我正在开发一个Android应用程序，通过数据库中的php，mysql，json检索数据。我需要每10分钟创建一个服务或任何方式来调用 getData（） 方法。我尝试将这两种方法放在广播接收器中，并使用报警管理器每10分钟重复一次，但它没有正常运行，只适用于 Toast 和< strong> Log.d （简单操作）。有没有一种简单的方法来实现我想要的？我做了很多搜索，但无法找到明确的答案
//METHOD 1
private void getData() {
loading = ProgressDialog.show(this,"Please wait...","Fetching...",false,false);
String url = Config.DATA_URL;
StringRequest stringRequest = new StringRequest(url, new Response.Listener<String>() {
@Override
public void onResponse(String response) {
loading.dismiss();
showJSON(response);
}
},
new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
Toast.makeText(MainActivity.this,error.getMessage().toString(),Toast.LENGTH_LONG).show();
}
});
RequestQueue requestQueue = Volley.newRequestQueue(this);
requestQueue.add(stringRequest);
}
// METHOD 2
private void showJSON(String response){
String id="";
String time="";
String value = "";
try {
JSONObject jsonObject = new JSONObject(response);
JSONArray result = jsonObject.getJSONArray(Config.JSON_ARRAY);
for (int i = 0; i < result.length(); i++) {
JSONObject tempData = result.getJSONObject(i);
id = tempData.getString(Config.KEY_NAME);
time = tempData.getString(Config.KEY_ADDRESS);
value = tempData.getString(Config.KEY_VC);
String data = "Id:\t"+id+", Time:\t" +time+ ", Value:\t"+ value;
all += data+"\n";
}
}
catch (JSONException e) {
e.printStackTrace();
}
textViewResult.setText(all);
}
答案 0 :(得分：1)
您使用广播接收器（BR）和闹钟管理器的方式听起来是一种很好的方法，我不确定您遇到了什么问题。你能告诉我们更多吗？
如果没有所有细节我会说潜在的问题是广播接收器通常在Android的UI线程中执行，并且例如不允许您执行网络访问，它必须在X秒内完成。 / p>
1）您没有正确的权限访问互联网？从我记得的这个日志可以很容易错过。 2）您可以请求BR运行后台线程，我知道您可以执行此操作，而不是自己尝试。 3）你可以开始另一个线程。如您所见，为了更新UI，您应该使用异步任务。因此，您可以在后台线程中执行网络，然后在UI线程中使用新数据进行调用。 （这可能是选择）
旁注：为了解析json，我建议你看看Gson。它是谷歌的一个库，使得Json的分析更加简单。 https://github.com/google/gson
答案 1 :(得分：0)
<div className={this.state.checked ? : 'mapping-check' : ''}></div>}
import com.google.android.gms.gcm.GcmTaskService;
import com.google.android.gms.gcm.TaskParams;
import android.content.Context;
import android.content.SharedPreferences;
import android.location.Address;
import android.location.Geocoder;
import android.net.ConnectivityManager;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;
import android.widget.Toast;
import com.google.android.gms.gcm.GcmNetworkManager;
import com.google.android.gms.gcm.OneoffTask;
import com.google.android.gms.gcm.PeriodicTask;
import com.google.android.gms.gcm.Task;
import com.rcsplcms.ess.Constant;
import com.rcsplcms.ess.GPSTracker;
import com.rcsplcms.ess.R;
import com.rcsplcms.ess.application.ESSApplication;
import com.rcsplcms.ess.util.AppLog;
import org.ksoap2.SoapEnvelope;
import org.ksoap2.serialization.SoapObject;
import org.ksoap2.serialization.SoapPrimitive;
import org.ksoap2.serialization.SoapSerializationEnvelope;
import org.ksoap2.transport.HttpTransportSE;
import java.util.List;
import java.util.Locale;
/**
* Created by MAYURKUMAR TERAIYA on 20-09-2017.
*/
public class GCMServiceTracking extends GcmTaskService {
private static final String TAG = GCMServiceTracking.class.getSimpleName();
public static final String GCM_ONEOFF_TAG = "oneoff|[0,0]";
public static final String GCM_REPEAT_TAG = "repeat|[7200,1800]";
@Override
public void onInitializeTasks() {
//called when app is updated to a new version, reinstalled etc.
//you have to schedule your repeating tasks again
super.onInitializeTasks();
}
@Override
public int onRunTask(TaskParams taskParams) {
//do some stuff (mostly network) - executed in background thread (async)
//Toast.makeText(getApplicationContext(), "Service Executed",
Toast.LENGTH_SHORT).show();
//obtain your data
Bundle extras = taskParams.getExtras();
Handler h = new Handler(getMainLooper());
Log.v(TAG, "onRunTask");
if (taskParams.getTag().equals(GCM_ONEOFF_TAG)) {
h.post(new Runnable() {
@Override
public void run() {
//Toast.makeText(GCMServiceTracking.this, "ONEOFF executed",
Toast.LENGTH_SHORT).show();
}
});
} else if (taskParams.getTag().equals(GCM_REPEAT_TAG)) {
h.post(new Runnable() {
@Override
public void run() {
//Toast.makeText(GCMServiceTracking.this, "REPEATING executed", Toast.LENGTH_SHORT).show();
gpsTracker = new GPSTracker(GCMServiceTracking.this);
Toast.makeText(getApplicationContext(), "Data Syncing.", Toast.LENGTH_SHORT).show();
}
});
}
return GcmNetworkManager.RESULT_SUCCESS;
}
public static void scheduleOneOff(Context context) {
//in this method, single OneOff task is scheduled (the target service
that will be called is MyTaskService.class)
Bundle data = new Bundle();
data.putString("some key", "some budle data");
try {
OneoffTask oneoff = new OneoffTask.Builder()
//specify target service - must extend GcmTaskService
.setService(GCMServiceTracking.class)
//tag that is unique to this task (can be used to cancel task)
.setTag(GCM_ONEOFF_TAG)
//executed between 0 - 10s from now
.setExecutionWindow(10, 10)
//set required network state, this line is optional
.setRequiredNetwork(Task.NETWORK_STATE_ANY)
//request that charging must be connected, this line is optional
.setRequiresCharging(false)
//set some data we want to pass to our task
.setExtras(data)
//if another task with same tag is already scheduled, replace it with this task
.setUpdateCurrent(true)
.build();
GcmNetworkManager.getInstance(context).schedule(oneoff);
Log.v(TAG, "oneoff task scheduled");
} catch (Exception e) {
e.printStackTrace();
}
}
public static void scheduleRepeat(Context context) {
//in this method, single Repeating task is scheduled (the target service that will be called is MyTaskService.class)
try {
PeriodicTask periodic = new PeriodicTask.Builder()
//specify target service - must extend GcmTaskService
.setService(GCMServiceTracking.class)
//repeat every 60 seconds
.setPeriod(300)
//specify how much earlier the task can be executed (in seconds)
.setFlex(30)
//tag that is unique to this task (can be used to cancel task)
.setTag(GCM_REPEAT_TAG)
//whether the task persists after device reboot
.setPersisted(true)
//if another task with same tag is already scheduled, replace it with this task
.setUpdateCurrent(true)
//set required network state, this line is optional
.setRequiredNetwork(Task.NETWORK_STATE_ANY)
//request that charging must be connected, this line is optional
.setRequiresCharging(false)
.build();
GcmNetworkManager.getInstance(context).schedule(periodic);
Log.v(TAG, "repeating task scheduled");
} catch (Exception e) {
Log.e(TAG, "scheduling failed");
e.printStackTrace();
}
}
public static void cancelOneOff(Context context) {
GcmNetworkManager
.getInstance(context)
.cancelTask(GCM_ONEOFF_TAG, GCMServiceTracking.class);
}
public static void cancelRepeat(Context context) {
GcmNetworkManager
.getInstance(context)
.cancelTask(GCM_REPEAT_TAG, GCMServiceTracking.class);
}
public static void cancelAll(Context context) {
GcmNetworkManager
.getInstance(context)
.cancelAllTasks(GCMServiceTracking.class);
}