Firebase User Authentication Tutorial – Login using Email and Password

July 31, 2016 by Belal Khan 21 Comments

In this post we will learn about Firebase User Authentication or Signin. If you have read the last tutorial about Firebase Authentication then you already know that in the last tutorial we covered the User Registration part using Firebase. In this Firebase User Authentication tutorial we will create a login option in our app using Email and Password.

First I will recommend you to go through the last tutorial from the below link, as I will be working on the same project.

Android Firebase Tutorial – User Registration with Authentication

Firebase User Authentication Video Tutorial

Modifying the User Registration Screen

If you don’t want to read the tutorial, just view this 20 minutes youtube video.

Firebase User Authentication Tutorial

First open the last project we created.
Go inside activity_main.xml and change the layout as follows. We are adding a TextView where user can click to go to the login activity directly.

<?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"
    android:orientation="vertical"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="net.simplifiedcoding.firebaseauthdemo.MainActivity">

    <LinearLayout
        android:layout_centerVertical="true"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">


        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceLarge"
            android:text="User Registration"
            android:id="@+id/textView"
            android:layout_gravity="center_horizontal" />

        <EditText
            android:id="@+id/editTextEmail"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_margin="15dp"
            android:hint="Enter email"
            android:inputType="textEmailAddress" />

        <EditText
            android:id="@+id/editTextPassword"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_margin="15dp"
            android:hint="Enter password"
            android:inputType="textPassword" />

        <Button
            android:id="@+id/buttonSignup"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_margin="15dp"
            android:text="Signup" />

        <TextView
            android:text="Already Registered? Signin Here"
            android:id="@+id/textViewSignin"
            android:textAlignment="center"
            android:layout_margin="15dp"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />

    </LinearLayout>

</RelativeLayout>

<?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"

android:orientation="vertical"

android:paddingBottom="@dimen/activity_vertical_margin"

android:paddingLeft="@dimen/activity_horizontal_margin"

android:paddingRight="@dimen/activity_horizontal_margin"

android:paddingTop="@dimen/activity_vertical_margin"

tools:context="net.simplifiedcoding.firebaseauthdemo.MainActivity">

<LinearLayout

android:layout_centerVertical="true"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:orientation="vertical">

<TextView

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:textAppearance="?android:attr/textAppearanceLarge"

android:text="User Registration"

android:id="@+id/textView"

android:layout_gravity="center_horizontal" />

<EditText

android:id="@+id/editTextEmail"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:layout_margin="15dp"

android:hint="Enter email"

android:inputType="textEmailAddress" />

<EditText

android:id="@+id/editTextPassword"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:layout_margin="15dp"

android:hint="Enter password"

android:inputType="textPassword" />

<Button

android:id="@+id/buttonSignup"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:layout_margin="15dp"

android:text="Signup" />

<TextView

android:text="Already Registered? Signin Here"

android:id="@+id/textViewSignin"

android:textAlignment="center"

android:layout_margin="15dp"

android:layout_width="match_parent"

android:layout_height="wrap_content" />

</LinearLayout>

</RelativeLayout>

Now your Activity will look as follow in the preview.

Now come inside MainActivity.java and modify your code as follows.

package net.simplifiedcoding.firebaseauthdemo;

import android.app.ProgressDialog;
import android.content.Intent;
import android.support.annotation.NonNull;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.auth.AuthResult;
import com.google.firebase.auth.FirebaseAuth;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    //defining view objects
    private EditText editTextEmail;
    private EditText editTextPassword;
    private Button buttonSignup;
    
    private TextView textViewSignin;

    private ProgressDialog progressDialog;


    //defining firebaseauth object
    private FirebaseAuth firebaseAuth;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        //initializing firebase auth object
        firebaseAuth = FirebaseAuth.getInstance();

        //if getCurrentUser does not returns null 
        if(firebaseAuth.getCurrentUser() != null){
            //that means user is already logged in 
            //so close this activity
            finish();
            
            //and open profile activity
            startActivity(new Intent(getApplicationContext(), ProfileActivity.class));
        }

        //initializing views
        editTextEmail = (EditText) findViewById(R.id.editTextEmail);
        editTextPassword = (EditText) findViewById(R.id.editTextPassword);
        textViewSignin = (TextView) findViewById(R.id.textViewSignin);

        buttonSignup = (Button) findViewById(R.id.buttonSignup);

        progressDialog = new ProgressDialog(this);

        //attaching listener to button
        buttonSignup.setOnClickListener(this);
        textViewSignin.setOnClickListener(this);
    }

    private void registerUser(){

        //getting email and password from edit texts
        String email = editTextEmail.getText().toString().trim();
        String password  = editTextPassword.getText().toString().trim();

        //checking if email and passwords are empty
        if(TextUtils.isEmpty(email)){
            Toast.makeText(this,"Please enter email",Toast.LENGTH_LONG).show();
            return;
        }

        if(TextUtils.isEmpty(password)){
            Toast.makeText(this,"Please enter password",Toast.LENGTH_LONG).show();
            return;
        }

        //if the email and password are not empty
        //displaying a progress dialog

        progressDialog.setMessage("Registering Please Wait...");
        progressDialog.show();

        //creating a new user
        firebaseAuth.createUserWithEmailAndPassword(email, password)
                .addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
                    @Override
                    public void onComplete(@NonNull Task<AuthResult> task) {
                        //checking if success
                        if(task.isSuccessful()){
                                finish();
                                startActivity(new Intent(getApplicationContext(), ProfileActivity.class));
                        }else{
                            //display some message here
                            Toast.makeText(MainActivity.this,"Registration Error",Toast.LENGTH_LONG).show();
                        }
                        progressDialog.dismiss();
                    }
                });

    }

    @Override
    public void onClick(View view) {

        if(view == buttonSignup){
            registerUser();
        }

        if(view == textViewSignin){
            //open login activity when user taps on the already registered textview
            startActivity(new Intent(this, LoginActivity.class));
        }

    }
}

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package net.simplifiedcoding.firebaseauthdemo;

import android.app.ProgressDialog;

import android.content.Intent;

import android.support.annotation.NonNull;

import android.support.v7.app.AppCompatActivity;

import android.os.Bundle;

import android.text.TextUtils;

import android.view.View;

import android.widget.Button;

import android.widget.EditText;

import android.widget.TextView;

import android.widget.Toast;

import com.google.android.gms.tasks.OnCompleteListener;

import com.google.android.gms.tasks.Task;

import com.google.firebase.auth.AuthResult;

import com.google.firebase.auth.FirebaseAuth;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

//defining view objects

private EditText editTextEmail;

private EditText editTextPassword;

private Button buttonSignup;

private TextView textViewSignin;

private ProgressDialog progressDialog;

//defining firebaseauth object

private FirebaseAuth firebaseAuth;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

//initializing firebase auth object

firebaseAuth = FirebaseAuth.getInstance();

//if getCurrentUser does not returns null

if(firebaseAuth.getCurrentUser() != null){

//that means user is already logged in

//so close this activity

finish();

//and open profile activity

startActivity(new Intent(getApplicationContext(), ProfileActivity.class));

}

//initializing views

editTextEmail = (EditText) findViewById(R.id.editTextEmail);

editTextPassword = (EditText) findViewById(R.id.editTextPassword);

textViewSignin = (TextView) findViewById(R.id.textViewSignin);

buttonSignup = (Button) findViewById(R.id.buttonSignup);

progressDialog = new ProgressDialog(this);

//attaching listener to button

buttonSignup.setOnClickListener(this);

textViewSignin.setOnClickListener(this);

}

private void registerUser(){

//getting email and password from edit texts

String email = editTextEmail.getText().toString().trim();

String password = editTextPassword.getText().toString().trim();

//checking if email and passwords are empty

if(TextUtils.isEmpty(email)){

Toast.makeText(this,"Please enter email",Toast.LENGTH_LONG).show();

return;

}

if(TextUtils.isEmpty(password)){

Toast.makeText(this,"Please enter password",Toast.LENGTH_LONG).show();

return;

}

//if the email and password are not empty

//displaying a progress dialog

progressDialog.setMessage("Registering Please Wait...");

progressDialog.show();

//creating a new user

firebaseAuth.createUserWithEmailAndPassword(email, password)

.addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {

@Override

public void onComplete(@NonNull Task<AuthResult> task) {

//checking if success

if(task.isSuccessful()){

finish();

startActivity(new Intent(getApplicationContext(), ProfileActivity.class));

}else{

//display some message here

Toast.makeText(MainActivity.this,"Registration Error",Toast.LENGTH_LONG).show();

}

progressDialog.dismiss();

}

});

}

@Override

public void onClick(View view) {

if(view == buttonSignup){

registerUser();

}

if(view == textViewSignin){

//open login activity when user taps on the already registered textview

startActivity(new Intent(this, LoginActivity.class));

}

Now we will create the Profile Activity.

Adding Profile Activity to Project

Right click on package and create new activity named ProfileActivity.
Inside the layout file of this activity write the following xml code. (In my case it is activity_profile.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"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="net.simplifiedcoding.firebaseauthdemo.ProfileActivity">


    <LinearLayout
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_centerVertical="true"
        android:layout_centerHorizontal="true">


        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceLarge"
            android:text="Large Text"
            android:id="@+id/textViewUserEmail"
            android:layout_gravity="center_horizontal" />

        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Logout"
            android:id="@+id/buttonLogout"
            android:layout_gravity="center_horizontal" />
    </LinearLayout>
</RelativeLayout>

<?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"

android:paddingBottom="@dimen/activity_vertical_margin"

android:paddingLeft="@dimen/activity_horizontal_margin"

android:paddingRight="@dimen/activity_horizontal_margin"

android:paddingTop="@dimen/activity_vertical_margin"

tools:context="net.simplifiedcoding.firebaseauthdemo.ProfileActivity">

<LinearLayout

android:orientation="vertical"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:layout_centerVertical="true"

android:layout_centerHorizontal="true">

<TextView

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:textAppearance="?android:attr/textAppearanceLarge"

android:text="Large Text"

android:id="@+id/textViewUserEmail"

android:layout_gravity="center_horizontal" />

<Button

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="Logout"

android:id="@+id/buttonLogout"

android:layout_gravity="center_horizontal" />

</LinearLayout>

</RelativeLayout>

We haven’t done much on this activity as it contains a TextView and a Button only. In TextView we will show the logged in user email and the button will be used for logout.
The above XML code will show you the following layout.

Now come inside ProfileActivity.java and write the following code.

package net.simplifiedcoding.firebaseauthdemo;

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;

public class ProfileActivity extends AppCompatActivity implements View.OnClickListener {

    //firebase auth object
    private FirebaseAuth firebaseAuth;

    //view objects 
    private TextView textViewUserEmail;
    private Button buttonLogout;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_profile);

        //initializing firebase authentication object
        firebaseAuth = FirebaseAuth.getInstance();

        //if the user is not logged in
        //that means current user will return null 
        if(firebaseAuth.getCurrentUser() == null){
            //closing this activity 
            finish();
            //starting login activity
            startActivity(new Intent(this, LoginActivity.class));
        }
        
        //getting current user
        FirebaseUser user = firebaseAuth.getCurrentUser();

        //initializing views
        textViewUserEmail = (TextView) findViewById(R.id.textViewUserEmail);
        buttonLogout = (Button) findViewById(R.id.buttonLogout);
        
        //displaying logged in user name
        textViewUserEmail.setText("Welcome "+user.getEmail());

        //adding listener to button 
        buttonLogout.setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        //if logout is pressed
        if(view == buttonLogout){
            //logging out the user
            firebaseAuth.signOut();
            //closing activity
            finish();
            //starting login activity 
            startActivity(new Intent(this, LoginActivity.class));
        }
    }
}

package net.simplifiedcoding.firebaseauthdemo;

import android.content.Intent;

import android.support.v7.app.AppCompatActivity;

import android.os.Bundle;

import android.view.View;

import android.widget.Button;

import android.widget.TextView;

import com.google.firebase.auth.FirebaseAuth;

import com.google.firebase.auth.FirebaseUser;

public class ProfileActivity extends AppCompatActivity implements View.OnClickListener {

//firebase auth object

private FirebaseAuth firebaseAuth;

//view objects

private TextView textViewUserEmail;

private Button buttonLogout;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_profile);

//initializing firebase authentication object

firebaseAuth = FirebaseAuth.getInstance();

//if the user is not logged in

//that means current user will return null

if(firebaseAuth.getCurrentUser() == null){

//closing this activity

finish();

//starting login activity

startActivity(new Intent(this, LoginActivity.class));

}

//getting current user

FirebaseUser user = firebaseAuth.getCurrentUser();

//initializing views

textViewUserEmail = (TextView) findViewById(R.id.textViewUserEmail);

buttonLogout = (Button) findViewById(R.id.buttonLogout);

//displaying logged in user name

textViewUserEmail.setText("Welcome "+user.getEmail());

//adding listener to button

buttonLogout.setOnClickListener(this);

}

@Override

public void onClick(View view) {

//if logout is pressed

if(view == buttonLogout){

//logging out the user

firebaseAuth.signOut();

//closing activity

finish();

//starting login activity

startActivity(new Intent(this, LoginActivity.class));

}

Now we will add Login Activity to our project.

Adding Login Activity to Project

Again right click on package and new -> activity -> empty activity, and create a new Activity. Name it LoginActivity.
Inside the layout file of this activity activity_login.xml write the following xml code.

<?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"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="net.simplifiedcoding.firebaseauthdemo.LoginActivity">


    <LinearLayout
        android:layout_centerVertical="true"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceLarge"
            android:text="User Login"
            android:id="@+id/textView"
            android:layout_gravity="center_horizontal" />

        <EditText
            android:id="@+id/editTextEmail"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_margin="15dp"
            android:hint="Enter email"
            android:inputType="textEmailAddress" />

        <EditText
            android:id="@+id/editTextPassword"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_margin="15dp"
            android:hint="Enter password"
            android:inputType="textPassword" />

        <Button
            android:id="@+id/buttonSignin"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_margin="15dp"
            android:text="Signup" />

        <TextView
            android:text="Not have an account? Signup Here"
            android:id="@+id/textViewSignUp"
            android:textAlignment="center"
            android:layout_margin="15dp"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />

    </LinearLayout>

</RelativeLayout>

<?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"

android:paddingBottom="@dimen/activity_vertical_margin"

android:paddingLeft="@dimen/activity_horizontal_margin"

android:paddingRight="@dimen/activity_horizontal_margin"

android:paddingTop="@dimen/activity_vertical_margin"

tools:context="net.simplifiedcoding.firebaseauthdemo.LoginActivity">

<LinearLayout

android:layout_centerVertical="true"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:orientation="vertical">

<TextView

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:textAppearance="?android:attr/textAppearanceLarge"

android:text="User Login"

android:id="@+id/textView"

android:layout_gravity="center_horizontal" />

<EditText

android:id="@+id/editTextEmail"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:layout_margin="15dp"

android:hint="Enter email"

android:inputType="textEmailAddress" />

<EditText

android:id="@+id/editTextPassword"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:layout_margin="15dp"

android:hint="Enter password"

android:inputType="textPassword" />

<Button

android:id="@+id/buttonSignin"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:layout_margin="15dp"

android:text="Signup" />

<TextView

android:text="Not have an account? Signup Here"

android:id="@+id/textViewSignUp"

android:textAlignment="center"

android:layout_margin="15dp"

android:layout_width="match_parent"

android:layout_height="wrap_content" />

</LinearLayout>

</RelativeLayout>

You will see the following layout in preview.

Now lets code this activity, so come inside LoginActivity.java and write the following code.

package net.simplifiedcoding.firebaseauthdemo;

import android.app.ProgressDialog;
import android.content.Intent;
import android.support.annotation.NonNull;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.auth.AuthResult;
import com.google.firebase.auth.FirebaseAuth;

public class LoginActivity extends AppCompatActivity implements View.OnClickListener {


    //defining views
    private Button buttonSignIn;
    private EditText editTextEmail;
    private EditText editTextPassword;
    private TextView textViewSignup;

    //firebase auth object
    private FirebaseAuth firebaseAuth;

    //progress dialog
    private ProgressDialog progressDialog;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);

        //getting firebase auth object
        firebaseAuth = FirebaseAuth.getInstance();

        //if the objects getcurrentuser method is not null 
        //means user is already logged in 
        if(firebaseAuth.getCurrentUser() != null){
            //close this activity
            finish();
            //opening profile activity 
            startActivity(new Intent(getApplicationContext(), ProfileActivity.class));
        }

        //initializing views
        editTextEmail = (EditText) findViewById(R.id.editTextEmail);
        editTextPassword = (EditText) findViewById(R.id.editTextPassword);
        buttonSignIn = (Button) findViewById(R.id.buttonSignin);
        textViewSignup  = (TextView) findViewById(R.id.textViewSignUp);

        progressDialog = new ProgressDialog(this);

        //attaching click listener 
        buttonSignIn.setOnClickListener(this);
        textViewSignup.setOnClickListener(this);
    }

    //method for user login 
    private void userLogin(){
        String email = editTextEmail.getText().toString().trim();
        String password  = editTextPassword.getText().toString().trim();


        //checking if email and passwords are empty
        if(TextUtils.isEmpty(email)){
            Toast.makeText(this,"Please enter email",Toast.LENGTH_LONG).show();
            return;
        }

        if(TextUtils.isEmpty(password)){
            Toast.makeText(this,"Please enter password",Toast.LENGTH_LONG).show();
            return;
        }

        //if the email and password are not empty
        //displaying a progress dialog

        progressDialog.setMessage("Registering Please Wait...");
        progressDialog.show();

        //logging in the user
        firebaseAuth.signInWithEmailAndPassword(email, password)
                .addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
                    @Override
                    public void onComplete(@NonNull Task<AuthResult> task) {
                        progressDialog.dismiss();
                        //if the task is successfull 
                        if(task.isSuccessful()){
                            //start the profile activity
                            finish();
                            startActivity(new Intent(getApplicationContext(), ProfileActivity.class));
                        }
                    }
                });

    }

    @Override
    public void onClick(View view) {
        if(view == buttonSignIn){
            userLogin();
        }

        if(view == textViewSignup){
            finish();
            startActivity(new Intent(this, MainActivity.class));
        }
    }
}

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package net.simplifiedcoding.firebaseauthdemo;

import android.app.ProgressDialog;

import android.content.Intent;

import android.support.annotation.NonNull;

import android.support.v7.app.AppCompatActivity;

import android.os.Bundle;

import android.text.TextUtils;

import android.view.View;

import android.widget.Button;

import android.widget.EditText;

import android.widget.TextView;

import android.widget.Toast;

import com.google.android.gms.tasks.OnCompleteListener;

import com.google.android.gms.tasks.Task;

import com.google.firebase.auth.AuthResult;

import com.google.firebase.auth.FirebaseAuth;

public class LoginActivity extends AppCompatActivity implements View.OnClickListener {

//defining views

private Button buttonSignIn;

private EditText editTextEmail;

private EditText editTextPassword;

private TextView textViewSignup;

//firebase auth object

private FirebaseAuth firebaseAuth;

//progress dialog

private ProgressDialog progressDialog;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_login);

//getting firebase auth object

firebaseAuth = FirebaseAuth.getInstance();

//if the objects getcurrentuser method is not null

//means user is already logged in

if(firebaseAuth.getCurrentUser() != null){

//close this activity

finish();

//opening profile activity

startActivity(new Intent(getApplicationContext(), ProfileActivity.class));

}

//initializing views

editTextEmail = (EditText) findViewById(R.id.editTextEmail);

editTextPassword = (EditText) findViewById(R.id.editTextPassword);

buttonSignIn = (Button) findViewById(R.id.buttonSignin);

textViewSignup = (TextView) findViewById(R.id.textViewSignUp);

progressDialog = new ProgressDialog(this);

//attaching click listener

buttonSignIn.setOnClickListener(this);

textViewSignup.setOnClickListener(this);

}

//method for user login

private void userLogin(){

String email = editTextEmail.getText().toString().trim();

String password = editTextPassword.getText().toString().trim();

//checking if email and passwords are empty

if(TextUtils.isEmpty(email)){

Toast.makeText(this,"Please enter email",Toast.LENGTH_LONG).show();

return;

}

if(TextUtils.isEmpty(password)){

Toast.makeText(this,"Please enter password",Toast.LENGTH_LONG).show();

return;

}

//if the email and password are not empty

//displaying a progress dialog

progressDialog.setMessage("Registering Please Wait...");

progressDialog.show();

//logging in the user

firebaseAuth.signInWithEmailAndPassword(email, password)

.addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {

@Override

public void onComplete(@NonNull Task<AuthResult> task) {

progressDialog.dismiss();

//if the task is successfull

if(task.isSuccessful()){

//start the profile activity

finish();

startActivity(new Intent(getApplicationContext(), ProfileActivity.class));

}

});

}

@Override

public void onClick(View view) {

if(view == buttonSignIn){

userLogin();

}

if(view == textViewSignup){

finish();

startActivity(new Intent(this, MainActivity.class));

}

Thats it now just run your app go to login and try logging in.

Bingo! it is working absolutely fine. You can also get the source code from the link given below.

So thats all for this Firebase User Authentication Example friends. In the next Firebase User Authentication Tutorial we will do some more operations like password reset, email change, account deletion etc. And don’t forget to share this Firebase user Authentication Tutorial among your friends. Thank You 🙂

About Belal Khan

I am Belal Khan, I am currently pursuing my MCA. In this blog I write tutorials and articles related to coding, app development, android etc.

Comments

Kashifa khan says

August 3, 2016 at 5:45 pm

can we use same database to insert multiple data like data from the Items list and the data from the New organization registrations into firebase database.

Reply
jason roland says

August 5, 2016 at 3:31 pm

thank you so much tutorial works great but i have a question i made a button in the profile activity that brings me to a list activity (this is a listview that is synced with my database at firebase and its giiving me an error if u could plz take a look at my code and mayb try to help me i think i know were the problum is i just dont know how to fix it

Reply
hardik says

August 18, 2016 at 12:38 pm

can you give tutorial about google signing with firebase?

Reply
cytyler says

August 19, 2016 at 9:17 am

can’t wait for the next firebase tutorial ! thanks very much! hope to see the next tutorial very soon

Reply
stevian says

September 2, 2016 at 7:18 am

Thank you for the tutorial, so simple to learning firebase and android at here 😀

Reply
Bruno says

October 15, 2016 at 1:53 am

can i use it on hostinger?

Reply
ilham says

October 24, 2016 at 2:29 am

I did not receive a push notification since implementing login authentication

Reply
shangba says

November 10, 2016 at 6:38 am

sir, i got a problem. help me plz

E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.a603.shangba, PID: 3877
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.a603.shangba/com.example.a603.shangba.MainActivity}: android.content.ActivityNotFoundException: Unable to find explicit activity class {com.example.a603.shangba/com.example.a603.shangba.ProfileActivity}; have you declared this activity in your AndroidManifest.xml?
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2646)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707)
at android.app.ActivityThread.-wrap12(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6077)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)
Caused by: android.content.ActivityNotFoundException: Unable to find explicit activity class {com.example.a603.shangba/com.example.a603.shangba.ProfileActivity}; have you declared this activity in your AndroidManifest.xml?
at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java:1805)
at android.app.Instrumentation.execStartActivity(Instrumentation.java:1523)
at android.app.Activity.startActivityForResult(Activity.java:4224)
at android.support.v4.app.BaseFragmentActivityJB.startActivityForResult(BaseFragmentActivityJB.java:48)
at android.support.v4.app.FragmentActivity.startActivityForResult(FragmentActivity.java:75)
at android.app.Activity.startActivityForResult(Activity.java:4183)
at android.support.v4.app.FragmentActivity.startActivityForResult(FragmentActivity.java:856)
at android.app.Activity.startActivity(Activity.java:4507)
at android.app.Activity.startActivity(Activity.java:4475)
at com.example.a603.shangba.MainActivity.onCreate(MainActivity.java:49)
at android.app.Activity.performCreate(Activity.java:6664)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1118)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2599)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707)
at android.app.ActivityThread.-wrap12(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6077)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)

Reply
- shangba says
  
  November 10, 2016 at 6:52 am
  
  it was about manifest, i fixed it khan, thank you godbless your tutorial
  
  Reply
Zack says

November 24, 2016 at 11:50 am

This is great, it did work for me.. Thanks very much chap but I tried to get User name Here:
textViewUserEmail.setText(“Welcome ” + user.getDisplayName()); it returned null… How can I get a User Name?

Reply
Ryan says

December 7, 2016 at 8:50 am

Bro, can you help me to complete your tutorial?

I have try your tutorial above, and done! it’s work.
But, How about resetting password? I try to find but nothing found. Just your tutorial of firebase auth was work. And now please create a post that show us how to resetting password in firebase auth in android.

Please. Thank you. I’ll be back, so I’ll be wait your response.

Reply
Cem says

April 29, 2017 at 9:30 pm

Hi,

Thank you for your tutorial, it’s so usefull. But I got a problem I think. I compiled your code and it worked but when I enter the e-mail and password, it says only “registering please wait..” and does nothing. I think it couldn’t connect to firebase. Can you help me?

Reply
sammra says

May 14, 2017 at 6:29 pm

i have a prblm when i run my app n enter the email n password so when i register its says after buffering that registration error. why?

Reply
EKTA SAHU says

July 11, 2017 at 2:01 pm

How can i store Username at the time of user registration?

Reply
Shane says

July 18, 2017 at 4:00 pm

Thank you for this tutorial. I am a beginner and it has been so helpful.

My problem is that the “User Registration” works fine and add’s my info to Firebase Auth. However, I am not taken to logged in screen to log out….Also, “Already Registered” does not work. Any ideas why?

Reply
KK says

July 27, 2017 at 12:56 pm

post firebase tutorial for registration with name, email, password, profile image, cover image, birthdate and so on

Reply
Nagesh Badole says

October 5, 2017 at 11:47 am

I am gettin this run time exception

java.lang.NullPointerException: Attempt to invoke interface method ‘void com.google.firebase.auth.FirebaseAuth$AuthStateListener.onAuthStateChanged(com.google.firebase.auth.FirebaseAuth)’ on a null object reference at com.google.firebase.auth.zzi.run(Unknown Source)

What should I do?

Reply
Joao Ignacio says

December 4, 2017 at 4:02 am

Best Firebase tutorial found ever.

Reply
otong says

September 26, 2018 at 3:27 am

sir please make tutorial register with name, address with firebase

Reply
Muhammad Toheed says

October 18, 2018 at 10:03 am

it is very helpful to create video tuts along with pdf page.
thaks a lot

Reply
Aslam tarakwadiya says

October 22, 2018 at 11:50 am

How can i get all registered user list from Firebase in my android App ?

Reply

About Belal Khan

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About Simplified Coding

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Firebase User Authentication Video Tutorial

Modifying the User Registration Screen

Firebase User Authentication Tutorial

Adding Profile Activity to Project

Adding Login Activity to Project

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