Android How to execute a method every x hours or minutes

Question

Im trying to run a method called Updater() with the alarm service and for testing i want it to update every 1 minutes and eventually every 2 hours. The Sceduled task excuted itself on a timer if a toggle button is on and stops the timer when the toggle button is off this is my code so far. Can someone show my what i'm doing wrong please?

 public class AlarmReceiver extends BroadcastReceiver
{
    @Override
    public void onReceive(Context context, Intent intent) {
        Updater();
    }
}
public void autoUpdateClick(View view)
{
    AlarmManager alarmManager=(AlarmManager) this.getSystemService(Context.ALARM_SERVICE);
    Intent intent = new Intent(this,AlarmReceiver.class);
    PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0, intent, 0);
    boolean on = ((ToggleButton) view).isChecked();
    if (on)
    {
      alarmManager.setRepeating(AlarmManager.RTC_WAKEUP,System.currentTimeMillis(),30000,pendingIntent);
        Toast.makeText(getBaseContext(),"Check-In will be done every 2 hours",Toast.LENGTH_SHORT).show();
    }
    else
    {
     alarmManager.cancel(pendingIntent);
        Toast.makeText(getBaseContext(),"Manual Check-In enabled",Toast.LENGTH_SHORT).show();
    }

}

Answer 1

As you mentioned we will schedule an alarm to execute a method at a particular time in future.

We will have two classes

1. MainAcitvity: in this class, we will schedule the alarm to be triggered at particular time .
2. AlarmReciever: when the alarm triggers at scheduled time , this class will receive the alarm, and execute a method.

AlarmReciever class extends BroadcastReceiver and overrides onRecieve() method. inside onReceive() you can start an activity or service depending on your need like you can start an activity to vibrate phone or to ring the phone

Permission Required we need permission to use the AlarmManger in our application, so do not forget to declare the permission in manifest file

AndroidManifest file

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.test.src"
    android:versionCode="1"
    android:versionName="1.0" >

        <uses-sdk android:minSdkVersion="8"
                         android:targetSdkVersion="17" />
         <!-- permission required to use Alarm Manager -->
        <uses-permission android:name="com.android.alarm.permission.SET_ALARM"/>


        <application
                 android:icon="@drawable/ic_launcher"
                 android:label="Demo App" >
                <activity
                           android:name=".MainActivity"
                           android:label="Demo App" >
                          <intent-filter>
                                       <action android:name="android.intent.action.MAIN" />
                                       <category android:name="android.intent.category.LAUNCHER" />
                          </intent-filter>
               </activity>


            <!-- Register the Alarm Receiver -->
                   <receiver android:name=".AlarmReciever"/> 
            
         </application>
</manifest>

main.xml

<LinearLayout
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" 
    android:orientation="vertical"
    android:gravity="center_vertical"
    xmlns:android="http://schemas.android.com/apk/res/android">


<TextView
    android:id="@+id/textView1"
    android:gravity="center_horizontal"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="Alarm Manager Example"
    android:textAppearance="?android:attr/textAppearanceLarge" />

<Button
    android:id="@+id/button1"
    android:layout_marginTop="25dp"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="Schedule The Alarm" 
    android:onClick="scheduleAlarm"/>

</LinearLayout>

MainActivity.java

public class MainActivity extends Activity
{
       @Override
       public void onCreate(Bundle savedInstanceState) 
      {
                super.onCreate(savedInstanceState);
                setContentView(R.layout.main);
      }

    public void scheduleAlarm(View V)
    {
            // time at which alarm will be scheduled here alarm is scheduled at 1 day from current time, 
            // we fetch  the current time in milliseconds and added 1 day time
            // i.e. 24*60*60*1000= 86,400,000   milliseconds in a day        
            Long time = new GregorianCalendar().getTimeInMillis()+24*60*60*1000;

            // create an Intent and set the class which will execute when Alarm triggers, here we have
            // given AlarmReciever in the Intent, the onRecieve() method of this class will execute when
            // alarm triggers and 
            //we call the method inside onRecieve() method of Alarmreciever class
            Intent intentAlarm = new Intent(this, AlarmReciever.class);
       
            // create the object
            AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);

            //set the alarm for particular time
            alarmManager.set(AlarmManager.RTC_WAKEUP,time, PendingIntent.getBroadcast(this,1,  intentAlarm, PendingIntent.FLAG_UPDATE_CURRENT));
            Toast.makeText(this, "Alarm Scheduled for Tommrrow", Toast.LENGTH_LONG).show();
         
    }
}

AlarmReciever.java

public class AlarmReciever extends BroadcastReceiver

{
         @Override
            public void onReceive(Context context, Intent intent)
            {
               //call the method here
                         
             }
      
}