Facebook login integration in Android

In this example we will discuss How verify mobile number in android.

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:gravity="center"
    android:orientation="vertical">


    <TextView
        android:id="@+id/txtUsername"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text=""
        android:padding="8dp"
        android:textSize="25sp"
        android:textColor="#000"/>
    <com.facebook.login.widget.LoginButton
        android:id="@+id/login_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_marginTop="30dp"
        android:layout_marginBottom="30dp"
        />

</LinearLayout>

activity_user.xml

<?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=".UserActivity">

</androidx.constraintlayout.widget.ConstraintLayout>

MainActivity.java

package com.example.facebookloginexample;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.content.pm.Signature;
import android.os.Bundle;
import android.util.Base64;
import android.util.Log;
import android.widget.TextView;

import com.facebook.AccessToken;
import com.facebook.CallbackManager;
import com.facebook.FacebookCallback;
import com.facebook.FacebookException;
import com.facebook.FacebookSdk;

import com.facebook.GraphRequest;
import com.facebook.GraphResponse;
import com.facebook.Profile;
import com.facebook.ProfileTracker;
import com.facebook.appevents.AppEventsLogger;
import com.facebook.login.LoginManager;
import com.facebook.login.LoginResult;
import com.facebook.login.widget.LoginButton;

import org.json.JSONException;
import org.json.JSONObject;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;

    public class MainActivity extends AppCompatActivity {
    private LoginButton loginButton;
    private CallbackManager callbackManager;
    private TextView txtUsername;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        txtUsername = findViewById(R.id.txtUsername);
        //check login status
        AccessToken accessToken = AccessToken.getCurrentAccessToken();
        boolean isLoggedIn = accessToken != null && !accessToken.isExpired();
        // LoginManager.getInstance().logInWithReadPermissions(this, Arrays.asList("public_profile"));
        if (isLoggedIn) {

            //Using Graph API
            LoginManager.getInstance().logInWithReadPermissions(this, Arrays.asList("public_profile"));


        }else{
            txtUsername.setText("");
        }

        callbackManager = CallbackManager.Factory.create();

        loginButton = (LoginButton) findViewById(R.id.login_button);
        callbackManager = CallbackManager.Factory.create();
        ProfileTracker profileTracker = new ProfileTracker() {
            @Override
            protected void onCurrentProfileChanged(
                    Profile oldProfile,
                    Profile currentProfile) {

                if(currentProfile == null){
                    txtUsername.setText("");
                }
            }
        };
            LoginManager.getInstance().registerCallback(callbackManager,
                    new FacebookCallback() {
                        @Override
                        public void onSuccess(LoginResult loginResult) {

                            boolean loggedIn = AccessToken.getCurrentAccessToken() == null;

                            // App code
                            Log.d("loggedIn", String.valueOf(loggedIn));


                            Bundle parameters = new Bundle();
                            parameters.putString("fields", "id, first_name, last_name ,email, gender, birthday");
                            GraphRequest gr = GraphRequest.newMeRequest(loginResult.getAccessToken(), new GraphRequest.GraphJSONObjectCallback() {
                                @Override
                                public void onCompleted(JSONObject object, GraphResponse response) {
                                    if (response.getError() != null) {
                                        // handle error
                                        System.out.println("ERROR " + response.getError().toString());
                                    } else {

                                        try {
                                            String first_name = object.getString("first_name");
                                            String last_name = object.getString("last_name");

                                            txtUsername.setText("Welcome, " + first_name + " " + last_name);
                                            //txtEmail.setText(email);

                                        } catch (JSONException e) {
                                            e.printStackTrace();
                                        }


                                    }


                                }
                            });

                            gr.setParameters(parameters);
                            gr.executeAsync();


                        }

                        @Override
                        public void onCancel() {
                            // App code

                        }

                        @Override
                        public void onError(FacebookException exception) {
                            // App code
                        }


                    });


        try {
            PackageInfo info = getPackageManager().getPackageInfo(
                    "com.example.facebookloginexample",
                    PackageManager.GET_SIGNATURES);
            for (Signature signature : info.signatures) {
                MessageDigest md = MessageDigest.getInstance("SHA");
                md.update(signature.toByteArray());
                Log.d("KeyHash", Base64.encodeToString(md.digest(), Base64.DEFAULT));
            }
        } catch (PackageManager.NameNotFoundException e) {

        } catch (NoSuchAlgorithmException e) {

        }

    }


    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        callbackManager.onActivityResult(requestCode, resultCode, data);
        super.onActivityResult(requestCode, resultCode, data);
    }

    private void getUserProfile(AccessToken currentAccessToken, LoginResult loginResults){

       // private void getUserProfile(AccessToken currentAccessToken, LoginResult loginResults){
            GraphRequest request = GraphRequest.newMeRequest(
                    loginResults.getAccessToken(),
                    new GraphRequest.GraphJSONObjectCallback() {
                        @Override
                        public void onCompleted(
                                JSONObject object,
                                GraphResponse response) {
                            // Application code
                            Log.v("LoginActivity", response.toString());

                            try {
                                String first_name = object.getString("first_name");
                                String last_name = object.getString("last_name");
                            String email = object.getString("email");
                            String id = object.getString("id");

                                txtUsername.setText("First Name: " + first_name + "\nLast Name: " + last_name);


                            } catch (JSONException e) {
                                e.printStackTrace();
                            }
//
                        }
                    });
            Bundle parameters = new Bundle();
            parameters.putString("fields", "id,name,email,gender, birthday");
            request.setParameters(parameters);
            request.executeAsync();
     request.executeAsync();
    }
}

UserActivity.java

package com.example.facebookloginexample;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;

public class UserActivity extends AppCompatActivity {

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