Implementing Facebook Login Using Android SDK

Facebook Login allows you to obtain a token to access Facebook's API on behalf of someone using your app. You can use this feature in place of building your own account system or to add Facebook services to your existing accounts.

To properly handle Facebook Login using the Facebook for Android app, make the following changes in the App Dashboard.

Create a Facebook App

URL to create FB App:

https://developers.facebook.com/?advanced_app_create=true

Once created, note down the app ID shown at the top of the dashboard page. You'll need to add this to your project files.

Next, you will also need to associate your Android keys hashes with the app. The key hash is used by Facebook as a security check for authenticity. By default, the app's package is signed with a machine specific debug key. When publishing the app it is typically signed with a different, release key. Therefore, you want to make sure you have the hashes of all the related keys set on Facebook:

Go to 'Settings' in the left nav, then click on the 'Add Platform' button, and select Android. Add the debug key hash that you obtained at the end of the previous step with the keytool app:

If you have a release key, you will need to add its hash in the same way. To obtain the release key hash, use the 'keytool' in the same way as in the steps above except for the alias and path. On OS X, run:

On Windows, use:

keytool -exportcert -alias <RELEASE_KEY_ALIAS> -keystore <RELEASE_KEY_PATH> | openssl sha1 -binary | openssl base64

Make sure to use the password that you set when you first created the release key.

Save this change.

You will also need to return to this dashboard and add your app's package name and main activity class once you have created a new Android project itself.

If you don’t have openssl please download from below location:

https://code.google.com/p/openssl-for-windows/downloads/detail?name=openssl-0.9.8k_X64.zip

Command to create App ID: [Example]

keytool -exportcert -alias quesponkey -keystore "C:\Users\Sujay.A\Documents\quespon\keystore.keystore" | "C:\Users\Sujay.A\Documents\ Facebook_RND\openssl-0.9.8k_X64\bin\openssl.exe" sha1 -binary | "C:\Users\Sujay.A\Documents\ Facebook_RND\openssl-0.9.8k_X64\bin\openssl.exe" base64

Download Facebook SDK from below location:

https://developers.facebook.com/resources/facebook-android-sdk-current.zip

Import the SDK into Eclipse

Select only FacebookSDK from that and import that.

Create a new Android Project with Facebook Login

Create a new Android Application Project in Eclipse, using 'File' > 'New' > 'Project...' and select 'Android Application Project':

Finish the wizard, and your new project will have been created, along with the main activity class:

Register the package and activity with Facebook
Link to the SDK project and configure the Facebook app ID
package com.firstandroidapp;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.widget.TextView;
import com.facebook.*;
import com.facebook.model.*;
 
public class MainActivity extends Activity {
 
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
 
    // start Facebook Login
    Session.openActiveSession(this, true, new Session.StatusCallback() {
 
      // callback when session changes state
      @Override
      public void call(Session session, SessionState state, Exception exception) {
        if (session.isOpened()) {
 
          // make request to the /me API
          Request.newMeRequest(session, new Request.GraphUserCallback() {
 
            // callback after Graph API response with user object
            @Override
            public void onCompleted(GraphUser user, Response response) {
              if (user != null) {
                TextView welcome = (TextView) findViewById(R.id.welcome);
                welcome.setText("Hello " + user.getName() + "!");
              }
            }
          }).executeAsync();
        }
      }
    });
  }
 
  @Override
  public void onActivityResult(int requestCode, int resultCode, Intent data) {
      super.onActivityResult(requestCode, resultCode, data);
      Session.getActiveSession().onActivityResult(this, requestCode, resultCode, data);
  }
 
}
 

At this point, you should return to the App Dashboard on the Facebook Developers site and add your Android app's package and activity names. To do this, in the app dashboard, go to 'Settings' on the left nav and there, in the Android section, complete the two missing fields. Also enable 'Single Sign On':

Returning to Eclipse, your new application needs to be linked to the SDK library project. View the properties for the project, and navigate to the 'Android' tab. In the lower part of the dialog, click 'Add' and choose the 'FacebookSDK' project from the workspace:

To add the Facebook app ID into your project, open up the strings.xml file in the res/values folder of your project. You need to add an app_id string containing the ID you obtained in the previous step.

(If you view the source of the strings.xml file, you will see the resulting <string name="app_id">497906953566757</string> in the document.)

Next, open the AndroidManifest.xml file in the root of the project. Add a 'Uses Permission' item named android.permission.INTERNET:

Also, in the 'Application' tab, add a 'Meta Data' item called com.facebook.sdk.ApplicationId, with a value of the app_id string you just configured:

Finally, add a new Activity to the app, with the name com.facebook.LoginActivity

(Again, if you check the source of the file, you should see the three corresponding new lines in the XML,<uses-permission android:name="android.permission.INTERNET"/>, <meta-data android:name="com.facebook.sdk.ApplicationId" android:value="@string/app_id"/>, and <activity android:name="com.facebook.LoginActivity"/>)

Output: