在Android应用程序的Manifest文件中，添加以下权限：

在代码中使用WakefulBroadcastReceiver和IntentService：

public class MyWakefulReceiver extends WakefulBroadcastReceiver {

@Override
public void onReceive(Context context, Intent intent) {
    // Start the service, keeping the device awake while it is launching.
    startWakefulService(context, intent);
}

}

public class MyIntentService extends IntentService {

public MyIntentService() {
    super("MyIntentService");
}

@Override
protected void onHandleIntent(Intent intent) {
    // Connect to the server and get data
    // Perform any background operations here
    // Release the wake lock provided by the WakefulBroadcastReceiver
    MyWakefulReceiver.completeWakefulIntent(intent);
}

}

在应用程序代码中，使用以下代码启动服务：

Intent service = new Intent(context, MyIntentService.class); startWakefulService(context, service);

这将启动后台服务，并在连接服务器时保持设备处于唤醒状态。这样就可以从后台连接服务器了！