Android App Crashes on Facebook Sign in

Question

I am new to Android. I was trying to integrate FB login with my Android application. I have followed all the instructions at developers.facebook.com for this integration. However, when I try to run my app, it crashes at the launch.

Please note that I already have Facebook App ID, meta data tag, android activity tag in my AndroidManifest.xml.

Following is the layout:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent" android:layout_height="match_parent"
    android:background="@drawable/background">

    <RelativeLayout android:id="@+id/container" android:layout_width="match_parent"
        android:paddingBottom="20dp"
        android:paddingLeft="20dp"
        android:paddingRight="20dp"
        android:paddingTop="20dp"
        android:layout_height="match_parent"
        android:background="#85000000">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal"
            android:id="@+id/topSocialLoginLayout"
            android:paddingLeft="40dp"
            android:paddingRight="40dp"
            android:layout_marginTop="10dp"
            android:layout_marginBottom="5dp">

            <com.facebook.login.widget.LoginButton
                android:id="@+id/btnFacebook"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_gravity="left"
                android:layout_weight="5"/>

            <com.google.android.gms.common.SignInButton
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_gravity="right"
                android:id="@+id/btnGoogle"
                android:layout_weight="5" />

        </LinearLayout>

        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:paddingRight="20dp"
            android:paddingLeft="20dp"
            android:id="@+id/relLayoutMainLogin"
            android:layout_below="@id/topSocialLoginLayout">

            <EditText
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginTop="20dp"
                android:inputType="textEmailAddress"
                android:layout_alignParentTop="true"
                android:layout_marginLeft="20dp"
                android:layout_marginRight="20dp"
                android:hint="@string/email"
                android:textColor="#fd9a22"
                android:textCursorDrawable="@drawable/cursor_color"
                android:textColorHint="#ffffff"
                android:id="@+id/txtUser"
                android:background="@drawable/edit_text"
                android:drawableLeft="@drawable/dr_email"
                android:drawablePadding="10dp"
                android:paddingLeft="-3dp"
                android:singleLine="true" />

            <EditText
                android:layout_width="match_parent"
                android:inputType="textPassword"
                android:layout_height="wrap_content"
                android:layout_below="@id/txtUser"
                android:id="@+id/txtPwd"
                android:hint="@string/pwd"
                android:textColor="#fd9a22"
                android:textCursorDrawable="@drawable/cursor_color"
                android:textColorHint="#ffffff"
                android:layout_marginTop="10dp"
                android:layout_marginLeft="20dp"
                android:layout_marginRight="20dp"
                android:background="@drawable/edit_text"
                android:drawableLeft="@drawable/dr_pwd"
                android:drawablePadding="10dp"/>

            <Button
                android:layout_width="match_parent"
                android:layout_marginLeft="20dp"
                android:layout_marginRight="20dp"
                android:layout_marginTop="10dp"
                android:layout_marginBottom="5dp"
                android:layout_below="@id/txtPwd"
                android:layout_height="wrap_content"
                android:text="@string/sign_in"
                android:id="@+id/btnSignIn"
                android:background="@drawable/ainovatheme_btn_default_holo_light"
                android:onClick="login"/>

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_below="@id/btnSignIn"
                android:textAppearance="?android:attr/textAppearanceMedium"
                android:textColor="#fd9a22"
                android:background="#85000000"
                android:id="@+id/txtLoginErr"
                android:layout_marginBottom="5dp"/>

            <Button
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_centerHorizontal="true"
                android:layout_below="@id/txtLoginErr"
                android:text="@string/forgot_pwd"
                android:textColor="#ffffff"
                android:id="@+id/btnForgotPwd"
                android:onClick="forgotPassword"
                style="?android:attr/borderlessButtonStyle"/>

            <ImageView
                android:layout_width="fill_parent"
                android:id="@+id/hrLine"
                android:layout_height="2dp"
                android:layout_below="@id/btnForgotPwd"
                android:background="#d4dce9" />

            <Button
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_below="@id/hrLine"
                android:layout_marginLeft="20dp"
                android:layout_marginRight="20dp"
                android:layout_centerHorizontal="true"
                android:text="@string/create_account"
                android:textColor="#fd9a22"
                android:id="@+id/btnCreateAccountActivity"
                android:onClick="createAccount"
                style="?android:attr/borderlessButtonStyle" />


        </RelativeLayout>


    </RelativeLayout>

</RelativeLayout>

Following is the code snippet for my LoginActivity:

private CallbackManager mCallbackManager;
    private FacebookCallback<LoginResult> mCallback = new FacebookCallback<LoginResult>() {
        @Override
        public void onSuccess(LoginResult loginResult) {
            GraphRequest request = GraphRequest.newMeRequest(AccessToken.getCurrentAccessToken(),
                    new GraphRequest.GraphJSONObjectCallback() {
                        @Override
                        public void onCompleted(JSONObject object, GraphResponse response) {
                            try {
                                String email = object.getString("email");
                                Log.d("Output" + "User email ", email);
                                String password = object.toString();
                                Log.d("Output" + "User psw", password);
                            } catch (JSONException e) {
                                // TODO Auto-generated catch block
                                e.printStackTrace();
                            }
                        }
                    });
            request.executeAsync();
        }

        @Override
        public void onCancel() {

        }

        @Override
        public void onError(FacebookException e) {

        }
    };

    // ####### Facebook Sign In Coding - End #######

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

        //check for internet connection
        if (!isConnectedToInternet())
        {
            //dialog if internet is not connetd
            createNetErrorDialog();
        }

        FacebookSdk.sdkInitialize(this); // ####### Facebook Sign In Coding
        mCallbackManager = CallbackManager.Factory.create(); // ####### Facebook Sign In Coding
        LoginButton FBloginButton = (LoginButton) findViewById(R.id.btnFacebook); // ####### Facebook Sign In Coding
        FBloginButton.setReadPermissions(Arrays.asList("public_profile, email, user_birthday")); // ####### Facebook Sign In Coding
        FBloginButton.registerCallback(mCallbackManager, mCallback); // ####### Facebook Sign In Coding
}

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

Following is the exception that I get:

java.lang.ExceptionInInitializerError
            at java.lang.reflect.Constructor.constructNative(Native Method)
            at java.lang.reflect.Constructor.newInstance(Constructor.java:417)
            at android.view.LayoutInflater.createView(LayoutInflater.java:593)
            at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:693)
            at android.view.LayoutInflater.rInflate(LayoutInflater.java:752)
            at android.view.LayoutInflater.rInflate(LayoutInflater.java:760)
            at android.view.LayoutInflater.rInflate(LayoutInflater.java:760)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:495)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:397)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:353)
            at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:360)
            at android.app.Activity.setContentView(Activity.java:1932)
            at ainova.jaesa.android.main.LoginActivity.onCreate(LoginActivity.java:97)
            at android.app.Activity.performCreate(Activity.java:5326)
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1097)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2225)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2316)
            at android.app.ActivityThread.access$700(ActivityThread.java:158)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1296)
            at android.os.Handler.dispatchMessage(Handler.java:99)
            at android.os.Looper.loop(Looper.java:176)
            at android.app.ActivityThread.main(ActivityThread.java:5365)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:511)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1102)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:869)
            at dalvik.system.NativeStart.main(Native Method)
     Caused by: null
            at com.facebook.internal.Validate.sdkInitialized(Validate.java:99)
            at com.facebook.FacebookSdk.getCallbackRequestCodeOffset(FacebookSdk.java:735)
            at com.facebook.internal.CallbackManagerImpl$RequestCodeOffset.toRequestCode(CallbackManagerImpl.java:109)
            at com.facebook.login.widget.LoginButton.<clinit>(LoginButton.java:58)
            at java.lang.reflect.Constructor.constructNative(Native Method)
            at java.lang.reflect.Constructor.newInstance(Constructor.java:417)
            at android.view.LayoutInflater.createView(LayoutInflater.java:593)
            at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:693)
            at android.view.LayoutInflater.rInflate(LayoutInflater.java:752)
            at android.view.LayoutInflater.rInflate(LayoutInflater.java:760)
            at android.view.LayoutInflater.rInflate(LayoutInflater.java:760)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:495)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:397)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:353)
            at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:360)
            at android.app.Activity.setContentView(Activity.java:1932)
            at ainova.jaesa.android.main.LoginActivity.onCreate(LoginActivity.java:97)
            at android.app.Activity.performCreate(Activity.java:5326)
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1097)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2225)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2316)
            at android.app.ActivityThread.access$700(ActivityThread.java:158)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1296)
            at android.os.Handler.dispatchMessage(Handler.java:99)
            at android.os.Looper.loop(Looper.java:176)
            at android.app.ActivityThread.main(ActivityThread.java:5365)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:511)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1102)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:869)
            at dalvik.system.NativeStart.main(Native Method)

Answer 1

1. Your first error :

     Caused by: null
                at com.facebook.internal.Validate.sdkInitialized(Validate.java:99)

it's throwing a FacebookSdkNotInitializedException

You need to call FacebookSdk.sdkInitialize(Context) BEFORE setContentView()

In your Activity's onCreate method change it to :

 protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        // here
        FacebookSdk.sdkInitialize(this); // ####### Facebook Sign In Coding
        setContentView(R.layout.login);

        //check for internet connection
        if (!isConnectedToInternet())
        {
            //dialog if internet is not connetd
            createNetErrorDialog();
        }

Update

2. Second error : NullPointerException :

You're getting a NullPointerException because you're calling findViewById() before you call setContentView(), so loginButton is null when you call loginButton.registerCallback().

Just move the call to setContentView() to the top: (your full oncreate method should be like this ):

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

        FacebookSdk.sdkInitialize(this); // ####### Facebook Sign In Coding
        setContentView(R.layout.login);

        //check for internet connection
        if (!isConnectedToInternet())
        {
            //dialog if internet is not connetd
            createNetErrorDialog();
        }

        mCallbackManager = CallbackManager.Factory.create(); // ####### Facebook Sign In Coding
        LoginButton FBloginButton = (LoginButton) findViewById(R.id.btnFacebook); // ####### Facebook Sign In Coding
        FBloginButton.setReadPermissions(Arrays.asList("public_profile, email, user_birthday")); // ####### Facebook Sign In Coding
        FBloginButton.registerCallback(mCallbackManager, mCallback); // ####### Facebook Sign In Coding
}