I have been trying to parse an XML which is automatically generated by google (http://maps.googleapis.com).
This is the exact XML I used as an example for my program:
My code:
public class MapDirection {
public final static String MODE_DRIVING = "driving";
public final static String MODE_WALKING = "walking";
public MapDirection() { }
public Document getDocument(LatLng start, LatLng end, String mode) {
try {
URL url = new URL("http://maps.googleapis.com/maps/api/directions/xml?"
+ "origin=" + start.latitude + "," + start.longitude
+ "&destination=" + end.latitude + "," + end.longitude
+ "&sensor=false&units=metric&mode=driving");
DocumentBuilderFactory mDocumentBuilderFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder mDocumentBuilder = mDocumentBuilderFactory.newDocumentBuilder();
Document mDocument = mDocumentBuilder.parse(new InputSource(url.openStream()));
mDocument.getDocumentElement().normalize();
return mDocument;
}
catch (Exception e) {
System.out.println("XML Parsing Exception = " + e);
}
return null;
}
public String getDurationText (Document mDocument) {
NodeList nodeList1 = mDocument.getElementsByTagName("DirectResponse");
Node node1 = nodeList1.item(getNodeIndex(nodeList1, "route"));
NodeList nodeList2 = node1.getChildNodes();
Node node2 = nodeList2.item(getNodeIndex(nodeList2, "leg"));
NodeList nodeList3 = node2.getChildNodes();
Node node3 = nodeList3.item(getNodeIndex(nodeList3, "duration"));
NodeList nodeList4 = node3.getChildNodes();
Node node4 = nodeList4.item(getNodeIndex(nodeList4, "text"));
return node4.getTextContent();
}
public int getDurationValue (Document mDocument) {
NodeList nodeList1 = mDocument.getElementsByTagName("DirectResponse");
Node node1 = nodeList1.item(getNodeIndex(nodeList1, "route"));
NodeList nodeList2 = node1.getChildNodes();
Node node2 = nodeList2.item(getNodeIndex(nodeList2, "leg"));
NodeList nodeList3 = node2.getChildNodes();
Node node3 = nodeList3.item(getNodeIndex(nodeList3, "duration"));
NodeList nodeList4 = node3.getChildNodes();
Node node4 = nodeList4.item(getNodeIndex(nodeList4, "value"));
return Integer.parseInt(node4.getTextContent());
}
public String getDistanceText (Document mDocument) {
NodeList nodeList1 = mDocument.getElementsByTagName("DirectResponse");
Node node1 = nodeList1.item(getNodeIndex(nodeList1, "route"));
NodeList nodeList2 = node1.getChildNodes();
Node node2 = nodeList2.item(getNodeIndex(nodeList2, "leg"));
NodeList nodeList3 = node2.getChildNodes();
Node node3 = nodeList3.item(getNodeIndex(nodeList3, "distance"));
NodeList nodeList4 = node3.getChildNodes();
Node node4 = nodeList4.item(getNodeIndex(nodeList4, "text"));
return node4.getTextContent();
}
public int getDistanceValue (Document mDocument) {
NodeList nodeList1 = mDocument.getElementsByTagName("DirectResponse");
Node node1 = nodeList1.item(getNodeIndex(nodeList1, "route"));
NodeList nodeList2 = node1.getChildNodes();
Node node2 = nodeList2.item(getNodeIndex(nodeList2, "leg"));
NodeList nodeList3 = node2.getChildNodes();
Node node3 = nodeList3.item(getNodeIndex(nodeList3, "distance"));
NodeList nodeList4 = node3.getChildNodes();
Node node4 = nodeList4.item(getNodeIndex(nodeList4, "value"));
return Integer.parseInt(node4.getTextContent());
}
public String getStartAddress (Document mDocument) {
NodeList nodeList1 = mDocument.getElementsByTagName("DirectResponse");
Node node1 = nodeList1.item(getNodeIndex(nodeList1, "route"));
NodeList nodeList2 = node1.getChildNodes();
Node node2 = nodeList2.item(getNodeIndex(nodeList2, "leg"));
NodeList nodeList3 = node2.getChildNodes();
Node node3 = nodeList3.item(getNodeIndex(nodeList3, "start_address"));
return node3.getTextContent();
}
public String getEndAddress (Document mDocument) {
NodeList nodeList1 = mDocument.getElementsByTagName("DirectResponse");
Node node1 = nodeList1.item(getNodeIndex(nodeList1, "route"));
NodeList nodeList2 = node1.getChildNodes();
Node node2 = nodeList2.item(getNodeIndex(nodeList2, "leg"));
NodeList nodeList3 = node2.getChildNodes();
Node node3 = nodeList3.item(getNodeIndex(nodeList3, "end_address"));
return node3.getTextContent();
}
public String getCopyRights (Document mDocument) {
NodeList nodeList1 = mDocument.getElementsByTagName("DirectResponse");
Node node1 = nodeList1.item(getNodeIndex(nodeList1, "route"));
NodeList nodeList2 = node1.getChildNodes();
Node node2 = nodeList2.item(getNodeIndex(nodeList2, "copyrights"));
return node2.getTextContent();
}
private int getNodeIndex(NodeList nodeList, String nodeName) {
for(int i = 0 ; i < nodeList.getLength() ; i++) {
if(nodeList.item(i).getNodeName().equals(nodeName))
return i;
}
return -1;
}
Example of implementation:
private void getRoute(LatLng startLocation, LatLng endLocation) {
MapDirection mMapDirection = new MapDirection();
Document mDocument = mMapDirection.getDocument(startLocation, endLocation, MODE_DRIVING);
String mDuration = mMapDirection.getDurationText(mDocument);
String mDistance = mMapDirection.getDistanceText(mDocument);
String mStartAddress = mMapDirection.getStartAddress(mDocument);
String mEndAddress = mMapDirection.getEndAddress(mDocument);
Toast.makeText(getBaseContext(), "Duration: " + mDuration +
"Distance: " + mDistance +
"Start: " + mStartAddress +
"End: " + mEndAddress, Toast.LENGTH_LONG).show();
}
My final question is, what am I doing wrong ? The errors I get:
09-13 10:52:57.791: E/AndroidRuntime(13720): FATAL EXCEPTION: main
09-13 10:52:57.791: E/AndroidRuntime(13720): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.raulbutuc.taxifinder/com.raulbutuc.menu.items.OpenMap}: java.lang.NullPointerException
09-13 10:52:57.791: E/AndroidRuntime(13720): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2185)
09-13 10:52:57.791: E/AndroidRuntime(13720): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2210)
09-13 10:52:57.791: E/AndroidRuntime(13720): at android.app.ActivityThread.access$600(ActivityThread.java:142)
09-13 10:52:57.791: E/AndroidRuntime(13720): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1208)
09-13 10:52:57.791: E/AndroidRuntime(13720): at android.os.Handler.dispatchMessage(Handler.java:99)
09-13 10:52:57.791: E/AndroidRuntime(13720): at android.os.Looper.loop(Looper.java:137)
09-13 10:52:57.791: E/AndroidRuntime(13720): at android.app.ActivityThread.main(ActivityThread.java:4931)
09-13 10:52:57.791: E/AndroidRuntime(13720): at java.lang.reflect.Method.invokeNative(Native Method)
09-13 10:52:57.791: E/AndroidRuntime(13720): at java.lang.reflect.Method.invoke(Method.java:511)
09-13 10:52:57.791: E/AndroidRuntime(13720): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:791)
09-13 10:52:57.791: E/AndroidRuntime(13720): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:558)
09-13 10:52:57.791: E/AndroidRuntime(13720): at dalvik.system.NativeStart.main(Native Method)
09-13 10:52:57.791: E/AndroidRuntime(13720): Caused by: java.lang.NullPointerException
09-13 10:52:57.791: E/AndroidRuntime(13720): at com.raulbutuc.GPSMapping.MapDirection.getDurationText(MapDirection.java:63)
09-13 10:52:57.791: E/AndroidRuntime(13720): at com.raulbutuc.menu.items.OpenMap.getRoute(OpenMap.java:170)
09-13 10:52:57.791: E/AndroidRuntime(13720): at com.raulbutuc.menu.items.OpenMap.onCreate(OpenMap.java:163)
09-13 10:52:57.791: E/AndroidRuntime(13720): at android.app.Activity.performCreate(Activity.java:5008)
09-13 10:52:57.791: E/AndroidRuntime(13720): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
09-13 10:52:57.791: E/AndroidRuntime(13720): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2139)
09-13 10:52:57.791: E/AndroidRuntime(13720): ... 11 more
