- update dependancy.

app/build.gradle

@@ -9,14 +9,14 @@ apply plugin: 'com.google.gms.google-services'
 apply plugin: 'kotlin-kapt'
 
 android {
-    compileSdkVersion 28
-    dataBinding {
-        enabled = true
+    compileSdkVersion 29
+    buildFeatures{
+        dataBinding = true
     }
     defaultConfig {
         applicationId "com.libandexample"
         minSdkVersion 21
-        targetSdkVersion 28
+        targetSdkVersion 29
         versionCode 1
         versionName "1.0"
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
@@ -29,7 +29,7 @@ android {
             proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
         }
     }
-    buildToolsVersion '28.0.3'
+    buildToolsVersion '29.0.2'
     compileOptions {
         sourceCompatibility JavaVersion.VERSION_1_8
         targetCompatibility JavaVersion.VERSION_1_8
@@ -55,52 +55,52 @@ dependencies {
     implementation 'androidx.multidex:multidex:2.0.1'
 
     implementation 'androidx.legacy:legacy-support-v4:1.0.0'
-    implementation 'androidx.appcompat:appcompat:1.1.0-beta01'
-    implementation 'androidx.constraintlayout:constraintlayout:2.0.0-beta2'
-    implementation 'androidx.room:room-runtime:2.1.0'
-    annotationProcessor 'androidx.room:room-compiler:2.1.0'
-    testImplementation 'androidx.room:room-testing:2.1.0'
+    implementation 'androidx.appcompat:appcompat:1.2.0-alpha01'
+    implementation 'androidx.constraintlayout:constraintlayout:2.0.0-beta4'
+    implementation 'androidx.room:room-runtime:2.2.3'
+    annotationProcessor 'androidx.room:room-compiler:2.2.3'
+    testImplementation 'androidx.room:room-testing:2.2.3'
 
-    implementation 'androidx.lifecycle:lifecycle-extensions:2.2.0-alpha01'
-    implementation 'androidx.lifecycle:lifecycle-common-java8:2.2.0-alpha01'
-    implementation 'androidx.lifecycle:lifecycle-reactivestreams:2.2.0-alpha01'
-    testImplementation 'androidx.arch.core:core-testing:2.0.1'
+    implementation 'androidx.lifecycle:lifecycle-extensions:2.2.0-rc03'
+    implementation 'androidx.lifecycle:lifecycle-common-java8:2.2.0-rc03'
+    implementation 'androidx.lifecycle:lifecycle-reactivestreams:2.2.0-rc03'
+    testImplementation 'androidx.arch.core:core-testing:2.1.0'
 
     implementation 'com.google.android.gms:play-services-maps:17.0.0'
 
     implementation 'androidx.cardview:cardview:1.0.0'
-    implementation 'androidx.recyclerview:recyclerview:1.1.0-alpha06'
-    implementation 'com.google.android.material:material:1.1.0-alpha07'
+    implementation 'androidx.recyclerview:recyclerview:1.2.0-alpha01'
+    implementation 'com.google.android.material:material:1.2.0-alpha03'
 
 
-    implementation 'com.google.firebase:firebase-core:17.0.0'
-    implementation 'com.google.firebase:firebase-auth:18.0.0'
-    implementation 'com.google.firebase:firebase-database:18.0.0'
-    implementation 'com.google.firebase:firebase-messaging:19.0.0'
-    implementation 'com.google.firebase:firebase-auth:18.0.0'
+    implementation 'com.google.firebase:firebase-core:17.2.1'
+    implementation 'com.google.firebase:firebase-auth:19.2.0'
+    implementation 'com.google.firebase:firebase-database:19.2.0'
+    implementation 'com.google.firebase:firebase-messaging:20.1.0'
+    implementation 'com.google.firebase:firebase-auth:19.2.0'
 
 
-    implementation 'org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.3.40'
-    implementation 'androidx.constraintlayout:constraintlayout:2.0.0-beta2'
-    implementation 'com.google.android.material:material:1.1.0-alpha07'
+    implementation 'org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.3.61'
+    implementation 'androidx.constraintlayout:constraintlayout:2.0.0-beta4'
+    implementation 'com.google.android.material:material:1.2.0-alpha03'
 
     // architecture components
-    implementation 'androidx.lifecycle:lifecycle-extensions:2.2.0-alpha01'
-    implementation 'androidx.lifecycle:lifecycle-runtime:2.2.0-alpha01'
-    implementation 'androidx.room:room-runtime:2.1.0'
-    implementation 'androidx.paging:paging-runtime:2.1.0'
-    kapt 'androidx.room:room-compiler:2.1.0'
+    implementation 'androidx.lifecycle:lifecycle-extensions:2.2.0-rc03'
+    implementation 'androidx.lifecycle:lifecycle-runtime:2.2.0-rc03'
+    implementation 'androidx.room:room-runtime:2.2.3'
+    implementation 'androidx.paging:paging-runtime:2.1.1'
+    kapt 'androidx.room:room-compiler:2.2.3'
 
     // retrofit
-    implementation 'com.squareup.retrofit2:retrofit:2.6.0'
-    implementation 'com.squareup.retrofit2:converter-gson:2.6.0'
-    implementation 'com.squareup.retrofit2:retrofit-mock:2.6.0'
-    implementation 'com.squareup.okhttp3:logging-interceptor:3.14.2'
+    implementation 'com.squareup.retrofit2:retrofit:2.7.1'
+    implementation 'com.squareup.retrofit2:converter-gson:2.7.1'
+    implementation 'com.squareup.retrofit2:retrofit-mock:2.7.1'
+    implementation 'com.squareup.okhttp3:logging-interceptor:4.3.1'
 
     // testing
-    testImplementation 'junit:junit:4.13-beta-3'
-    androidTestImplementation 'androidx.test:runner:1.3.0-alpha01'
-    androidTestImplementation 'androidx.test.espresso:espresso-core:3.3.0-alpha01'
+    testImplementation 'junit:junit:4.13'
+    androidTestImplementation 'androidx.test:runner:1.3.0-alpha03'
+    androidTestImplementation 'androidx.test.espresso:espresso-core:3.3.0-alpha03'
 
 
 }

app/src/main/java/com/libandexample/courses/udemy/kotlin/noteapp/AddNotes.kt

@@ -17,11 +17,16 @@ class AddNotes : AppCompatActivity() {
 
 
        try{
-           val bundle:Bundle=intent.extras
-           id=bundle.getInt("ID",0)
+           val bundle: Bundle? =intent.extras
+           if (bundle != null) {
+               id=bundle.getInt("ID",0)
+           }
            if(id!=0) {
-               etTitle.setText(bundle.getString("name") )
-               etDes.setText(bundle.getString("des") )
+               if (bundle != null) {
+                   etTitle.setText(bundle.getString("name") )
+                   etDes.setText(bundle.getString("des") )
+               }
+
 
            }
        }catch (ex:Exception){}

app/src/main/java/com/libandexample/tutorials/simplifiedcoding/androidnotificationtutorial/MyFirebaseMessagingService.kt

@@ -5,12 +5,14 @@ import com.google.firebase.messaging.RemoteMessage
 
 class MyFirebaseMessagingService : FirebaseMessagingService() {
 
-    override fun onMessageReceived(remoteMessage: RemoteMessage?) {
-        super.onMessageReceived(remoteMessage)
+    override fun onMessageReceived(p0: RemoteMessage) {
+        if (p0 != null) {
+            super.onMessageReceived(p0)
+        }
 
-        if (remoteMessage!!.notification != null) {
-            val title = remoteMessage.notification!!.title
-            val body = remoteMessage.notification!!.body
+        if (p0!!.notification != null) {
+            val title = p0.notification!!.title
+            val body = p0.notification!!.body
 
             NotificationHelper.displayNotification(applicationContext, title!!, body!!)
         }

build.gradle

@@ -6,9 +6,9 @@ buildscript {
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.5.0-beta04'
-        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:1.3.40"
-        classpath 'com.google.gms:google-services:4.2.0'
+        classpath 'com.android.tools.build:gradle:4.0.0-alpha08'
+        classpath 'org.jetbrains.kotlin:kotlin-gradle-plugin:1.3.61'
+        classpath 'com.google.gms:google-services:4.3.3'
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
-#Wed May 22 15:31:01 EET 2019
+#Tue Jan 14 12:45:38 EET 2020
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-5.4.1-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.1-rc-1-all.zip