How to display route between two points (geopoints) on Google Maps in Android

UPDATE: Now this is not working. Google API changed.

Recently a have some task in my Android project.

I needed to show route (directions) between two points (geopoins)on google maps in Android.

I thought it can be simple task. But It was a lot of interesting things :).

I’ve discovered a lot of topics of this problem.

I find one usefull. This is IT

But, it didn’t works for me.

Here I want to show my changes of this project.

Below you can download source code of sample Android project.

Here is screenshot:

The major changes is in KML parser. Here is this class:

package com.hrupin.maproute.route;

import java.io.InputStream;

import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathExpression;
import javax.xml.xpath.XPathFactory;

import org.w3c.dom.Document;

public class RoadProvider {
	private static Document xmlDocument;

	public static Road getRoute(InputStream is) {
		Road mRoad = new Road();
		String expression = "string(//Placemark/GeometryCollection/LineString/coordinates)";
		String expression2 = "string(//Placemark[contains(name, 'Route')]/description)";
		try {
			xmlDocument = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(is);
			XPathFactory xPathFactory = XPathFactory.newInstance();
			XPath xPath = xPathFactory.newXPath();
			XPathExpression xPathExpression = xPath.compile(expression);
			String result = xPathExpression.evaluate(xmlDocument);
			String[] arr1 = result.split(" ");
			for (String str : arr1) {
				String[] coords = str.split(",");
				if (coords.length == 3) {
					double[] xy = new double[] {};
					double x = Double.parseDouble(coords[0]);
					double y = Double.parseDouble(coords[1]);

					xy = addDouble(xy, x);
					xy = addDouble(xy, y);
					mRoad.mRoute = addDouble(mRoad.mRoute, xy);
					System.out.println("PARSING ..... ");
				}
			}
			
			xPathExpression = xPath.compile(expression2);
			String description = xPathExpression.evaluate(xmlDocument);
			
			mRoad.mDescription = cleanup(description);
			
			System.out.println("DESCRIPTION = " + mRoad.mDescription);
			
		} catch (Exception ex) {
			ex.printStackTrace();
		} 
		return mRoad;
	}

	static double[][] addDouble(double[][] array, double[] element) {
		int arrayLength = array.length;
		double[][] result = new double[arrayLength + 1][];
		for (int i = 0; i < arrayLength; i++) {
			int elementLength = array[i].length;
			result[i] = new double[elementLength];
			for (int j = 0; j < elementLength; j++)
				result[i][j] = array[i][j];
		}
		int newElementLength = element.length;
		result[arrayLength] = new double[newElementLength];
		for (int j = 0; j < newElementLength; j++)
			result[arrayLength][j] = element[j];
		return result;
	}

	static double[] addDouble(double[] array, double element) {
		int arrayLength = array.length;
		double[] result = new double[arrayLength + 1];
		for (int i = 0; i < arrayLength; i++)
			result[i] = array[i];
		result[arrayLength] = element;
		return result;
	}

	public static String getUrl(double fromLat, double fromLon, double toLat, double toLon) {
		StringBuffer urlString = new StringBuffer();
		urlString.append("http://maps.google.com/maps?f=d&hl=en");
		urlString.append("&saddr=");
		urlString.append(Double.toString(fromLat));
		urlString.append(",");
		urlString.append(Double.toString(fromLon));
		urlString.append("&daddr=");
		urlString.append(Double.toString(toLat));
		urlString.append(",");
		urlString.append(Double.toString(toLon));
		urlString.append("&ie=UTF8&0&om=0&output=kml");
		return urlString.toString();
	}
	
	private static String cleanup(String value) {
		String remove = "<br/>";
		int index = value.indexOf(remove);
		if (index != -1)
			value = value.substring(0, index);
		remove = "&#160;";
		index = value.indexOf(remove);
		int len = remove.length();
		while (index != -1) {
			value = value.substring(0, index).concat(value.substring(index + len, value.length()));
			index = value.indexOf(remove);
		}
		return value;
	}
}

Enjoy! 🙂

Here you can download the source code of this Android Project.