Alarm Manager Example in Android

 

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<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"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/btn_start_alarm"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:text="Start Alarm"
        android:textAllCaps="false"/>

</RelativeLayout>


MainActivity.java

import androidx.appcompat.app.AppCompatActivity;

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.Button;

public class MainActivity extends AppCompatActivity {

    private Button mBtnStart;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        mBtnStart = findViewById(R.id.btn_start_alarm);

        mBtnStart.setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View view) {

                startAlarm(MainActivity.this);

            }

        });

    }

    public static void startAlarm(Context context) {

        Intent intent = new Intent(context, MyAlarmReceiver.class);

        PendingIntent pendingIntent = PendingIntent.getBroadcast(

                context.getApplicationContext(), 0 , intent, 0);

        AlarmManager alarmManager = (AlarmManager) context.getSystemService(ALARM_SERVICE);

        alarmManager.set(AlarmManager.RTC_WAKEUP, System.currentTimeMillis()

                + (10 * 1000), pendingIntent); //10 seconds interval

    }

}

MyAlarmReceiver.java

import android.content.BroadcastReceiver;

import android.content.Context;

import android.content.Intent;

import android.widget.Toast;

public class MyAlarmReceiver extends BroadcastReceiver {

    @Override

    public void onReceive(Context context, Intent intent) {

        Toast.makeText(context, "Alarm Started Successfully", Toast.LENGTH_SHORT).show();

    }

}  

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

    package="com.surabhiglobal.alarmexample">

    <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />

    <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.AlarmExample">

        <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=".MyAlarmReceiver" />

    </application>

</manifest>

Foreground Service Example in Android

 

 

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout 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:orientation="vertical"

    tools:context=".MainActivity">

    <Button

        android:id="@+id/btn_start"

        android:layout_width="match_parent"

        android:layout_height="wrap_content"

        android:text="Start Service"

        android:layout_margin="20sp"/>

    <Button

        android:id="@+id/btn_stop"

        android:layout_width="match_parent"

        android:layout_height="wrap_content"

        android:text="Stop Service"

        android:layout_margin="20sp"/>

</LinearLayout>

MainActivity.java

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;

import android.os.Bundle;

import android.view.View;

import android.widget.Button;

public class MainActivity extends AppCompatActivity {

    private Button btn_start,btn_stop;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        btn_start = findViewById(R.id.btn_start);

        btn_stop = findViewById(R.id.btn_stop);

        btn_start.setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View v) {

                startService(new Intent(MainActivity.this,ForegroundService.class));

            }

        });

        btn_stop.setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View v) {

                stopService(new Intent(MainActivity.this,ForegroundService.class));

            }

        });

    }

}

ForegroundService.java

import android.app.NotificationChannel;

import android.app.NotificationManager;

import android.app.PendingIntent;

import android.app.Service;

import android.content.Intent;

import android.os.Binder;

import android.os.Build;

import android.os.IBinder;

import androidx.core.app.NotificationCompat;

public class ForegroundService extends Service {

    private final IBinder mBinder = new MyBinder();

    private static final String CHANNEL_ID = "2";

    @Override

    public IBinder onBind(Intent intent) {

        return mBinder;

    }

    @Override

    public int onStartCommand(Intent intent, int flags, int startId) {

        return START_STICKY;

    }

    @Override

    public void onCreate() {

        super.onCreate();

        buildNotification();

    }

    private void buildNotification() {

        String stop = "stop";

        PendingIntent broadcastIntent = PendingIntent.getBroadcast(

                this, 0, new Intent(stop), PendingIntent.FLAG_UPDATE_CURRENT);

        // Create the persistent notification

        NotificationCompat.Builder builder = new NotificationCompat.Builder(this, CHANNEL_ID)

                .setContentTitle(getString(R.string.app_name))

                .setContentText("Foreground service is working")

                .setOngoing(true)

                .setContentIntent(broadcastIntent);

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {

            NotificationChannel channel = new NotificationChannel(CHANNEL_ID, getString(R.string.app_name),

                    NotificationManager.IMPORTANCE_DEFAULT);

            channel.setShowBadge(false);

            channel.setDescription("Foreground service is working");

            channel.setSound(null, null);

            NotificationManager manager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);

            manager.createNotificationChannel(channel);

        }

        startForeground(1, builder.build());

    }

    public class MyBinder extends Binder {

        public ForegroundService getService() {

            return ForegroundService.this;

        }

    }

}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

    package="com.surabhiglobal.foregroundserviceexample">

    <uses-permission android:name="android.permission.FOREGROUND_SERVICE"/>

    <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.ForegroundServiceExample">

        <activity

            android:name=".MainActivity"

            android:configChanges="orientation|screenSize">

            <intent-filter>

                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />

            </intent-filter>

        </activity>

        <service

            android:name=".ForegroundService"

            android:enabled="true"

            android:exported="false"/>

    </application>

</manifest>

Background location tracking in android even if the app get closed

  

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout 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:orientation="vertical"

    tools:context=".MainActivity">

    <Button

        android:id="@+id/btn_get"

        android:layout_width="match_parent"

        android:layout_height="wrap_content"

        android:text="Get Location"

        android:layout_margin="20sp"/>

</LinearLayout>

MainActivity.java

import androidx.appcompat.app.AppCompatActivity;

import android.Manifest;

import android.app.AlertDialog;

import android.content.Context;

import android.content.DialogInterface;

import android.content.Intent;

import android.content.IntentSender;

import android.location.LocationManager;

import android.net.Uri;

import android.os.Bundle;

import android.provider.Settings;

import android.view.View;

import android.widget.Button;

import com.google.android.gms.common.api.ResolvableApiException;

import com.google.android.gms.location.LocationRequest;

import com.google.android.gms.location.LocationServices;

import com.google.android.gms.location.LocationSettingsRequest;

import com.google.android.gms.location.LocationSettingsResponse;

import com.karumi.dexter.Dexter;

import com.karumi.dexter.MultiplePermissionsReport;

import com.karumi.dexter.PermissionToken;

import com.karumi.dexter.listener.PermissionRequest;

import com.karumi.dexter.listener.multi.MultiplePermissionsListener;

import java.util.List;

public class MainActivity extends AppCompatActivity {

    private Button btn_get;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        final LocationManager manager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);

        btn_get = findViewById(R.id.btn_get);

        btn_get.setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View v) {

                if (!manager.isProviderEnabled(LocationManager.GPS_PROVIDER)) {

                    enableLocationSettings();

                } else {

                    requestAppPermissions();

                }

            }

        });

    }

    private void requestAppPermissions() {

        Dexter.withActivity(MainActivity.this)

                .withPermissions(

                        Manifest.permission.ACCESS_FINE_LOCATION,

                        Manifest.permission.ACCESS_COARSE_LOCATION)

                .withListener(new MultiplePermissionsListener() {

                    @Override

                    public void onPermissionsChecked(MultiplePermissionsReport report) {

                        // check if all permissions are granted

                        if (report.areAllPermissionsGranted()) {

                            // do you work now

                            //interact.downloadImage(array);

                            startService(new Intent(MainActivity.this, ForegroundService.class));

                        }

                        // check for permanent denial of any permission

                        if (report.isAnyPermissionPermanentlyDenied()) {

                            // permission is denied permenantly, navigate user to app settings

                            showSettingsDialog();

                            //finish();

                        }

                    }

                    @Override

                    public void onPermissionRationaleShouldBeShown(List<PermissionRequest> permissions, PermissionToken token) {

                        token.continuePermissionRequest();

                    }

                })

                .onSameThread()

                .check();

    }

    private void showSettingsDialog() {

        AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);

        builder.setTitle("Need Permissions");

        builder.setMessage("This app needs permission to use this feature. You can grant them in app settings.");

        builder.setPositiveButton("GOTO SETTINGS", new DialogInterface.OnClickListener() {

            @Override

            public void onClick(DialogInterface dialog, int which) {

                dialog.cancel();

                openSettings();

            }

        });

        builder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {

            @Override

            public void onClick(DialogInterface dialog, int which) {

                dialog.cancel();

            }

        });

        builder.show();

    }

    private void openSettings() {

        Intent intent = new Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);

        Uri uri = Uri.fromParts("package", getPackageName(), null);

        intent.setData(uri);

        startActivityForResult(intent, 101);

    }

    protected void enableLocationSettings() {

        LocationRequest locationRequest = LocationRequest.create()

                .setInterval(1000)

                .setFastestInterval(3000)

                .setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);

        LocationSettingsRequest.Builder builder = new LocationSettingsRequest.Builder()

                .addLocationRequest(locationRequest);

        LocationServices

                .getSettingsClient(this)

                .checkLocationSettings(builder.build())

                .addOnSuccessListener(this, (LocationSettingsResponse response) -> {

                    // startUpdatingLocation(...);

                })

                .addOnFailureListener(this, ex -> {

                    if (ex instanceof ResolvableApiException) {

                        // Location settings are NOT satisfied,  but this can be fixed  by showing the user a dialog.

                        try {

                            // Show the dialog by calling startResolutionForResult(),  and check the result in onActivityResult().

                            ResolvableApiException resolvable = (ResolvableApiException) ex;

                            resolvable.startResolutionForResult(this, 123);

                        } catch (IntentSender.SendIntentException sendEx) {

                            // Ignore the error.

                        }

                    }

                });

    }

}

ForegroundService.java

import android.Manifest;

import android.app.NotificationChannel;

import android.app.NotificationManager;

import android.app.PendingIntent;

import android.app.Service;

import android.content.Intent;

import android.content.pm.PackageManager;

import android.os.Binder;

import android.os.Build;

import android.os.IBinder;

import android.widget.Toast;

import androidx.core.app.NotificationCompat;

import androidx.core.content.ContextCompat;

import com.google.android.gms.location.FusedLocationProviderClient;

import com.google.android.gms.location.LocationCallback;

import com.google.android.gms.location.LocationRequest;

import com.google.android.gms.location.LocationResult;

import com.google.android.gms.location.LocationServices;

public class ForegroundService extends Service {

    private final IBinder mBinder = new MyBinder();

    private static final String CHANNEL_ID = "2";

    @Override

    public IBinder onBind(Intent intent) {

        return mBinder;

    }

    @Override

    public int onStartCommand(Intent intent, int flags, int startId) {

        return START_STICKY;

    }

    @Override

    public void onCreate() {

        super.onCreate();

        buildNotification();

        requestLocationUpdates();

    }

    private void buildNotification() {

        String stop = "stop";

        PendingIntent broadcastIntent = PendingIntent.getBroadcast(

                this, 0, new Intent(stop), PendingIntent.FLAG_UPDATE_CURRENT);

        // Create the persistent notification

        NotificationCompat.Builder builder = new NotificationCompat.Builder(this, CHANNEL_ID)

                .setContentTitle(getString(R.string.app_name))

                .setContentText("Location tracking is working")

                .setOngoing(true)

                .setContentIntent(broadcastIntent);

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {

            NotificationChannel channel = new NotificationChannel(CHANNEL_ID, getString(R.string.app_name),

                    NotificationManager.IMPORTANCE_DEFAULT);

            channel.setShowBadge(false);

            channel.setDescription("Location tracking is working");

            channel.setSound(null, null);

            NotificationManager manager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);

            manager.createNotificationChannel(channel);

        }

        startForeground(1, builder.build());

    }

    private void requestLocationUpdates() {

        LocationRequest request = new LocationRequest();

        request.setInterval(1000);

        request.setFastestInterval(3000);

        request.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);

        FusedLocationProviderClient client = LocationServices.getFusedLocationProviderClient(this);

        int permission = ContextCompat.checkSelfPermission(this,

                Manifest.permission.ACCESS_FINE_LOCATION);

        if (permission == PackageManager.PERMISSION_GRANTED) {

            // Request location updates and when an update is

            // received, store the location in Firebase

            client.requestLocationUpdates(request, new LocationCallback() {

                @Override

                public void onLocationResult(LocationResult locationResult) {

                    String location = "Latitude : " + locationResult.getLastLocation().getLatitude() +

                            "\nLongitude : " + locationResult.getLastLocation().getLongitude();

                    Toast.makeText(ForegroundService.this, location, Toast.LENGTH_SHORT).show();

                }

            }, null);

        } else {

            stopSelf();

        }

    }

    public class MyBinder extends Binder {

        public ForegroundService getService() {

            return ForegroundService.this;

        }

    }

}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

    package="com.surabhiglobal.foregroundserviceexample">

    <uses-permission android:name="android.permission.FOREGROUND_SERVICE"/>

    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />

    <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.ForegroundServiceExample">

        <activity

            android:name=".MainActivity"

            android:configChanges="orientation|screenSize">

            <intent-filter>

                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />

            </intent-filter>

        </activity>

        <service

            android:name=".ForegroundService"

            android:enabled="true"

            android:exported="false"/>

    </application>

</manifest>

build.gradle (app level file)

plugins {

    id 'com.android.application'

}

android {

    compileSdkVersion 30

    buildToolsVersion "30.0.3"

    defaultConfig {

        applicationId "com.surabhiglobal.foregroundserviceexample"

        minSdkVersion 16

        targetSdkVersion 30

        versionCode 1

        versionName "1.0"

        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"

    }

    buildTypes {

        release {

            minifyEnabled false

            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'

        }

    }

    compileOptions {

        sourceCompatibility JavaVersion.VERSION_1_8

        targetCompatibility JavaVersion.VERSION_1_8

    }

}

dependencies {

    implementation 'androidx.appcompat:appcompat:1.2.0'

    implementation 'com.google.android.material:material:1.3.0'

    implementation 'androidx.constraintlayout:constraintlayout:2.0.4'

    testImplementation 'junit:junit:4.13.2'

    androidTestImplementation 'androidx.test.ext:junit:1.1.2'

    androidTestImplementation 'androidx.test.espresso:espresso-core:3.3.0'

    //add this two dependencies

    implementation 'com.google.android.gms:play-services-location:18.0.0'

    implementation 'com.karumi:dexter:4.2.0'

}

Capture photos in android without opening camera

 

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>

<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"

    tools:context=".MainActivity">

    <LinearLayout

        android:layout_width="match_parent"

        android:layout_height="wrap_content"

        android:orientation="horizontal"

        android:weightSum="2"

        android:layout_margin="10dp">

        <Button

            android:id="@+id/btn_front"

            android:layout_width="0dp"

            android:layout_height="wrap_content"

            android:layout_weight="1"

            android:text="Front Camera"

            android:layout_marginEnd="10dp" />

        <Button

            android:id="@+id/btn_back"

            android:layout_width="0dp"

            android:layout_height="wrap_content"

            android:layout_weight="1"

            android:text="Back Camera" />

    </LinearLayout>

    <ImageView

        android:id="@+id/iv_image"

        android:layout_width="250dp"

        android:layout_height="250dp"

        android:layout_centerInParent="true"/>

</RelativeLayout>

MainActivity.java

package com.surabhiglobal.example;

import android.Manifest;

import android.app.AlertDialog;

import android.content.DialogInterface;

import android.content.Intent;

import android.graphics.Bitmap;

import android.graphics.BitmapFactory;

import android.graphics.SurfaceTexture;

import android.hardware.Camera;

import android.net.Uri;

import android.os.Bundle;

import android.provider.Settings;

import android.util.Log;

import android.view.View;

import android.widget.Button;

import android.widget.ImageView;

import androidx.appcompat.app.AppCompatActivity;

import com.karumi.dexter.Dexter;

import com.karumi.dexter.MultiplePermissionsReport;

import com.karumi.dexter.PermissionToken;

import com.karumi.dexter.listener.PermissionRequest;

import com.karumi.dexter.listener.multi.MultiplePermissionsListener;

import java.util.List;

public class MainActivity extends AppCompatActivity {

    private Button btn_front, btn_back;

    private String TAG = MainActivity.class.getName();

    private ImageView iv_image;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        btn_front = findViewById(R.id.btn_front);

        btn_back = findViewById(R.id.btn_back);

        iv_image = findViewById(R.id.iv_image);

        btn_front.setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View v) {

                requestAppPermissions("1");

            }

        });

        btn_back.setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View v) {

                requestAppPermissions("0");

            }

        });

    }

    private void requestAppPermissions(String type) {

        Dexter.withActivity(MainActivity.this)

                .withPermissions(

                        Manifest.permission.CAMERA)

                .withListener(new MultiplePermissionsListener() {

                    @Override

                    public void onPermissionsChecked(MultiplePermissionsReport report) {

                        if (report.areAllPermissionsGranted()) {

                            if (type.equals("0")) {

                                CaptureBackPhoto();

                            } else {

                                CaptureFrontPhoto();

                            }

                        }

                        // check for permanent denial of any permission

                        if (report.isAnyPermissionPermanentlyDenied()) {

                            // permission is denied permenantly, navigate user to app settings

                            showSettingsDialog();

                        }

                    }

                    @Override

                    public void onPermissionRationaleShouldBeShown(List<PermissionRequest> permissions, PermissionToken token) {

                        token.continuePermissionRequest();

                    }

                })

                .onSameThread()

                .check();

    }

    private void showSettingsDialog() {

        AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);

        builder.setTitle("Need Permissions");

        builder.setMessage("This app needs permission to use this feature. You can grant them in app settings.");

        builder.setPositiveButton("GOTO SETTINGS", new DialogInterface.OnClickListener() {

            @Override

            public void onClick(DialogInterface dialog, int which) {

                dialog.cancel();

                openSettings();

            }

        });

        builder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {

            @Override

            public void onClick(DialogInterface dialog, int which) {

                dialog.cancel();

            }

        });

        builder.show();

    }

    private void openSettings() {

        Intent intent = new Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);

        Uri uri = Uri.fromParts("package", getPackageName(), null);

        intent.setData(uri);

        startActivityForResult(intent, 101);

    }

    private void CaptureFrontPhoto() {

        Log.d(TAG, "Preparing to take photo");

        Camera camera = null;

        Camera.CameraInfo cameraInfo = new Camera.CameraInfo();

        int frontCamera = 1;

        //int backCamera=0;

        Camera.getCameraInfo(frontCamera, cameraInfo);

        try {

            camera = Camera.open(frontCamera);

            camera.enableShutterSound(false);

        } catch (RuntimeException e) {

            Log.d(TAG, "Camera not available: " + 1);

            camera = null;

            //e.printStackTrace();

        }

        try {

            if (null == camera) {

                Log.d(TAG, "Could not get camera instance");

            } else {

                Log.d(TAG, "Got the camera, creating the dummy surface texture");

                try {

                    camera.setPreviewTexture(new SurfaceTexture(0));

                    camera.startPreview();

                } catch (Exception e) {

                    Log.d(TAG, "Could not set the surface preview texture");

                    e.printStackTrace();

                }

                camera.takePicture(null, null, new Camera.PictureCallback() {

                    @Override

                    public void onPictureTaken(byte[] data, Camera camera) {

                        try {

                            Bitmap bmp = BitmapFactory.decodeByteArray(data, 0, data.length);

                            iv_image.setImageBitmap(bmp);

                        } catch (Exception e) {

                            System.out.println(e.getMessage());

                        }

                        camera.release();

                    }

                });

            }

        } catch (Exception e) {

            camera.release();

        }

    }

    private void CaptureBackPhoto() {

        Log.d(TAG, "Preparing to take photo");

        Camera camera = null;

        try {

            camera = Camera.open();

            camera.enableShutterSound(false);

        } catch (RuntimeException e) {

            Log.d(TAG, "Camera not available: " + 1);

            camera = null;

            //e.printStackTrace();

        }

        try {

            if (null == camera) {

                Log.d(TAG, "Could not get camera instance");

            } else {

                Log.d(TAG, "Got the camera, creating the dummy surface texture");

                try {

                    camera.setPreviewTexture(new SurfaceTexture(0));

                    camera.startPreview();

                } catch (Exception e) {

                    Log.d(TAG, "Could not set the surface preview texture");

                    e.printStackTrace();

                }

                camera.takePicture(null, null, new Camera.PictureCallback() {

                    @Override

                    public void onPictureTaken(byte[] data, Camera camera) {

                        try {

                            Bitmap bmp = BitmapFactory.decodeByteArray(data, 0, data.length);

                            iv_image.setImageBitmap(bmp);

                        } catch (Exception e) {

                            System.out.println(e.getMessage());

                        }

                        camera.release();

                    }

                });

            }

        } catch (Exception e) {

            camera.release();

        }

    }

}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

    package="com.surabhiglobal.example">

    <uses-permission android:name="android.permission.CAMERA"/>

    <uses-feature android:name="android.hardware.camera" />

    <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.ForegroundServiceExample">

        <activity

            android:name=".MainActivity"

            android:configChanges="orientation|screenSize">

            <intent-filter>

                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />

            </intent-filter>

        </activity>

    </application>

</manifest>

build.gradle (app level file)

plugins {

    id 'com.android.application'

}

android {

    compileSdkVersion 30

    buildToolsVersion "30.0.3"

    defaultConfig {

        applicationId "com.surabhiglobal.example"

        minSdkVersion 17

        targetSdkVersion 30

        versionCode 1

        versionName "1.0"

        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"

    }

    buildTypes {

        release {

            minifyEnabled false

            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'

        }

    }

    compileOptions {

        sourceCompatibility JavaVersion.VERSION_1_8

        targetCompatibility JavaVersion.VERSION_1_8

    }

}

dependencies {

    implementation 'androidx.appcompat:appcompat:1.2.0'

    implementation 'com.google.android.material:material:1.3.0'

    implementation 'androidx.constraintlayout:constraintlayout:2.0.4'

    testImplementation 'junit:junit:4.13.2'

    androidTestImplementation 'androidx.test.ext:junit:1.1.2'

    androidTestImplementation 'androidx.test.espresso:espresso-core:3.3.0'

    //add this dependency

    implementation 'com.karumi:dexter:4.2.0'

}

Keyboard Shortcut for Android Studio in Windows & Mac Osx

By using keyboard shortcuts of Android Studio you can increase the productivity and you can do so many tasks in short period of time.

Here you can see some of the shortcuts of android studio in windows and Mac.

Please comment shortcuts whatever i missed here.

thanking you..

Description	Windows/Linux	Mac
General
Save all	Control + S	Command + S
Synchronize	Control + Alt + Y	Command + Option + Y
Maximize/minimize editor	Control + Shift + F12	Control + Command + F12
Add to favorites	Alt + Shift + F	Option + Shift + F
Inspect current file with current profile	Alt + Shift + I	Option + Shift + I
Quick switch scheme	Control + ` (backquote)	Control + ` (backquote)
Open settings dialogue	Control + Alt + S	Command + , (comma)
Open project structure dialog	Control + Alt + Shift + S	Command + ; (semicolon)
Switch between tabs and tool window	Control + Tab	Control + Tab
Navigating and Searching Within Studio
Search everything (including code and menus)	Press Shift twice	Press Shift twice
Find	Control + F	Command + F
Find next	F3	Command + G
Find previous	Shift + F3	Command + Shift + G
Replace	Control + R	Command + R
Find action	Control + Shift + A	Command + Shift + A
Search by symbol name	Control + Alt + Shift + N	Command + Option + O
Find class	Control + N	Command + O
Find file (instead of class)	Control + Shift + N	Command + Shift + O
Find in path	Control + Shift + F	Command + Shift + F
Open file structure pop-up	Control + F12	Command + F12
Navigate between open editor tabs	Alt + Right/Left Arrow	Control + Right/Left Arrow
Jump to source	F4 / Control + Enter	F4 / Command + Down Arrow
Open current editor tab in new window	Shift + F4	Shift + F4
Recently opened files pop-up	Control + E	Command + E
Recently edited files pop-up	Control + Shift + E	Command + Shift + E
Go to last edit location	Control + Shift + Backspace	Command + Shift + Backspace
Close active editor tab	Control + F4	Command + W
Return to editor window from a tool window	Esc	Esc
Hide active or last active tool window	Shift + Esc	Shift + Esc
Go to line	Control + G	Command + L
Open type hierarchy	Control + H	Control + H
Open method hierarchy	Control + Shift + H	Command + Shift + H
Open call hierarchy	Control + Alt + H	Control + Option + H
Writing Code
Generate code (getters, setters, constructors, hashCode/equals, toString, new file, new class)	Alt + Insert	Command + N
Override methods	Control + O	Control + O
Implement methods	Control + I	Control + I
Surround with (if…else / try…catch / etc.)	Control + Alt + T	Command + Option + T
Delete line at caret	Control + Y	Command + Backspace
Collapse/expand current code block	Control + minus/plus	Command + minus/plus
Collapse/expand all code blocks	Control + Shift + minus/plus	Command + Shift + minus/plus
Duplicate current line or selection	Control + D	Command + D
Basic code completion	Control + Space	Control + Space
Smart code completion (filters the list of methods and variables by expected type)	Control + Shift + Space	Control + Shift + Space
Complete statement	Control + Shift + Enter	Command + Shift + Enter
Quick documentation lookup	Control + Q	Control + J
Show parameters for selected method	Control + P	Command + P
Go to declaration (directly)	Control + B or Control + Click	Command + B or Command + Click
Go to implementations	Control + Alt + B	Command + Alt + B
Go to super-method/super-class	Control + U	Command + U
Open quick definition lookup	Control + Shift + I	Command + Y
Toggle project tool window visibility	Alt + 1	Command + 1
Toggle bookmark	F11	F3
Toggle bookmark with mnemonic	Control + F11	Option + F3
Comment/uncomment with line comment	Control + /	Command + /
Comment/uncomment with block comment	Control + Shift + /	Command + Shift + /
Select successively increasing code blocks	Control + W	Option + Up
Decrease current selection to previous state	Control + Shift + W	Option + Down
Move to code block start	Control + [	Option + Command + [
Move to code block end	Control + ]	Option + Command + ]
Select to the code block start	Control + Shift + [	Option + Command + Shift + [
Select to the code block end	Control + Shift + ]	Option + Command + Shift + ]
Delete to end of word	Control + Delete	Option + Delete
Delete to start of word	Control + Backspace	Option + Backspace
Optimize imports	Control + Alt + O	Control + Option + O
Project quick fix (show intention actions and quick fixes)	Alt + Enter	Option + Enter
Reformat code	Control + Alt + L	Command + Option + L
Auto-indent lines	Control + Alt + I	Control + Option + I
Indent/unindent lines	Tab/Shift + Tab	Tab/Shift + Tab
Smart line join	Control + Shift + J	Control + Shift + J
Smart line split	Control + Enter	Command + Enter
Start new line	Shift + Enter	Shift + Enter
Next/previous highlighted error	F2 / Shift + F2	F2 / Shift + F2
Build and Run
Build	Control + F9	Command + F9
Build and run	Shift + F10	Control + R
Apply changes (with Instant Run)	Control + F10	Control + Command + R
Debugging
Debug	Shift + F9	Control + D
Step over	F8	F8
Step into	F7	F7
Smart step into	Shift + F7	Shift + F7
Step out	Shift + F8	Shift + F8
Run to cursor	Alt + F9	Option + F9
Evaluate expression	Alt + F8	Option + F8
Resume program	F9	Command + Option + R
Toggle breakpoint	Control + F8	Command + F8
View breakpoints	Control + Shift + F8	Command + Shift + F8
Refactoring
Copy	F5	F5
Move	F6	F6
Safe delete	Alt + Delete	Command + Delete
Rename	Shift + F6	Shift + F6
Change signature	Control + F6	Command + F6
Inline	Control + Alt + N	Command + Option + N
Extract method	Control + Alt + M	Command + Option + M
Extract variable	Control + Alt + V	Command + Option + V
Extract field	Control + Alt + F	Command + Option + F
Extract constant	Control + Alt + C	Command + Option + C
Extract parameter	Control + Alt + P	Command + Option + P
Version Control / Local History
Commit project to VCS	Control + K	Command + K
Update project from VCS	Control + T	Command + T
View recent changes	Alt + Shift + C	Option + Shift + C
Open VCS popup	Alt + ` (backquote)	Control + V