java - 无法在Android代码中的Alarm OnReceive方法上执行select.php

Question

我在android应用程序中有MainActivity.java

因为我有 setRepeatingAlarm() ，它在每 120sec 后执行一次，并执行 select.php 来检查表中是否可用的名称。

public void setRepeatingAlarm() {
    Intent intent = new Intent(MainActivity.this, TimeAlarm.class);
    PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0,
    intent, PendingIntent.FLAG_UPDATE_CURRENT);

    am.setRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis()+120000,
    (120000), pendingIntent);
}

广播接收器:

public class TimeAlarm extends BroadcastReceiver {

    public void onReceive(Context context, Intent intent) {
        //get select query data
        try {
            HttpClient httpclient = new DefaultHttpClient();
            HttpPost httppost = new HttpPost("http://www.myweb.com/select.php");

            HttpResponse response = httpclient.execute(httppost); 
            HttpEntity entity = response.getEntity();
            is = entity.getContent();   
            if(is != null) {
                Intent notificationIntent = new Intent(context, MainActivity.class);
                PendingIntent contentIntent = PendingIntent.getActivity(context, 0, notificationIntent, 0);

                 NotificationManager notificationManager = (NotificationManager) context
                            .getSystemService(Context.NOTIFICATION_SERVICE);

                 Notification noti = new NotificationCompat.Builder(context)
                                    .setSmallIcon(R.drawable.ic_launcher)
                                    .setTicker("mytestapp")

                                    .setContentTitle("mytestapp")
                                    .setContentText("Please check new update!")
                                    .setContentIntent(contentIntent)
                                    //At most three action buttons can be added
                                    .setAutoCancel(true).build();
                int notifyID =0;
                notificationManager.notify(notifyID, noti);
            }

            is.close();
        } catch(Exception e) {

        }
    }
}

but i'm unable to execute HttpResponse response = httpclient.execute(httppost); goes into catch block . not getting any error details :(

select.php 给出类似 {"name":"mynametest"} OR null

的输出

请告诉我这里出了什么问题

Answer 1

根据我对您的问题的评论 - 您可以将网络代码移至 IntentService 中，然后只需从您的 BroadcastReceiver 启动它即可。 IntentService 中的所有工作均由运行 onHandleIntent(...) 方法的工作线程处理，因此在其中执行网络任务是安全的。

IntentService:

public class MyIntentService extends IntentService {

    // You must have a parameter-less ctor for an IntentService
    public MyIntentService() {
        super("MyIntentService");
    }

    public MyIntentService(String name) {
        super(name);
    }

    @Override
    protected void onHandleIntent(Intent intent) {

        // This method is run on a separate worker thread so it's
        // safe to put all of your network code here

    }
}

将 BroadcastReceiver onReceive(...) 方法中当前的所有内容复制到您的 onHandleIntent(...) 方法中IntentService 并将其替换为启动服务的代码，如下所示...

public class TimeAlarm extends BroadcastReceiver {

    public void onReceive(Context context, Intent intent) {
        Intent i = new Intent(context, MyIntentService.class);
        context.startService(i);
    }
}