Code isn't working on Android

Question

My questions keep getting lost and I really need help with this, been stuck for 2 weeks now without any luck :( My app is basically a map that has markers placed on it from an XML file which is stored in res\raw\markers.xml. The map loads fine and show my current position, the Logcat is logging my xml data so I can only assume that it is parsing fine, but no markers are showing on the map. I'm having to use a SAX Parser because when I use xmlPullParser it is very slow and unresponsive on startup. I just don't know why SAX Parser isn't showing any markers but my xmlPullParser does. My XML file has about 7000+ lines in it.

Can anyone help me? Thanks in advance

MainActivity:

import java.io.InputStream;
import java.util.ArrayList;

import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

import org.xml.sax.InputSource;
import org.xml.sax.XMLReader;

import com.androidmapsextensions.ClusteringSettings;
import com.androidmapsextensions.GoogleMap.OnMarkerClickListener;
import com.androidmapsextensions.MapView;
import com.androidmapsextensions.Marker;
import com.androidmapsextensions.MarkerOptions;
import com.androidmapsextensions.SupportMapFragment;
import com.androidmapsextensions.GoogleMap;

import android.support.v4.app.FragmentActivity;
import android.content.ActivityNotFoundException;
import android.content.Intent;
import android.content.res.Resources;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.net.Uri;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Toast;

import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GooglePlayServicesClient;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.LocationSource;
import com.google.android.gms.maps.model.BitmapDescriptorFactory;
import com.google.android.gms.maps.model.CameraPosition;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.LatLngBounds;

public class MainActivity extends FragmentActivity implements OnMarkerClickListener, LocationListener,
GooglePlayServicesClient.ConnectionCallbacks,
GooglePlayServicesClient.OnConnectionFailedListener, LocationSource {

private OnLocationChangedListener mListener;
private LocationManager locationmanager;
GoogleMap mMap;
LatLng myposition;


@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
locationmanager = (LocationManager) getSystemService(LOCATION_SERVICE);

if(locationmanager != null){
boolean gpsIsEnabled = locationmanager.isProviderEnabled(LocationManager.GPS_PROVIDER);
boolean networkIsEnabled = locationmanager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);

if(gpsIsEnabled){
locationmanager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 5000L, 10F, this);
}
else if(networkIsEnabled)
{
locationmanager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 5000L, 10F, this);
}
else
{
Toast.makeText(this, "GPS is not enabled", Toast.LENGTH_SHORT).show();
}
setUpMapIfNeeded();

}
}

@Override
public void onPause()
{
if(locationmanager != null){
locationmanager.removeUpdates(this);
}
super.onPause();

}

@Override
public void onResume(){
super.onResume();
setUpMapIfNeeded();
if(locationmanager != null){
mMap.setMyLocationEnabled(true);
}
}

private void setUpMapIfNeeded() {
if (mMap == null){
mMap = ((SupportMapFragment)getSupportFragmentManager().findFragmentById(R.id.the_map)).getExtendedMap();

if (mMap != null){
setUpMap();
}
mMap.setLocationSource(this);
mMap.setMyLocationEnabled(true);
showmypoi();
}
}

private void setUpMap() {
mMap.setMyLocationEnabled(true);
mMap.setOnMarkerClickListener(this);

}   

private void showmypoi() {
try {
SAXParserFactory spf = SAXParserFactory.newInstance();
SAXParser sp = spf.newSAXParser();
XMLReader xr = sp.getXMLReader();
InputStream localfile;
localfile = getResources().openRawResource(R.raw.markers);
XMLHandlers myXMLHandler = new XMLHandlers();
xr.setContentHandler(myXMLHandler);
xr.parse(new InputSource(localfile));
}
catch (Exception e){
System.out.println("XML Parsing Exception = " + e);
e.printStackTrace();
}

for(int i = 0; i < Locations.size(); i++){
Double latitude = Double.valueOf(Locations.size());
Double longitude = Double.valueOf(Locations.size());
LatLng Lng = new LatLng(latitude,longitude);
mMap = ((SupportMapFragment)getSupportFragmentManager().findFragmentById(R.id.the_map)).getExtendedMap();
String icon = null;
mMap.getMarkers();
mMap.addMarker(new MarkerOptions().position(Lng).icon(BitmapDescriptorFactory.fromResource(getResources().getIdentifier(icon, "drawable", getPackageName()))));         
}

}


@Override
public void activate(OnLocationChangedListener listener) {
mListener = listener;
}

@Override
public void deactivate() {
mListener = null;
}

@Override
public void onConnectionFailed(ConnectionResult result) {}

@Override
public void onConnected(Bundle connectionHint) {}
@Override
public void onDisconnected() {}

public void onCameraChange(CameraPosition cameraPosition){

}

@Override
public void onLocationChanged(Location location) {
if( mListener != null){
mListener.onLocationChanged( location );

LatLngBounds bounds = this.mMap.getProjection().getVisibleRegion().latLngBounds;

if(!bounds.contains(new LatLng(location.getAltitude(), location.getLongitude())));{
mMap.animateCamera(CameraUpdateFactory.newLatLng(new LatLng(location.getLatitude(), location.getLongitude())));

}
}
}

@Override
public void onProviderDisabled(String provider) {
Toast.makeText(this, "No Network Data Available", Toast.LENGTH_SHORT).show();

}
@Override
public void onProviderEnabled(String provider) {
Toast.makeText(this, "Using Network Data", Toast.LENGTH_SHORT).show();
}

@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
Toast.makeText(this, "GPS Data Used", Toast.LENGTH_SHORT).show();

}
@Override
public boolean onMarkerClick(Marker marker) {
double latitude = marker.getPosition().latitude;
double longitude = marker.getPosition().longitude;
double latitudeCurr = mMap.getMyLocation().getLatitude();
double longitudeCurr = mMap.getMyLocation().getLongitude();
Intent intent = new Intent(android.content.Intent.ACTION_VIEW,
Uri.parse("https://maps.google.co.uk/maps?" + "saddr="
+ latitudeCurr + "," + longitudeCurr + "&daddr="
+ latitude + "," + longitude + "&mode=driving"));
intent.setClassName("com.google.android.apps.maps",
"com.google.android.maps.MapsActivity");
try
{
startActivity(intent);
}
catch(ActivityNotFoundException ex)
{
try
{
Intent unrestrictedIntent = new Intent(Intent.ACTION_VIEW, Uri.parse("https://maps.google.co.uk/maps?" + "saddr="
+ latitudeCurr + "," + longitudeCurr + "&daddr="
+ latitude + "," + longitude + "&mode=driving"));
startActivity(unrestrictedIntent);
}
catch(ActivityNotFoundException innerEx)
{
Toast.makeText(this, "Please install a maps application", Toast.LENGTH_LONG).show();
}
}

return false;
}

@Override
public boolean onCreateOptionsMenu(Menu menu){
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item){
if (item.getItemId() == R.id.action_legalnotices){
startActivity(new Intent(this, LegalNoticesActivity.class));
}
return super.onOptionsItemSelected(item);
}
}

XMLHandler:

import java.util.ArrayList;

import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

public class XMLHandlers extends DefaultHandler {
ArrayList<Locations> locations = null;
private Locations loc = null;

public ArrayList<Locations> getLocations(){
return locations;
}

boolean bLat = false;
boolean bLng = false;
boolean bIcon = false;

@Override
public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {

if (qName.equalsIgnoreCase("marker")){
loc = new Locations();
if (locations == null)
locations = new ArrayList<Locations>();
} else if (qName.equalsIgnoreCase("lat")){
bLat = true;
} else if (qName.equalsIgnoreCase("lng")){
bLng = true;
} else if (qName.equalsIgnoreCase("icon")){
bIcon = true;
}

}
@Override
public void endElement(String uri, String localName, String qName) throws SAXException {
if (qName.equalsIgnoreCase("marker")) {
locations.add(loc);
}
}

@Override
public void characters(char ch[], int start, int length) throws SAXException {
if (bIcon){
loc.setIcon(new String(ch, start, length));
bIcon = false;
}
}
}

XMLArray Class:

import android.util.Log;

public class Locations {
private double lat;
private double lng;
private String icon;

public double getLat(){
return lat;
}

public void setLat(double lat){
this.lat = lat;

}
public double getLng(){
return lng;
}

public void setLng(double lng){
this.lng = lng;
}

public String getIcon(){
return icon;
}

public void setIcon(String icon){
this.icon = icon;
Log.i("....", icon);
}

public static int size() {
return 0;
}
}

XML Layout:

<lat>51.60002</lat>
<lng>0.518862</lng>
<icon>motel</icon>
</marker>
<marker>
<lat>51.61325</lat>
<lng>0.524572</lng>
<icon>hotel</icon>
</marker>
<marker>
<lat>51.591483</lat>
<lng>0.502149</lng>
<icon>hotel</icon>
</marker>
<marker>
<lat>51.590816</lat>
<lng>0.473675</lng>
<icon>bnb</icon>
</marker>
</markers>

Answer 1

Woah... I hope that's Stackoverflow's formatting and not yours. I can see quite a few potential bugs in your code, but I don't have time to point them all out now, the relevant one relevant is this:

for(int i = 0; i < Locations.size(); i++){
    // Add marker here...
}

Locations is a class, not a list of locations. With a static method called size(), which always returns 0

public static int size() {
    return 0;
}

What I think you actually want is a list of the locations i.e. List<Location> locations, then you can call locations.size()

When in doubt - print out everything! If you had added a Log.d('Tag', 'index: ' + i); within that for loop, you would see that it never gets executed, and you'd know that i was never > 0.