Develop Reference

How to Pass Data From a BroadcastReceiver to an Activity in Android

I am working on my first Android app, which is a paging device. It will intercept a SMS message from a certain number with a certain content in it, display that and then allow the user to send a pre-defined reply back to that same number. I have gathered up code snippets from numerous sources (including stackoverflow of course) but I haven't yet got it working.
My file structure is as shown here
The part I am struggling with is SmsBroadcastReceiver and ReceiveAlert, which should display the content of the SMS and has a button to initiate the reply.
SmsBroadcastReceiver.java looks like this:
package com.example.alert6;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.provider.Telephony;
import android.telephony.SmsMessage;
public class SmsBroadcastReceiver extends BroadcastReceiver {
public static final String EXTRA_MESSAGE = "com.example.alert6.MESSAGE";
#Override
public void onReceive(Context context, Intent intent) {
String smsSender = "";
String smsBody = "";
for (SmsMessage smsMessage : Telephony.Sms.Intents.getMessagesFromIntent(intent)) {
smsSender = smsMessage.getOriginatingAddress();
smsBody = smsMessage.getMessageBody();
}
if (smsSender.equals("+420775367297")) {
if (smsBody.contains("Test")) {
intent.putExtra(EXTRA_MESSAGE, smsBody);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK); // adding this flag starts the new Activity in a new Task
context.startActivity();
}
}
}
}
ReceiveAlertActivity.java is this:
package com.example.alert6;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;
import android.Manifest;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;
public class ReceiveAlertActivity extends AppCompatActivity {
private static final int SMS_PERMISSION_CODE = 101;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_receive_alert);
}
// Get the Intent that started this activity and extract the string
Intent intent = getIntent();
String taskingalert = intent.getStringExtra(SmsBroadcastReceiver.EXTRA_MESSAGE);
// Capture the layout's TextView and set the string as its text
TextView receivedAlert = findViewById(R.id.receivedAlert);
receivedAlert.setText(taskingalert);
public boolean respond(View view) {
if (!hasReadSmsPermission()) {
requestReadAndSendSmsPermission();
return false;
}
Intent intent = new Intent(this, SendResponseActivity.class);
startActivity(intent);
return false;
}
/**
* Runtime permission shenanigans
*/
private boolean hasReadSmsPermission() {
return (ContextCompat.checkSelfPermission(ReceiveAlertActivity.this,
Manifest.permission.READ_SMS) == PackageManager.PERMISSION_GRANTED) &&
(ContextCompat.checkSelfPermission(ReceiveAlertActivity.this,
Manifest.permission.RECEIVE_SMS) == PackageManager.PERMISSION_GRANTED) &&
(ContextCompat.checkSelfPermission(ReceiveAlertActivity.this,
Manifest.permission.SEND_SMS) == PackageManager.PERMISSION_GRANTED);
}
private void requestReadAndSendSmsPermission() {
ActivityCompat.requestPermissions(ReceiveAlertActivity.this, new String[]{Manifest.permission.READ_SMS, Manifest.permission.RECEIVE_SMS, Manifest.permission.SEND_SMS},
SMS_PERMISSION_CODE);
}
}
And the manifest is this:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
package="com.example.alert6">
<uses-permission android:name="android.permission.RECEIVE_SMS" />
<uses-permission android:name="android.permission.READ_SMS" />
<uses-permission android:name="android.permission.SEND_SMS" />
<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/Theme.Alert6">
<activity
android:name=".SendResponseActivity"
android:parentActivityName=".ReceiveAlertActivity">
</activity>
<activity
android:name=".ReceiveAlertActivity"
android:parentActivityName=".MainActivity">
</activity>
<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=".SmsBroadcastReceiver"
android:enabled="true"
android:exported="true"
tools:ignore="Instantiatable">
<intent-filter android:priority="999" >
<action android:name="android.provider.Telephony.SMS_RECEIVED" />
</intent-filter>
</receiver>
</application>
</manifest>
Android Studio is showing errors in SmsBroadcastReceiver and ReceiveAlertActivity but not giving enough information to resolve them.
In SmsBroadcastReceiver, it tells me it cannot resolve method 'startActivity()'. Something needs to go in the brackets, but what?
In ReceiveAlertActivity the problems revolve around receivedalert and taskingalert. It cannot resolve setText because taskingalert is an unknown class. Obviously it's not a class, it's a string so I'm doing something wrong, but what?
Sorting out these problems may not be the end. At the moment I can't test if the app works because the build fails due to the above. Then if I get this lot working, I have some other challenges, like waking up the screen and playing a sound the broadcast receiver is triggered, and stopping the sound when the button is pressed.

You can use an Observable object in your BroadcastReceiver to store the piece of information you want to send and implement the Observer interface in your Activity so that it will be warned of every change occuring to the Observable object.

why can't i get my call recording app to work?

I'm trying to implement an app that allows me to record the audio of calls, activating the service via a toggle button. I can't figure out what is wrong with my code as once I set the toggle button to ON and initiate the call, there is no file saved.
I don't understand if the problem is in saving (maybe I'm looking for the file in the wrong directory?), Or in the fact that it doesn't actually record.
I'm using AndroidStudio 4.0 and i'm trying my app on my Samsung S9.
Thanks in andvance for helping !
RecordService.java
package com.example.registrachiamate;
import android.app.MediaRouteButton;
import android.app.Service;
import android.content.Intent;
import android.media.MediaRecorder;
import android.os.Environment;
import android.os.IBinder;
import android.telephony.PhoneStateListener;
import android.telephony.TelephonyManager;
import android.text.format.DateFormat;
import java.io.File;
import java.io.IOException;
import java.util.Date;
public class RecordService extends Service {
private MediaRecorder rec;
private File file;
#Override
public IBinder onBind(Intent intent) {
return null;
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
//return super.onStartCommand(intent, flags, startId);
file= Environment.getExternalStorageDirectory();
Date date=new Date();
CharSequence sdf= DateFormat.format("MM-dd-yy-hh-mm--ss",date.getTime());
rec=new MediaRecorder();
rec.setAudioSource(MediaRecorder.AudioSource.MIC);
rec.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
rec.setOutputFile(file.getAbsolutePath()+"/"+sdf+"rec.3gp");
rec.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
TelephonyManager manager=(TelephonyManager) getApplicationContext().getSystemService(getApplicationContext().TELEPHONY_SERVICE);
assert manager != null;
manager.listen(new PhoneStateListener(){
#Override
public void onCallStateChanged(int state, String phoneNumber) {
//super.onCallStateChanged(state, phoneNumber) {
if (TelephonyManager.CALL_STATE_IDLE==state){
rec.stop();
rec.reset();
rec.release();
stopSelf();
}else if(TelephonyManager.CALL_STATE_OFFHOOK==state && rec==null){
try {
rec.prepare();
} catch (IOException e) {
e.printStackTrace();
}
rec.start();
}
}
},PhoneStateListener.LISTEN_CALL_STATE);
return START_STICKY;
}
}
ActivityButton1.java
package com.example.registrachiamate;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Toast;
import android.widget.ToggleButton;
import androidx.appcompat.app.AppCompatActivity;
public class ActivityButton1 extends AppCompatActivity {
ToggleButton startandoff;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.button1);
startandoff=(ToggleButton)findViewById(R.id.toggleButton);
}
public void tooglebutton(View view)
{
boolean checked=((ToggleButton)view).isChecked();
if (checked){
Intent intent=new Intent(this,RecordService.class);
startService(intent);
Toast.makeText(getApplicationContext(),"Call Record STARTED",Toast.LENGTH_SHORT).show();
}else {
Intent intent=new Intent(this,RecordService.class);
stopService(intent);
Toast.makeText(getApplicationContext(),"Call Record STOPPED",Toast.LENGTH_SHORT).show();
}
}
}
AndroidManifest.xml, if i put the RecordService, in it stops running
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
package="com.example.registrachiamate">
<uses-permission android:name="android.permission.PROCESS_OUTGOING_CALLS"/>
<uses-permission android:name="android.permission.READ_PHONE_STATE"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<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"
tools:ignore="GoogleAppIndexingWarning">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<action android:name="android.intent.action.NEW_OUTGOING_CALL"/>
<action android:name="android.intent.action.PHONE_STATE"/>
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".ActivityButton1"></activity>
<activity android:name=".ActivityButton2"></activity>
<activity android:name=".ActivityButton3"></activity>
<activity android:name=".ActivityButton4"></activity>
<activity android:name=".RecordService"></activity>
</application>
</manifest>

How to Listen for Bluetooth Headset Buttons in an Android App?

What is the proper way to handle Bluetooth media buttons in an Android app? At this point, all I want is an event to fire when I press the pause/play button on my Bluetooth headset. Somehow, I had a working solution yesterday, and today it just doesn't work. Without reinstalling the app, or any update happening on my phone, the onReceive method of my subclass of BroadcastReceiver is never entered. I'm targeting Android 9.0, since this is just for myself.
I used the information in these two questions for the solution:
How to capture key events from bluetooth headset with android
BroadcastReceiver for ACTION_MEDIA_BUTTON not working
This is a bare minimum version of what was working yesterday, which currently does not work:
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"
package="com.example.myapplication">
<uses-permission android:name="android.permission.BLUETOOTH" />
<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"
tools:ignore="GoogleAppIndexingWarning">
<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=".MediaButtonIntentReceiver">
<intent-filter android:priority="2139999999">
<action android:name="android.intent.action.MEDIA_BUTTON" />
</intent-filter>
</receiver>
</application>
</manifest>
MainActivity.java
package com.example.myapplication;
import androidx.appcompat.app.AppCompatActivity;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.media.AudioManager;
import android.os.Bundle;
public class MainActivity extends AppCompatActivity {
MediaButtonIntentReceiver mMediaButtonReceiver = new MediaButtonIntentReceiver();
IntentFilter mediaFilter = new IntentFilter(Intent.ACTION_MEDIA_BUTTON);
AudioManager mAudioManager = null;
ComponentName mReceiverComponent = null;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mAudioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
mReceiverComponent = new ComponentName(this, MediaButtonIntentReceiver.class);
mediaFilter.setPriority(2139999999);
registerReceiver(mMediaButtonReceiver, mediaFilter);
}
}
MediaButtonIntentReceiver.java
package com.example.myapplication;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.util.Log;
public class MediaButtonIntentReceiver extends BroadcastReceiver {
public MediaButtonIntentReceiver() {
super();
Log.i("mylog", "init");
}
#Override
public void onReceive(Context context, Intent intent) {
Log.i("mylog", "receive");
abortBroadcast();
}
}

Why the Broadcast receiver is not working dynamicly?

I tried to do a broadcast receiver dynamically for incoming SMS will show a toast but the app doesn't show anything.
I register the broadcast dynamically in the mainActivity like this.
MainActivity.java
package com.example.smsreader;
import android.content.Intent;
import android.content.IntentFilter;
import android.net.ConnectivityManager;
import android.support.v4.content.LocalBroadcastManager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
public class MainActivity extends AppCompatActivity {
BroadcastReader reader = new BroadcastReader();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
IntentFilter filter = new IntentFilter("android.provider.Telephony.SMS_RECEIVED");
registerReceiver(reader, filter);
}
}
This is brodcast class, the app will show a toast when the phone will receive a SMS but it doesn't
package com.example.smsreader;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.widget.Toast;
public class BroadcastReader extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
if("android.provider.Telephony.SMS_RECEIVED".equals(intent.getAction())){
Toast.makeText(context, "it is working", Toast.LENGTH_LONG).show();
}
}
}
I don't register anything in the manifest file.
Manifest file
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.smsreader">
<uses-permission android:name="android.permission.RECEIVE_SMS"/>
<uses-permission android:name="android.permission.READ_SMS"/>
<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>
</application>
</manifest>

Try the following :
intentFilter.addAction("android.provider.Telephony.SMS_RECEIVED");

You need to use the following method for registering local broadcastReceiver ;)
LocalBroadcastManager.getInstance(this).registerReceiver(reader, filter)

Android Block Incoming SMS using BroadCastReceiver

I want to block incoming SMS message as long as my application is running . I could achieve that but the problem is after I close the app or even restart or even uninstall it the user will not be able to receive SMS message anymore . So How can I make the application to block incoming SMS only when it's running and when it gets closed or uninstalled etc.. to stop blocking SMS. Here's my code :
BroadCastReceiver.Java
package com.example.sms;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.telephony.SmsMessage;
import android.widget.Toast;
public class BroadCastReceiver extends BroadcastReceiver
{
public void onReceive(Context context, Intent intent)
{
abortBroadcast();
}
}
MainActivity.java
package com.example.sms;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
}
Manifiest :
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.sms"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="19" />
<uses-permission android:name="android.permission.RECEIVE_SMS"/>
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<receiver android:name=".BroadCastReceiver">
<intent-filter android:priority="2147483647">
<action android:name="android.provider.Telephony.SMS_RECEIVED" />
</intent-filter>
</receiver>
<activity
android:name="com.example.sms.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>
</application>
</manifest>
Note: I've tested the application on android 2.2 on my android emulator "Sent SMS messages using Telnet"

Check if your app is running then only abort broadcast receiver else not
//define this variable above onReceive() with default value as false;
boolean appRunningInBack=false;
ActivityManager am = (ActivityManager) mContext.getSystemService(Activity.ACTIVITY_SERVICE);
String packageName = am.getRunningTasks(1).get(0).topActivity.getPackageName();
if(packageName.equalIgnoreCase("your app package name") || appRunningInBack)
{
appRunningInBack=true;
abortBroadCast();
} else {
}
Also add Permission in AndroidManifest.xml
<uses-permission android:name="android.permission.GET_TASKS" />
After this when your app goes in background.or while running .this variable will be true.