Introduction

This article explains the Broadcast Receiver in Android.
A Broadcast Receiver is a receiver that helps to catch Android operating system specific events. A Broadcast Receiver is an Android component that listens for device orientation changes like SMS message received, phone call received, battery status received and WiFi comes on.
A Broadcast Receiver is used when a call is received. We then save the call details in our SQLite database. When the phone changes its state after receiving a call then the receiver notices the state change and saves the call into the SQLite database.
How to create a Broadcast Receiver
There are two ways to register and create a Broadcast Receiver. The first way is by the Android Manifest.xml file.
  1. <receiver
  2. android:name="BatteryChanged">
  3. <intent-filter >
  4. <action android:name="android.intent.action.BATTERY_CHANGED"/>
  5. </intent-filter>
  6. </receiver>
In Java file
On firing of the action android:name="android.intent.action.BATTERY_CHANGED" the onRecieve method will automatically call:
  1. public class BatteryCheck extends BroadcastReceiver
  2. {
  3. public void onRecieve(Context context,Intent intent)
  4. {
  5. //Battery status will be received
  6. }
  7. }
Second way is to register dynamically
  1. private BroadcastReceiver reciever=new BatteryChange();
  2. private IntentFilter filter=new IntentFilter(Intent.ACTION_BATTERY_CHANGED);
  3. this.registerReciever(receiver,filter);
  4. public class BatteryChange extends BroadcastReceiver
  5. {
  6. public void onReceive(Context context,Intent intent)
  7. {
  9. }
  10. }
How to create a custom event and BroadcastReciever
Register a BroadcastReciever in the Android menifest.xml file like this:
  1. <receiver
  2. android:name="Reciever">
  3. <intent-filter>
  4. <action android:name="ax.example.mybroadcast"/>
  5. </intent-filter>
  6. </receiver>
Create a Java file and write this:
  1. class Reciever extends BroadcastReceiver
  2. {
  3. public void onRecieve(Context context,Intent intent)
  4. {
  6. }
  7. }
Send Broadcast event
Send a broadcast event using the following:
  1. Intent intent = new Intent();
  2. intent.setAction("ax.example.myBroadcast");
  3. sendBroadCast(intent);
Another way to define a receiver
  1. public class RecieverExample extends Activity
  2. {
  3. private BroadcastReceiver receiver = new BroadcastReceiver()
  4. {
  5. @Override
  6. public void onReceive(Context context, Intent intent) {}
  7. };
  8. private IntentFilter filter = new IntentFilter(Intent.ACTION_CONFIGURATION_CHANGED);
  9. @Override
  10. public void onCreate(Bundle savedInstanceState)
  11. {
  12. super.onCreate(savedInstanceState);
  13. setContentView(R.layout.activity_main);
  14. }
  15. @Override
  16. protected void onResume()
  17. {
  18. this.registerReceiver(receiver, filter);
  19. super.onResume();
  20. }
  21. @Override
  22. protected void onPause()
  23. {
  24. this.unregisterReceiver(receiver);
  25. super.onPause();
  26. }
  27. }
Image of BroadcastReciever
android_broadcast_intent.jpg