从服务设置警报：

package yourPackage;

import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.os.IBinder;

public class YourService extends Service
{
    Alarm alarm = new Alarm();
    public void onCreate()
    {
        super.onCreate();       
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId)
    {
        alarm.setAlarm(this);
        return START_STICKY;
    }

   @Override        
   public void onStart(Intent intent, int startId)
    {
        alarm.setAlarm(this);
    }

    @Override
    public IBinder onBind(Intent intent)
    {
        return null;
    }
}

如果要设置在电话启动时重复发出警报：

向Manifest.xml添加权限和服务：

<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"></uses-permission>
...
<receiver android:name=".AutoStart">
    <intent-filter>
        <action android:name="android.intent.action.BOOT_COMPLETED"></action>
    </intent-filter>
</receiver>
...
<service
        android:name=".YourService"
        android:enabled="true"
        android:process=":your_service" >
</service>

并创建一个新类：

package yourPackage;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;

public class AutoStart extends BroadcastReceiver
{   
    Alarm alarm = new Alarm();
    @Override
    public void onReceive(Context context, Intent intent)
    {   
        if (intent.getAction().equals(Intent.ACTION_BOOT_COMPLETED))
        {
            alarm.setAlarm(context);
        }
    }
}