在google地图上画出两个地点的行走路线

Google Direction API提供了更丰富的路线信息数据。由于访问量过大吧，谷歌现在不提供了查询路线的接口API，现在要想获得一个路线我们可以通过URL访问google然后解析得到的KML文件，得到路线的每个点的经纬度，然互在一个图层上画出这些点。代码来自于对一些网上资源的整理，一共提供了连个方法，一个通过两个地方的名字，一个是通过两个地点的经纬度，但是有时候会出现错误的别是对中国的城市，还有就是别用中文，要不会很惨，希望有人给出一个更好的方法

[图片] 未命名1.jpg

[代码] 新建一个图层

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01	package com.android.antkingwei.google.direction;

02

03	import android.graphics.Canvas;

04	import android.graphics.Color;

05	import android.graphics.Paint;

06	import android.graphics.Point;

07

08	import com.google.android.maps.GeoPoint;

09	import com.google.android.maps.MapView;

10	import com.google.android.maps.Overlay;

11	import com.google.android.maps.Projection;

12

13	public class DirectionPathOverlay extends Overlay {

14	private GeoPoint gp1;

15	private GeoPoint gp2;

16

17	public DirectionPathOverlay(GeoPoint gp1, GeoPoint gp2) {

18	this.gp1 = gp1;

19	this.gp2 = gp2;

20

}

21

22

@Override

23	public boolean draw(Canvas canvas, MapView mapView, boolean shadow, long when) {

24	Projection projection = mapView.getProjection();

25	if(shadow == false) {

26	Paint paint = new Paint();

27	paint.setAntiAlias(true);

28	Point point = new Point();

29	projection.toPixels(gp1, point);

30	paint.setColor(Color.BLUE);

31	Point point2 = new Point();

32	projection.toPixels(gp2, point2);

33	paint.setStrokeWidth(2);

34	canvas.drawLine((float) point.x, (float) point.y, (float) point2.x, (float) point2.y, paint);

35

}

36	return super.draw(canvas, mapView, shadow, when);

37

}

38

39

@Override

40	public void draw(Canvas canvas, MapView mapView, boolean shadow) {

41	super.draw(canvas, mapView, shadow);

42

}

43

}

[代码] 主类

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001	package com.android.antkingwei.google.direction;

002

003	import java.net.HttpURLConnection;

004	import java.net.URL;

005

006	import javax.xml.parsers.DocumentBuilder;

007	import javax.xml.parsers.DocumentBuilderFactory;

008

009	import org.w3c.dom.Document;

010	import org.w3c.dom.Node;

011	import org.w3c.dom.NodeList;

012

013	import com.google.android.maps.GeoPoint;

014	import com.google.android.maps.MapActivity;

015	import com.google.android.maps.MapController;

016	import com.google.android.maps.MapView;

017

018	import android.app.Activity;

019	import android.os.Bundle;

020	import android.util.Log;

021

022	public class MainActivity extends MapActivity {

023	private MapView myMapView;

024	private GeoPoint geoPoint;

025	private MapController myMC;

026	private String[] pairs;

027	/** Called when the activity is first created. */

028

@Override

029	public void onCreate(Bundle savedInstanceState) {

030	super.onCreate(savedInstanceState);

031	setContentView(R.layout.main);

032

033	myMapView = (MapView) findViewById(R.id.mapview);

034	geoPoint = null;

035	myMapView.setSatellite(false);

036

//通过地名

037	//pairs = getDirectionData("ahmedabad", "vadodara");

038

//通过四个坐标

039	pairs = getUrl(22.5348,113.97246,35.422006,119.524095);

040	String[] lngLat = pairs[0].split(",");

041	// STARTING POINT

042	GeoPoint startGP = new GeoPoint((int)(Double.parseDouble(lngLat[1]) * 1E6), (int) (Double.parseDouble(lngLat[0]) * 1E6));

043	myMC = myMapView.getController();

044	geoPoint = startGP;

045	myMC.setCenter(geoPoint);

046	myMC.setZoom(8);

047	myMapView.getOverlays().add(new DirectionPathOverlay(startGP, startGP));

048	// NAVIGATE THE PATH

049	GeoPoint gp1;

050	GeoPoint gp2 = startGP;

051	for (int i = 1; i < pairs.length; i++) {

052	lngLat = pairs[i].split(",");

053	gp1 = gp2;

054	// watch out! For GeoPoint, first:latitude, second:longitude

055	gp2 = new GeoPoint((int) (Double.parseDouble(lngLat[1]) * 1E6),(int) (Double.parseDouble(lngLat[0]) * 1E6));

056	myMapView.getOverlays().add(new DirectionPathOverlay(gp1, gp2));

057	Log.d("xxx", "pair:" + pairs[i]);

058

}

059	// END POINT

060	myMapView.getOverlays().add(new DirectionPathOverlay(gp2, gp2));

061	myMapView.getController().animateTo(startGP);

062	myMapView.setBuiltInZoomControls(true);

063	myMapView.displayZoomControls(true);

064

065

}

066

@Override

067	protected boolean isRouteDisplayed() {

068	// TODO Auto-generated method stub

069	return false;

070

}

071

/**

072	* 通过四个坐标点，获得KML然后通过DOM解析

073	* @param fromLat

074	* @param fromLon

075	* @param toLat

076	* @param toLon

077

* @return

078

*/

079	public String[] getUrl(double fromLat,double fromLon,double toLat,double toLon){

080	String urlString = "http://maps.google.com/maps?f=d&hl=en&saddr="+fromLat+","+fromLon+"&daddr="+toLat+","+toLon+"&ie=UTF8&0&om=0&output=kml";

081	Log.d("URL", urlString);

082	Document doc = null;

083	HttpURLConnection urlConnection = null;

084	URL url = null;

085	String pathConent = "";

086

087

try{

088	url = new URL(urlString.toString());

089	urlConnection = (HttpURLConnection) url.openConnection();

090	urlConnection.setRequestMethod("GET");

091	urlConnection.setDoOutput(true);

092	urlConnection.setDoInput(true);

093	urlConnection.connect();

094	DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();

095	DocumentBuilder db = dbf.newDocumentBuilder();

096	doc = db.parse(urlConnection.getInputStream());

097	} catch (Exception e){}

098	NodeList nl = doc.getElementsByTagName("LineString");

099	for(int s=0; s< nl.getLength(); s++){

100	Node rootNode = nl.item(s);

101	NodeList configItems = rootNode.getChildNodes();

102	for(int x=0; x < configItems.getLength(); x++) {

103	Node lineStringNode = configItems.item(x);

104	NodeList path = lineStringNode.getChildNodes();

105	pathConent = path.item(0).getNodeValue();

106

}

107

}

108	String[] tempContent = pathConent.split(" ");

109	return tempContent;

110

}

111

/**

112	* 通过连个地名获得KML然后进行DOM解析

113	* @param srcPlace

114	* @param destPlace

115

* @return

116

*/

117	private String[] getDirectionData(String srcPlace, String destPlace) {

118	String urlString = "http://maps.google.com/maps?f=d&hl=en&saddr="+srcPlace+"&daddr="+destPlace+"&ie=UTF&om=0&output=kml";

119	Log.d("URL", urlString);

120	Document doc = null;

121	HttpURLConnection urlConnection = null;

122	URL url = null;

123	String pathConent = "";

124

try{

125	url = new URL(urlString.toString());

126	urlConnection = (HttpURLConnection) url.openConnection();

127	urlConnection.setRequestMethod("GET");

128	urlConnection.setDoOutput(true);

129	urlConnection.setDoInput(true);

130	urlConnection.connect();

131	DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();

132	DocumentBuilder db = dbf.newDocumentBuilder();

133	doc = db.parse(urlConnection.getInputStream());

134	} catch (Exception e){}

135	NodeList nl = doc.getElementsByTagName("LineString");

136	for(int s=0; s< nl.getLength(); s++){

137	Node rootNode = nl.item(s);

138	NodeList configItems = rootNode.getChildNodes();

139	for(int x=0; x < configItems.getLength(); x++) {

140	Node lineStringNode = configItems.item(x);

141	NodeList path = lineStringNode.getChildNodes();

142	pathConent = path.item(0).getNodeValue();

143

}

144

}

145	String[] tempContent = pathConent.split(" ");

146	return tempContent;

147

}

148

}

[代码] main.xml

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01	<?xml version="1.0" encoding="utf-8"?>

02	<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

03	android:orientation="vertical"

04	android:layout_width="fill_parent"

05	android:layout_height="fill_parent"

06

>

07

<TextView

08	android:layout_width="fill_parent"

09	android:layout_height="wrap_content"

10	android:text="@string/hello"

11

/>

12	<com.google.android.maps.MapView

13	xmlns:android="http://schemas.android.com/apk/res/android"

14	android:id="@+id/mapview"

15	android:layout_width="fill_parent"

16	android:layout_height="fill_parent"

17	android:enabled="true"

18	android:clickable="true"

19	android:apiKey="0FZLYf-YM4SRrJrJum55MeeaO4Gd_IitVFmtUeA"/>

20	</LinearLayout>

[代码] AndroidManifest.xml

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01	<?xml version="1.0" encoding="utf-8"?>

02	<manifest xmlns:android="http://schemas.android.com/apk/res/android"

03	package="com.android.antkingwei.google.direction"

04	android:versionCode="1"

05	android:versionName="1.0">

06	<uses-sdk android:minSdkVersion="7" />

07

08	<application android:icon="@drawable/icon" android:label="@string/app_name">

09	<activity android:name=".MainActivity"

10	android:label="@string/app_name">

11	<intent-filter>

12	<action android:name="android.intent.action.MAIN" />

13	<category android:name="android.intent.category.LAUNCHER" />

14	</intent-filter>

15

16	</activity>

17	<uses-library android:name="com.google.android.maps" />

18	</application>

19	<uses-permission android:name="android.permission.INTERNET"></uses-permission>

20	<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>

21	<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>

22	<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>

23	</manifest>