通过Java访问Google Directions API

import java.net.HttpURLConnection;
import java.net.URL;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;

import org.w3c.dom.Document;

public class directionService{


    public static void main(String[] args) {

        String start = \"geelong\";
        String finish = \"melbourne\";

        String region = \"au\";

        System.out.println(calculateRoute(start,finish,region));
    }

    private static String calculateRoute(String start, String finish, String region){
        String result = \"\";
        String urlString = \"http://maps.googleapis.com/maps/api/directions/json?sensor=false&origin=\"+start+\"&destination=\"+finish;
        System.out.println(urlString);

        try{
            URL urlGoogleDirService = new URL(urlString);

            HttpURLConnection urlGoogleDirCon = (HttpURLConnection)urlGoogleDirService.openConnection();

            urlGoogleDirCon.setAllowUserInteraction( false );
            urlGoogleDirCon.setDoInput( true );
            urlGoogleDirCon.setDoOutput( false );
            urlGoogleDirCon.setUseCaches( true );
            urlGoogleDirCon.setRequestMethod(\"GET\");
            urlGoogleDirCon.connect();

            DocumentBuilderFactory factoryDir = DocumentBuilderFactory.newInstance();
            DocumentBuilder parserDirInfo = factoryDir.newDocumentBuilder();
            Document docDir = parserDirInfo.parse(urlGoogleDirCon.getInputStream());

            urlGoogleDirCon.disconnect();
            result = docDir.toString();


        return result; 
        }

        catch(Exception e)
        {
            System.out.println(e);
            return null;
        }

    };

}