Email authentication

Email Authentication Using Firebase in Android

In this article, we will learn about Authentication- integrating Email authentication in Android application using firebase. If you want to integrate Email and password authentication into your Android app, you’ve come to the right place.

We’ll use the Email and Password SignIn method to implement the Firebase Authentication Android service provided by Firebase. Authentication with Firebase Backend services is provided to Android developers in order to authenticate users in their apps.

The technology used to set up service-access permissions is called Firebase authentication. It accomplishes this by utilizing Google’s Firebase APIs and Firebase console to create and manage valid user accounts. You’ll learn how to use Firebase authentication in an Android application in this tutorial.

Output:

If you don’t know what is firebase and its services then please refer to What is Firebase | All about Firebase.

Google SignIn Using Firebase in Android | Authentication

Step by step explanation:

Step 1: Go to the Main Menu and select “Tools” and after that select “Firebase”.

firebase

Step 2: Select Authentication as shown in the below figure.

firebase

Step 3: Select the option- “Authentication using custom authentication system Kotlin”.

firebase authentication

Step 4: Connect your app to firebase: First.

  • After that Add the Firebase Authentication SDK to your app as shown in figure given below:
email/password authentication

Step 5: Go to Firebase console: Enable Email/Password Authentication as shown below:

firebase console

Step 6: Enable it, Click save button as shown below.

firebase

dependency required in Google Signin

Step 8: Add this to your file build.gradle(Module:app):

//Firebase
implementation platform(‘com.google.firebase:firebase-bom:28.4.0’)
implementation ‘com.google.firebase:firebase-auth-ktx’
implementation ‘com.google.android.gms:play-services-auth:19.2.0’

Plugin required in Google Signin

Add this to your file build.gradle(Module:app):

id ‘com.google.gms.google-services’

Add dependencies in build.gradle(Project:app)

classpath ‘com.google.gms:google-services:4.3.10’

Finally, your build.gradle(Module:app) file code look like this:

plugins {
    id 'com.android.application'
    id 'kotlin-android'
    id 'com.google.gms.google-services'
}

android {
    compileSdkVersion 30
    buildToolsVersion "30.0.3"

    defaultConfig {
        applicationId "com.sagar.emailauthentication"
        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
    }
    kotlinOptions {
        jvmTarget = '1.8'
    }
}

dependencies {

    implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
    implementation 'androidx.core:core-ktx:1.6.0'
    implementation 'androidx.appcompat:appcompat:1.3.1'
    implementation 'com.google.android.material:material:1.4.0'
    implementation 'androidx.constraintlayout:constraintlayout:2.1.0'
    testImplementation 'junit:junit:4.+'
    androidTestImplementation 'androidx.test.ext:junit:1.1.3'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'

    //Firebase
    implementation platform('com.google.firebase:firebase-bom:28.4.0')
    implementation 'com.google.firebase:firebase-auth-ktx'
    implementation 'com.google.android.gms:play-services-auth:19.2.0'
}

and build.gradle(Project:app) code look like this:

// Top-level build file where you can add configuration options common to all sub-projects/modules.
buildscript {
    ext.kotlin_version = "1.5.10"
    repositories {
        google()
        mavenCentral()
    }
    dependencies {
        classpath "com.android.tools.build:gradle:4.2.2"
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
        classpath 'com.google.gms:google-services:4.3.10'

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        google()
        mavenCentral()
        jcenter() // Warning: this repository is going to shut down soon
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

Step 9: Your AndroidManifest.xml file is look like:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.sagar.emailauthentication">

    
    <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.EmailAuthentication">
        <activity android:name=".LoginActivity"></activity>
        <activity android:name=".RegisterActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name=".MainActivity">

        </activity>
    </application>

</manifest>

Step 10: Create a new activity(Empty Activity ), name it RegisterActivity, and add the code given below:

 import android.content.Intent
 import android.os.Bundle
 import android.text.TextUtils
 import android.view.Window
 import android.view.WindowManager
 import android.widget.Button
 import android.widget.TextView
 import android.widget.Toast
 import androidx.appcompat.app.AppCompatActivity
 import com.google.android.material.textfield.TextInputEditText
 import com.google.firebase.auth.FirebaseAuth


class RegisterActivity : AppCompatActivity() {
    var etRegEmail: TextInputEditText? = null
    var etRegPassword: TextInputEditText? = null
    var tvLoginHere: TextView? = null
    var btnRegister: Button? = null
    var mAuth: FirebaseAuth? = null
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
        setContentView(R.layout.activity_register)
        etRegEmail = findViewById(R.id.etRegEmail)
        etRegPassword = findViewById(R.id.etRegPass)
        tvLoginHere = findViewById(R.id.tvLoginHere)
        btnRegister = findViewById(R.id.btnRegister)
        mAuth = FirebaseAuth.getInstance()
        findViewById<Button>(R.id.btnRegister).setOnClickListener { createUser() }
        findViewById<TextView>(R.id.tvLoginHere).setOnClickListener {
            startActivity(
                Intent(
                    this@RegisterActivity,
                    LoginActivity::class.java
                )
            )
        }
    }

    private fun createUser() {
        val email = etRegEmail!!.text.toString()
        val password = etRegPassword!!.text.toString()
        if (TextUtils.isEmpty(email)) {
            etRegEmail!!.error = "Email cannot be empty"
            etRegEmail!!.requestFocus()
        } else if (TextUtils.isEmpty(password)) {
            etRegPassword!!.error = "Password cannot be empty"
            etRegPassword!!.requestFocus()
        } else {
            mAuth!!.createUserWithEmailAndPassword(email, password).addOnCompleteListener { task ->
                if (task.isSuccessful) {
                    Toast.makeText(
                        this@RegisterActivity,
                        "User registered successfully",
                        Toast.LENGTH_SHORT
                    ).show()
                    startActivity(Intent(this@RegisterActivity, MainActivity::class.java))
                } else {
                    Toast.makeText(
                        this@RegisterActivity,
                        "Registration Error: " + task.exception?.message,
                        Toast.LENGTH_SHORT
                    ).show()
                }
            }
        }
    }
}

Step 11: Design a layout for activity_register.xml, add the code given below:

<?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"
    android:padding="24dp"
    tools:context=".RegisterActivity">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        android:layout_gravity="center"
        android:layout_marginTop="25dp">

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Register"
            android:textSize="30sp"
            android:textStyle="bold"
            android:textColor="@color/teal_700"
            android:gravity="center_horizontal"
            android:layout_marginVertical="16dp"/>


        <com.google.android.material.textfield.TextInputLayout
            android:layout_width="match_parent"
            style="@style/Widget.MaterialComponents.TextInputLayout.OutlinedBox"
            android:layout_height="wrap_content">

            <com.google.android.material.textfield.TextInputEditText
                android:id="@+id/etRegEmail"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:hint="Email"
                android:inputType="textEmailAddress"/>
        </com.google.android.material.textfield.TextInputLayout>


        <com.google.android.material.textfield.TextInputLayout
            android:layout_width="match_parent"
            style="@style/Widget.MaterialComponents.TextInputLayout.OutlinedBox"
            android:layout_height="wrap_content"
            android:layout_marginTop="12dp">

            <com.google.android.material.textfield.TextInputEditText
                android:id="@+id/etRegPass"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:hint="Password"
                android:inputType="textPassword"/>
        </com.google.android.material.textfield.TextInputLayout>

        <com.google.android.material.button.MaterialButton
            android:id="@+id/btnRegister"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="24dp"
            android:text="Register"/>

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="15dp"
            android:gravity="center"
            android:orientation="horizontal">

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="Already registered"
                android:textSize="16sp"/>

            <TextView
                android:id="@+id/tvLoginHere"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginLeft="8dp"
                android:text="Login here"
                android:textColor="@color/teal_700"
                android:textStyle="bold"
                android:textSize="20sp"/>

        </LinearLayout>

    </LinearLayout>

</LinearLayout>

Step 12: Create another activity(Empty Activity), name it LoginActivity, and add the code given below:

 import android.content.Intent
 import android.os.Bundle
 import android.text.TextUtils
 import android.view.Window
 import android.view.WindowManager
 import android.widget.Button
 import android.widget.TextView
 import android.widget.Toast
 import androidx.appcompat.app.AppCompatActivity
 import com.google.android.material.textfield.TextInputEditText
 import com.google.firebase.auth.FirebaseAuth


class LoginActivity : AppCompatActivity() {
    var etLoginEmail: TextInputEditText? = null
    var etLoginPassword: TextInputEditText? = null
    var tvRegisterHere: TextView? = null
    var btnLogin: Button? = null
    var mAuth: FirebaseAuth? = null
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
        setContentView(R.layout.activity_login)
        etLoginEmail = findViewById(R.id.etLoginEmail)
        etLoginPassword = findViewById(R.id.etLoginPass)
        tvRegisterHere = findViewById(R.id.tvRegisterHere)
        btnLogin = findViewById(R.id.btnLogin)
        mAuth = FirebaseAuth.getInstance()
        findViewById<Button>(R.id.btnLogin).setOnClickListener { loginUser() }
        findViewById<TextView>(R.id.tvRegisterHere).setOnClickListener {
            startActivity(
                Intent(
                    this@LoginActivity,
                    RegisterActivity::class.java
                )
            )
        }
    }

    private fun loginUser() {
        val email = etLoginEmail!!.text.toString()
        val password = etLoginPassword!!.text.toString()
        if (TextUtils.isEmpty(email)) {
            etLoginEmail!!.error = "Email cannot be empty"
            etLoginEmail!!.requestFocus()
        } else if (TextUtils.isEmpty(password)) {
            etLoginPassword!!.error = "Password cannot be empty"
            etLoginPassword!!.requestFocus()
        } else {
            mAuth!!.signInWithEmailAndPassword(email, password).addOnCompleteListener { task ->
                if (task.isSuccessful) {
                    Toast.makeText(
                        this@LoginActivity,
                        "User logged in successfully",
                        Toast.LENGTH_SHORT
                    ).show()
                    startActivity(Intent(this@LoginActivity, MainActivity::class.java))
                } else {
                    Toast.makeText(
                        this@LoginActivity,
                        "Log in Error: " + task.exception?.message,
                        Toast.LENGTH_SHORT
                    ).show()
                }
            }
        }
    }
}

Step 13: Design a layout for activity_login.xml, add the code given below: 

<?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"
    android:padding="24dp"
    tools:context=".LoginActivity">


    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_gravity="center"
        android:layout_marginTop="25dp"
        android:orientation="vertical">

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginVertical="16dp"
            android:gravity="center_horizontal"
            android:text="Login"
            android:textColor="@color/teal_700"
            android:textSize="30sp"
            android:textStyle="bold" />


        <com.google.android.material.textfield.TextInputLayout
            style="@style/Widget.MaterialComponents.TextInputLayout.OutlinedBox"
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

            <com.google.android.material.textfield.TextInputEditText
                android:id="@+id/etLoginEmail"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:hint="Email"
                android:inputType="textEmailAddress" />
        </com.google.android.material.textfield.TextInputLayout>


        <com.google.android.material.textfield.TextInputLayout
            style="@style/Widget.MaterialComponents.TextInputLayout.OutlinedBox"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="12dp">

            <com.google.android.material.textfield.TextInputEditText
                android:id="@+id/etLoginPass"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:hint="Password"
                android:inputType="textPassword" />
        </com.google.android.material.textfield.TextInputLayout>

        <com.google.android.material.button.MaterialButton
            android:id="@+id/btnLogin"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="24dp"
            android:text="Login" />

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="15dp"
            android:gravity="center"
            android:orientation="horizontal">

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="Not registered yet"
                android:textSize="16sp" />

            <TextView
                android:id="@+id/tvRegisterHere"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginLeft="8dp"
                android:text="Register here"
                android:textColor="@color/teal_700"
                android:textSize="20sp"
                android:textStyle="bold" />

        </LinearLayout>

    </LinearLayout>

</LinearLayout>

Step 14: In MainActivity.kt file add the code given below:

import android.content.Intent
import android.os.Bundle
import android.view.Window
import android.view.WindowManager
import android.widget.Button
import androidx.appcompat.app.AppCompatActivity
import com.google.firebase.auth.FirebaseAuth


class MainActivity : AppCompatActivity() {
    var btnLogOut: Button? = null
    var mAuth: FirebaseAuth? = null
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);
        setContentView(R.layout.activity_main)
        btnLogOut = findViewById(R.id.btnLogout)
        mAuth = FirebaseAuth.getInstance()
        findViewById<Button>(R.id.btnLogout).setOnClickListener { view ->
            mAuth!!.signOut()
            startActivity(Intent(this@MainActivity, LoginActivity::class.java))
        }
    }

    override fun onStart() {
        super.onStart()
        val user = mAuth!!.currentUser
        if (user == null) {
            startActivity(Intent(this@MainActivity, LoginActivity::class.java))
        }
    }
}

Step 15: In activity_main.xml add the code given below:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:gravity="center_horizontal"
        android:text="Congratulation- You Successfully Created Email Authentication "
        android:textAlignment="center"
        android:textSize="25sp"
        android:textStyle="bold"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.241" />

    <Button
        android:id="@+id/btnLogout"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="136dp"
        android:text="Logout"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.498"
        app:layout_constraintStart_toStartOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

Run the application now. You will get the output shown in the output section.

For video reference:

email authentication firebase, email authentication firebase

email authentication, email authentication, email authentication.

Source Code:

We’ve completed the development of Email Authentication using Firebase in the Android application. You can get the Source code from the given below button.

Download Code
  • We hope that this guide will assist you in understanding all about the concepts of Email authentication using firebase in android application. We have concentrated on making a basic, meaningful and easy-to -learn guide to the concepts of Email authentication using firebase with suitable examples. Still if you have any problems regarding this, please post them in the comments section, we will be glad to assist you.

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