How to give notice by AlarmManager?

[Oba22]

There are two classes.

First... AlarmManager - causing an event at a certain interval,

Second - NotificationManager - removes direct notices.

Both classes work correctly, but I can't combine them at a certain interval in the class. AlarmManager a class method NotificationManager

First Class

package com.example.reminder;
import android.app.AlarmManager;

import android.app.PendingIntent;

import android.content.BroadcastReceiver;

import android.content.Context;

import android.content.Intent;

import android.os.Bundle;

import android.os.PowerManager;

import android.widget.Toast;
import java.text.Format;

import java.text.SimpleDateFormat;

import java.util.Date;

import java.util.Random;
public class ReminderManager extends BroadcastReceiver{

ReminderNotifications rn = new ReminderNotifications();

final public static String ONE_TIME = "onetime";

Random random = new Random();

int time;
@Override
public void onReceive(Context context, Intent intent) {
    PowerManager pm = (PowerManager)context.getSystemService(Context.POWER_SERVICE);
    PowerManager.WakeLock wl = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "YOUR_TAG");
    wl.acquire();

    Bundle extras = intent.getExtras();
    StringBuilder msgStr = new StringBuilder();

    Format formatter = new SimpleDateFormat("hh:mm:ss a");
    msgStr.append(formatter.format(new Date()));

    //rn.MyNotification(); //метод из второго класса, при вызове приложение прерывается
    Toast.makeText(context, msgStr, Toast.LENGTH_SHORT).show();

    wl.release();
}

public void setAlarm(Context context){
    AlarmManager am = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
    Intent intent = new Intent(context, ReminderManager.class);
    intent.putExtra(ONE_TIME, Boolean.FALSE);
    PendingIntent pi = PendingIntent.getBroadcast(context, 0, intent, 0);
    time = random.nextInt(1000 * 10) + 1000;
    am.setRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis(), time, pi);
}

public void cancelAlarm(Context context){
    Intent intent = new Intent(context, ReminderManager.class);
    PendingIntent sender = PendingIntent.getBroadcast(context, 0, intent, 0);
    AlarmManager alarmManager = (AlarmManager)context.getSystemService(Context.ALARM_SERVICE);
    alarmManager.cancel(sender);
}

}

Second Class

package com.example.reminder;

import android.app.Notification;

import android.app.NotificationManager;

import android.app.PendingIntent;

import android.content.Context;

import android.content.Intent;

import android.content.res.Resources;

import android.graphics.BitmapFactory;

import android.support.v7.app.AppCompatActivity;
public class ReminderNotifications extends AppCompatActivity{

private final static int NOTIFY_ID = 101;
public void MyNotification(){
    Context context = getApplicationContext();

    Intent notificationIntent = new Intent(context, ReminderNotifications.class);
    PendingIntent contentIntent = PendingIntent.getActivity(context, 0, notificationIntent, PendingIntent.FLAG_CANCEL_CURRENT);

    Resources res = context.getResources();
    Notification.Builder builder = new Notification.Builder(context);

    builder.setContentIntent(contentIntent)
            .setSmallIcon(R.mipmap.ic_launcher)
            .setLargeIcon(BitmapFactory.decodeResource(res, R.mipmap.ic_launcher))
            .setTicker("Attention")
            .setWhen(System.currentTimeMillis())
            .setAutoCancel(true)
            .setContentTitle("Напоминание")
            .setContentText("Пора уходить домой");

    Notification notification = builder.getNotification(); //до 16 API
    //Notification notification = builder.build();

    NotificationManager notificationManager = (NotificationManager)context.getSystemService(Context.NOTIFICATION_SERVICE);
    notificationManager.notify(NOTIFY_ID, notification);
}

}

I'm sorry if the problem is too trivial, but it hasn't figured out yet.

[Avante]

BroadcastReceiver He doesn't know anything about your activism, he's being created by a system in his own context, which is transmitted to the method. onReceive()♪ That context should be used to create notifications.

That's why your notification code isn't so easy to use. BroadcastReceiver♪

Just take it apart from activating, the context can be presented as a parameter, then it'll work.