#broadcastreceiver

Before I began coding Android apps, I was amazed how verification processes go like this: The Android app tells you they’ll send you an SMS containing verification code, and that you need to enter such code into a text field on the Android app. But when you receive the SMS, the verification code appears on the text field before you even type! I was like, whoa, how do they do that?

Now that I am…

Connectivity Status – Android

Determine and Monitoring Connectivity Status

Today most of the android application depends on the Internet connectivity for regular updates of application data from Internet resources or to execute long running downloads.

In this article I will try to provide a solution, which constantly monitors connectivity changes in the application and let developer pleasantly handle those changes.

In order…

package YourPackage; import android.content.BroadcastReceiver; import android.content.Context; import android.content.Intent; public class Internet extends BroadcastReceiver { @Override public void onReceive(final Context context, Intent intent) { if (intent.getAction().equalsIgnoreCase("android.net.conn.CONNECTIVITY_CHANGE")) { if isInternet(context) { // Your Code download, upload, request,... } } } public boolean isInternet(Context context) { ConnectivityManager IM = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE); NetworkInfo activeNetworkInfo = IM.getActiveNetworkInfo(); return activeNetwork != null &&

                      activeNetwork.isConnectedOrConnecting();

Fixed Trying to start a service on boot on Android #dev #it #asnwer

Trying to start a service on boot on Android

I’ve been trying to start a service when a device boots up on android, but I cannot get it to work. I’ve looked at a number of links online but none of the code works. Am I forgetting something?

AndroidManifest.xml

How to: Sending and Receiving SMS and MMS in Android (pre Kit Kat Android 4.4)

Sending and Receiving SMS and MMS in Android (pre Kit Kat Android 4.4)

I have figured out how to send and receive SMS messages. To send SMS messages I had to call the sendTextMessage() and sendMultipartTextMessage() methods of the SmsManager class. To receive SMS messages, I had to register a receiver in the AndroidMainfest.xml file. Then I had to override the onReceive() method of the Broadcast…

how to use LocalBroadcastManager?

can any one tell me how to use/locate LocalBroadcastManager as described in google docs and Service broadcast doc?

i tried to google it, but theres no code available to start with?

the documents say that i should use it if i want to do broadcast internally with in my app’s process but i dont know where to look for this

any help/comment?

Update: I know how to use…

New Post has been published on http://javatechig.com/android/repeat-alarm-example-in-android

Repeat Alarm Example In Android Using AlarmManager

Table of Contents

1. AlarmManager in android

2. Setting repeat alarm

3. Defining Alarm BroadcastReceiver

4. Schedule and cancel alarm from activity

5. Starting alarm service on device reboot

6. Declaring Application Manifest

7. Download source code

In the context of this tutorial we will learn how to create a repeat alarm example in android using AlarmManager class.

1. AlarmManager in android

AlarmManager is a class in Android which is used access device alarm service. This allow your application to execute certain piece of code on a given scheduled time. This can run outside the lifetime of your application.

Once alarm is scheduled, it will invoke even when your application is not running or even when your device is in sleep.

An alarm can wake your device, but this consumes more battery. So you have to be careful while scheduling an alarm task which executes more frequently. The schedule frequency should be be set to minimum as possible.

Once an Alarm Started, this will execute until it is stopped explicitly or until device reboots.

For example, an AlarmManager is used to initiate long running operations such as syncing data from server once a day.

AlarmManger help you to fire Intent at given intervals

This can be used along with broadcast receivers to start a service to perform network operations.

It is different form java Timer and TimerTask, as they execute with in application life cycle.

2. Setting repeat alarm

Android supports two clock types for alarm service. Once is elapsed real time and other is real time clock (RTC)

Elapsed real time uses the time since device last booted

Real time clock (RTC) uses UTC time for alarm service clock. RTC is most commonly used for setting alarm service in android.

In this example, we’ll show you to schedule alarm using RTC. The application using a single activity containing three buttons. One button is for starting an alarm service, another to cancel scheduled alarm. The third button is to start the alarm at specified calendar time. For example, if you have set a time for your birthday reminder. It will invoke at 10:30 PM and will repeat on every 30 mins.

Let us have a look into our activity layout file (my_activity.xml)

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" tools:context=".MyActivity"> <TextView android:id="@+id/textView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginBottom="20dp" android:text="@string/hint" android:textAppearance="?android:attr/textAppearanceLarge" /> <Button android:id="@+id/startAlarm" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_alignParentLeft="true" android:layout_alignParentStart="true" android:layout_below="@+id/textView" android:layout_marginBottom="20dp" android:text="Start Alarm Service" /> <Button android:id="@+id/stopAlarm" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_below="@+id/startAlarm" android:layout_marginBottom="20dp" android:text="Stop Alarm" /> <Button android:id="@+id/stopAlarmAt10" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_below="@+id/stopAlarm" android:text="Stop Alarm at 10:30" /> </RelativeLayout>

3. Defining Alarm BroadcastReceiver

In this example, we are associating alarm service with broadcast receiver. Alarm service will invoke this receiver on scheduled time. For the sake of simplicity we are just showing an toast to user for each time the alarm is invoked. You may write your logic to start a service or download task.

Note: If your alarm has to perform network task, then start a download service inside onRecieve() method of your alarm broadcast.

package com.javatechig.alarmservice; import android.content.BroadcastReceiver; import android.content.Context; import android.content.Intent; import android.widget.Toast; public class AlarmReceiver extends BroadcastReceiver @Override public void onReceive(Context context, Intent intent) // For our recurring task, we'll just display a message Toast.makeText(context, "I'm running", Toast.LENGTH_SHORT).show();

4. Schedule and cancel alarm from activity

In the above two steps we have defined activity layout and alarm broadcast receiver. Let us have a look into MainActivity.java file. Inside MyActivity class, we have defined three simple methods start(), stop() and startAt10(). The start() method schedule the alarm, cancel() method cancel the scheduled alarm, and startAt!0() method will start the alarm at 10:30 PM with a fixed 20 minutes interval.

package com.javatechig.alarmservice; import android.app.Activity; import android.app.AlarmManager; import android.app.PendingIntent; import android.content.Context; import android.content.Intent; import android.os.Bundle; import android.view.View; import android.widget.Toast; import java.util.Calendar; public class MyActivity extends Activity private PendingIntent pendingIntent; @Override protected void onCreate(Bundle savedInstanceState) super.onCreate(savedInstanceState); setContentView(R.layout.activity_my); /* Retrieve a PendingIntent that will perform a broadcast */ Intent alarmIntent = new Intent(MyActivity.this, AlarmReceiver.class); pendingIntent = PendingIntent.getBroadcast(MyActivity.this, 0, alarmIntent, 0); findViewById(R.id.startAlarm).setOnClickListener(new View.OnClickListener() @Override public void onClick(View v) start(); ); findViewById(R.id.stopAlarm).setOnClickListener(new View.OnClickListener() @Override public void onClick(View v) cancel(); ); findViewById(R.id.stopAlarmAt10).setOnClickListener(new View.OnClickListener() @Override public void onClick(View v) startAt10(); ); public void start() AlarmManager manager = (AlarmManager) getSystemService(Context.ALARM_SERVICE); int interval = 8000; manager.setInexactRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis(), interval, pendingIntent); Toast.makeText(this, "Alarm Set", Toast.LENGTH_SHORT).show(); public void cancel() AlarmManager manager = (AlarmManager) getSystemService(Context.ALARM_SERVICE); manager.cancel(pendingIntent); Toast.makeText(this, "Alarm Canceled", Toast.LENGTH_SHORT).show(); public void startAt10() AlarmManager manager = (AlarmManager) getSystemService(Context.ALARM_SERVICE); int interval = 1000 * 60 * 20; /* Set the alarm to start at 10:30 AM */ Calendar calendar = Calendar.getInstance(); calendar.setTimeInMillis(System.currentTimeMillis()); calendar.set(Calendar.HOUR_OF_DAY, 10); calendar.set(Calendar.MINUTE, 30); /* Repeating on every 20 minutes interval */ manager.setRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), 1000 * 60 * 20, pendingIntent);

5. Starting alarm service on device reboot

As discussed earlier, once an alarm service is started, it execute until it is explicitly stopped or until device reboots. This means that, if your device is restarted then your alarm is stopped. To avoid such situatation, you have to restart your alarm service as soon as device boot completes. Below code snippet will help you to start alarm service once device reboots.

package com.javatechig.alarmservice; import android.app.AlarmManager; import android.app.PendingIntent; import android.content.BroadcastReceiver; import android.content.Context; import android.content.Intent; import android.widget.Toast; /** * @author Neel * <p/> * Broadcast reciever, starts when the device gets starts. * Start your repeating alarm here. */ public class DeviceBootReceiver extends BroadcastReceiver @Override public void onReceive(Context context, Intent intent) if (intent.getAction().equals("android.intent.action.BOOT_COMPLETED")) /* Setting the alarm here */ Intent alarmIntent = new Intent(context, AlarmReceiver.class); PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, alarmIntent, 0); AlarmManager manager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE); int interval = 8000; manager.setInexactRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis(), interval, pendingIntent); Toast.makeText(context, "Alarm Set", Toast.LENGTH_SHORT).show();

6. Declaring Application Manifest

To start your alarm on device reboot, you have to register your above declared DeviceBootReciever class in your application manifest. This also need android.permission.RECEIVE_BOOT_COMPLETED

<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.javatechig.alarmservice" > <application android:allowBackup="true" android:icon="@drawable/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme" > <!-- Permission to start Alarm on device reboot --> <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/> <activity android:name=".MyActivity" android:label="@string/app_name" > <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> <!-- Will not be called unless the application explicitly enables it --> <receiver android:name=".DeviceBootReceiver" android:enabled="false"> <intent-filter> <action android:name="android.intent.action.BOOT_COMPLETED"/> </intent-filter> </receiver> </application> </manifest>

7. Download source code

1. Introducción

Como comenté el otro día la clase BroadcastReceiver es un componente Android que nos permite registrarnos para recivir eventos del sistema o eventos de ciertas aplicaciones. Los BroadcastReceiver que estén registrados para un cierto evento serán notificados por el runtime de Android cuando esto ocurra.

Para el ejemplo que propuse el otro día, el del nivel de la batería, tenemos que registrar nuestro BroadcastReceiver para el evento ACTION_BATTERY_LOW.

2. BroadcastReceiver

Los eventos que se producen, ya sean eventos del sistema o de aplicaciones, están representados mediante Intents. Estos son enviados por el sistema para que los BroadcastReceiver registrados para ese evento los recivan.

El Intent es recivido por el BroadcastReceiver en la llamada al método onReceive().

Vale, y ¿cómo registramos ahora el BroadcastReceiver? Pues existen dos maneras:

Estáticamente, en el AndroidManifest.xml

Dinámicamente, es decir, en tiempo de ejecución mediante el método registerReceiver()

2.1. Registración estática

Esta manera de registro se realiza en el AndroidManifest.xml. Con la etiqueta <receiver> le indicaremos a la aplicación el nombre del BroadcastReceiver y una serie de atributos opcionales

<receiver android:enabled=["true" | "false"] android:exported=["true" | "false"] android:icon="drawable resource" android:label="string resource" android:name="string" android:permission="string" android:process="string" > </receiver>

Para consultar el uso de estos atributos podeis consultar AndroidManifestReceiver.

Dentro de la etiqueta debemos especificar también el Intent filter para saber el evento que va a escuchar el BroadcastReceiver. Utilizaremos la etiquieta <intent-filter>.

Con este tipo de registración los BroadcastReceiver son registrados en el momento de arranque del sistema o cuando se añade la aplicación en tiempo de ejecución.

2.1.1. Aplicación

Vamos a dejar un poco la teoría a parte y ponernos a hacer un sencillo ejemplo para aplicar lo aprendido. Para explicar la registración estática de los BroadcastReceiver vamos a crear dos apps.

Sender. Esta aplicación será la responsable de desatar un evento que nosotros vamos a crear. Dispondrá de un botón para realizar la emisión del evento.

Receiver. Esta se registrará para recivir el evento que desencadena el Sender. Cuando recive el evento muestra una actividad en la que se muestra el número de veces que se ha recivido el evento.

Con estas dos apps creo que es más sencillo entender los BroadcastReceiver. Así por un lado tenemos la aplicación que envía los eventos, la cual puede sustituir al controlador de la batería en nuestro ejemplo inicial, y por otro lado el receptor del evento, el cual manejará el evento recivido para reaccionar a su antojo.

Empecemos por el Sender. En nuestro layout creamos un botón centrado en el centro, tal que así:

<Button android:id="@+id/buttonSender" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_centerHorizontal="true" android:layout_centerVertical="true" android:text="@string/button_send_event" />

Ahora pasamos a programar un poco. Vamos a la clase principal en la que buscaremos el botón a través del id y luego le añadimos el evento de click para que cuando el usuario pulse el botón envie nuestro evento al Receiver. El evento está representado con un Intent al que le vamos a dar el siguiente nombre.

final static String SEND_INTENT = "ble180.BroadcastReceiver.event";

Pues ya tenemos todo lo necesario, ahora simplemente tenemos que crear un Intent y enviarlo con el método sendBroadcast().

import android.os.Bundle; import android.app.Activity; import android.content.Intent; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; public class MainActivity extends Activity { final static String SEND_INTENT = "ble180.BroadcastReceiver.event"; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); final Button buttonSender = (Button) findViewById(R.id.buttonSender); buttonSender.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // Send the intent that the other app received sendBroadcast(new Intent(SEND_INTENT)); } }); } }

Pues pasemos ahora al Receiver. Lo primero que tenemos que hacer es registrar el Receiver en nuestro AndroidManifest.xml para la recepción de nuestro evento ble180.BroadcastReceiver.event.

<receiver android:name=".Receiver" android:exported="true"> <intent-filter> <action android:name="ble180.BroadcastReceiver.event"/> </intent-filter> </receiver>

Al hacer esto nos saldrá un Warning indicando que al ser el Receiver exported cualquier aplicación podrá enviar eventos los cuales sean recividos por nuestra app. Para ello vamos a crear un permiso el cual se le daremos al Receiver. Así solo los Sender que tengan este permiso en su AndroidManifest.xml podrán enviar el evento ble180.BroadcastReceiver.event y que sea recivido por la app. Entonces nuestro AndroidManifest.xml quedará así:

<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="ble180.BroadcastReceiver.BroadcastReceiverRec" android:versionCode="1" android:versionName="1.0" > <uses-sdk android:minSdkVersion="8" android:targetSdkVersion="19" /> <permission android:name="ble180.BroadcastReceiver.START_RECEIVER"/> <application android:allowBackup="true" android:icon="@drawable/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme" > <activity android:name="ble180.BroadcastReceiver.BroadcastReceiverRec.MainActivity" android:label="@string/app_name" > <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> <receiver android:name=".Receiver" android:exported="true" android:permission="ble180.BroadcastReceiver.START_RECEIVER"> <intent-filter> <action android:name="ble180.BroadcastReceiver.event"/> </intent-filter> </receiver> </application> </manifest>

Como hemos añadido el permiso ahora debemos añadirselo también al AndroidManifest.xml del Sender. Simplemente será añadir la linea <uses-permission android:name="ble180.BroadcastReceiver.START_RECEIVER"/>

Pues pasemos al código del Receiver. A parte de la clase principal vamos a crear una para implementar el Receiver que extienda de BroadcasReceiver. Esta clase tendrá el método onReceive() que será desencadenado cuando reciva el evento emitido por el Sender. Aquí es donde se realizan las operaciones que deseemos que se desencadenen con la recepción del evento.

Como dije antes, cuando reciva el evento queremos que inicie una actividad con el número de veces que se ha recivido el evento. Para ello creamos un Intent con la clase principal de nuestra aplicación, en este caso MainActivity.class. A este Intent le ponemos información extra, en este caso el número de veces que se ha recivido el evento, y lo lanzamos.

import android.content.BroadcastReceiver; import android.content.Context; import android.content.Intent; public class Receiver extends BroadcastReceiver{ // Times that we have received an event static int TIMES_RECEIVED = 0; @Override public void onReceive(Context context, Intent intent) { TIMES_RECEIVED++; // New intent with the main class Intent intentRec = new Intent(context, MainActivity.class); intentRec.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK); // Put the times for the MainActivity can show the times // that we have received an event intentRec.putExtra("times", TIMES_RECEIVED); // Start the activity context.startActivity(intentRec); } }

Por último nos queda nuestra clase principal la MainActivity. Es la clase más sencilla de todas, solo obtenemos la información extra del Intent lanzado en la clase anterior para mostrarla por pantalla en un TextView que contiene la vista pricipal de la aplicación.

import android.os.Bundle; import android.widget.TextView; import android.app.Activity; import android.content.Intent; public class MainActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); int times = 0; Intent intent = getIntent(); Integer extraTimes = intent.getIntExtra("times", 0); // If there are times, we keep in times variable to show it if(extraTimes != null){ times = extraTimes; } // Change the TextView message TextView textViewReceiver = (TextView) findViewById(R.id.textViewReceiver); textViewReceiver.setText("Received Event num " + times + " by Receiver"); } }

Ahora es turno de vosotros probarlo. Simplemente teneis que instalar las dos apps en vuestro smartphone o en el simulador. Una vez que las dos estén instaladas, abrís el Sender y le dais al botón de enviar y seguidamente vereis como se abre una nueva actividad con un mensaje y el número de veces que se ha recivido el evento.

Github:Enlace al código