString.toString());
urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setRequestMethod("GET");
urlConnection.setDoOutput(true);
urlConnection.setDoInput(true);
urlConnection.connect();
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder db = dbf.newDocumentBuilder();
doc = db.parse(urlConnection.getInputStream());
//The above code "doc" is getting null value so thats why its getting crashed here itself not going further execution and returning as `nullpointerexception`
} catch (Exception e) {
}
NodeList nl = doc.getElementsByTagName("LineString");
for (int s = 0; s < nl.getLength(); s++) {
Node rootNode = nl.item(s);
NodeList configItems = rootNode.getChildNodes();
for (int x = 0; x < configItems.getLength(); x++) {
Node lineStringNode = configItems.item(x);
NodeList path = lineStringNode.getChildNodes();
pathConent = path.item(0).getNodeValue();
}
}
String[] tempContent = pathConent.split(" ");
return tempContent;
}
}
和我的另一部分代码包com.hands;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Point;
import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapView;
import com.google.android.maps.Overlay;
import com.google.android.maps.Projection;
public class DirectionPathOverlay extends Overlay {
private GeoPoint gp1;
private GeoPoint gp2;
public DirectionPathOverlay(GeoPoint gp1, GeoPoint gp2) {
this.gp1 = gp1;
this.gp2 = gp2;
}
@Override
public boolean draw(Canvas canvas, MapView mapView, boolean shadow,
long when) {
// TODO Auto-generated method stub
Projection projection = mapView.getProjection();
if (shadow == false) {
Paint paint = new Paint();
paint.setAntiAlias(true);
Point point = new Point();
projection.toPixels(gp1, point);
paint.setColor(Color.BLUE);
Point point2 = new Point();
projection.toPixels(gp2, point2);
paint.setStrokeWidth(2);
canvas.drawLine((float) point.x, (float) point.y, (float) point2.x,
(float) point2.y, paint);
}
return super.draw(canvas, mapView, shadow, when);
}
@Override
public void draw(Canvas canvas, MapView mapView, boolean shadow) {
// TODO Auto-generated method stub
super.draw(canvas, mapView, shadow);
}
}
以上是我的完整源代码请帮我解决这个问题