I am writing a simple Android program that triggers an alarm 15 seconds after the application initialization (plays the default ringtone and pushes a notification) through AlarmManager. Below is my code:
MainActivity.java:
package com.example.basicalarmsetter;
import androidx.annotation.RequiresApi;
import androidx.appcompat.app.AppCompatActivity;
import android.app.AlarmManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.os.Build;
import android.os.Bundle;
import android.os.SystemClock;
public class MainActivity extends AppCompatActivity {
private int uniqueId = 0;
// Schedules a notification in the future given the delay
@RequiresApi(api = Build.VERSION_CODES.O)
private void scheduleNotification(int matchId, long delay) {
// Construct the PendingIntent which will trigger our alarm to go off
Intent notificationIntent = new Intent();
notificationIntent.setAction("com.example.basicalarmsetter.MatchNotification");
PendingIntent pendingIntent = PendingIntent.getBroadcast(getApplicationContext(), matchId, notificationIntent, PendingIntent.FLAG_UPDATE_CURRENT) ;
long futureInMillis = SystemClock.elapsedRealtime() + delay;
// Set off our PendingIntent
AlarmManager alarmManager = (AlarmManager) getApplicationContext().getSystemService(Context.ALARM_SERVICE);
alarmManager.setExactAndAllowWhileIdle(AlarmManager.RTC_WAKEUP, futureInMillis, pendingIntent);
assert alarmManager != null;
alarmManager.setExact(AlarmManager. ELAPSED_REALTIME_WAKEUP, futureInMillis, pendingIntent);
}
// Sets an Alarm at a future specified date
@RequiresApi(api = Build.VERSION_CODES.O)
private void setAlarm(long notificationDelay) {
try {
System.out.println("Setting alarm at " + notificationDelay + " seconds");
// Sets off a notification after 5 seconds
scheduleNotification(uniqueId, notificationDelay);
uniqueId++;
} catch (Exception ex) {
System.out.println("Cannot print alarm!");
System.out.println("Exception: " + ex.toString());
}
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
setAlarm(15000);
}
}
AndroidManifest.xml:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.basicalarmsetter">
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<receiver
android:name="com.example.basicalarmsetter.MatchNotification"
android:enabled="true"
android:exported="true">
<intent-filter>
...
<action android:name="com.example.notificationtest.MatchNotification" />
</intent-filter>
</receiver>
</application>
</manifest>
MatchNotification.kt:
package com.example.basicalarmsetter
import android.app.Notification
import android.app.NotificationManager
import android.content.BroadcastReceiver
import android.content.Context
import android.content.Intent
import android.media.MediaPlayer
import android.media.RingtoneManager
import android.net.Uri
import androidx.core.app.NotificationCompat
class MatchNotification : BroadcastReceiver() {
var NOTIFICATION_ID = "notification-id"
var NOTIFICATION_CHANNEL_ID = "10001";
private lateinit var player: MediaPlayer;
private lateinit var context: Context;
// Construct the notification to push to the user given the teams in the match
private fun getNotification(
content: String
): Notification? {
val builder = NotificationCompat.Builder(
context,
"default"
)
builder.setContentTitle("NBA Alarm")
builder.setStyle(NotificationCompat.BigTextStyle().bigText(content))
builder.setContentText(content)
builder.setSmallIcon(R.drawable.ic_launcher_foreground)
builder.setAutoCancel(true)
builder.setChannelId(NOTIFICATION_CHANNEL_ID)
return builder.build()
}
override fun onReceive(context: Context, intent: Intent) {
System.out.println("Match Notification Activated.");
this.context = context
val notificationManager =
context.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
val id = intent.getIntExtra(NOTIFICATION_ID, 0)
notificationManager.notify(id, getNotification("Trigger Notification!"))
// Retrieve the URI of the alarm the user has set
var ringtoneUri:Uri = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_RINGTONE)
player = MediaPlayer.create(context, ringtoneUri)
player.start()
}
}
This seems strange, consdering that I have specified my MatchNotification class as a receiver in my AndroidManifest.xml file.
Devices Tested On:
Note: The solution should have the MainActivity code in Java
This part of your code seems wrong:
notificationIntent.setAction("com.example.basicalarmsetter.MatchNotification");
You're using the class name here. You need to use the action of the broadcast receiver, the one you put in your intent filter, a.k.a:
notificationIntent.setAction("com.example.notificationtest.MatchNotification");
Another issue: You're creating two alarms, which is unnecessary, at here:
AlarmManager alarmManager = (AlarmManager) getApplicationContext().getSystemService(Context.ALARM_SERVICE);
alarmManager.setExactAndAllowWhileIdle(AlarmManager.RTC_WAKEUP, futureInMillis, pendingIntent);
assert alarmManager != null;
alarmManager.setExact(AlarmManager. ELAPSED_REALTIME_WAKEUP, futureInMillis, pendingIntent);
At this section, following lines are unnecessary:
alarmManager.setExactAndAllowWhileIdle(AlarmManager.RTC_WAKEUP, futureInMillis, pendingIntent);
assert alarmManager != null;
The value RTC_WAKEUP is supposed to be used with System.currentTimeMillis(), not SystemClock.elapsedRealtime().
The final of your MainActivity.java would look like this:
package com.example.basicalarmsetter;
import androidx.annotation.RequiresApi;
import androidx.appcompat.app.AppCompatActivity;
import android.app.AlarmManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.os.Build;
import android.os.Bundle;
import android.os.SystemClock;
public class MainActivity extends AppCompatActivity {
private int uniqueId = 0;
// Schedules a notification in the future given the delay
@RequiresApi(api = Build.VERSION_CODES.O)
private void scheduleNotification(int matchId, long delay) {
// Construct the PendingIntent which will trigger our alarm to go off
Intent notificationIntent = new Intent();
notificationIntent.setAction("com.example.notificationtest.MatchNotification");
PendingIntent pendingIntent = PendingIntent.getBroadcast(getApplicationContext(), matchId, notificationIntent, PendingIntent.FLAG_UPDATE_CURRENT) ;
long futureInMillis = SystemClock.elapsedRealtime() + delay;
// Set off our PendingIntent
AlarmManager alarmManager = (AlarmManager) getApplicationContext().getSystemService(Context.ALARM_SERVICE);
alarmManager.setExact(AlarmManager. ELAPSED_REALTIME_WAKEUP, futureInMillis, pendingIntent);
}
// Sets an Alarm at a future specified date
@RequiresApi(api = Build.VERSION_CODES.O)
private void setAlarm(long notificationDelay) {
try {
System.out.println("Setting alarm at " + notificationDelay + " seconds");
// Sets off a notification after 5 seconds
scheduleNotification(uniqueId, notificationDelay);
uniqueId++;
} catch (Exception ex) {
System.out.println("Cannot print alarm!");
System.out.println("Exception: " + ex.toString());
}
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
setAlarm(15000);
}
}