User Permission - Install and Run time Permission

To use sensitive feature or data of Android System or User, application must get permission of doing it. It;s the privacy of Android System User. Depend on system feature, if its not much harmful for user than get it during installation, otherwise application need to get it using popup before using the feature at run time.
We must register permission in manifest file whether it's dangerous or not.

<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android"   package="com.codeexpo.alert">   <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />   <uses-permission android:name="android.permission.CHANGE_NETWORK_STATE" />   <uses-permission android:name="android.permission.INTERNET" />   <application       android:allowBackup="true"       android:icon="@drawable/ustb_logo"       android:label="@string/app_name"       android:supportsRtl="true"       android:theme="@style/AppTheme">       <activity android:name=".SignIn">           <intent-filter>               <action android:name="android.intent.action.MAIN" />               <category android:name="android.intent.category.LAUNCHER" />           </intent-filter>       </activity>       <activity android:name=".SignUp"></activity>       <activity android:name=".ProcessActivity"></activity>       <activity           android:name=".StaffportalActivity"           android:label="@string/app_name"           android:theme="@style/AppTheme.NoActionBar"></activity>       <activity           android:name=".StudentportalActivity"           android:label="@string/app_name"           android:theme="@style/AppTheme.NoActionBar"></activity>   </application> </manifest>

We can use two type of method to implement it. We may use a the default method or a Dexter Library for implementation of dangerous permissions.

1. Use Dexter Library

Implement dependencies of Dexter Library and Sync it

dependencies {   //noinspection GradleCompatible   implementation 'com.android.support:appcompat-v7:27.1.0'   //noinspection GradleCompatible   implementation 'com.android.support:design:27.1.0'   implementation 'com.karumi:dexter:4.2.0' }

Code it for a single permission as As

Dexter.withActivity(PagerActivity.this)       .withPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE)       .withListener(new PermissionListener() {           @Override           public void onPermissionGranted(PermissionGrantedResponse response) {               //Implement the task here for which this permission is needed           }           @Override           public void onPermissionDenied(PermissionDeniedResponse response) {               // check for permanent denial of permission               if (response.isPermanentlyDenied()) {                   Intent intent = new Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS,                           Uri.parse("package:" + getPackageName()));                   intent.addCategory(Intent.CATEGORY_DEFAULT);                   intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);                   startActivity(intent);               }           }           @Override           public void onPermissionRationaleShouldBeShown(PermissionRequest permission, PermissionToken token) {               token.continuePermissionRequest();           }       }).check();

Code it for a multiple permission as As

void permissionCheck(){   Dexter.withActivity(this)           .withPermissions(                   Manifest.permission.READ_PHONE_STATE,                   Manifest.permission.READ_CONTACTS,                   Manifest.permission.READ_SMS           ).withListener(new MultiplePermissionsListener() {       @Override       public void onPermissionsChecked(MultiplePermissionsReport report) {           if (!report.areAllPermissionsGranted()) {               permissionCheck();           }           if (report.isAnyPermissionPermanentlyDenied()) {               Intent intent = new Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS,                       Uri.parse("package:" + getPackageName()));               intent.addCategory(Intent.CATEGORY_DEFAULT);               intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);               startActivity(intent);           }       }       @Override       public void onPermissionRationaleShouldBeShown(List<PermissionRequest> permissions, PermissionToken token) {           token.continuePermissionRequest();       }   }).onSameThread().check(); }

2. Default Method

In the default method, we will Manifest Class as

public class MainActivity extends Activity {   /////////////////////////////////////   String[] permissions = new String[]{           Manifest.permission.CAMERA,           Manifest.permission.CALL_PHONE,           Manifest.permission.RECEIVE_SMS,           Manifest.permission.RECEIVE_MMS,           Manifest.permission.READ_PHONE_STATE,           Manifest.permission.READ_CONTACTS,           Manifest.permission.WRITE_EXTERNAL_STORAGE,           Manifest.permission.READ_EXTERNAL_STORAGE   };   ////////////////////////////////////   @Override   protected void onCreate(Bundle savedInstanceState) {       super.onCreate(savedInstanceState);       setContentView(R.layout.main_activity);       // /////////////////////////       checkPermissions();   }   private boolean checkPermissions() {       int result;       List<String> listPermissionsNeeded = new ArrayList<>();       for (String p : permissions) {           result = ContextCompat.checkSelfPermission(this, p);           if (result != PackageManager.PERMISSION_GRANTED) {               listPermissionsNeeded.add(p);           }       }       if (!listPermissionsNeeded.isEmpty()) {           ActivityCompat.requestPermissions(this,                   listPermissionsNeeded.toArray(new String[listPermissionsNeeded.size()]), 100);           return false;       }       return true;   }   @Override   public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {       if (requestCode == 100) {           if (grantResults.length > 0                   && grantResults[0] == PackageManager.PERMISSION_GRANTED) {           } else               checkPermissions();           return;       }   } }