Facebook Login Integration

The Facebook SDK for Android enables people to sign into your app with Facebook Login. When people log into your app with Facebook they can grant permissions to your app so you can retrieve information or perform actions on Facebook on their behalf.

Generate your app signature for facebook

1)Open Command prompt
2)Fire Keytool command

keytool -exportcert -alias androiddebugkey -keystore "<path-to-users-directory>\.android\debug.keystore" | openssl sha1 -binary | openssl base64

KeyTool Path from file location

keytool -exportcert -alias androiddebugkey -keystore "C:\Users\Your name\.android\debug.keystore" | openssl sha1 -binary | openssl base64

3)While you generating key hash it will ask for password you have to give password android

Create Application after generating kayhash

Create your new facebook application using below link

https://developers.facebook.com/apps

Add Gradle dependency to build.gradle in your android studio project

compile 'com.facebook.android:facebook-android-sdk:4.23.0'

Add to your AndroidManifest.xml

<meta-data
            android:name="com.facebook.sdk.ApplicationId"
            android:value="your created facebook_app_id" />
        <meta-data
            android:name="com.facebook.sdk.AutoLogAppEventsEnabled"
            android:value="false" />

        <activity
            android:name="com.facebook.FacebookActivity"
            android:configChanges="keyboard|keyboardHidden|screenLayout|screenSize|orientation"
            android:label="@string/app_name" />
        <activity
            android:name="com.facebook.CustomTabActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.VIEW" />

                <category android:name="android.intent.category.DEFAULT" />
                <category android:name="android.intent.category.BROWSABLE" />

                <data android:scheme="@string/fb_login_protocol_scheme" />
            </intent-filter>
        </activity>

        <provider
            android:name="com.facebook.FacebookContentProvider"
            android:authorities="com.facebook.app.FacebookContentProvider1234"

            android:exported="true" />



==> activity_facebook_login.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_margin="15dp"
    android:gravity="center"
    android:orientation="vertical">


    <RelativeLayout
        android:id="@+id/rl_facebook_invite"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginBottom="15dp"
        android:background="@drawable/bg_btn_rounded_fb"
        android:gravity="center">

        <ImageView
            android:id="@+id/iv_fb_logo"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerVertical="true"
            android:layout_marginRight="10dp"
            android:src="@drawable/icon_facebook" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentTop="true"
            android:layout_toEndOf="@+id/iv_fb_logo"
            android:layout_toRightOf="@+id/iv_fb_logo"
            android:paddingBottom="10dp"
            android:paddingTop="10dp"
            android:text="Invite Friend"
            android:textColor="@color/white"
            android:textSize="18dp"
            android:textStyle="bold" />

    </RelativeLayout>


    <com.facebook.login.widget.LoginButton
        android:id="@+id/login_button"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginBottom="15dp"
        android:paddingBottom="10dp"
        android:paddingTop="10dp"
        android:textSize="18dp" />



</LinearLayout>


==>FaceBookLoginActivity.java

import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.content.pm.Signature;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.util.Base64;
import android.util.Log;
import android.view.View;
import android.widget.RelativeLayout;

import com.facebook.CallbackManager;
import com.facebook.FacebookCallback;
import com.facebook.FacebookException;
import com.facebook.FacebookSdk;
import com.facebook.appevents.AppEventsLogger;
import com.facebook.login.LoginManager;
import com.facebook.login.LoginResult;
import com.facebook.login.widget.LoginButton;
import com.facebook.share.model.AppInviteContent;
import com.facebook.share.widget.AppInviteDialog;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

import butterknife.BindView;
import butterknife.ButterKnife;


public class FaceBookLoginActivity extends AppCompatActivity implements View.OnClickListener {

    @BindView(R.id.rl_facebook_invite)
    RelativeLayout rl_facebook_invite;

    @BindView(R.id.login_button)
    LoginButton login_button;


    String appLinkUrl, previewImageUrl;
    CallbackManager callbackManager;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_facebook_login);
        ButterKnife.bind(this);

        init();
        printHashKey();
        rl_facebook_invite.setOnClickListener(this);
    }

    public void printHashKey() {
        // Add code to print out the key hash
        try {
            PackageInfo info = getPackageManager().getPackageInfo(
                    "com.yourpackage.name",
                    PackageManager.GET_SIGNATURES);
            for (Signature signature : info.signatures) {
                MessageDigest md = MessageDigest.getInstance("SHA");
                md.update(signature.toByteArray());
                Log.d("Facebook KeyHash:", Base64.encodeToString(md.digest(), Base64.DEFAULT));
            }
        } catch (PackageManager.NameNotFoundException e) {

        } catch (NoSuchAlgorithmException e) {

        }
    }

    private void init() {
        FacebookSdk.sdkInitialize(getApplicationContext());
        AppEventsLogger.activateApp(this);

//        if User want to logout from facebook than use following statement
//        LoginManager.getInstance().logOut();

        callbackManager = CallbackManager.Factory.create();

        // Callback registration
        login_button.registerCallback(callbackManager, new FacebookCallback<LoginResult>() {
            @Override
            public void onSuccess(LoginResult loginResult) {
                // App code
            }

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

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

        LoginManager.getInstance().registerCallback(callbackManager,
                new FacebookCallback<LoginResult>() {
                    @Override
                    public void onSuccess(LoginResult loginResult) {
                        // App code
                    }

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

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

    @Override
    public void onClick(View view) {
        if (view.getId() == R.id.rl_facebook_invite) {
            //Facebook App invites friends
            appLinkUrl = "your app link url";
            previewImageUrl = "preview image url";

//                Uri targetUrl = AppLinks.getTargetUrlFromInboundIntent(SocialMediaLoginActivity.this, getIntent());
//                if (targetUrl != null) {
//                    Log.i("Activity", "App Link Target URL: " + targetUrl.toString());
//                }

            if (AppInviteDialog.canShow()) {
                AppInviteContent content = new AppInviteContent.Builder()
                        .setApplinkUrl(appLinkUrl)
                        .setPreviewImageUrl(previewImageUrl)
//                    .setPromotionDetails("Example Promotional Message", "EXAMPLEPROMO ")
                        .build();
                AppInviteDialog.show(FaceBookLoginActivity.this, content);
            }
        }
    }

}