我一直在关注教程，以便创建一个使用Google Maps和Places API显示附近地点的应用。具体来说，我正在尝试查看附近的餐馆或外卖店。实际上，应用程序显示地图片段，但没有地方显示为标记。
我尝试增加radius值，并将类型更改为此处列出的一些类型：https://developers.google.com/places/documentation/supported_types，但是我得到了相同的FileNotFoundException错误。任何人都可以看到出了什么问题吗？
这是我的LogCat。
03-13 17:21:51.076: E/GooglePlayServicesUtil(13109): The Google Play services resources were not found. Check your project configuration to ensure that the resources are included.
03-13 17:21:51.436: D/dalvikvm(13109): GC_FOR_ALLOC freed 2262K, 24% free 8393K/10920K, paused 65ms, total 83ms
03-13 17:21:51.536: D/dalvikvm(13109): GC_FOR_ALLOC freed 1339K, 23% free 8409K/10920K, paused 21ms, total 23ms
03-13 17:21:51.586: W/ActivityThread(13109): ClassLoader.loadClass: The class loader returned by Thread.getContextClassLoader() may fail for processes that host multiple applications. You should explicitly specify a context class loader. For example: Thread.setContextClassLoader(getClass().getClassLoader());
03-13 17:21:52.137: D/dalvikvm(13109): GC_FOR_ALLOC freed 739K, 19% free 8928K/10920K, paused 31ms, total 32ms
03-13 17:21:52.387: D/dalvikvm(13109): GC_FOR_ALLOC freed 775K, 18% free 9233K/11192K, paused 18ms, total 19ms
03-13 17:21:52.457: W/SystemClock(13109): time going backwards: prev 232776411235435(ioctl) vs now 232776411021793(ioctl), tid=13531
03-13 17:21:53.308: D/dalvikvm(13109): GC_FOR_ALLOC freed 1516K, 19% free 9496K/11604K, paused 21ms, total 21ms
03-13 17:21:53.619: D/Exception while downloading url(13109): java.io.FileNotFoundException: https://maps.googleapis.com/maps/api/place/nearbysearch/json??types=meal_takeawaylocation=55.94395494, -3.12815476&radius=10000&sensor=true&key=[My API Key]
03-13 17:21:53.629: D/Background Task(13109): java.lang.NullPointerException
03-13 17:21:53.659: D/Exception(13109): java.lang.NullPointerException
这是我的代码：
public class GPSActivity extends FragmentActivity implements LocationListener{
GoogleMap mGoogleMap;
String[] mPlaceType=null;
String[] mPlaceTypeName=null;
double mLatitude=0;
double mLongitude=0;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_gps);
mPlaceType = getResources().getStringArray(R.array.place_type);
mPlaceTypeName = getResources().getStringArray(R.array.place_type_name);
int status = GooglePlayServicesUtil.isGooglePlayServicesAvailable(getBaseContext());
if(status!=ConnectionResult.SUCCESS) {
int requestCode = 10;
Dialog dialog = GooglePlayServicesUtil.getErrorDialog(status, this, requestCode);
dialog.show();
} else {
SupportMapFragment fragment = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);
mGoogleMap = fragment.getMap();
mGoogleMap.setMyLocationEnabled(true);
LocationManager locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
Criteria criteria = new Criteria();
String provider = locationManager.getBestProvider(criteria, true);
Location location = locationManager.getLastKnownLocation(provider);
if (location!=null) {
onLocationChanged(location);
}
locationManager.requestLocationUpdates(provider, 20000, 0, this);
String type = mPlaceType[0];
StringBuilder sb = new StringBuilder("https://maps.googleapis.com/maps/api/place/nearbysearch/json?");
sb.append("?types=meal_takeaway");
sb.append("location="+mLatitude+", "+mLongitude);
sb.append("&radius=10000");
sb.append("&sensor=true");
sb.append("&key=[My API Key]");
PlacesTask placesTask = new PlacesTask();
placesTask.execute(sb.toString());
}
}
public void onLocationChanged(Location location) {
mLatitude = location.getLatitude();
mLongitude = location.getLongitude();
LatLng latLng = new LatLng(mLatitude, mLongitude);
mGoogleMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));
mGoogleMap.animateCamera(CameraUpdateFactory.zoomTo(12));
}
protected void onPostExecute(List<HashMap<String,String>> list) {
mGoogleMap.clear();
for (int i=0; i<list.size(); i++) {
MarkerOptions markerOptions = new MarkerOptions();
HashMap<String,String> hmPlace = list.get(i);
double lat = Double.parseDouble(hmPlace.get("lat"));
double lng = Double.parseDouble(hmPlace.get("lng"));
String name = hmPlace.get("meal_takeaway");
String vicinity = hmPlace.get("vicinity");
LatLng latLng = new LatLng(lat, lng);
markerOptions.title(name+" : "+vicinity);
mGoogleMap.addMarker(markerOptions);
}
}
@Override
public void onProviderDisabled(String provider) {
// TODO Auto-generated method stub
}
@Override
public void onProviderEnabled(String provider) {
// TODO Auto-generated method stub
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub
}
}
class PlacesTask extends AsyncTask<String,Integer,String> {
String data = null;
private String downloadUrl(String strUrl) throws IOException {
String data = "";
InputStream iStream = null;
HttpURLConnection urlConnection = null;
try {
URL url = new URL(strUrl);
urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.connect();
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;
}
protected String doInBackground(String... url) {
try {
data = downloadUrl(url[0]);
} catch(Exception e) {
Log.d("Background Task", e.toString());
}
return data;
}
protected void onPostExecute(String result) {
ParserTask parserTask = new ParserTask();
parserTask.execute(result);
}
}
谢谢，我很感激任何帮助。
修改：异常现已消失，但标记仍未显示在地图上。
答案 0 :(得分：1)
看起来您的网址构建器已损坏。你有：
StringBuilder sb = new StringBuilder("https://maps.googleapis.com/maps/api/place/nearbysearch/json?");
sb.append("?types=meal_takeaway");
sb.append("location="+mLatitude+", "+mLongitude);
sb.append("&radius=10000");
sb.append("&sensor=true");
sb.append("&key=[My API Key]");
这意味着?和json之间两个 types，而{{1>}之间的没有 & 1}}和types=meal_takeaway。像这样修复它：
location（注意：前两个StringBuilder sb = new StringBuilder("https://maps.googleapis.com/maps/api/place/nearbysearch/json?");
sb.append("types=meal_takeaway");
sb.append("&location="+mLatitude+","+mLongitude);
sb.append("&radius=10000");
sb.append("&sensor=true");
sb.append("&key=[My API Key]");
调用中只有更改 - 也删除了空格）
FWIW，从长远来看，使用Volley或类似的JSON请求可能会更容易，而不是下载url并单独解析它。
答案 1 :(得分：0)
尝试删除api url中位置坐标之间的空格。
答案 2 :(得分：0)
您的网址已损坏，您在纬度坐标后面的逗号后面添加了一个空格。
如果您想抽象场所API处理，我最近开发了一个Java库，它是Place API的1对1映射。到附近的餐馆就像。
GooglePlaces client = new GooglePlaces("apiKey");
List<Place> places = client.getNearbyPlaces(lat, lng, GooglePlaces.MAXIMUM_RESULTS, Param.name("types").value("restaurant"));
for (Place place : places) {
System.out.println(place.getName());
}