我正试图创建一个Android应用程序，从我的mySQL数据库中在谷歌地图v2上绘制标记，但它不起作用。
Mapactivity.java
public class MapsActivity extends FragmentActivity {
// Creating JSON Parser object
JSONParser jParser = new JSONParser();
// url to get all products list
private static String url_all_products = "http://127.0.0.1/get_marker.php";
// JSON Node names
private static final String TAG_SUCCESS = "success";
private static final String TAG_Coordinates = "products";
private static final String TAG_PID = "pid";
private static final String TAG_X = "x_coordinate";
private static final String TAG_Y = "y_coordinate";
// products JSONArray
JSONArray products = null;
private GoogleMap mMap; // Might be null if Google Play services APK is not available.
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_maps);
setUpMapIfNeeded();
}
@Override
protected void onResume() {
super.onResume();
setUpMapIfNeeded();
}
private void setUpMapIfNeeded() {
// Do a null check to confirm that we have not already instantiated the map.
if (mMap == null) {
// Try to obtain the map from the SupportMapFragment.
mMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map))
.getMap();
// Check if we were successful in obtaining the map.
if (mMap != null) {
// Add marker info window click listener
// mMap.setOnInfoWindowClickListener(this);
//Zooming Buttons
UiSettings mapSettings;
mapSettings = mMap.getUiSettings();
mapSettings.setZoomControlsEnabled(true);
//Zooming Buttons
GetMarker();
}
}
}
private void GetMarker()
{
mMap.setMapType(GoogleMap.MAP_TYPE_TERRAIN);
mMap.setMyLocationEnabled(true);
double xi = 49.999065;
double yi = 8.273978;
LatLng MUSEUM = new LatLng(xi , yi);
Marker museum = mMap.addMarker(new MarkerOptions()
.position(MUSEUM)
.title("Mainzer Dom")
.snippet("Der Mainzer Dom"));
new Thread(new Runnable() {
public void run() {
retrieveAndAddCities();
}
}).start();
}
private void retrieveAndAddCities() {
List params = new ArrayList();
// getting JSON string from URL
JSONObject json = jParser.makeHttpRequest(url_all_products, "GET", params);
// Check your log cat for JSON reponse
Log.d("All Products: ", json.toString());
try {
// Checking for SUCCESS TAG
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// products found
// Getting Array of Products
products = json.getJSONArray(TAG_Coordinates);
// looping through All Products
for (int i = 0; i < products.length(); i++) {
JSONObject c = products.getJSONObject(i);
// Storing each json item in variable
int id = c.getInt(TAG_PID);
double x_coordinate = c.getDouble(TAG_X);
double y_coordinate = c.getDouble(TAG_Y);
mMap.addMarker(new MarkerOptions()
.position(new LatLng(x_coordinate,y_coordinate )));
}
} else {
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}
我的php代码：get_marker.php
<?php
/*
* Following code will list all the products
*/
$response = array();
require_once __DIR__ . '/db_connect.php';
$db = new DB_CONNECT();
$result = mysql_query("SELECT *FROM products") or die(mysql_error());
if (mysql_num_rows($result) > 0) {
$response["products"] = array();
while ($row = mysql_fetch_array($result)) {
$product = array();
$product["pid"] = $row["pid"];
$product["x_coordinate"] = $row["x_coordinate"];
$product["y_coordinate"] = $row["y_coordinate"];
$product["created_at"] = $row["created_at"];
$product["updated_at"] = $row["updated_at"];
array_push($response["products"], $product);
}
$response["success"] = 1;
// echoing JSON response
echo json_encode($response);
} else {
$response["success"] = 0;
$response["message"] = "No products found";
echo json_encode($response);
}
?>
这是JsonParser
public class JSONParser {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// constructor
public JSONParser() {
}
// function get json from url
// by making HTTP POST or GET mehtod
public JSONObject makeHttpRequest(String url, String method,
List<NameValuePair> params) {
// Making HTTP request
try {
// check for request method
if(method == "POST"){
// request method is POST
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
httpPost.setEntity(new UrlEncodedFormEntity(params));
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
}else if(method == "GET"){
// request method is GET
DefaultHttpClient httpClient = new DefaultHttpClient();
String paramString = URLEncodedUtils.format(params, "utf-8");
url += "?" + paramString;
HttpGet httpGet = new HttpGet(url);
HttpResponse httpResponse = httpClient.execute(httpGet);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
}
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "'n");
}
is.close();
json = sb.toString();
} catch (Exception e) {
Log.e("Buffer Error", "Error converting result " + e.toString());
}
// try parse the string to a JSON object
try {
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
// return JSON String
return jObj;
}
}
如果我尝试启动retrieveAndAddCities（）；
new Thread(new Runnable() {
public void run() {
retrieveAndAddCities();
}
}).start();
我的应用程序将崩溃。
我希望有人能帮我。非常感谢
编辑：Logcat:
04-06 01:50:04.268 5153-5168/flo.myapplication D/OpenGLRenderer﹕ Render dirty regions requested: true
04-06 01:50:04.271 5153-5153/flo.myapplication D/﹕ HostConnection::get() New Host Connection established 0xae0d8560, tid 5153
04-06 01:50:04.304 5153-5153/flo.myapplication D/Atlas﹕ Validating map...
04-06 01:50:04.364 5153-5168/flo.myapplication D/﹕ HostConnection::get() New Host Connection established 0xae0d8ae0, tid 5168
04-06 01:50:04.373 5153-5168/flo.myapplication I/OpenGLRenderer﹕ Initialized EGL, version 1.4
04-06 01:50:04.446 5153-5168/flo.myapplication D/OpenGLRenderer﹕ Enabling debug mode 0
04-06 01:50:04.465 5153-5168/flo.myapplication W/EGL_emulation﹕ eglSurfaceAttrib not implemented
04-06 01:50:04.465 5153-5168/flo.myapplication W/OpenGLRenderer﹕ Failed to set EGL_SWAP_BEHAVIOR on surface 0xa605e2c0, error=EGL_SUCCESS
04-06 01:50:11.068 5153-5153/flo.myapplication I/zzx﹕ Making Creator dynamically
04-06 01:50:11.071 5153-5153/flo.myapplication W/ResourcesManager﹕ Asset path '/system/framework/com.android.media.remotedisplay.jar' does not exist or contains no resources.
04-06 01:50:11.071 5153-5153/flo.myapplication W/ResourcesManager﹕ Asset path '/system/framework/com.android.location.provider.jar' does not exist or contains no resources.
04-06 01:50:11.088 5153-5153/flo.myapplication I/Google Maps Android API﹕ Google Play services client version: 7095000
04-06 01:50:11.092 5153-5153/flo.myapplication I/Google Maps Android API﹕ Google Play services package version: 7097470
04-06 01:50:11.205 5153-5165/flo.myapplication I/art﹕ Background partial concurrent mark sweep GC freed 11075(592KB) AllocSpace objects, 0(0B) LOS objects, 38% free, 6MB/10MB, paused 5.446ms total 25.641ms
04-06 01:50:11.363 5153-5165/flo.myapplication I/art﹕ Background sticky concurrent mark sweep GC freed 49928(2039KB) AllocSpace objects, 3(561KB) LOS objects, 0% free, 11MB/11MB, paused 2.593ms total 119.732ms
04-06 01:50:11.423 5153-5165/flo.myapplication I/art﹕ Background partial concurrent mark sweep GC freed 12702(547KB) AllocSpace objects, 2(1015KB) LOS objects, 28% free, 10MB/14MB, paused 5.173ms total 52.148ms
04-06 01:50:11.551 5153-5153/flo.myapplication I/Choreographer﹕ Skipped 31 frames! The application may be doing too much work on its main thread.
04-06 01:50:11.608 5153-5168/flo.myapplication W/EGL_emulation﹕ eglSurfaceAttrib not implemented
04-06 01:50:11.608 5153-5168/flo.myapplication W/OpenGLRenderer﹕ Failed to set EGL_SWAP_BEHAVIOR on surface 0xa602e720, error=EGL_SUCCESS
04-06 01:50:11.648 5153-5185/flo.myapplication D/﹕ HostConnection::get() New Host Connection established 0xa5491d90, tid 5185
04-06 01:50:11.657 5153-5186/flo.myapplication D/All Products:﹕ {"products":[{"pid":"1","x_coordinate":"50","y_coordinate":"8","created_at":"2015-04-06 01:13:22","updated_at":"0000-00-00 00:00:00"}],"success":1}
04-06 01:50:11.657 5153-5186/flo.myapplication E/AndroidRuntime﹕ FATAL EXCEPTION: Thread-378
Process: flo.myapplication, PID: 5153
java.lang.IllegalStateException: Not on the main thread
at com.google.l.a.cd.b(Unknown Source)
at com.google.maps.api.android.lib6.c.ca.a(Unknown Source)
at com.google.maps.api.android.lib6.c.el.a(Unknown Source)
at com.google.android.gms.maps.internal.l.onTransact(SourceFile:167)
at android.os.Binder.transact(Binder.java:380)
at com.google.android.gms.maps.internal.IGoogleMapDelegate$zza$zza.addMarker(Unknown Source)
at com.google.android.gms.maps.GoogleMap.addMarker(Unknown Source)
at flo.myapplication.MapsActivity.retrieveAndAddCities(MapsActivity.java:201)
at flo.myapplication.MapsActivity.access$000(MapsActivity.java:98)
at flo.myapplication.MapsActivity$1.run(MapsActivity.java:168)
at java.lang.Thread.run(Thread.java:818)
好的，我现在用AsyncTask修改了代码，但也有错误
package flo.myapplication;
import android.os.StrictMode;
import android.support.v4.app.FragmentActivity;
import android.os.Bundle;
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.Marker;
import com.google.android.gms.maps.model.MarkerOptions;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.Log;
import android.view.View;
import android.app.Activity;
import android.app.Dialog;
import android.app.ProgressDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Typeface;
import android.graphics.drawable.Drawable;
import android.location.Location;
import android.location.LocationManager;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.util.DisplayMetrics;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup.LayoutParams;
import android.widget.Button;
import android.widget.EditText;
import android.widget.RelativeLayout;
import android.widget.TextView;
import com.google.android.gms.maps.UiSettings;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GooglePlayServicesUtil;
import com.google.android.gms.maps.CameraUpdate;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.GoogleMap.OnMarkerClickListener;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.BitmapDescriptorFactory;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;
import org.apache.http.NameValuePair;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GooglePlayServicesUtil;
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.BitmapDescriptorFactory;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Dialog;
import android.location.Criteria;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.util.Log;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
public class MapsActivity extends FragmentActivity {
// Creating JSON Parser object
JSONParser jParser = new JSONParser();
// url to get all products list
private static String url_all_products = "http://88.198.46.8/get_marker.php";
// JSON Node names
private static final String TAG_SUCCESS = "success";
private static final String TAG_Coordinates = "products";
private static final String TAG_PID = "pid";
private static final String TAG_X = "x_coordinate";
private static final String TAG_Y = "y_coordinate";
// products JSONArray
JSONArray products = null;
private GoogleMap mMap; // Might be null if Google Play services APK is not available.
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_maps);
setUpMapIfNeeded();
}
@Override
protected void onResume() {
super.onResume();
setUpMapIfNeeded();
}
private void setUpMapIfNeeded() {
// Do a null check to confirm that we have not already instantiated the map.
if (mMap == null) {
// Try to obtain the map from the SupportMapFragment.
mMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map))
.getMap();
// Check if we were successful in obtaining the map.
if (mMap != null) {
// Add marker info window click listener
// mMap.setOnInfoWindowClickListener(this);
//Zooming Buttons
UiSettings mapSettings;
mapSettings = mMap.getUiSettings();
mapSettings.setZoomControlsEnabled(true);
//Zooming Buttons
GetMarker();
}
}
}
private void GetMarker()
{
mMap.setMapType(GoogleMap.MAP_TYPE_TERRAIN);
mMap.setMyLocationEnabled(true);
double xi = 49.999065;
double yi = 8.273978;
LatLng MUSEUM = new LatLng(xi , yi);
Marker museum = mMap.addMarker(new MarkerOptions()
.position(MUSEUM)
.title("Mainzer Dom")
.snippet("Der Mainzer Dom"));
// Loading products in Background Thread
new retrieveAndAddCities().execute();
}
class retrieveAndAddCities extends AsyncTask<String, String, String> {
protected String doInBackground(String... args) {
List params = new ArrayList();
// getting JSON string from URL
JSONObject json = jParser.makeHttpRequest(url_all_products, "GET", params);
// Check your log cat for JSON reponse
Log.d("All Products: ", json.toString());
try {
// Checking for SUCCESS TAG
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// products found
// Getting Array of Products
products = json.getJSONArray(TAG_Coordinates);
// looping through All Products
for (int i = 0; i < products.length(); i++) {
JSONObject c = products.getJSONObject(i);
// Storing each json item in variable
int id = c.getInt(TAG_PID);
double x_coordinate = c.getDouble(TAG_X);
double y_coordinate = c.getDouble(TAG_Y);
mMap.addMarker(new MarkerOptions()
.position(new LatLng(x_coordinate,y_coordinate )));
}
} else {
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
}
}
和Logcat文件：
04-06 02:29:30.055 5324-5339/flo.myapplication D/OpenGLRenderer﹕ Render dirty regions requested: true
04-06 02:29:30.076 5324-5324/flo.myapplication D/﹕ HostConnection::get() New Host Connection established 0xae0d5550, tid 5324
04-06 02:29:30.129 5324-5324/flo.myapplication D/Atlas﹕ Validating map...
04-06 02:29:30.274 5324-5339/flo.myapplication D/﹕ HostConnection::get() New Host Connection established 0xae0d59a0, tid 5339
04-06 02:29:30.397 5324-5339/flo.myapplication I/OpenGLRenderer﹕ Initialized EGL, version 1.4
04-06 02:29:30.574 5324-5339/flo.myapplication D/OpenGLRenderer﹕ Enabling debug mode 0
04-06 02:29:30.693 5324-5339/flo.myapplication W/EGL_emulation﹕ eglSurfaceAttrib not implemented
04-06 02:29:30.693 5324-5339/flo.myapplication W/OpenGLRenderer﹕ Failed to set EGL_SWAP_BEHAVIOR on surface 0xa604a400, error=EGL_SUCCESS
04-06 02:29:30.788 5324-5324/flo.myapplication I/Choreographer﹕ Skipped 37 frames! The application may be doing too much work on its main thread.
04-06 02:29:37.319 5324-5324/flo.myapplication I/zzx﹕ Making Creator dynamically
04-06 02:29:37.321 5324-5324/flo.myapplication W/ResourcesManager﹕ Asset path '/system/framework/com.android.media.remotedisplay.jar' does not exist or contains no resources.
04-06 02:29:37.321 5324-5324/flo.myapplication W/ResourcesManager﹕ Asset path '/system/framework/com.android.location.provider.jar' does not exist or contains no resources.
04-06 02:29:37.336 5324-5324/flo.myapplication I/Google Maps Android API﹕ Google Play services client version: 7095000
04-06 02:29:37.361 5324-5324/flo.myapplication I/Google Maps Android API﹕ Google Play services package version: 7097470
04-06 02:29:37.396 5324-5336/flo.myapplication I/art﹕ Background sticky concurrent mark sweep GC freed 0(0B) AllocSpace objects, 0(0B) LOS objects, 1% free, 2MB/2MB, paused 5.461ms total 9.101ms
04-06 02:29:37.582 5324-5336/flo.myapplication I/art﹕ Background partial concurrent mark sweep GC freed 45498(2MB) AllocSpace objects, 11(2MB) LOS objects, 29% free, 9MB/13MB, paused 999us total 105.746ms
04-06 02:29:37.835 5324-5324/flo.myapplication I/Choreographer﹕ Skipped 32 frames! The application may be doing too much work on its main thread.
04-06 02:29:37.924 5324-5339/flo.myapplication W/EGL_emulation﹕ eglSurfaceAttrib not implemented
04-06 02:29:37.924 5324-5339/flo.myapplication W/OpenGLRenderer﹕ Failed to set EGL_SWAP_BEHAVIOR on surface 0xa6078180, error=EGL_SUCCESS
04-06 02:29:37.977 5324-5358/flo.myapplication D/All Products:﹕ {"products":[{"pid":"1","x_coordinate":"50","y_coordinate":"8","created_at":"2015-04-06 01:13:22","updated_at":"0000-00-00 00:00:00"}],"success":1}
04-06 02:29:37.978 5324-5358/flo.myapplication E/AndroidRuntime﹕ FATAL EXCEPTION: AsyncTask #1
Process: flo.myapplication, PID: 5324
java.lang.RuntimeException: An error occured while executing doInBackground()
at android.os.AsyncTask$3.done(AsyncTask.java:300)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
at java.util.concurrent.FutureTask.setException(FutureTask.java:222)
at java.util.concurrent.FutureTask.run(FutureTask.java:242)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:818)
Caused by: java.lang.IllegalStateException: Not on the main thread
at com.google.l.a.cd.b(Unknown Source)
at com.google.maps.api.android.lib6.c.ca.a(Unknown Source)
at com.google.maps.api.android.lib6.c.el.a(Unknown Source)
at com.google.android.gms.maps.internal.l.onTransact(SourceFile:167)
at android.os.Binder.transact(Binder.java:380)
at com.google.android.gms.maps.internal.IGoogleMapDelegate$zza$zza.addMarker(Unknown Source)
at com.google.android.gms.maps.GoogleMap.addMarker(Unknown Source)
at flo.myapplication.MapsActivity$retrieveAndAddCities.doInBackground(MapsActivity.java:200)
at flo.myapplication.MapsActivity$retrieveAndAddCities.doInBackground(MapsActivity.java:174)
at android.os.AsyncTask$2.call(AsyncTask.java:288)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:818)
04-06 02:29:38.024 5324-5357/flo.myapplication D/﹕ HostConnection::get() New Host Connection established 0x9fbe30a0, tid 5357
04-06 02:29:38.833 5324-5336/flo.myapplication I/art﹕ Background partial concurrent mark sweep GC freed 10277(451KB) AllocSpace objects, 32(1505KB) LOS objects, 23% free, 13MB/17MB, paused 795us total 118.120ms
您的应用程序正在崩溃，因为您正试图从主线程更新UI。您的JSON请求成功，但当您的代码命中mMap.addMarker（）.时，应用程序崩溃
http://developer.android.com/guide/components/processes-and-threads.html
使用AsyncTask是个好主意，但您只需要在doInBackground（）中执行JSON请求，因为doInBackbackground不会在主线程上运行，您的应用程序将以当前的方式崩溃。如果您确实使用AsyncTask，请查看文档。谷歌有一个很好的例子。
http://developer.android.com/reference/android/os/AsyncTask.html
我修改了您的retrieveAndAddCities类以使其正常工作。doInBackground现在返回一个产品的JSONArray。doInBackground完成后，产品的JSONArray将作为参数传递到onPostExecute中。onPostExecute在主线程上运行。它现在包含for循环，您在其中循环产品并添加地图标记。
class retrieveAndAddCities extends AsyncTask< Void, Void, JSONArray > {
protected JSONArray doInBackground(Void... args) {
List params = new ArrayList();
// getting JSON string from URL
JSONObject json = jParser.makeHttpRequest(url_all_products, "GET", params);
// Check your log cat for JSON reponse
Log.d("All Products: ", json.toString());
try {
// Checking for SUCCESS TAG
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// products found
// Getting Array of Products
return json.getJSONArray(TAG_Coordinates);
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
protected void onPostExecute(JSONArray products) {
if (products != null) {
for (int i = 0; i < products.length(); i++) {
JSONObject c = null;
try {
c = products.getJSONObject(i);
// Storing each json item in variable
int id = c.getInt(TAG_PID);
double x_coordinate = c.getDouble(TAG_X);
double y_coordinate = c.getDouble(TAG_Y);
mMap.addMarker(new MarkerOptions()
.position(new LatLng(x_coordinate, y_coordinate)));
} catch (JSONException e) {
e.printStackTrace();
}
}
} else {
//Handle case of no products or failure
}
}
}
好的，然后你可以像这样使用异步任务，我的代码中可能有一些语法错误，但你可以这样做。
public class myclass extends Asynctask<Void,Void,Void>{
@Override
public void doInBackground(){
retrieveAndAddCities(); }
}