Android key hash and Facebook login

Question

I have some problems whith the Android hash key and the Facebook SDK. I implemented an Login page like explained here and when I first tried to log in everything worked fine. After that I logged out and tried to log in again and now I get an error concerning the Android kay hash that looks exactly like this.

I have signed my app up both in the Android developers control and in the Facebook Dashboard. My hash key is SHA1 and looks like 9A:BC:08...

Here is the source code:

activity_facebook_login.xml

<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="com.axelfiedler.stayup.FacebookLoginActivity" >

<com.facebook.widget.LoginButton
    android:id="@+id/authButton"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center_horizontal"
    android:layout_marginTop="30dp"
    />

FacebookLoginActivity.java

package com.axelfiedler.stayup;

import android.support.v4.app.FragmentActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;

public class FacebookLoginActivity extends FragmentActivity {

private MainFragment mainFragment;


@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    if (savedInstanceState == null) {
        // Add the fragment on initial activity setup
        mainFragment = new MainFragment();
        getSupportFragmentManager()
        .beginTransaction()
        .add(android.R.id.content, mainFragment)
        .commit();
    } else {
        // Or set the fragment from restored state info
        mainFragment = (MainFragment) getSupportFragmentManager()
        .findFragmentById(android.R.id.content);
    }
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.facebook_login, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();
    if (id == R.id.action_settings) {
        return true;
    }
    return super.onOptionsItemSelected(item);
}
}

MainFragment.java

package com.axelfiedler.stayup;

import com.facebook.Session;
import com.facebook.SessionState;
import com.facebook.UiLifecycleHelper;
import com.facebook.widget.LoginButton;

import android.support.v4.app.Fragment;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class MainFragment extends Fragment {

private static final String TAG = "MainFragment";
private UiLifecycleHelper uiHelper;


private Session.StatusCallback callback = new Session.StatusCallback() {
    @Override
    public void call(Session session, SessionState state, Exception exception) {
        onSessionStateChange(session, state, exception);
    }
};

private void onSessionStateChange(Session session, SessionState state, Exception    exception) {
    if (state.isOpened()) {
        Log.i(TAG, "Logged in...");
    } else if (state.isClosed()) {
        Log.i(TAG, "Logged out...");
    }
}

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    uiHelper = new UiLifecycleHelper(getActivity(), callback);
    uiHelper.onCreate(savedInstanceState);
}

@Override
public View onCreateView(LayoutInflater inflater, 
        ViewGroup container, 
        Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.activity_facebook_login, container, false);
    LoginButton authButton = (LoginButton) view.findViewById(R.id.authButton);
    authButton.setFragment(this);

    return view;



}

@Override
public void onResume() {
    super.onResume();
    uiHelper.onResume();
    // For scenarios where the main activity is launched and user
    // session is not null, the session state change notification
    // may not be triggered. Trigger it if it's open/closed.
    Session session = Session.getActiveSession();
    if (session != null &&
           (session.isOpened() || session.isClosed()) ) {
        onSessionStateChange(session, session.getState(), null);
    }

    uiHelper.onResume();
}

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

@Override
public void onPause() {
    super.onPause();
    uiHelper.onPause();
}

@Override
public void onDestroy() {
    super.onDestroy();
    uiHelper.onDestroy();
}

@Override
public void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
    uiHelper.onSaveInstanceState(outState);
}

}

Answer 1

Did you try getting the hashkey that is being sent through the app? You can do this by this code:

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);

try {
    PackageInfo info = getPackageManager().getPackageInfo(
            "com.facebook.samples.loginhowto", 
            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 (NameNotFoundException e) {

} catch (NoSuchAlgorithmException e) {

}
...

This will Log a hashkey. This will verify if you have the correct hashkey. If not, add this hashkey to your console and it should work. This is what I did to get my correct hashkey.