我想使用来自服务器的图像作为谷歌地图项目的图标图标。但我得到一个空指针异常。代码如下
package com.igloo.storelocater;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.List;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
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.UiSettings;
import com.google.android.gms.maps.model.BitmapDescriptor;
import com.google.android.gms.maps.model.BitmapDescriptorFactory;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;
import com.igloo.classes.ConnectionDetector;
import com.igloo.classes.Store_data;
import com.igloo.constants.Constants.Config;
import android.location.Criteria;
import android.location.Location;
import android.location.LocationManager;
import android.os.AsyncTask;
import android.os.Bundle;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.ProgressDialog;
import android.content.DialogInterface;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.view.Menu;
import android.widget.Toast;
public class MainActivity extends FragmentActivity {
String URL_store="http://footballultimate.com/storelocator/index.php/api/getStoreData";
String URL_image="http://footballultimate.com/storelocator/resource/uploads/";
private ConnectionDetector cd;
private GoogleMap googleMap;
FragmentManager fragManager;
ProgressDialog progressDialog;
double current_latitude,current_longitude;
int bound_radius=10;
HttpResponse response;
String result;
JSONObject jsonobj;
JSONArray category_array;
String[] catarr;
Store_data sobj;
ArrayList<Store_data> list;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
cd = new ConnectionDetector(MainActivity.this);
Config.isInternetPresent = cd.isConnectingToInternet();
if (!Config.isInternetPresent) {
AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
// Shuld be fail icon
builder.setIcon(R.drawable.ic_launcher);
builder.setMessage("Connection Not Available !" + "\n"
+ "Please enable your Internet Connection");
builder.setTitle("INTERNET CONNECTION");
builder.setPositiveButton("OK",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub
dialog.cancel();
}
});
AlertDialog alert = builder.create();
alert.show();
}
else{
getcurrentlocation();
initialiseMap();
new RetrieveStoreDetails().execute();
}
}
@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;
}
public void getcurrentlocation()
{
LocationManager locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
// Creating a criteria object to retrieve provider
Criteria criteria = new Criteria();
// Getting the name of the best provider
String provider = locationManager.getBestProvider(criteria, true);
// Getting Current Location
Location location = locationManager.getLastKnownLocation(provider);
// Getting latitude of the current location
current_latitude=location.getLatitude();
// Getting longitude of the current location
current_longitude= location.getLongitude();
}
public void initialiseMap()
{
if (googleMap == null) {
googleMap = ( (SupportMapFragment) getSupportFragmentManager().findFragmentById(
R.id.map)).getMap();
}
// check if map is created successfully or not
if (googleMap == null) {
Toast.makeText(getApplicationContext(),
"Sorry! unable to create maps", Toast.LENGTH_SHORT)
.show();
}
else
{
googleMap.setMyLocationEnabled(true);
googleMap.getUiSettings().setMyLocationButtonEnabled(true);
googleMap.getUiSettings().setCompassEnabled(true);
// UiSettings uiSettings = googleMap.getUiSettings();
// uiSettings.setMyLocationButtonEnabled(true);
}
//locationManager.requestLocationUpdates(provider, 20000, 0, this);
LatLng latLng = new LatLng(current_latitude, current_longitude);
googleMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));
// Zoom in the Google Map
//googleMap.animateCamera(CameraUpdateFactory.zoomTo(15));
googleMap.animateCamera(CameraUpdateFactory.newLatLngZoom(latLng, 12.0f));
}
public class RetrieveStoreDetails extends AsyncTask<String,Void,Void>
{
@Override
protected void onPreExecute() {
progressDialog = new ProgressDialog(MainActivity.this);
progressDialog.setTitle("Processing...");
progressDialog.setMessage("Please wait...");
progressDialog.setCancelable(false);
progressDialog.show();
}
@Override
protected Void doInBackground(String... arg0) {
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(URL_store);
List<NameValuePair> pairs = new ArrayList<NameValuePair>();
pairs.add(new BasicNameValuePair("current_latitude",""+current_latitude));
pairs.add(new BasicNameValuePair("current_longitude",""+current_longitude));
pairs.add(new BasicNameValuePair("bound_radius",""+bound_radius));
try {
httppost.setEntity(new UrlEncodedFormEntity(pairs));
response = httpclient.execute(httppost);
result=responsetostring.getResponseBody(response);
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void result1) {
getstorevalues(result);
try{
if(progressDialog.isShowing()){
progressDialog.dismiss();
}
}
catch(Exception e){
e.printStackTrace();
}
finally
{
progressDialog.dismiss();
}
}
}
public void getstorevalues(String result)
{
if(result!=null)
{
try {
list=new ArrayList<Store_data>();
jsonobj=new JSONObject(result);
category_array=jsonobj.getJSONArray("category");
catarr=new String[category_array.length()];
JSONObject store_data=jsonobj.getJSONObject("store_data");
for(int i=0;i<category_array.length();i++)
{
catarr[i]=category_array.getString(i);
}
for(int i=0;i<category_array.length();i++)
{
JSONArray arrsub=store_data.getJSONArray(catarr[i]);
for(int j=0;j<arrsub.length();j++)
{
sobj=new Store_data();
JSONObject d=arrsub.getJSONObject(j);
sobj.store_name=d.getString("store_name");
sobj.store_image=d.getString("store_image");
sobj.store_address=d.getString("store_address");
sobj.store_phone=d.getString("store_phone");
sobj.store_description=d.getString("store_description");
sobj.store_url=d.getString("store_url");
sobj.store_latitude=d.getString("store_latitude");
sobj.store_longitude=d.getString("store_longitude");
sobj.category=catarr[i];
list.add(sobj);
}
}
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
setvaluesonmap();
}
public void setvaluesonmap()
{
for(int i=0;i<list.size();i++)
{
Store_data s=list.get(i);
MarkerOptions marker = new MarkerOptions().position(new LatLng(Double.parseDouble(s.store_latitude),Double.parseDouble(s.store_longitude))).title(s.store_name);
marker.icon(BitmapDescriptorFactory.fromPath(URL_image+s.category+".png"));
// adding marker
googleMap.addMarker(marker);
}
}
}
LOGCAT如下
07-15 17:09:13.710: E/AndroidRuntime(19588): at com.google.android.gms.maps.GoogleMap.addMarker(Unknown Source)
07-15 17:28:34.523: E/AndroidRuntime(20295): FATAL EXCEPTION: main
07-15 17:28:34.523: E/AndroidRuntime(20295): java.lang.NullPointerException
07-15 17:28:34.523: E/AndroidRuntime(20295): at ouq.a(Unknown Source)
07-15 17:28:34.523: E/AndroidRuntime(20295): at ouq.a(Unknown Source)
07-15 17:28:34.523: E/AndroidRuntime(20295): at oyg.a(Unknown Source)
07-15 17:28:34.523: E/AndroidRuntime(20295): at grm.onTransact(SourceFile:167)
07-15 17:28:34.523: E/AndroidRuntime(20295): at android.os.Binder.transact(Binder.java:279)
07-15 17:28:34.523: E/AndroidRuntime(20295): at com.google.android.gms.maps.internal.IGoogleMapDelegate$a$a.addMarker(Unknown Source)
07-15 17:28:34.523: E/AndroidRuntime(20295): at com.google.android.gms.maps.GoogleMap.addMarker(Unknown Source)
07-15 17:28:34.523: E/AndroidRuntime(20295): at com.igloo.storelocater.MainActivity.setvaluesonmap(MainActivity.java:266)
07-15 17:28:34.523: E/AndroidRuntime(20295): at com.igloo.storelocater.MainActivity.getstorevalues(MainActivity.java:254)
07-15 17:28:34.523: E/AndroidRuntime(20295): at com.igloo.storelocater.MainActivity$RetrieveStoreDetails.onPostExecute(MainActivity.java:195)
07-15 17:28:34.523: E/AndroidRuntime(20295): at com.igloo.storelocater.MainActivity$RetrieveStoreDetails.onPostExecute(MainActivity.java:1)
07-15 17:28:34.523: E/AndroidRuntime(20295): at android.os.AsyncTask.finish(AsyncTask.java:417)
07-15 17:28:34.523: E/AndroidRuntime(20295): at android.os.AsyncTask.access$300(AsyncTask.java:127)
07-15 17:28:34.523: E/AndroidRuntime(20295): at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:429)
07-15 17:28:34.523: E/AndroidRuntime(20295): at android.os.Handler.dispatchMessage(Handler.java:99)
07-15 17:28:34.523: E/AndroidRuntime(20295): at android.os.Looper.loop(Looper.java:130)
07-15 17:28:34.523: E/AndroidRuntime(20295): at android.app.ActivityThread.main(ActivityThread.java:3689)
07-15 17:28:34.523: E/AndroidRuntime(20295): at java.lang.reflect.Method.invokeNative(Native Method)
07-15 17:28:34.523: E/AndroidRuntime(20295): at java.lang.reflect.Method.invoke(Method.java:507)
07-15 17:28:34.523: E/AndroidRuntime(20295): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:842)
07-15 17:28:34.523: E/AndroidRuntime(20295): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
07-15 17:28:34.523: E/AndroidRuntime(20295): at dalvik.system.NativeStart.main(Native Method)
麻烦的代码似乎是
MarkerOptions marker = new MarkerOptions().position(new LatLng(Double.parseDouble(s.store_latitude),Double.parseDouble(s.store_longitude))).title(s.store_name);
marker.icon(BitmapDescriptorFactory.fromPath(URL_image+s.category+".png"));
// adding marker
googleMap.addMarker(marker);
网址正确但我仍然收到错误。请帮忙！