Alarm Clock with Notifications in Android Studio using Java – Alarm Manager Easy 4 Steps
Table of Contents
Alarm Manager
The Alarm Manager sets the system alarm as per your scheduled time. Even, if you are not currently running the application it will still throw a notification as per the scheduled time.
In this project, we have created an alarm clock where you can select a time as per your choice then click on set alarm and it will be set. We also provide a cancel alarm button.
Once you have selected the time and clicked on set alarm then a notification will appear on that particular time. To keep the project simple, we have not provided a user input notification so it will default as per the code. In further upcoming projects, I will create a fully functional alarm clock.
Step-by-Step Implementation
Step 1: Open Android Studio, Click on New Project and Choose Empty Activity.
Step 2: Pre-requisites:
Gradle (module)
buildFeatures{
viewBinding true
}
colors.xml
<color name="lavender">#8692f7</color>
themes.xml
<resources xmlns:tools="http://schemas.android.com/tools">
<!-- Base application theme. -->
<style name="Theme.AlarmClock" parent="Theme.MaterialComponents.DayNight.DarkActionBar">
<!-- Primary brand color. -->
<item name="colorPrimary">@color/lavender</item>
<item name="colorPrimaryVariant">@color/lavender</item>
<item name="colorOnPrimary">@color/white</item>
<!-- Secondary brand color. -->
<item name="colorSecondary">@color/teal_200</item>
<item name="colorSecondaryVariant">@color/teal_700</item>
<item name="colorOnSecondary">@color/black</item>
<!-- Status bar color. -->
<item name="android:statusBarColor">?attr/colorPrimaryVariant</item>
<!-- Customize your theme here. -->
</style>
</resources>
Drawables
Add vector assets – notifications icon.
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools">
<application
android:allowBackup="true"
android:dataExtractionRules="@xml/data_extraction_rules"
android:fullBackupContent="@xml/backup_rules"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/Theme.AlarmClock"
tools:targetApi="31">
<activity
android:name=".NotificationActivity"
android:exported="false">
<meta-data
android:name="android.app.lib_name"
android:value="" />
</activity>
<activity
android:name=".MainActivity"
android:exported="true">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
<meta-data
android:name="android.app.lib_name"
android:value="" />
</activity>
<receiver android:name=".AlarmReceiver"/>
</application>
</manifest>
Download Background Image:
Step 3: XML Layouts:
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:gravity="center_vertical"
android:background="@drawable/alarm"
tools:context=".MainActivity">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Select \nTime"
android:id="@+id/selectTime"
android:textSize="40sp"
android:layout_marginTop="280dp"
android:layout_gravity="center_horizontal"
android:textColor="@color/white"
android:textAlignment="center"/>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<Button
android:layout_width="150dp"
android:layout_height="wrap_content"
android:id="@+id/setAlarm"
android:text="Set \nAlarm"
android:textSize="20sp"
android:padding="8dp"
android:layout_marginStart="40dp"
android:layout_marginTop="250dp"/>
<Button
android:layout_width="150dp"
android:layout_height="wrap_content"
android:id="@+id/cancelAlarm"
android:text="Cancel \nAlarm"
android:textSize="20sp"
android:padding="8dp"
android:layout_alignParentEnd="true"
android:layout_marginTop="250dp"
android:layout_marginEnd="40dp"/>
</RelativeLayout>
</LinearLayout>
activity_notifications.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".NotificationActivity">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Welcome to \nNotification Activity"
android:textSize="36sp"
android:textAlignment="center"
android:textColor="@color/lavender"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent"/>
</androidx.constraintlayout.widget.ConstraintLayout>
Step 4: Java Files
AlarmReceiver.java
package com.example.alarmclock;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import androidx.core.app.NotificationCompat;
import androidx.core.app.NotificationManagerCompat;
public class AlarmReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
Intent nextActivity = new Intent(context, NotificationActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
PendingIntent pendingIntent = PendingIntent.getActivity(context, 0, nextActivity, 0);
NotificationCompat.Builder builder = new NotificationCompat.Builder(context, "androidknowledge")
.setSmallIcon(R.drawable.ic_baseline_notifications_24)
.setContentTitle("Reminder")
.setContentText("It's time to wake up")
.setAutoCancel(true)
.setDefaults(NotificationCompat.DEFAULT_ALL)
.setPriority(NotificationCompat.PRIORITY_HIGH)
.setContentIntent(pendingIntent);
NotificationManagerCompat notificationManagerCompat = NotificationManagerCompat.from(context);
notificationManagerCompat.notify(123,builder.build());
}
}
MainActivity.java
package com.example.alarmclock;
import androidx.appcompat.app.AppCompatActivity;
import android.app.AlarmManager;
import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.os.Build;
import android.os.Bundle;
import android.view.View;
import android.widget.Toast;
import com.example.alarmclock.databinding.ActivityMainBinding;
import com.google.android.material.timepicker.MaterialTimePicker;
import com.google.android.material.timepicker.TimeFormat;
import java.util.Calendar;
public class MainActivity extends AppCompatActivity {
private ActivityMainBinding binding;
private MaterialTimePicker timePicker;
private Calendar calendar;
private AlarmManager alarmManager;
private PendingIntent pendingIntent;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
binding = ActivityMainBinding.inflate(getLayoutInflater());
setContentView(binding.getRoot());
createNotificationChannel();
binding.selectTime.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
timePicker = new MaterialTimePicker.Builder()
.setTimeFormat(TimeFormat.CLOCK_12H)
.setHour(12)
.setMinute(0)
.setTitleText("Select Alarm Time")
.build();
timePicker.show(getSupportFragmentManager(), "androidknowledge");
timePicker.addOnPositiveButtonClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if (timePicker.getHour() > 12){
binding.selectTime.setText(
String.format("%02d",(timePicker.getHour()-12)) +":"+ String.format("%02d", timePicker.getMinute())+"PM"
);
} else {
binding.selectTime.setText(timePicker.getHour()+":" + timePicker.getMinute()+ "AM");
}
calendar = Calendar.getInstance();
calendar.set(Calendar.HOUR_OF_DAY, timePicker.getHour());
calendar.set(Calendar.MINUTE, timePicker.getMinute());
calendar.set(Calendar.SECOND, 0);
calendar.set(Calendar.MILLISECOND, 0);
}
});
}
});
binding.setAlarm.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
Intent intent = new Intent(MainActivity.this, AlarmReceiver.class);
pendingIntent = PendingIntent.getBroadcast(MainActivity.this, 0, intent, 0);
alarmManager.setInexactRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), AlarmManager.INTERVAL_DAY, pendingIntent);
Toast.makeText(MainActivity.this, "Alarm Set", Toast.LENGTH_SHORT).show();
}
});
binding.cancelAlarm.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent intent = new Intent(MainActivity.this, AlarmReceiver.class);
pendingIntent = PendingIntent.getBroadcast(MainActivity.this, 0, intent, 0);
if (alarmManager == null){
alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
}
alarmManager.cancel(pendingIntent);
Toast.makeText(MainActivity.this, "Alarm Canceled", Toast.LENGTH_SHORT).show();
}
});
}
private void createNotificationChannel(){
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O){
CharSequence name = "akchannel";
String desc = "Channel for Alarm Manager";
int imp = NotificationManager.IMPORTANCE_HIGH;
NotificationChannel channel = new NotificationChannel("androidknowledge", name, imp);
channel.setDescription(desc);
NotificationManager notificationManager = getSystemService(NotificationManager.class);
notificationManager.createNotificationChannel(channel);
}
}
}
Output
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Watch our Detailed Youtube Video: Alarm Clock with Notifications in Android Studio using Java
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