我想将谷歌地图用于在谷歌地图 android api v2 中定位用户输入地址与地理编码 api 与我的 Android 应用程序
下面是我的代码：
MainActivity.java
package com.example.googlemaps;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.util.HashMap;
import java.util.List;
import org.json.JSONObject;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;
public class MainActivity extends FragmentActivity {
Button mBtnFind;
GoogleMap mMap;
EditText etPlace;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Getting reference to the find button
mBtnFind = (Button) findViewById(R.id.btn_show);
// Getting reference to the SupportMapFragment
SupportMapFragment mapFragment = (SupportMapFragment)getSupportFragmentManager().findFragmentById(R.id.map);
// Getting reference to the Google Map
mMap = mapFragment.getMap();
// Getting reference to EditText
etPlace = (EditText) findViewById(R.id.et_place);
// Setting click event listener for the find button
mBtnFind.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// Getting the place entered
String location = etPlace.getText().toString();
if(location==null || location.equals("")){
Toast.makeText(getBaseContext(), "No Place is entered", Toast.LENGTH_SHORT).show();
return;
}
String url = "https://maps.googleapis.com/maps/api/geocode/json?";
try {
// encoding special characters like space in the user input place
location = URLEncoder.encode(location, "utf-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
String address = "address=" + location;
String sensor = "sensor=false";
// url , from where the geocoding data is fetched
url = url + address + "&" + sensor;
// Instantiating DownloadTask to get places from Google Geocoding service
// in a non-ui thread
DownloadTask downloadTask = new DownloadTask();
// Start downloading the geocoding places
downloadTask.execute(url);
}
});
}
private String downloadUrl(String strUrl) throws IOException{
String data = "";
InputStream iStream = null;
HttpURLConnection urlConnection = null;
try{
URL url = new URL(strUrl);
// Creating an http connection to communicate with url
urlConnection = (HttpURLConnection) url.openConnection();
// Connecting to url
urlConnection.connect();
// Reading data from url
iStream = urlConnection.getInputStream();
BufferedReader br = new BufferedReader(new InputStreamReader(iStream));
StringBuffer sb = new StringBuffer();
String line = "";
while( ( line = br.readLine()) != null){
sb.append(line);
}
data = sb.toString();
br.close();
}catch(Exception e){
Log.d("Exception while downloading url", e.toString());
}finally{
iStream.close();
urlConnection.disconnect();
}
return data;
}
/** A class, to download Places from Geocoding webservice */
private class DownloadTask extends AsyncTask<String, Integer, String>{
String data = null;
// Invoked by execute() method of this object
@Override
protected String doInBackground(String... url) {
try{
data = downloadUrl(url[0]);
}catch(Exception e){
Log.d("Background Task",e.toString());
}
return data;
}
// Executed after the complete execution of doInBackground() method
@Override
protected void onPostExecute(String result){
// Instantiating ParserTask which parses the json data from Geocoding webservice
// in a non-ui thread
ParserTask parserTask = new ParserTask();
// Start parsing the places in JSON format
// Invokes the "doInBackground()" method of the class ParseTask
parserTask.execute(result);
}
}
/** A class to parse the Geocoding Places in non-ui thread */
class ParserTask extends AsyncTask<String, Integer, List<HashMap<String,String>>>{
JSONObject jObject;
// Invoked by execute() method of this object
@Override
protected List<HashMap<String,String>> doInBackground(String... jsonData) {
List<HashMap<String, String>> places = null;
GeocodeJSONParser parser = new GeocodeJSONParser();
try{
jObject = new JSONObject(jsonData[0]);
/** Getting the parsed data as a an ArrayList */
places = parser.parse(jObject);
}catch(Exception e){
Log.d("Exception",e.toString());
}
return places;
}
// Executed after the complete execution of doInBackground() method
@Override
protected void onPostExecute(List<HashMap<String,String>> list){
// Clears all the existing markers
mMap.clear();
for(int i=0;i<list.size();i++){
// Creating a marker
MarkerOptions markerOptions = new MarkerOptions();
// Getting a place from the places list
HashMap<String, String> hmPlace = list.get(i);
// Getting latitude of the place
double lat = Double.parseDouble(hmPlace.get("lat"));
// Getting longitude of the place
double lng = Double.parseDouble(hmPlace.get("lng"));
// Getting name
String name = hmPlace.get("formatted_address");
LatLng latLng = new LatLng(lat, lng);
// Setting the position for the marker
markerOptions.position(latLng);
// Setting the title for the marker
markerOptions.title(name);
// Placing a marker on the touched position
mMap.addMarker(markerOptions);
// Locate the first location
if(i==0)
mMap.animateCamera(CameraUpdateFactory.newLatLng(latLng));
}
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
GeoCodeJSONParser.java
package com.example.googlemaps;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
public class GeocodeJSONParser {
/** Receives a JSONObject and returns a list */
public List<HashMap<String,String>> parse(JSONObject jObject){
JSONArray jPlaces = null;
try {
/** Retrieves all the elements in the 'places' array */
jPlaces = jObject.getJSONArray("results");
} catch (JSONException e) {
e.printStackTrace();
}
/** Invoking getPlaces with the array of json object
* where each json object represent a place
*/
return getPlaces(jPlaces);
}
private List<HashMap<String, String>> getPlaces(JSONArray jPlaces){
int placesCount = jPlaces.length();
List<HashMap<String, String>> placesList = new ArrayList<HashMap<String,String>>();
HashMap<String, String> place = null;
/** Taking each place, parses and adds to list object */
for(int i=0; i<placesCount;i++){
try {
/** Call getPlace with place JSON object to parse the place */
place = getPlace((JSONObject)jPlaces.get(i));
placesList.add(place);
} catch (JSONException e) {
e.printStackTrace();
}
}
return placesList;
}
/** Parsing the Place JSON object */
private HashMap<String, String> getPlace(JSONObject jPlace){
HashMap<String, String> place = new HashMap<String, String>();
String formatted_address = "-NA-";
String lat="";
String lng="";
try {
// Extracting formatted address, if available
if(!jPlace.isNull("formatted_address")){
formatted_address = jPlace.getString("formatted_address");
}
lat = jPlace.getJSONObject("geometry").getJSONObject("location").getString("lat");
lng = jPlace.getJSONObject("geometry").getJSONObject("location").getString("lng");
place.put("formatted_address", formatted_address);
place.put("lat", lat);
place.put("lng", lng);
} catch (JSONException e) {
e.printStackTrace();
}
return place;
}
}
activity_main.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity" >
<Button
android:id="@+id/btn_show"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/find"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true" />
<EditText
android:id="@+id/et_place"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:hint="@string/hint"
android:inputType="text"
android:layout_toLeftOf="@id/btn_show" />
<fragment
android:id="@+id/map"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="@id/et_place"
class="com.google.android.gms.maps.SupportMapFragment" />
</RelativeLayout>
AndroidManifest.XML
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.googlemaps"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17" />
<permission
android:name="com.example.googlemaps.permission.MAPS_RECEIVE"
android:protectionLevel="signature"/>
<uses-permission android:name="com.example.googlemaps.permission.MAPS_RECEIVE"/>
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES"/>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-feature
android:glEsVersion="0x00020000"
android:required="true"/>
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.googlemaps.MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<meta-data
android:name="com.google.android.maps.v2.API_KEY"
android:value="XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"/>
</application>
</manifest>
我收到一个错误
Caused by: java.lang.IllegalStateException: The meta-data tag in your app's AndroidManifest.xml does not have the right value. Expected 6111000 but found 0. You must have the following declaration within the <application> element: <meta-data android:name="com.google.android.gms.version" android:value="@integer/google_play_services_version" />
请帮忙。
提前致谢。